WO2024239697A1

WO2024239697A1 - Fec based discard

Info

Publication number: WO2024239697A1
Application number: PCT/CN2024/073730
Authority: WO
Inventors: Mingzeng Dai; Xiaoying Xu; Lianhai WU
Original assignee: Lenovo (Beijing) Limited
Priority date: 2024-01-23
Filing date: 2024-01-23
Publication date: 2024-11-28

Abstract

Various aspects of the present disclosure relate to UL FEC based discard. In one aspect, a UE receives, from a network entity, a configuration for FEC based discard. Then, the UE determines at least one FEC parameter of a PDU set. In turn, the UE discards at least one PDU in the PDU set based on the configuration and the at least one FEC parameter of the PDU set.

Description

FEC BASED DISCARD

TECHNICAL FIELD

The present disclosure relates to wireless communications, and more specifically to user equipment (UE) , network entity and methods for supporting uplink (UL) forward error correction (FEC) based discard.

BACKGROUND

A wireless communications system may include one or multiple network communication devices, such as base stations, which may be otherwise known as an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. Each network communication devices, such as a base station may support wireless communications for one or multiple user communication devices, which may be otherwise known as UE, or other suitable terminology. The wireless communications system may support wireless communications with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) . Additionally, the wireless communications system may support wireless communications across various radio access technologies including third generation (3G) radio access technology, fourth generation (4G) radio access technology, fifth generation (5G) radio access technology, among other suitable radio access technologies beyond 5G (e.g., sixth generation (6G) ) .

For extended reality (XR) and media traffic, a concept of a protocol data unit (PDU) set is introduced. A PDU set may comprise one or more PDUs carrying a payload of one unit of information generated at an application level. For example, the unit of information may be a frame or video slice for XR services. All the PDUs of a PDU set are transmitted within the same quality of service (QoS) flow.

Application layer FEC may be used in multicast applications, broadcast applications or conversational applications. If the application layer FEC is applied, some PDUs in a PDU set may be redundant. Even though some PDUs are lost, the application layer can still recover the whole PDU set. In the case of congestion, proactive discard is useful to alleviate the congestion. For example, a UE can discard some of the redundant PDUs in the PDU set to alleviate the congestion by achieving a well trade-off between the congestion alleviation and service experience. Therefore, there is a need to study FEC based discard for UL data transmission.

SUMMARY

The present disclosure relates to a UE, network entity and methods that support UL FEC based discard. With the UE, network entity, and methods, the UE may discard at least one PDU in the PDU set during uplink transmission, thereby alleviating network congestion while ensuring service experience.

Some implementations of a UE described herein may include a processor and a transceiver coupled to the processor, wherein the processor is configured to: receive, via the transceiver from a network entity, a configuration for FEC based discard; determine at least one FEC parameter of a PDU set; and discard at least one PDU in the PDU set based on the configuration and the at least one FEC parameter of the PDU set.

In some implementations, the PDU set is associated with a block of source data, and the at least one FEC parameter of the PDU set comprises at least one of the following: a first number of PDUs in the PDU set which carry source symbols of the block, a second number of PDUs in the PDU set which carry repair symbols of the block, or a total number of the source symbols and the repair symbols of the block.

In some implementations, the processor is further configured to: obtain first FEC information about at least one QoS flow, wherein the first FEC information comprises at least one of the following: an indication indicating whether the FEC is to be applied to the at least one QoS flow, an FEC encoding type which is to be applied to the at least one QoS flow, a redundant ratio for the at least one QoS flow, or an identifier of the at least one QoS flow.

In some implementations, the processor is further configured to: transmit the first FEC information via the transceiver to the network entity.

In some implementations, the processor is further configured to: obtain second FEC information about at least one PDU set, wherein each of the at least one PDU set is associated with a block of source data, and the second FEC information comprises at least one of the following: an indication indicating whether the FEC is to be applied to the at least one PDU set, an FEC encoding type which is to be applied to each of the at least one PDU set, a first number of PDUs in each of the at least one PDU set which carry source symbols of the block, a second number of PDUs in each of the at least one PDU set which carry repair symbols of the block, or a total number of the source symbols and the repair symbols of the block, a size of each of the source symbols and the repair symbols, a last symbol among the source symbols which comprises padding bits, an FEC payload identifier (ID) of each of the source symbols and the repair symbols of the block, or a sequence number of each of the at least one PDU set.

In some implementations, the processor is further configured to: transmit the second FEC information via the transceiver to the network entity.

In some implementations, the at least one FEC parameter of the PDU set comprises at least part of the second FEC information.

In some implementations, the processor is further configured to: obtain third FEC information about at least one PDU set with at least one protocol data unit set importance (PSI) value within a QoS flow, wherein each of the at least one PDU set with the at least one PSI value is associated with a block of source data, and the third FEC information comprises at least one of the following: an indication indicating whether the FEC is to be applied to the at least one PDU set with the at least one PSI value, an FEC encoding type which is to be applied to each of the at least one PDU set with the at least one PSI value, or a redundant ratio for the at least one PDU set with the at least one PSI value.

In some implementations, the processor is further configured to: transmit the third FEC information via the transceiver to the network entity.

In some implementations, the configuration for FEC based discard comprises at least one of the following: a discard ratio, a maximum discard ratio, a minimum discard ratio, a list of discard ratios, a list of maximum discard ratios, a list of minimum discard ratios, a third number of PDUs to be discarded for each of at least one PDU set, a maximum number of PDUs to be discarded for each of the at least one PDU set, a minimum number of PDUs to be discarded for each of the at least one PDU set, a list of numbers of PDUs to be discarded for each of the at least one PDU set, a list of maximum numbers of PDUs to be discarded for each of the at least one PDU set, or a list of minimum numbers of PDUs to be discarded for each of the at least one PDU set.

In some implementations, the configuration for FEC based discard is associated with a QoS flow or a data radio bearer (DRB) to which the FEC is to be applied, and the configuration further comprises at least one of the following: a first identifier of the QoS flow, or a second identifier of the DRB; and wherein: the discard ratio is for the DRB or the QoS flow, the maximum discard ratio is for the DRB or the QoS flow, the minimum discard ratio is for the DRB or the QoS flow, the list of discard ratios is for the DRB or the QoS flow, the list of maximum discard ratios is for the DRB or the QoS flow, or the list of minimum discard ratios is for the DRB or the QoS flow.

In some implementations, the configuration for FEC based discard is associated with a PSI value of a QoS flow, the FEC is to be applied to at least one PDU set with the PSI value, and the configuration further comprises the PSI value; and wherein: the discard ratio is for the PSI value, the maximum discard ratio is for the PSI value, the minimum discard ratio is for the PSI value, the list of discard ratios is for the PSI value, the list of maximum discard ratios is for the PSI value, or the list of minimum discard ratios is for the PSI value.

In some implementations, the configuration for FEC based discard is associated with at least one PDU set to which the FEC is to be applied, and the configuration further comprises at least one sequence number of the at least one PDU set; and wherein: the discard ratio is for the at least one PDU set, the maximum discard ratio is for the at least one PDU set, the minimum discard ratio is for the at least one PDU set, the list of discard ratios is for the at least one PDU set, the list of maximum discard ratios is for the at least one PDU set, the list of minimum discard ratios is for the at least one PDU set, the third number of PDUs to be discarded is for each of the at least one PDU set, the maximum number of PDUs to be discarded is for each of the at least one PDU set, the minimum number of PDUs to be discarded is for each of the at least one PDU set, or the list of numbers of PDUs to be discarded is for each of the at least one PDU set, the list of maximum numbers of PDUs to be discarded is for each of the at least one PDU set, or the list of minimum numbers of PDUs to be discarded is for each of the at least one PDU set.

In some implementations, the processor is configured to discard the at least one PDU in the PDU set based on the configuration, the at least one FEC parameter of the PDU set and at least one discard rule, the at least one discard rule indicates at least one of the following: discarding a third number of PDUs in the PDU set which arrive at an access stratum (AS) layer of the UE last, discarding the third number of PDUs in the PDU set in an ascending order of remaining time of discard timers for PDUs in the PDU set, prioritizing to discard a first PDU in the PDU set, wherein the first PDU comprises padding bits, prioritizing to discard a second PDU in the PDU set, wherein the second PDU carries a repair symbol of a block of source data, or starting a discard timer for each of the third number of PDUs in the PDU set which arrive at the AS layer of the UE last and discarding a third PDU among the third number of PDUs based on determining that a third discard timer for the third PDU expires.

In some implementations, the configuration for FEC based discard comprises the at least one discard rule, or the at least one discard rule is predefined.

In some implementations, the processor is configured to discard the at least one PDU in the PDU set by: determining the third number based on a total number of PDUs in the PDU set and one of the following: the discard ratio, the maximum discard ratio, or the minimum discard ratio; or determining the third number based on one of the following: the third number of PDUs to be discarded for each of at least one PDU set, a maximum number of PDUs to be discarded for each of the at least one PDU set, or a minimum number of PDUs to be discarded for each of the at least one PDU set; and discarding the third number of PDUs in the PDU set which arrive at the AS layer of the UE last.

In some implementations, the processor is configured to discard the at least one PDU in the PDU set by: determining the third number based on a total number of PDUs in the PDU set and one of the following: the discard ratio, the maximum discard ratio, or the minimum discard ratio; or determining the third number based on one of the following: the third number of PDUs to be discarded for each of at least one PDU set, a maximum number of PDUs to be discarded for each of the at least one PDU set, or a minimum number of PDUs to be discarded for each of the at least one PDU set; and discarding the third number of PDUs in the PDU set in the ascending order of remaining time of discard timers for PDUs in the PDU set.

In some implementations, the processor is configured to discard the at least one PDU in the PDU set by: determining the third number of PDUs to be discarded for the PDU set based on a total number of PDUs in the PDU set and one of the following: the discard ratio, the maximum discard ratio, or the minimum discard ratio; or determining the third number based on one of the following: the third number of PDUs to be discarded for each of at least one PDU set, a maximum number of PDUs to be discarded for each of the at least one PDU set, or a minimum number of PDUs to be discarded for each of the at least one PDU set; and prioritizing to discard the first PDU in the PDU set, wherein the first PDU comprises the padding bits, the third number of the PDUs comprises the first PDU.

In some implementations, the processor is configured to discard the at least one PDU in the PDU set by: determining the third number based on a total number of PDUs in the PDU set and one of the following: the discard ratio, the maximum discard ratio, or the minimum discard ratio; or determining the third number based on one of the following: the third number of PDUs to be discarded for each of at least one PDU set, a maximum number of PDUs to be discarded for each of the at least one PDU set, or a minimum number of PDUs to be discarded for each of the at least one PDU set; and prioritizing to discard the second PDU in the PDU set, wherein the second PDU carries the repair symbol of the block of source data, the third number of the PDUs comprises the second PDU.

In some implementations, the processor is configured to discard the at least one PDU in the PDU set by: determining the third number based on a total number of PDUs in the PDU set and one of the following: the discard ratio, the maximum discard ratio, or the minimum discard ratio; or determining the third number based on one of the following: the third number of PDUs to be discarded for each of at least one PDU set, a maximum number of PDUs to be discarded for each of the at least one PDU set, or a minimum number of PDUs to be discarded for each of the at least one PDU set; and discarding a third PDU among the third number of PDUs which arrive at the AS layer of the UE last based on determining that a third discard timer for the third PDU expires.

In some implementations, the configuration for FEC based discard comprises one of the following: the discard ratio, the maximum discard ratio, or the minimum discard ratio.

In some implementations, the configuration for FEC based discard comprises one of the following: the third number of PDUs to be discarded for each of at least one PDU set, the maximum number of PDUs to be discarded for each of the at least one PDU set, or the minimum number of PDUs to be discarded for each of the at least one PDU set.

In some implementations, the processor is further configured to: receive a medium access control control element (MAC CE) comprising an indication via the transceiver from the network entity, wherein the indication indicates whether to activate or deactivate the FEC based discard; and activate or deactivate the FEC based discard based on the indication.

In some implementations, the configuration for FEC based discard comprises a list of discard ratios; the MAC CE further comprises a first index of a first discard ratio in the list of discard ratios; and the processor is further configured to: determine the discard ratio based on the first index of the first discard ratio.

In some implementations, the configuration for FEC based discard comprises a list of maximum discard ratios; the MAC CE further comprises a second index of a first maximum discard ratio in the list of maximum discard ratios; and the processor is further configured to: determine the maximum discard ratio based on the second index of the first maximum discard ratio.

In some implementations, the configuration for FEC based discard comprises a list of minimum discard ratios; the MAC CE further comprises a third index of a first minimum discard ratio in the list of minimum discard ratios; and the processor is further configured to: determine the minimum discard ratio based on the third index of the first minimum discard ratio.

In some implementations, the configuration for FEC based discard comprises a list of numbers of PDUs to be discarded for each of the at least one PDU set; the MAC CE further comprises a fourth index of the third number in the list of numbers of PDUs; and the processor is configured to determine the third number based on the fourth index of the third number.

In some implementations, the configuration for FEC based discard comprises a list of maximum numbers of PDUs to be discarded for each of the at least one PDU set; the MAC CE further comprises a fifth index of the maximum number in the list of maximum numbers of PDUs; and the processor is configured to determine the maximum number based on the fifth index of the maximum number and determine the third number to be equal to or less than the maximum number.

In some implementations, the configuration for FEC based discard comprises a list of minimum numbers of PDUs to be discarded for each of the at least one PDU set; the MAC CE further comprises a sixth index of the minimum number in the list of minimum numbers of PDUs; and the processor is configured to determine the minimum number based on the sixth index of the minimum number and determine the third number to be equal to or greater than the minimum number.

In some implementations, the processor is configured to activate or deactivate the FEC based discard based on the indication by: activating or deactivating the FEC based discard for one of the following to which the FEC based discard is to be applied: at least one QoS flow, at least one DRB, at least one PSI value, or at least one PDU set.

In some implementations, the MAC CE comprises a first bitmap, each of at least one bit in the first bitmap is associated with one of at least one DRB to which the FEC based discard is allowed to be applied, and each of the at least one bit indicates that the FEC based discard is to be activated or deactivated for a respective one of the at least one DRB.

In some implementations, the MAC CE comprises a second bitmap, each of at least one bit in the second bitmap is associated with one of at least one QoS flow to which the FEC based discard is allowed to be applied, and each of the at least one bit indicates that the FEC based discard is to be activated or deactivated for a respective one of the at least one QoS flow.

In some implementations, the MAC CE comprises a third bitmap, each of at least one bit in the third bitmap is associated with one of at least one PSI value of a quality of QoS flow, the FEC based discard is allowed to be applied to at least one PDU set with the at least one PSI value, and each of the at least one bit indicates that the FEC based discard is to be activated or deactivated for a respective one of the at least one PSI value.

In some implementations, the processor is further configured to: receive a first indication or a second indication via the transceiver from the network entity, wherein the first indication indicates to activate the FEC based discard and the second indication indicates to deactivate the FEC based discard; and activate the FEC based discard based on the first indication; or deactivate the FEC based discard based on the second indication.

Some implementations of a network entity described herein may include a processor and a transceiver coupled to the processor, wherein the processor is configured to:transmit, via the transceiver to a UE, a configuration for FEC based discard.

In some implementations, the processor is further configured to receive, via the transceiver from the UE, first FEC information about at least one QoS flow, wherein the first FEC information comprises at least one of the following: an indication indicating whether the FEC is to be applied to the at least one QoS flow, an FEC encoding type which is to be applied to the at least one QoS flow, a redundant ratio for the at least one QoS flow, or an identifier of the at least one QoS flow.

In some implementations, the processor is further configured to: receive, via the transceiver from the UE, second FEC information about at least one PDU set, wherein each of the at least one PDU set is associated with a block of source data, and the second FEC information comprises at least one of the following: an indication indicating whether the FEC is to be applied to the at least one PDU set, an FEC encoding type which is to be applied to each of the at least one PDU set, a first number of PDUs in each of the at least one PDU set which carry source symbols of the block, a second number of PDUs in each of the at least one PDU set which carry repair symbols of the block, or a total number of the source symbols and the repair symbols of the block, a size of each of the source symbols and the repair symbols, a last symbol among the source symbols which comprises padding bits, an FEC payload ID of each of the source symbols and the repair symbols of the block, or a sequence number of each of the at least one PDU set.

In some implementations, the processor is further configured to: receive, via the transceiver from the UE, third FEC information about at least one PDU set with at least one PSI value within a QoS flow, wherein each of the at least one PDU set with the at least one PSI value is associated with a block of source data, and the third FEC information comprises at least one of the following: an indication indicating whether the FEC is to be applied to the at least one PDU set with the at least one PSI value, an FEC encoding type which is to be applied to each of the at least one PDU set with the at least one PSI value, or a redundant ratio for the at least one PDU set with the at least one PSI value.

In some implementations, the configuration for FEC based discard is associated with a QoS flow or a DRB to which the FEC is to be applied, and the configuration further comprises at least one of the following: a first identifier of the QoS flow, or a second identifier of the DRB; and wherein: the discard ratio is for the DRB or the QoS flow, the maximum discard ratio is for the DRB or the QoS flow, the minimum discard ratio is for the DRB or the QoS flow, the list of discard ratios is for the DRB or the QoS flow, the list of maximum discard ratios is for the DRB or the QoS flow, or the list of minimum discard ratios is for the DRB or the QoS flow.

In some implementations, the configuration for FEC based discard comprises at least one discard rule, and the at least one discard rule indicates at least one of the following: discarding a third number of PDUs in the PDU set which arrive at an AS layer of the UE last, discarding the third number of PDUs in the PDU set in an ascending order of remaining time of discard timers for PDUs in the PDU set, prioritizing to discard a first PDU in the PDU set, wherein the first PDU comprises padding bits, prioritizing to discard a second PDU in the PDU set, wherein the second PDU carries a repair symbol of a block of source data, or starting a discard timer for each of the third number of PDUs in the PDU set which arrive at the AS layer of the UE last and discarding a third PDU among the third number of PDUs based on determining that a third discard timer for the third PDU expires.

In some implementations, the processor is further configured to: transmit, via the transceiver to the UE, a MAC CE comprising an indication, wherein the indication indicates whether to activate or deactivate the FEC based discard.

In some implementations, the configuration for FEC based discard comprises a list of discard ratios; and the MAC CE further comprises a first index of a first discard ratio in the list of discard ratios.

In some implementations, the configuration for FEC based discard comprises a list of maximum discard ratios; and the MAC CE further comprises a second index of a first maximum discard ratio in the list of maximum discard ratios.

In some implementations, the configuration for FEC based discard comprises a list of minimum discard ratios; and the MAC CE further comprises a third index of a first minimum discard ratio in the list of minimum discard ratios.

In some implementations, the configuration for FEC based discard comprises a list of numbers of PDUs to be discarded for each of the at least one PDU set; and the MAC CE further comprises a fourth index of the third number in the list of numbers of PDUs.

In some implementations, the configuration for FEC based discard comprises a list of maximum numbers of PDUs to be discarded for each of the at least one PDU set; and the MAC CE further comprises a fifth index of the maximum number in the list of maximum numbers of PDUs

In some implementations, the configuration for FEC based discard comprises a list of minimum numbers of PDUs to be discarded for each of the at least one PDU set; and the MAC CE further comprises a sixth index of the minimum number in the list of minimum numbers of PDUs.

In some implementations, the processor is further configured to: transmit a first indication or a second indication via the transceiver to the UE, wherein the first indication indicates to activate the FEC based discard and the second indication indicates to deactivate the FEC based discard.

Some implementations of a method described herein may include: receiving, via the transceiver from a network entity, a configuration for FEC based discard; determining at least one FEC parameter of a PDU set; and discarding at least one PDU in the PDU set based on the configuration and the at least one FEC parameter of the PDU set.

Some implementations of a method described herein may include: transmitting, via the transceiver to a UE, a configuration for FEC based discard.

Some implementations of a processor described herein may include at least one memory and a controller coupled with the at least one memory and configured to cause the controller to: receive, via the transceiver from a network entity, a configuration for FEC based discard; determine at least one FEC parameter of a PDU set; and discard at least one PDU in the PDU set based on the configuration and the at least one FEC parameter of the PDU set.

It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 illustrates an example of a wireless communications system that supports UL FEC based discard in accordance with aspects of the present disclosure;

Fig. 2 illustrates a signaling diagram illustrating an example process that supports UL FEC based discard in accordance with aspects of the present disclosure;

Fig. 3 illustrates an example of a block of source data in accordance with some implementations of the present disclosure;

Figs. 4 to 8 illustrate a flowchart of a method that supports UL FEC based discard in accordance with aspects of the present disclosure, respectively;

Fig. 9 illustrates a signaling diagram illustrating an example process that supports UL FEC based discard in accordance with some implementations of the present disclosure;

Figs. 10 and 11 illustrate an example of the FEC based Discard Activation/Deactivation MAC CE in accordance with some implementations of the present disclosure, respectively;

Figs. 12 and 13 illustrate a signaling diagram illustrating an example process that supports UL FEC based discard in accordance with some implementations of the present disclosure, respectively;

Fig. 14 illustrates an example of a device that supports UL FEC based discard in accordance with aspects of the present disclosure;

Fig. 15 illustrates an example of a processor that supports UL FEC based discard in accordance with aspects of the present disclosure; and

Figs. 16 and 17 illustrate a flowchart of a method that supports UL FEC based discard in accordance with aspects of the present disclosure, respectively.

DETAILED DESCRIPTION

Principles of the present disclosure will now be described with reference to some embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein may be implemented in various manners other than the ones described less than or equal to.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an example embodiment, ” “an embodiment, ” “some embodiments, ” and the like indicate that the embodiment (s) described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment (s) . Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” or the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element could also be termed as a second element, and similarly, a second element could also be termed as a first element, without departing from the scope of embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

As described above, if the application layer FEC is applied, some PDUs in a PDU set may be redundant. Even though some PDUs are lost, the application layer can still recover the whole PDU set. A UE can discard some of the redundant PDUs in the PDU set to alleviate the congestion. Therefore, there is a need to study FEC based discard for UL data transmission.

In view of the above, the present disclosure provides a solution that supports UL FEC based discard. In this solution, a UE receives, from a network entity, a configuration for FEC based discard. Then, the UE determines at least one FEC parameter of a PDU set. In turn, the UE discards at least one PDU in the PDU set based on the configuration and the at least one FEC parameter of the PDU set. The solution may alleviate congestion while ensuring service experience.

Aspects of the present disclosure are described in the context of a wireless communications system.

Fig. 1 illustrates an example of a wireless communications system 100 that supports UL FEC based discard in accordance with aspects of the present disclosure. The wireless communications system 100 may include one at least one of network entities 102 (also referred to as network equipment (NE) ) , one or more terminal devices or UEs 104, a core network 106, and a packet data network 108. The wireless communications system 100 may support various radio access technologies. In some implementations, the wireless communications system 100 may be a 4G network, such as an LTE network or an LTE-advanced (LTE-A) network. In some other implementations, the wireless communications system 100 may be a 5G network, such as an NR network. In other implementations, the wireless communications system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including institute of electrical and electronics engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20. The wireless communications system 100 may support radio access technologies beyond 5G. Additionally, the wireless communications system 100 may support technologies, such as time division multiple access (TDMA) , frequency division multiple access (FDMA) , or code division multiple access (CDMA) , etc.

The network entities 102 may be collectively referred to as network entities 102 or individually referred to as a network entity 102.

The network entities 102 may be dispersed throughout a geographic region to form the wireless communications system 100. One or more of the network entities 102 described herein may be or include or may be referred to as a network node, a base station (BS) , a network element, a radio access network (RAN) node, a base transceiver station, an access point, a NodeB, an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. A network entity 102 and a UE 104 may communicate via a communication link 110, which may be a wireless or wired connection. For example, a network entity 102 and a UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) over a Uu interface. The network entities 102 may be collectively referred to as network entities 102 or individually referred to as a network entity 102.

A network entity 102 may provide a geographic coverage area 112 for which the network entity 102 may support services (e.g., voice, video, packet data, messaging, broadcast, etc. ) for one or more UEs 104 within the geographic coverage area 112. For example, a network entity 102 and a UE 104 may support wireless communication of signals related to services (e.g., voice, video, packet data, messaging, broadcast, etc. ) according to one or multiple radio access technologies. In some implementations, a network entity 102 may be moveable, for example, a satellite associated with a non-terrestrial network. In some implementations, different geographic coverage areas 112 associated with the same or different radio access technologies may overlap, but the different geographic coverage areas 112 may be associated with different network entities 102. Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The one or more UEs 104 may be dispersed throughout a geographic region of the wireless communications system 100. A UE 104 may include or may be referred to as a mobile device, a wireless device, a remote device, a remote unit, a handheld device, or a subscriber device, or some other suitable terminology. In some implementations, the UE 104 may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally, or alternatively, the UE 104 may be referred to as an internet-of-things (IoT) device, an internet-of-everything (IoE) device, or machine-type communication (MTC) device, among other examples. In some implementations, a UE 104 may be stationary in the wireless communications system 100. In some other implementations, a UE 104 may be mobile in the wireless communications system 100.

The one or more UEs 104 may be devices in different forms or having different capabilities. Some examples of UEs 104 are illustrated in Fig. 1. A UE 104 may be capable of communicating with various types of devices, such as the network entities 102, other UEs 104, or network equipment (e.g., the core network 106, the packet data network 108, a relay device, an integrated access and backhaul (IAB) node, or another network equipment) , as shown in Fig. 1. Additionally, or alternatively, a UE 104 may support communication with other network entities 102 or UEs 104, which may act as relays in the wireless communications system 100.

A UE 104 may also be able to support wireless communication directly with other UEs 104 over a communication link 114. For example, a UE 104 may support wireless communication directly with another UE 104 over a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link 114 may be referred to as a sidelink. For example, a UE 104 may support wireless communication directly with another UE 104 over a PC5 interface.

A network entity 102 may support communications with the core network 106, or with another network entity 102, or both. For example, a network entity 102 may interface with the core network 106 through one or more backhaul links 116 (e.g., via an S1, N2, N2, or another network interface) . The network entities 102 may communicate with each other over the backhaul links 116 (e.g., via an X2, Xn, or another network interface) . In some implementations, the network entities 102 may communicate with each other directly (e.g., between the network entities 102) . In someother implementations, the network entities 102 may communicate with each other or indirectly (e.g., via the core network 106) . In some implementations, one or more network entities 102 may include subcomponents, such as an access network entity, which may be an example of an access node controller (ANC) . An ANC may communicate with the one or more UEs 104 through one or more other access network transmission entities, which may be referred to as a radio heads, smart radio heads, or transmission-reception points (TRPs) .

In some implementations, a network entity 102 may be configured in a disaggregated architecture, which may be configured to utilize a protocol stack physically or logically distributed among two or more network entities 102, such as an integrated access backhaul (IAB) network, an open radio access network (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance) , or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN) ) . For example, a network entity 102 may include one or more of a central unit (CU) , a distributed unit (DU) , a radio unit (RU) , a RAN intelligent controller (RIC) (e.g., a near-real time RIC (Near-RT RIC) , a non-real time RIC (Non-RT RIC) ) , a service management and orchestration (SMO) system, or any combination thereof.

An RU may also be referred to as a radio head, a smart radio head, a remote radio head (RRH) , a remote radio unit (RRU) , or a transmission reception point (TRP) . One or more components of the network entities 102 in a disaggregated RAN architecture may be co-located, or one or more components of the network entities 102 may be located in distributed locations (e.g., separate physical locations) . In some implementations, one or more network entities 102 of a disaggregated RAN architecture may be implemented as virtual units (e.g., a virtual CU (VCU) , a virtual DU (VDU) , a virtual RU (VRU) ) .

Split of functionality between a CU, a DU, and an RU may be flexible and may support different functionalities depending upon which functions (e.g., network layer functions, protocol layer functions, baseband functions, radio frequency functions, and any combinations thereof) are performed at a CU, a DU, or an RU. For example, a functional split of a protocol stack may be employed between a CU and a DU such that the CU may support one or more layers of the protocol stack and the DU may support one or more different layers of the protocol stack. In some implementations, the CU may host upper protocol layer (e.g., a layer 3 (L3) , a layer 2 (L2) ) functionality and signaling (e.g., radio resource control (RRC) , service data adaption protocol (SDAP) , packet data convergence protocol (PDCP) ) . The CU may be connected to one or more DUs or RUs, and the one or more DUs or RUs may host lower protocol layers, such as a layer 1 (L1) (e.g., physical (PHY) layer) or an L2 (e.g., radio link control (RLC) layer, medium access control (MAC) layer) functionality and signaling, and may each be at least partially controlled by the CU.

Additionally, or alternatively, a functional split of the protocol stack may be employed between a DU and an RU such that the DU may support one or more layers of the protocol stack and the RU may support one or more different layers of the protocol stack. The DU may support one or multiple different cells (e.g., via one or more RUs) . In some implementations, a functional split between a CU and a DU, or between a DU and an RU may be within a protocol layer (e.g., some functions for a protocol layer may be performed by one of a CU, a DU, or an RU, while other functions of the protocol layer are performed by a different one of the CU, the DU, or the RU) .

A CU may be functionally split further into CU control plane (CU-CP) and CU user plane (CU-UP) functions. A CU may be connected to one or more DUs via a midhaul communication link (e.g., F1, F1-c, F1-u) , and a DU may be connected to one or more RUs via a fronthaul communication link (e.g., open fronthaul (FH) interface) . In some implementations, a midhaul communication link or a fronthaul communication link may be implemented in accordance with an interface (e.g., a channel) between layers of a protocol stack supported by respective network entities 102 that are in communication via such communication links.

The core network 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The core network 106 may be an evolved packet core (EPC) , or a 5G core (5GC) , which may include a control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management functions (AMF) ) and a user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a packet data network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . In some implementations, the control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc. ) for the one or more UEs 104 served by the one or more network entities 102 associated with the core network 106.

The core network 106 may communicate with the packet data network 108 over one or more backhaul links 116 (e.g., via an S1, N2, N2, or another network interface) . The packet data network 108 may include an application server 118. In some implementations, one or more UEs 104 may communicate with the application server 118. A UE 104 may establish a session (e.g., a protocol data unit (PDU) session, or the like) with the core network 106 via a network entity 102. The core network 106 may route traffic (e.g., control information, data, and the like) between the UE 104 and the application server 118 using the established session (e.g., the established PDU session) . The PDU session may be an example of a logical connection between the UE 104 and the core network 106 (e.g., one or more network functions of the core network 106) .

In the wireless communications system 100, the network entities 102 and the UEs 104 may use resources of the wireless communications system 100 (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) ) to perform various operations (e.g., wireless communications) . In some implementations, the network entities 102 and the UEs 104 may support different resource structures. For example, the network entities 102 and the UEs 104 may support different frame structures. In some implementations, such as in 4G, the network entities 102 and the UEs 104 may support a single frame structure. In some other implementations, such as in 5G and among other suitable radio access technologies, the network entities 102 and the UEs 104 may support various frame structures (i.e., multiple frame structures) . The network entities 102 and the UEs 104 may support various frame structures based on one or more numerologies.

One or more numerologies may be supported in the wireless communications system 100, and a numerology may include a subcarrier spacing and a cyclic prefix. A first numerology (e.g., μ=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a normal cyclic prefix. In some implementations, the first numerology (e.g., μ=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one slot per subframe. A second numerology (e.g., μ=1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a normal cyclic prefix. A third numerology (e.g., μ=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth numerology (e.g., μ=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth numerology (e.g., μ=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a normal cyclic prefix.

A time interval of a resource (e.g., a communication resource) may be organized according to frames (also referred to as radio frames) . Each frame may have a duration, for example, a 10 millisecond (ms) duration. In some implementations, each frame may include multiple subframes. For example, each frame may include 10 subframes, and each subframe may have a duration, for example, a 1 ms duration. In some implementations, each frame may have the same duration. In some implementations, each subframe of a frame may have the same duration.

Additionally or alternatively, a time interval of a resource (e.g., a communication resource) may be organized according to slots. For example, a subframe may include a number (e.g., quantity) of slots. The number of slots in each subframe may also depend on the one or more numerologies supported in the wireless communications system 100. For instance, the first, second, third, fourth, and fifth numerologies (i.e., μ=0, μ=1, μ=2, μ=3, μ=4) associated with respective subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize a single slot per subframe, two slots per subframe, four slots per subframe, eight slots per subframe, and 16 slots per subframe, respectively. Each slot may include a number (e.g., quantity) of symbols (e.g., OFDM symbols) . In some implementations, the number (e.g., quantity) of slots for a subframe may depend on a numerology. For a normal cyclic prefix, a slot may include 14 symbols. For an extended cyclic prefix (e.g., applicable for 60 kHz subcarrier spacing) , a slot may include 12 symbols. The relationship between the number of symbols per slot, the number of slots per subframe, and the number of slots per frame for a normal cyclic prefix and an extended cyclic prefix may depend on a numerology. It should be understood that reference to a first numerology (e.g., μ=0) associated with a first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and slots.

In the wireless communications system 100, an electromagnetic (EM) spectrum may be split, based on frequency or wavelength, into various classes, frequency bands, frequency channels, etc. By way of example, the wireless communications system 100 may support one or multiple operating frequency bands, such as frequency range designations FR1 (410 MHz –7.125 GHz) , FR2 (24.25 GHz –52.6 GHz) , FR3 (7.125 GHz –24.25 GHz) , FR4 (52.6 GHz –114.25 GHz) , FR4a or FR4-1 (52.6 GHz –71 GHz) , and FR5 (114.25 GHz –300 GHz) . In some implementations, the network entities 102 and the UEs 104 may perform wireless communications over one or more of the operating frequency bands. In some implementations, FR1 may be used by the network entities 102 and the UEs 104, among other equipment or devices for cellular communications traffic (e.g., control information, data) . In some implementations, FR2 may be used by the network entities 102 and the UEs 104, among other equipment or devices for short-range, high data rate capabilities.

FR1 may be associated with one or multiple numerologies (e.g., at least three numerologies) . For example, FR1 may be associated with a first numerology (e.g., μ=0) , which includes 15 kHz subcarrier spacing; a second numerology (e.g., μ=1) , which includes 30 kHz subcarrier spacing; and a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing. FR2 may be associated with one or multiple numerologies (e.g., at least 2 numerologies) . For example, FR2 may be associated with a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing; and a fourth numerology (e.g., μ=3) , which includes 120 kHz subcarrier spacing.

Fig. 2 illustrates a signaling diagram illustrating an example process 200 that supports UL FEC based discard in accordance with aspects of the present disclosure. The process 200 may involve the UE 104 and the network entity 102 in Fig. 1. For the purpose of discussion, the process 200 will be described with reference to Fig. 1.

As shown in Fig. 2, the UE 104 receives 210, from the network entity 102, a configuration for FEC based discard.

In some implementations, the UE 104 may receive an RRC message from the network entity 102. The RRC message may comprise the configuration for FEC based discard.

In some implementations, the configuration for FEC based discard may indicate how many PDUs in a PDU set are to be discarded by indicating at least one of the following: a discard ratio, a maximum discard ratio or a minimum discard ratio.

In some implementations, the configuration for FEC based discard may comprise the discard ratio. For example, the discard ratio may be equal to a percentage of the number of PDUs to be discarded in a PDU set.

Alternatively or additionally, in some implementations, the configuration for FEC based discard may comprise the maximum discard ratio. For example, the maximum discard ratio may be equal to the maximum percentage of the number of PDUs to be discarded in a PDU set.

Alternatively or additionally, in some implementations, the configuration for FEC based discard may comprise a minimum discard ratio. For example, the minimum discard ratio may be equal to a minimum percentage of the number of PDUs to be discarded in a PDU set.

Alternatively or additionally, in some implementations, the configuration for FEC based discard may comprise a list of discard ratios. In some implementations, each of the discard ratios in the list of discard ratios may have an index.

Alternatively or additionally, in some implementations, the configuration for FEC based discard may comprise a list of maximum discard ratios. In some implementations, each of the maximum discard ratios in the list of maximum discard ratios may have an index.

Alternatively or additionally, in some implementations, the configuration for FEC based discard may comprise a list of minimum discard ratios. In some implementations, each of the minimum discard ratios in the list of minimum discard ratios may have an index.

Alternatively or additionally, in some implementations, the configuration for FEC based discard may indicate how many PDUs in a PDU set are to be discarded by indicating at least one of the following: a third number of PDUs to be discarded for a PDU set, a maximum number of PDUs to be discarded for the PDU set, a minimum number of PDUs to be discarded for the PDU set. Hereinafter, the third number may be represented by M.

In some implementations, the configuration for FEC based discard may comprise the third number of PDUs to be discarded for each of at least one PDU set.

Alternatively or additionally, in some implementations, the configuration for FEC based discard may comprise the maximum number of PDUs to be discarded for each of the at least one PDU set.

Alternatively or additionally, in some implementations, the configuration for FEC based discard may comprise the minimum number of PDUs to be discarded for each of the at least one PDU set.

In some implementations where the configuration comprises both the maximum number and the minimum number, the number of PDUs to be discarded may be less than the maximum number and greater than the minimum number.

Alternatively or additionally, in some implementations, the configuration for FEC based discard may comprise a list of numbers of PDUs to be discarded for each of the at least one PDU set. In some implementations, each of the discard ratios in the list of discard ratios may have an index.

Alternatively or additionally, in some implementations, the configuration for FEC based discard may comprise a list of maximum numbers of PDUs to be discarded for each of the at least one PDU set. In some implementations, each of the maximum numbers in the list of maximum numbers may have an index.

Alternatively or additionally, in some implementations, the configuration for FEC based discard may comprise a list of minimum numbers of PDUs to be discarded for each of the at least one PDU set. In some implementations, each of the minimum numbers in the list of minimum numbers may have an index.

In some implementations, the configuration for FEC based discard may comprise an indication indicating whether the FEC based discard is activated or deactivated. In other words, the configuration for FEC based discard may comprise an initial state of the FEC based discard.

In some implementations, upon receiving the configuration for FEC based discard, the UE 104 may determine that the FEC based discard is deactivated. In other words, the initial state of the FEC based discard is deactivated by default.

Alternatively, in some implementations, upon receiving the configuration for FEC based discard, the UE 104 may determine that the FEC based discard is activated. In other words, the initial state of the FEC based discard is activated by default.

In some implementations, the UE 104 may receive a medium access control control element (MAC CE) comprising an indication from the network entity 102. The indication indicates whether to activate or deactivate the FEC based discard. In turn, the UE 104 may activate or deactivate the FEC based discard based on the indication.

Hereinafter, the MAC CE comprising the indication is also referred to as an FEC based Discard Activation/Deactivation MAC CE. For example, when the network entity 102 is congested, the network entity 102 may transmit the FEC based Discard Activation/Deactivation MAC CE to activate the FEC based discard. When the network entity 102 is not congested, the network entity 102 may transmit the FEC based Discard Activation/Deactivation MAC CE to deactivate the FEC based discard. Some implementations of the FEC based Discard Activation/Deactivation MAC CE will be described later with reference to Figs. 9 to 11.

In some implementations, the FEC based Discard Activation/Deactivation MAC CE may be identified by a MAC subheader with a logical channel identity (LCID) or extended logical channel identity (eLCID) .

Alternatively, the UE 104 may receive a first indication from the network entity 102. The first indication indicates to activate the FEC based discard. In turn, the UE 104 may activate the FEC based discard based on the first indication.

Alternatively, the UE 104 may receive a second indication from the network entity 102. The second indication indicates to deactivate the FEC based discard. In turn, the UE 104 may deactivate the FEC based discard based on the second indication.

In some implementations, the UE 104 may receive a first MAC CE comprising the first indication from the network entity 102.

In some implementations, the UE 104 may receive a second MAC CE comprising the second indication from the network entity 102.

In some implementations, the first MAC CE and the second MAC CE may be identified by MAC subheaders with different LCIDs or eLCIDs.

With continued reference to Fig. 2, the UE 104 determines 220 at least one FEC parameter of a PDU set.

In some implementations, an upper layer of the UE 104 may provide the at least one FEC parameter of the PDU set to an AS layer of the UE 104. Accordingly, the AS layer may determine the at least one FEC parameter by obtaining the at least one FEC parameter from the upper layer.

In some implementations, the AS layer may comprise one of the following: an RRC layer, an SDAP layer, a PDCP layer, an RLC layer, a MAC layer or a PHY layer.

In some implementations, how the upper layer obtains the at least one FEC parameter and how the upper layer provides the at least one FEC parameter to the AS layer may depend on implementation of the UE 104. The scope of the present disclosure is not limited in this regard.

In turn, the UE 104 discards 230 at least one PDU in the PDU set based on the configuration for FEC based discard and the at least one FEC parameter of the PDU set.

In some implementations, the PDU set may be associated with a block of source data. In such implementations, the at least one FEC parameter of the PDU set may comprise at least one of the following: a first number of PDUs in the PDU set which carry source symbols of the block, a second number of PDUs in the PDU set which carry repair symbols of the block, or a total number of the source symbols and the repair symbols of the block. This will be described with reference to Fig. 3.

Fig. 3 illustrates an example of a block of source data 300 in accordance with some implementations of the present disclosure. As shown in Fig. 3, the block of source data 300 is also referred to as a source block 300. The source block 300 may be partitioned into equal-size pieces of data, called source symbols. The source block 300 may comprise one or more source symbols with specific bits. For example, the last source symbol in the source block 300 comprises padding bits.

Packets from 0 to K-1 identify the source symbols of the source block 300 in sequential order, where K is the number (i.e. the first number) of source symbols in the source block 300. Encoding Symbol IDs K onwards identify repair symbols generated from the source symbols using an FEC encoder. A total number of the source symbols and the repair symbols of the source block 300 is represented by N, where N >= K.

Typically, an FEC decoder requires only any K or only a small amount more than K packets of the N packets to recover the source symbols. Based on this, the definition of a PDU set may be applied to all packets of the source block 300. In other words, the PDU set is associated with the source block 300. The first number of PDUs (i.e., K PDUs) in the PDU set carry K source symbols of the source block 300. A second number of PDUs (i.e., N-K) PDUs in the PDU set carry (N-K) repair symbols of the source block 300. Any K PDUs in the PDU sets are sufficient to recover, i.e., all PDUs are of the same importance (which are of the same importance requirement at application layer) . As only K out N PDUs are required, the application layer can still recover parts of the information unit when some PDUs are missing.

For example, Raptor is an FEC technology and RaptorQ is the most flexible and powerful product in the Raptor technology line, pioneered by Digital Fountain. RaptorQ encodes and decodes the source block 300. The RaptorQ encoder generates repair symbols from the source symbols of the source block 300, where the repair symbols are the same size as the source symbols and the encoded symbols that can be transmitted comprise the combination of the source symbols and the repair symbols. Typically, each encoded symbol is transmitted in an individual packet together with a 32-bit header, called the FEC Payload identifier (ID) consisting of an 8-bit source block number and a 24-bit encoded symbol identifier (ESI) that allows the receiver to identify the encoded symbol carried in a packet.

In some implementations, the PDU set includes PDUs that are comprised of the source block and the PDU of the PDU set is equal to the source symbol or repair symbol. In some implementations, the UE 104 may discard the at least one PDU in the PDU set based on the configurationor FEC based discard, the at least one FEC parameter of the PDU set and at least one discard rule.

In some implementations, the at least one discard rule may indicate which PDUs in a PDU set should be discarded.

For example, the configuration for FEC based discard may indicate M PDUs in a PDU set are to be discarded and the at least one discard rule may indicate which M PDUs in the PDU set should be discarded.

For another example, the configuration for FEC based discard may indicate the discard ratio. The UE 104 may determine, based on the discard ratio, M PDUs in a PDU set are to be discarded and the at least one discard rule may indicate which M PDUs in the PDU set should be discarded.

In some implementations, the configuration for FEC based discard may comprise the at least one discard rule. Alternatively, the at least one discard rule may be predefined.

Hereinafter, some example implementations of discarding the at least one PDU in the PDU set will be described with reference to Figs. 4 to 8.

Fig. 4 illustrates a flowchart of a method 400 that supports UL FEC based discard in accordance with aspects of the present disclosure. The method 400 may be considered as an example implementation of the action 230 in Fig. 2. For the purpose of discussion, the method 400 will be described from the perspective of the UE 104 with reference to Fig. 1.

Generally, in the method 400, the at least one discard rule may indicate discarding the third number of PDUs in the PDU set which arrive at the AS layer of the UE 104 last. The UE 104 may discard, based on the at least one discard rule, the third number of PDUs in the PDU set which arrive at the AS layer of the UE 104 last.

Specifically, at 410, the UE 104 may determine the third number of the PDUs to be discarded based on a total number of PDUs in the PDU set and the discard ratio.

For example, the total number of PDUs in the PDU set is represented by N, the discard ratio is represented by X%, and the third number of the PDUs to be discarded is represented by M. M may be equal to floor [N*X%] , or ceil [N*X%] . The discard ratio X%may be equal to or less than (N-K) /N, where K represents the first number of number of PDUs in the PDU set which carry source symbols of the block.

Alternatively, the UE 104 may determine the third number based on the total number of PDUs in the PDU set and the maximum discard ratio. In such implementations, the UE 104 may determine a maximum number of PDUs to be discarded for the PDU set based on the total number of PDUs in the PDU set and the maximum discard ratio. Then, the UE 104 may determine the third number to be equal to or less than the maximum number.

Alternatively, the UE 104 may determine the third number based on the total number of PDUs in the PDU set and the minimum discard ratio. In such implementations, the UE 104 may determine a minimum number of PDUs to be discarded for the PDU set based on the total number of PDUs in the PDU set and the minimum discard ratio. Then, the UE 104 may determine the third number to be equal to or greater than the minimum number.

As described above, in some implementations, the configuration for FEC based discard may comprise one of the following: the discard ratio, the maximum discard ratio, or the minimum discard ratio.

Alternatively, in some implementations, the configuration for FEC based discard may comprise a list of discard ratios. The FEC based Discard Activation/Deactivation MAC CE may further comprise a first index of a first discard ratio in the list of discard ratios. The UE 104 may determine the discard ratio based on the first index of the first discard ratio. In other words, the UE 104 may determine the discard ratio as the first discard ratio based on the first index of the first discard ratio.

Alternatively, in some implementations, the configuration for FEC based discard may comprise a list of maximum discard ratios. The FEC based Discard Activation/Deactivation MAC CE may further comprise a second index of a first maximum discard ratio in the list of maximum discard ratios. The UE 104 may determine the maximum discard ratio based on the second index of the first maximum discard ratio. In other words, the UE 104 may determine the maximum discard ratio as the first discard ratio based on the second index of the first maximum discard ratio.

Alternatively, in some implementations, the configuration for FEC based discard may comprise a list of minimum discard ratios. The FEC based Discard Activation/Deactivation MAC CE may further comprise a third index of a first minimum discard ratio in the list of minimum discard ratios. The UE 104 may determine the minimum discard ratio based on the third index of the first minimum discard ratio. In other words, the UE 104 may determine the minimum discard ratio as the first minimum discard ratio based on the third index of the first minimum discard ratio.

Alternatively, in some implementations, the UE 104 may determine the third number based on one of the following: the third number of PDUs to be discarded for the PDU set, a maximum number of PDUs to be discarded for the PDU set, or a minimum number of PDUs to be discarded for the PDU set.

In some implementations, the configuration for FEC based discard may comprise the third number of PDUs to be discarded for the PDU set. Alternatively, the configuration for FEC based discard may comprise a list of numbers of PDUs to be discarded for the PDU set. The FEC based Discard Activation/Deactivation MAC CE may further comprise a fourth index of the third number in the list of numbers of PDUs. The UE 104 may determine the third number based on the fourth index of the third number.

In some implementations, the configuration for FEC based discard may comprise the maximum number of PDUs to be discarded for the PDU set. Alternatively, the configuration for FEC based discard may comprise a list of maximum numbers of PDUs to be discarded for the PDU set. The FEC based Discard Activation/Deactivation MAC CE may further comprise a fifth index of the maximum number in the list of maximum numbers of PDUs. The UE 104 may determine the maximum number based on the fifth index of the maximum number. Then, the UE 104 may determine the third number to be equal to or less than the maximum number.

In some implementations, the configuration for FEC based discard may comprise the minimum number of PDUs to be discarded for the PDU set. Alternatively, the configuration for FEC based discard may comprise a list of minimum numbers of PDUs to be discarded for the PDU set. The FEC based Discard Activation/Deactivation MAC CE may further comprise a sixth index of the minimum number in the list of minimum numbers of PDUs. The UE 104 may determine the minimum number based on the sixth index of the minimum number and determine the third number to be equal to or greater than the minimum number.

With continued reference to Fig. 4, at 420, the UE 104 may discard the third number of PDUs in the PDU set which arrive at the AS layer of the UE 104 last.

In some implementations, the FEC based discard may be performed at a PDCP entity of the UE 104. In such implementations, for a PDCP SDU received from upper layers, if the PDCP SDU is one of the M PDCP SDUs in the PDU set which arrive at the AS layer last, and the FEC based discard is activated, the transmitting PDCP entity of the UE 104 shall discard the PDCP PDU directly.

Alternatively, in some implementations, the FEC based discard may be performed at an SDAP entity of the UE 104 before mapping at least one QoS flow to one or more DRBs.

Fig. 5 illustrates a flowchart of a method 500 that supports UL FEC based discard in accordance with aspects of the present disclosure. The method 500 may be considered as an example implementation of the action 230 in Fig. 2. For the purpose of discussion, the method 500 will be described from the perspective of the UE 104 with reference to Fig. 1.

Generally, in the method 500, the at least one discard rule may indicate discarding the third number of PDUs in the PDU set in an ascending order of remaining time of discard timers for PDUs in the PDU set. The UE 104 may discard, based on the at least one discard rule, the third number of PDUs in the PDU set in the ascending order of remaining time of discard timers for PDUs in the PDU set.

Specifically, at 510, the UE 104 may determine the third number of the PDUs to be discarded based on the total number of PDUs in the PDU set and one of the following: the discard ratio, the maximum discard ratio, or the minimum discard ratio.

Alternatively, the UE 104 may determine the third number of the PDUs to be discarded based on one of the following: the third number of PDUs to be discarded for the PDU set, the maximum number of PDUs to be discarded for the PDU set, or the minimum number of PDUs to be discarded for the PDU set.

In some implementations, the third number of the PDUs to be discarded have not been transmitted to the network entity 102.

The action 510 is similar to the action 410 in Fig. 4. Thus, details of the action 510 are omitted for brevity.

At 520, the UE 104 may discard the third number of PDUs in the PDU set in the ascending order of remaining time of discard timers for PDUs in the PDU set.

For example, if remaining time of a discard timer for a first PDU in the PDU set is the smallest among the remaining time of the discard timers for the PDUs in the PDU set, the UE 104 may prioritize to discard the first PDU.

Fig. 6 illustrates a flowchart of a method 600 that supports UL FEC based discard in accordance with aspects of the present disclosure. The method 600 may be considered as an example implementation of the action 230 in Fig. 2. For the purpose of discussion, the method 600 will be described from the perspective of the UE 104 with reference to Fig. 1.

Generally, in the method 600, the at least one discard rule may indicate prioritizing to discard a first PDU which comprises padding bits. The UE 104 may prioritize to discard the first PDU based on the at least one discard rule.

Specifically, at 610, the UE 104 may determine the third number of the PDUs to be discarded based on the total number of PDUs in the PDU set and one of the following: the discard ratio, the maximum discard ratio, or the minimum discard ratio.

The action 610 is similar to the action 410 in Fig. 4. Thus, details of the action 610 are omitted for brevity.

At 620, the UE 104 may prioritize to discard the first PDU in the PDU set. The first PDU may comprise the padding bits. For example, the first PDU may be a PDU carrying the last source symbol of the block 300 in Fig. 3.

For example, the third number of the PDUs to be discarded is equal to 20. That is, M is equal to 20. The UE 104 may discard the first PDU in the PDU set firstly and then discard (M-1) PDUs in the PDU set.

Fig. 7 illustrates a flowchart of a method 700 that supports UL FEC based discard in accordance with aspects of the present disclosure. The method 700 may be considered as an example implementation of the action 230 in Fig. 2. For the purpose of discussion, the method 700 will be described from the perspective of the UE 104 with reference to Fig. 1.

Generally, in the method 700, the at least one discard rule may indicate prioritizing to discard a second PDU in the PDU set. The second PDU carries a repair symbol of a block of source data. The UE 104 may prioritize to discard the second PDU based on the at least one discard rule.

Specifically, at 710, the UE 104 may determine the third number of the PDUs to be discarded based on the total number of PDUs in the PDU set and one of the following: the discard ratio, the maximum discard ratio, or the minimum discard ratio.

The action 710 is similar to the action 410 in Fig. 4. Thus, details of the action 710 are omitted for brevity.

At 720, the UE 104 may prioritize to discard the second PDU which carries a repair symbol of a block of source data. For example, the second PDU may be a PDU carrying a repair symbol of the block 300 in Fig. 3.

For example, the third number of the PDUs to be discarded is equal to 20. That is, M is equal to 20. The UE 104 may discard the second PDU in the PDU set firstly and then discard (M-1) PDUs in the PDU set.

Fig. 8 illustrates a flowchart of a method 800 that supports UL FEC based discard in accordance with aspects of the present disclosure. The method 800 may be considered as an example implementation of the action 230 in Fig. 2. For the purpose of discussion, the method 800 will be described from the perspective of the UE 104 with reference to Fig. 1.

Generally, in the method 800, the at least one discard rule may indicate starting a discard timer for each of the third number of PDUs in the PDU set which arrive at the AS layer of the UE last and discarding a third PDU among the third number of PDUs based on determining that a third discard timer for the third PDU expires. The UE 104 may discard, based on the at least one discard rule, a third PDU among the third number of PDUs based on determining that a third discard timer for the third PDU expires.

Specifically, at 810, the UE 104 may determine the third number of the PDUs to be discarded based on the total number of PDUs in the PDU set and one of the following: the discard ratio, the maximum discard ratio, or the minimum discard ratio.

The action 810 is similar to the action 410 in Fig. 4. Thus, details of the action 810 are omitted for brevity.

At 820, the UE 104 may start a discard timer for each of the third number of PDUs in the PDU set which arrive at the AS layer of the UE 104 last.

At 830, if a third discard timer for a third PDU among the third number of PDUs expires, the UE 104 may discard the third PDU.

In some implementations, when the third PDU among the third number of PDUs in the PDU set arrives at the PDCP entity of the UE 104, the PDCP entity may start a short PDCP discard timer for the third PDU. The short PDCP discard timer may be configured by the network entity 102. The short PDCP discard timer may be defined as an FEC based discard timer. A value of the FEC based discard timer may be shorter than a regular PDCP discard timer. When the FEC based timer of the third PDU expires, the UE 104 may discard the third PDU.

Hereinafter, some example implementations of the process 200 will be described with reference to Figs. 9 to 13.

Fig. 9 illustrates a signaling diagram illustrating an example process 900 that supports UL FEC based discard in accordance with some implementations of the present disclosure. The process 900 may be considered as an example implementation of the process 200. The process 900 may involve the UE 104 and the network entity 102 in Fig. 1.For the purpose of discussion, the process 900 will be described with reference to Fig. 1.

Generally, in the process 900, the UE 104 obtains first FEC information about at least one QoS flow and transmits the first FEC information to the network entity 102. The network entity 102 transmits, to the UE 104, the configuration for FEC based discard which is associated with at least one QoS flow or at least one DRB.

Specifically, as shown in Fig. 9, the UE 104 obtains 910 the first FEC information about at least one QoS flow.

In some implementations, the first FEC information about at least one QoS flow may be provided by the upper layer of the UE 104 to the AS layer of the UE 104. In some implementations, how the upper layer obtains the first FEC information and how the upper layer provides the first FEC information to the AS layer may depend on implementation of the UE 104. The scope of the present disclosure is not limited in this regard.

In some implementations, the first FEC information about at least one QoS flow may comprise an indication indicating about whether the FEC is to be applied to the at least one QoS flow.

Alternatively or additionally, in some implementations, the first FEC information about at least one QoS flow may comprise an FEC encoding type which is to be applied to the at least one QoS flow. For example, the first FEC information about at least one QoS flow may comprise a first FEC encoding type which is to be applied to a first QoS flow and a second FEC encoding type which is to be applied to a second QoS flow. The first FEC encoding type may be the same as or different from the second FEC encoding type. For example, one of the first FEC encoding type and the second FEC encoding type may be RaptorQ and the other may be an FEC encoding type other than RaptorQ.

Alternatively or additionally, in some implementations, the first FEC information about at least one QoS flow may comprise a redundant ratio for the at least one QoS flow. In some implementations, the redundant ratio may be an average redundant ratio for the at least one QoS flow.

In some implementations, the redundant ratio may be equal to a ratio of the first number of PDUs in the PDU set which carry source symbols of the block to the total number of the source symbols and the repair symbols of the block. For example, the redundant ratio may be equal to K/N.

Alternatively, the redundant ratio may be equal to a ratio of the second number of PDUs in the PDU set which carry repair symbols of the block to the total number of the source symbols and the repair symbols of the block. For example, the redundant ratio may be equal to (N-K) /N.

Alternatively or additionally, in some implementations, the first FEC information about at least one QoS flow may comprise an identifier (ID) of the at least one QoS flow. For example, the first FEC information about at least one QoS flow may comprise a first ID of a first QoS flow and a second ID of a second QoS flow.

In turn, the UE 104 may transmit 920 the first FEC information to the network entity 102.

In some implementations, when the first FEC information about the at least one QoS flow is available at the AS of the UE 104 and configured to be provided to the network entity 102, the UE 104 may transmit the first FEC information to the network entity 102 by UE RRC signaling in UEAssitanceInformation message.

In some implementations, if any element in the first FEC information about the at least one QoS flow is updated, the UE 104 may transmit the updated FEC information about the at least one QoS flow to the network entity 102

In some implementations, a prohibit timer may be configured for transmission of the first FEC information to avoid frequent transmission. When the UE 104 transmits the first FEC information about the at least one QoS flow, the UE 104 starts the prohibit timer. When the prohibit timer is running, the UE 104 shall not transmit the updated FEC information about the at least one QoS flow. Once the prohibit timer expires, the UE 104 can transmit the updated FEC information about the at least of one QoS flow.

The UE 104 receives 930 the configuration for FEC based discard which is associated with at least one QoS flow or the configuration for FEC based discard which is associated with at least one DRB. The FEC is to be applied to the at least one QoS flow or the at least one DRB.

In some implementations, the UE 104 may receive the configuration for FEC based discard associated with the at least one QoS flow via an RRC message.

In some implementations, the configuration for FEC based discard associated with the at least one QoS flow may comprise at least one ID of the at least one QoS flow.

Alternatively or additionally, in some implementations, the configuration for FEC based discard associated with the at least one QoS flow may comprise at least one of the following: the discard ratio for the at least one QoS flow, the maximum discard ratio for the at least one QoS flow, or the minimum discard ratio for the at least one QoS flow.

Alternatively or additionally, in some implementations, the configuration for FEC based discard associated with the at least one QoS flow may comprise at least one of the following: the list of discard ratios for the at least one QoS flow, the list of maximum discard ratios for the at least one QoS flow, or the list of minimum discard ratios for the at least one QoS flow.

In some implementations, the configuration for FEC based discard associated with the at least one DRB may comprise at least one ID of the at least one DRB.

Alternatively or additionally, in some implementations, the configuration for FEC based discard associated with the at least one DRB may comprise at least one of the following: the discard ratio for the at least one DRB, the maximum discard ratio for the at least one DRB, or the minimum discard ratio for the at least one DRB.

Alternatively or additionally, in some implementations, the configuration for FEC based discard associated with the at least one DRB may comprise at least one of the following: the list of discard ratios for the at least one DRB, the list of maximum discard ratios for the at least one DRB, or the list of minimum discard ratios for the at least one DRB.

Optionally, the UE 104 may receive 940 the FEC based Discard Activation/Deactivation MAC CE.

In some implementations, when the network entity 102 is congested, the network entity 102 may transmit the FEC based Discard Activation/Deactivation MAC CE to activate the FEC based discard. When the network entity 102 is not congested, the network entity 102 may transmit the FEC based Discard Activation/Deactivation MAC CE to deactivate the FEC based discard.

The UE 104 activates or deactivates 950 the FEC based discard based on the FEC based Discard Activation/Deactivation MAC CE.

In some implementations, if the configuration for FEC based discard is associated with the at least one DRB, one bit in the FEC based Discard Activation/Deactivation MAC CE may be used for indicating whether the FEC based discard is activated or deactivated for the at least one DRB. In some example, when the bit is set to ‘1’ , it means that the FEC based discard is activated for all of the at least one DRB configured by the network entity 102 in the configuration for FEC based discard, and when the bit is set to ‘0’ , it means that the FEC based discard is deactivated for all of the at least one DRB configured by the network entity 102 in the configuration for FEC based discard.

In such implementations, when the MAC entity of the UE 104 receives the FEC based Discard Activation/Deactivation MAC CE, if the MAC CE comprises an indication indicating to activate the FEC based discard, the MAC entity shall indicate, for all of the at least one DRB configured with the FEC based discard, the activation of the FEC based discard to upper-layers of the UE 104. For example, the MAC entity shall indicate, for all of the at least one DRB configured with the FEC based discard, the activation of the FEC based discard to the PDCP entity.

On the other hand, if the MAC CE comprises an indication indicating to deactivate the FEC based discard, the MAC entity of the UE 104 shall indicate, for all of the at least one DRB configured with the FEC based discard, the deactivation of the FEC based discard to upper-layers of the UE 104. For example, the MAC entity shall indicate, for all of the at least one DRB configured with the FEC based discard, the deactivation of the FEC based discard to the PDCP entity.

In some implementations, if the configuration for FEC based discard is associated with the at least one DRB, the FEC based Discard Activation/Deactivation MAC CE may comprise an indication indicating to activate the FEC based discard for part or all of the at least one DRB configured with the FEC based discard. This will be described with reference to Fig. 10.

Fig. 10 illustrates an example of the FEC based Discard Activation/Deactivation MAC CE 1000 in accordance with some implementations of the present disclosure. As shown in Fig. 10, the MAC CE 1000 may comprise a Di field comprising the first bitmap, where i is the ascending or descending order of the DRB ID among the at least one DRB configured by the network entity 102 in the configuration for FEC based discard, and i is in the range of 0 to 7. Each of at least one bit in the first bitmap is associated with one of the at least one DRB to which the FEC based discard is allowed to be applied. In other words, each of at least one bit in the first bitmap is associated with one of the at least one DRB configured by the network entity 102 in the configuration for FEC based discard. Each of the at least one bit indicates that the FEC based discard is to be activated or deactivated for a respective one of the at least one DRB.

In some implementations, the Di field set to 1 indicates that the FEC based discard shall be activated for DRB i, and the Di field set to 0 indicates that the FEC based discard shall be deactivated for DRB i.

When the MAC entity of the UE 104 receives the MAC CE 1000, if the MAC CE 1000 comprises the first bitmap with a bit indicating to activate the FEC based discard for DRB i, the MAC entity shall indicate the activation of the FEC based discard for the DRB i to upper-layers of the UE 104. For example, the MAC entity shall indicate the activation of the FEC based discard for the DRB i to the PDCP entity.

On the other hand, if the MAC CE 1000 comprises the first bitmap with a bit indicating to deactivate the FEC based discard for DRB i, the MAC entity shall indicate the deactivation of the FEC based discard for the DRB i to upper-layers of the UE 104. For example, the MAC entity shall indicate the deactivation of the FEC based discard for the DRB i to the PDCP entity.

In some implementations, the MAC CE 1000 may further comprise an index of the discard ratio if the configuration for FEC based discard comprises the list of discard ratios for the at least one DRB. When receiving the MAC CE 1000, the MAC entity of the UE 104 shall indicate the index to upper-layers of the UE 104. For example, the MAC entity shall indicate the index to the PDCP entity.

Alternatively, in some implementations, the MAC CE 1000 may further comprise an index of the maximum discard ratio if the configuration for FEC based discard comprises the list of maximum discard ratios for the at least one DRB. When receiving the MAC CE 1000, the MAC entity shall indicate the index to upper-layers. For example, the MAC entity shall indicate the index to the PDCP entity.

Alternatively, in some implementations, the MAC CE 1000 may further comprise an index of the minimum discard ratio if the configuration for FEC based discard comprises the list of minimum discard ratios for the at least one DRB. When receiving the MAC CE 1000, the MAC entity shall indicate the index to upper-layers. For example, the MAC entity shall indicate the index to the PDCP entity.

In some implementations, if the configuration for FEC based discard is associated with the at least one QoS flow, the FEC based Discard Activation/Deactivation MAC CE may comprise an indication indicating to activate the FEC based discard for part or all of the at least one QoS flow configured with the FEC based discard. This will be described with reference to Fig. 11.

Fig. 11 illustrates an example of the FEC based Discard Activation/Deactivation MAC CE 1100 in accordance with some implementations of the present disclosure. As shown in Fig. 11, the MAC CE 1100 may comprise a Di field comprising the second bitmap, where i is the ascending or descending order of the QoS flow ID among the at least one QoS flow configured by the network entity 102 in the configuration for FEC based discard, and i is in the range of 0 to 7. Each of at least one bit in the second bitmap is associated with one of the at least one QoS flow to which the FEC based discard is allowed to be applied. In other words, each of at least one bit in the second bitmap is associated with one of the at least one QoS flow configured by the network entity 102 in the configuration for FEC based discard. Each of the at least one bit indicates that the FEC based discard is to be activated or deactivated for a respective one of the at least one QoS flow.

In some implementations, the Qi field set to 1 indicates that the FEC based discard shall be activated for QoS flow i, and the Qi field set to 0 indicates that the FEC based discard shall be deactivated for QoS flow i.

When the MAC entity of the UE 104 receives the MAC CE 1100, if the MAC CE 1100 comprises the second bitmap with a bit indicating to activate the FEC based discard for QoS flow i, the MAC entity shall indicate the activation of the FEC based discard for the QoS flow i to upper-layers. For example, the MAC entity shall indicate the activation of the FEC based discard for the QoS flow i to the SDAP entity.

On the other hand, if the MAC CE 1100 comprises the second bitmap with a bit indicating to deactivate the FEC based discard for QoS flow i, the MAC entity shall indicate the deactivation of the FEC based discard for the QoS flow i to upper-layers. For example, the MAC entity shall indicate the deactivation of the FEC based discard for the QoS flow i to the SDAP entity.

In some implementations, the Qi field set to 1 indicates that the FEC based discard shall be activated for all PSI values associated with QoS flow i, and the Qi field set to 0 indicates that the FEC based discard shall be deactivated for all PSI values associated with QoS flow i.

In some implementations, the MAC CE 1100 may further comprise at least one PSI value associated with QoS flow i, which is not shown in Fig. 11. In such implementations, the Qi field set to 1 indicates that the FEC based discard shall be activated for the at least one PSI value associated with QoS flow i, and the Qi field set to 0 indicates that the FEC based discard shall be deactivated for the at least one PSI value associated with QoS flow i.

If the FEC based discard is activated, the UE 104 determines 960 the at least one FEC parameter of the PDU set.

In some implementations, the at least one FEC parameter of the PDU set comprises at least one of the following: the first number of PDUs in the PDU set which carry source symbols of the block, the second number of PDUs in the PDU set which carry repair symbols of the block, or the total number of the source symbols and the repair symbols of the block.

The UE 104 discards 970 at least one PDU in the PDU set based on the configuration for FEC based discard associated with the at least one QoS flow or the at least one DRB and the at least one FEC parameter of the PDU set.

In some implementations, the UE 104 may discard the at least one PDU in the PDU set by performing any of the methods 400 to 800.

In some implementations, if the configuration for FEC based discard is associated with the at least one DRB, the PDCP entity of the UE 104 may discard the at least one PDU in the PDU set. In such implementations, for a PDCP SDU received from upper layers, if the PDCP SDU is one of the M PDCP SDUs in the PDU set which arrive at the AS layer last, and the FEC based discard is activated, the transmitting PDCP entity of the UE 104 shall discard the PDCP PDU directly.

In some implementations, if the configuration for FEC based discard is associated with the at least one QoS flow, the SDAP entity of the UE 104 may discard the at least one PDU in the PDU set before mapping of the at least one QoS flow to one or more DRBs.

Fig. 12 illustrates a signaling diagram illustrating an example process 1200 that supports UL FEC based discard in accordance with some implementations of the present disclosure. The process 1200 may be considered as an example implementation of the process 200. The process 1200 may involve the UE 104 and the network entity 102 in Fig. 1. For the purpose of discussion, the process 1200 will be described with reference to Fig. 1.

Generally, in the process 1200, the UE 104 obtains second FEC information about at least one PDU set and transmits the second FEC information to the network entity 102. The network entity 102 transmits, to the UE 104, the configuration for FEC based discard which is associated with at least one PDU set.

Specifically, as shown in Fig. 12, the UE 104 obtains 1210 the second FEC information about at least one PDU set.

In some implementations, each of the at least one PDU set is associated with a block of source data.

In some implementations, the second FEC information may comprise an indication indicating whether the FEC is to be applied to the at least one PDU set.

Alternatively or additionally, in some implementations, the second FEC information may comprise an FEC encoding type which is to be applied to each of the at least one PDU set. For example, the second FEC information may comprise a first FEC encoding type which is to be applied to a first PDU set and a second FEC encoding type which is to be applied to a second PDU set. The first FEC encoding type may be the same as or different from the second FEC encoding type. For example, one of the first FEC encoding type and the second FEC encoding type may be RaptorQ and the other may be an FEC encoding type other than RaptorQ.

Alternatively or additionally, in some implementations, the second FEC information may comprise at least one of the following: the first number of PDUs in each of the at least one PDU set which carry source symbols of the block; the second number of PDUs in each of the at least one PDU set which carry repair symbols of the block; or the total number of the source symbols and the repair symbols of the block; a size of each of the source symbols and the repair symbols; a last symbol among the source symbols which comprises padding bits; an FEC payload ID of each of the source symbols and the repair symbols of the block; or a sequence number (SN) of each of the at least one PDU set.

In some implementations, if the second FEC information does not comprise the SN of each of the at least one PDU set, the network entity 102 may assume the second FEC information is for the on-going transmitting PDU set.

In some example, the FEC payload ID may comprise an 8-bit source block number and a 24-bit ESI.

The UE 104 may transmit 1220 the second FEC information to the network entity.

In some example, when the second FEC Information is available at the AS and configured to be provided to the network entity 102, the UE 104 may transmit the second FEC information to the network entity 102 by UE RRC signaling in UEAssitanceInformation message.

Alternatively, in some implementations, the UE 104 may transmit the second FEC information to the network entity 102 via a MAC CE. Hereinafter, the MAC CE comprising the second FEC information is also referred to as a UL FEC Information MAC CE.

In such implementations, if the second FEC information is available at the AS of the UE 104 and configured to be provided, the UE 104 shall trigger the UL FEC Information MAC CE reporting procedure. The MAC entity of the UE 104 shall instruct the multiplexing and assembly procedure to generate the MAC CE if UL-SCH resources are available for a new transmission and the UL-SCH resources can accommodate the MAC CE plus its subheader as a result of logical channel prioritization. If the UL-SCH resources are not available for transmission the MAC CE plus its subheader, the MAC entity of the UE 104 may trigger a buffer status report (BSR) procedure. If the second FEC information is updated e.g., for a new PDU set that has never been reported, the UE 104 shall trigger a new UL FEC Information MAC CE reporting procedure for reporting the updated FEC information about the at least one PDU set.

In some implementations, the UL FEC Information MAC CE may be identified by MAC subheader with a one-octet LCID or eLCID.

The UE 104 receives 1230 the configuration for FEC based discard which is associated with at least one PDU set. The FEC is to be applied to the at least one PDU set.

In some implementations, the UE 104 may receive the configuration for FEC based discard associated with at least one PDU set via an RRC message.

In some implementations, the configuration for FEC based discard which is associated with at least one PDU set may comprise at least one SN of the at least one PDU set.

Alternatively or additionally, in some implementations, the configuration for FEC based discard associated with the at least one PDU set may comprise at least one of the following: the discard ratio for the at least one PDU set, the maximum discard ratio for the at least one PDU set, or the minimum discard ratio for the at least one PDU set.

Alternatively or additionally, in some implementations, the configuration for FEC based discard associated with the at least one PDU set may comprise at least one of the following: the list of discard ratios for the at least one PDU set, the list of maximum discard ratios for the at least one PDU set, or the list of minimum discard ratios for the at least one PDU set.

Alternatively or additionally, in some implementations, the configuration for FEC based discard associated with the at least one PDU set may comprise at least one of the following: the third number of PDUs to be discarded for each of the at least one PDU set, the maximum number of PDUs to be discarded for each of the at least one PDU set, the minimum number of PDUs to be discarded for each of the at least one PDU set.

Alternatively or additionally, in some implementations, the configuration for FEC based discard associated with the at least one PDU set may comprise at least one of the following: the list of numbers of PDUs to be discarded for each of the at least one PDU set, the list of maximum numbers of PDUs to be discarded for each of the at least one PDU set, or the list of minimum numbers of PDUs to be discarded for each of the at least one PDU set.

Optionally, the UE 104 may receive 1240 the FEC based Discard Activation/Deactivation MAC CE.

In some implementations, in the FEC based Discard Activation/Deactivation MAC CE may at least one SN of at least one PDU set and an indication indicating to activate or deactivate the FEC based discard for the at least one PDU set.

The UE 104 activates or deactivates 1250 the FEC based discard based on the MAC CE.

In some implementations, when the MAC entity of the UE 104 receives the FEC based Discard Activation/Deactivation MAC CE, if the MAC CE comprises an indication indicating to activate the FEC based discard, the MAC entity shall indicate, for the at least one PDU set, the activation of the FEC based discard to upper-layers. For example, the MAC entity shall indicate, for the at least one PDU set, the activation of the FEC based discard to the PDCP entity.

On the other hand, if the MAC CE comprises an indication indicating to deactivate the FEC based discard, the MAC entity shall indicate, for the at least one PDU set, the deactivation of the FEC based discard to upper-layers. For example, the MAC entity shall indicate, for the at least one PDU set, the deactivation of the FEC based discard to the PDCP entity.

In some implementations, the MAC CE may further comprise an index of the number of PDUs to be discarded for each of the at least one PDU set if the configuration for FEC based discard comprises the list of numbers of PDUs to be discarded for each of the at least one PDU set. When receiving the MAC CE, the MAC entity shall indicate the index to upper-layers. For example, the MAC entity shall indicate the index to the PDCP entity.

Alternatively, in some implementations, the MAC CE may further comprise an index of the maximum number of PDUs to be discarded for each of the at least one PDU set if the configuration for FEC based discard comprises the list of maximum numbers of PDUs to be discarded for each of the at least one PDU set. When receiving the MAC CE, the MAC entity shall indicate the index to upper-layers. For example, the MAC entity shall indicate the index to the PDCP entity.

Alternatively, in some implementations, the MAC CE may further comprise an index of the minimum number of PDUs to be discarded for each of the at least one PDU set if the configuration for FEC based discard comprises the list of minimum numbers of PDUs to be discarded for each of the at least one PDU set. When receiving the MAC CE, the MAC entity shall indicate the index to upper-layers. For example, the MAC entity shall indicate the index to the PDCP entity.

If the FEC based discard is activated, the UE 104 determines 1260 the at least one FEC parameter of the PDU set.

In some implementations, the at least one FEC parameter of the PDU set may comprise at least part of the second FEC information.

The UE 104 discards 1270 at least one PDU in the PDU set based on the configuration associated with at least one PDU set and the at least one FEC parameter of the PDU set.

Fig. 13 illustrates a signaling diagram illustrating an example process 1300 that supports UL FEC based discard in accordance with some implementations of the present disclosure. The process 1300 may be considered as an example implementation of the process 200. The process 1300 may involve the UE 104 and the network entity 102 in Fig. 1. For the purpose of discussion, the process 1300 will be described with reference to Fig. 1.

Generally, in the process 1300, the UE 104 obtains third FEC information about about at least one PDU set with at least one PSI value within a QoS flow and transmits the third FEC information to the network entity 102. The network entity 102 transmits, to the UE 104, the configuration for FEC based discard which is associated with at least one PSI value within the QoS flow.

The UE 104 obtains 1310 third FEC information about at least one PDU set with at least one PSI value within a QoS flow. The FEC is to be applied to at least one PDU set with the at least one PSI value.

In some implementations, PDU sets may carry different contents with different importance levels called PSI or PSI values. For example, PDU sets may carry I frames, B frames or P frames. For another example, PDU sets may carry slices or tiles within an I, B or P frame. A PSI value identifies the relative importance of a PDU set compared to other PDU sets within a QoS Flow.

In some implementations, the third FEC information may comprises an indication indicating whether the FEC is to be applied to the at least one PDU set with the at least one PSI value.

Alternatively or additionally, in some implementations, the third FEC information may comprise an FEC encoding type which is to be applied to each of the at least one PDU set with the at least one PSI value.

Alternatively or additionally, in some implementations, the third FEC information may comprise a redundant ratio for the at least one PDU set with the at least one PSI value.

The UE 104 may transmit 1320 the third FEC information to the network entity 102.

In some implementations, when the third FEC information is available at the AS and configured to be provided for the at least one PSI of the QoS flow, the UE 104 may transmit the third FEC information to the network entity 102 by UE RRC signaling in UEAssitanceInformation message.

In some implementations, if any element in the third FEC information is updated, the UE 104 may transmit the updated FEC information about the at least one PDU set with at least one PSI value to the network entity 102.

In some implementations, a prohibit timer may be configured for transmission of the third FEC information to avoid frequent transmission. When the UE 104 transmits the third FEC information, the UE 104 starts the prohibit timer. When the prohibit timer is running, the UE 104 shall not transmit the updated FEC information about the at least one PDU set with at least one PSI value. Once the prohibit timer expires, the UE 104 can transmit the updated FEC information about the at least one PDU set with at least one PSI value.

The UE 104 receives 1330 the configuration for FEC based discard which is associated with least one PSI.

In some implementations, the UE 104 may receive the configuration for FEC based discard associated with the at least one PSI value via an RRC message.

In some implementations, the configuration may comprise the at least one PSI value.

Alternatively or additionally, in some implementations, the configuration for FEC based discard associated with the at least one PSI value may comprise at least one of the following: the discard ratio for the at least one PSI value, the maximum discard ratio for the at least one PSI value, or the minimum discard ratio for the at least one PSI value.

Alternatively or additionally, in some implementations, the configuration for FEC based discard associated with the at least one PSI value may comprise at least one of the following: the list of discard ratios for the at least one PSI value, the list of maximum discard ratios for the at least one PSI value, or the list of minimum discard ratios for the at least one PSI value.

Optionally, the UE 104 may receive 1340 the FEC based Discard Activation/Deactivation MAC CE.

In some implementations, the FEC based Discard Activation/Deactivation MAC CE is identified by MAC subheader with an LCID or eLCID.

The UE 104 activates or deactivates 1350 the FEC based discard based on the FEC based Discard Activation/Deactivation MAC CE.

In some implementations, when the MAC entity of the UE 104 receives the FEC based Discard Activation/Deactivation MAC CE, if the MAC CE comprises an indication indicating to activate the FEC based discard, the MAC entity shall indicate, for the at least one PSI value, the activation of the FEC based discard to upper-layers. For example, the MAC entity shall indicate, for the at least one PSI value, the activation of the FEC based discard to the PDCP entity.

On the other hand, if the MAC CE comprises an indication indicating to deactivate the FEC based discard, the MAC entity shall indicate, for the at least one PSI value, the deactivation of the FEC based discard to upper-layers. For example, the MAC entity shall indicate, for the at least one PSI value, the deactivation of the FEC based discard to the PDCP entity.

In some implementations, the MAC CE may further comprise an index of the number of PDUs to be discarded for each of the at least one PDU set with the at least one PSI value, if the configuration for FEC based discard comprises the list of numbers of PDUs to be discarded for each of the at least one PDU set with the at least one PSI value. When receiving the MAC CE, the MAC entity shall indicate the index to upper-layers. For example, the MAC entity shall indicate the index to the PDCP entity.

Alternatively, in some implementations, the MAC CE may further comprise an index of the maximum number of PDUs to be discarded for each of the at least one PDU set with the at least one PSI value if the configuration for FEC based discard comprises the list of maximum numbers of PDUs to be discarded for each of the at least one PDU set with the at least one PSI value. When receiving the MAC CE, the MAC entity shall indicate the index to upper-layers. For example, the MAC entity shall indicate the index to the PDCP entity.

Alternatively, in some implementations, the MAC CE may further comprise an index of the minimum number of PDUs to be discarded for each of the at least one PDU set with the at least one PSI value if the configuration for FEC based discard comprises the list of minimum numbers of PDUs to be discarded for each of the at least one PDU set with the at least one PSI value. When receiving the MAC CE, the MAC entity shall indicate the index to upper-layers. For example, the MAC entity shall indicate the index to the PDCP entity.

If the FEC based discard is activated, the UE 104 determines 1360 at least one FEC parameter of the PDU set.

In some implementations, the at least one FEC parameter of the PDU set may comprise at least one of the following: the first number of PDUs in the PDU set which carry source symbols of the block, the second number of PDUs in the PDU set which carry repair symbols of the block, or the total number of the source symbols and the repair symbols of the block.

The UE 104 discards 1370 at least one PDU in the PDU set based on the configuration associated with at least one PSI value and the at least one FEC parameter of the PDU set.

For example, if the configuration for FEC based discard is associated with the at least one PSI value, the UE 104 may determine a PSI value for each of PDU sets. The UE 104 may determine the third number of PDUs to be discarded for the PDU set with the PSI value based on one of the following, the discard ratio, the maximum discard ratio, or the minimum discard ratio.

For example, if the at least one discard rule indicates to discard the third number of PDUs in the PDU set which arrive at the AS layer of the UE 104 last, the UE 104 discards the third number of PDUs in the PDU set which arrive at the AS layer of the UE 104 last and have the PSI value.

Fig. 14 illustrates an example of a device 1400 that supports UL FEC based discard in accordance with aspects of the present disclosure. The device 1400 may be an example of a network entity 102 or a UE 104 as described herein. The device 1400 may support wireless communication with one or more network entities 102, UEs 104, or any combination thereof. The device 1400 may include components for bi-directional communications including components for transmitting and receiving communications, such as a processor 1402, a memory 1404, a transceiver 1406, and, optionally, an I/O controller 1408. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 1402, the memory 1404, the transceiver 1406, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. For example, the processor 1402, the memory 1404, the transceiver 1406, or various combinations or components thereof may support a method for performing one or more of the operations described herein.

In some implementations, the processor 1402, the memory 1404, the transceiver 1006, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some implementations, the processor 1402 and the memory 1404 coupled with the processor 1402 may be configured to perform one or more of the functions described herein (e.g., executing, by the processor 1402, instructions stored in the memory 1404) .

For example, the processor 1402 may support wireless communication at the device 1400 in accordance with examples as disclosed herein. The processor 1402 may be configured to operable to support a means for performing the following: receiving a configuration for FEC based discard; determining at least one FEC parameter of a PDU set; and discarding at least one PDU in the PDU set based on the configuration and the at least one FEC parameter of the PDU set.

Alternatively, in some implementations, the processor 1402 may be configured to operable to support a means for performing the following: transmitting, to a UE, a configuration for FEC based discard.

The processor 1402 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some implementations, the processor 1402 may be configured to operate a memory array using a memory controller. In some other implementations, a memory controller may be integrated into the processor 1402. The processor 1402 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1404) to cause the device 1400 to perform various functions of the present disclosure.

The memory 1404 may include random access memory (RAM) and read-only memory (ROM) . The memory 1404 may store computer-readable, computer-executable code including instructions that, when executed by the processor 1402 cause the device 1400 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some implementations, the code may not be directly executable by the processor 1402 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some implementations, the memory 1404 may include, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The I/O controller 1408 may manage input and output signals for the device 1400. The I/O controller 1408 may also manage peripherals not integrated into the device M02. In some implementations, the I/O controller 1408 may represent a physical connection or port to an external peripheral. In some implementations, the I/O controller 1408 may utilize an operating system such as or another known operating system. In some implementations, the I/O controller 1408 may be implemented as part of a processor, such as the processor 1406. In some implementations, a user may interact with the device 1400 via the I/O controller 1408 or via hardware components controlled by the I/O controller 1408.

In some implementations, the device 1400 may include a single antenna 1410. However, in some other implementations, the device 1400 may have more than one antenna 1410 (i.e., multiple antennas) , including multiple antenna panels or antenna arrays, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 1406 may communicate bi-directionally, via the one or more antennas 1410, wired, or wireless links as described herein. For example, the transceiver 1406 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1406 may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas 1410 for transmission, and to demodulate packets received from the one or more antennas 1410. The transceiver 1406 may include one or more transmit chains, one or more receive chains, or a combination thereof.

A transmit chain may be configured to generate and transmit signals (e.g., control information, data, packets) . The transmit chain may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM) , frequency modulation (FM) , or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM) . The transmit chain may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmit chain may also include one or more antennas 1410 for transmitting the amplified signal into the air or wireless medium.

A receive chain may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receive chain may include one or more antennas 1410 for receive the signal over the air or wireless medium. The receive chain may include at least one amplifier (e.g., a low-noise amplifier (LNA) ) configured to amplify the received signal. The receive chain may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receive chain may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

Fig. 15 illustrates an example of a processor 1500 that supports UL FEC based discard in accordance with aspects of the present disclosure. The processor 1500 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 1500 may include a controller 1502 configured to perform various operations in accordance with examples as described herein. The processor 1500 may optionally include at least one memory 1504, such as L1/L2/L3 cache. Additionally, or alternatively, the processor 1500 may optionally include one or more arithmetic-logic units (ALUs) 1506. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 1500 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 1500) or other memory (e.g., random access memory (RAM) , read-only memory (ROM) , dynamic RAM (DRAM) , synchronous dynamic RAM (SDRAM) , static RAM (SRAM) , ferroelectric RAM (FeRAM) , magnetic RAM (MRAM) , resistive RAM (RRAM) , flash memory, phase change memory (PCM) , and others) .

The controller 1502 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 1500 to cause the processor 1500 to support various operations in accordance with examples as described herein. For example, the controller 1502 may operate as a control unit of the processor 1500, generating control signals that manage the operation of various components of the processor 1500. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

The controller 1502 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 1504 and determine subsequent instruction (s) to be executed to cause the processor 1500 to support various operations in accordance with examples as described herein. The controller 1502 may be configured to track memory address of instructions associated with the memory 1504. The controller 1502 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 1502 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 1500 to cause the processor 1500 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 1502 may be configured to manage flow of data within the processor 1500. The controller 1502 may be configured to control transfer of data between registers, arithmetic logic units (ALUs) , and other functional units of the processor 1500.

The memory 1504 may include one or more caches (e.g., memory local to or included in the processor 1500 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementation, the memory 1504 may reside within or on a processor chipset (e.g., local to the processor 1500) . In some other implementations, the memory 1504 may reside external to the processor chipset (e.g., remote to the processor 1500) .

The memory 1504 may store computer-readable, computer-executable code including instructions that, when executed by the processor 1500, cause the processor 1500 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 1502 and/or the processor 1500 may be configured to execute computer-readable instructions stored in the memory 1504 to cause the processor 1500 to perform various functions. For example, the processor 1500 and/or the controller 1502 may be coupled with or to the memory 1504, the processor 1500, the controller 1502, and the memory 1504 may be configured to perform various functions described herein. In some examples, the processor 1500 may include multiple processors and the memory 1504 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

The one or more ALUs 1506 may be configured to support various operations in accordance with examples as described herein. In some implementation, the one or more ALUs 1506 may reside within or on a processor chipset (e.g., the processor 1500) . In some other implementations, the one or more ALUs 1506 may reside external to the processor chipset (e.g., the processor 1500) . One or more ALUs 1506 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 1506 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 1506 be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 1506 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 1506 to handle conditional operations, comparisons, and bitwise operations.

The processor 1500 may support wireless communication in accordance with examples as disclosed herein. The processor 1500 may be configured to operable to support a means for performing the following: receiving, from a network entity, a configuration for FEC based discard; determining at least one FEC parameter of a PDU set; and discarding at least one PDU in the PDU set based on the configuration and the at least one FEC parameter of the PDU set.

Alternatively, in some implementations, the processor 1500 may be configured to operable to support a means for performing the following: transmitting, to a UE, a configuration for FEC based discard.

Fig. 16 illustrates a flowchart of a method 1600 that supports UL FEC based discard in accordance with aspects of the present disclosure. The operations of the method 1600 may be implemented by a device or its components as described herein. For example, the operations of the method 1600 may be performed by a UE 104 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 1610, the method may include receiving a configuration for FEC based discard. The operations of 1610 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1610 may be performed by a device as described with reference to Fig. 1.

At 1620, the method may include determining at least one FEC parameter of a PDU set. The operations of 1620 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1620 may be performed by a device as described with reference to Fig. 1.

At 1630, the method may include discarding at least one PDU in the PDU set based on the configuration and the at least one FEC parameter of the PDU set. The operations of 1630 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1630 may be performed by a device as described with reference to Fig. 1.

Fig. 17 illustrates a flowchart of a method 1700 that supports UL FEC based discard in accordance with aspects of the present disclosure. The operations of the method 1700 may be implemented by a device or its components as described herein. For example, the operations of the method 1700 may be performed by the network entity 102 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 1710, the method may include transmitting, to a UE, a configuration for FEC based discard. The operations of 1710 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1710 may be performed by a device as described with reference to Fig. 1.

It shall be noted that implementations of the present disclosure which have been described with reference to Figs. 1 to 13 are also applicable to the device 1400, the processor 1500 as well as the methods 1600 and 1700.

It should be noted that the methods described herein describes possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined.

The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer. By way of example, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor.

As used herein, including in the claims, an article “a” before an element is unrestricted and understood to refer to “at least one” of those elements or “one or more” of those elements. The terms “a, ” “at least one, ” “one or more, ” and “at least one of one or more” may be interchangeable. As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” or “one or both of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. Further, as used herein, including in the claims, a “set” may include one or more elements.

The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A user equipment (UE) , comprising:

a processor; and

a transceiver coupled to the processor,

wherein the processor is configured to:

receive, via the transceiver from a network entity, a configuration for forward error correction (FEC) based discard;

determine at least one FEC parameter of a protocol data unit (PDU) set; and

discard at least one PDU in the PDU set based on the configuration and the at least one FEC parameter of the PDU set.
The UE of claim 1, wherein the PDU set is associated with a block of source data, and the at least one FEC parameter of the PDU set comprises at least one of the following:

a first number of PDUs in the PDU set which carry source symbols of the block,

a second number of PDUs in the PDU set which carry repair symbols of the block, or

a total number of the source symbols and the repair symbols of the block.
The UE of claim 1, wherein the processor is further configured to:

obtain first FEC information about at least one quality of service (QoS) flow, wherein the first FEC information comprises at least one of the following:

an indication indicating whether the FEC is to be applied to the at least one QoS flow,

an FEC encoding type which is to be applied to the at least one QoS flow,

a redundant ratio for the at least one QoS flow, or

an identifier of the at least one QoS flow.
The UE of claim 1, wherein the processor is further configured to:

obtain second FEC information about at least one PDU set, wherein each of the at least one PDU set is associated with a block of source data, and the second FEC information comprises at least one of the following:

an indication indicating whether the FEC is to be applied to the at least one PDU set,

an FEC encoding type which is to be applied to each of the at least one PDU set,

a first number of PDUs in each of the at least one PDU set which carry source symbols of the block,

a second number of PDUs in each of the at least one PDU set which carry repair symbols of the block, or

a total number of the source symbols and the repair symbols of the block,

a size of each of the source symbols and the repair symbols,

a last symbol among the source symbols which comprises padding bits,

an FEC payload identifier (ID) of each of the source symbols and the repair symbols of the block, or

a sequence number of each of the at least one PDU set.
The UE of claim 1, wherein the processor is further configured to:

obtain third FEC information about at least one PDU set with at least one protocol data unit set importance (PSI) value within a quality of service (QoS) flow, wherein each of the at least one PDU set with the at least one PSI value is associated with a block of source data, and the third FEC information comprises at least one of the following:

an indication indicating whether the FEC is to be applied to the at least one PDU set with the at least one PSI value,

an FEC encoding type which is to be applied to each of the at least one PDU set with the at least one PSI value, or

a redundant ratio for the at least one PDU set with the at least one PSI value.
The UE of claim 1, wherein the configuration for FEC based discard comprises at least one of the following:

a discard ratio,

a maximum discard ratio,

a minimum discard ratio,

a list of discard ratios,

a list of maximum discard ratios,

a list of minimum discard ratios,

a third number of PDUs to be discarded for each of at least one PDU set,

a maximum number of PDUs to be discarded for each of the at least one PDU set,

a minimum number of PDUs to be discarded for each of the at least one PDU set,

a list of numbers of PDUs to be discarded for each of the at least one PDU set,

a list of maximum numbers of PDUs to be discarded for each of the at least one PDU set, or

a list of minimum numbers of PDUs to be discarded for each of the at least one PDU set.
The UE of claim 6, wherein the configuration for FEC based discard is associated with a quality of service (QoS) flow or a data radio bearer (DRB) to which the FEC is to be applied, and the configuration further comprises at least one of the following:

a first identifier of the QoS flow, or

a second identifier of the DRB; and

wherein:

the discard ratio is for the DRB or the QoS flow,

the maximum discard ratio is for the DRB or the QoS flow,

the minimum discard ratio is for the DRB or the QoS flow,

the list of discard ratios is for the DRB or the QoS flow,

the list of maximum discard ratios is for the DRB or the QoS flow, or

the list of minimum discard ratios is for the DRB or the QoS flow.
The UE of claim 6, wherein the configuration for FEC based discard is associated with a protocol data unit set importance (PSI) value of a quality of service (QoS) flow, the FEC is to be applied to at least one PDU set with the PSI value, and the configuration further comprises the PSI value; and

wherein:

the discard ratio is for the PSI value,

the maximum discard ratio is for the PSI value,

the minimum discard ratio is for the PSI value,

the list of discard ratios is for the PSI value,

the list of maximum discard ratios is for the PSI value, or

the list of minimum discard ratios is for the PSI value.
The UE of claim 6, wherein the configuration for FEC based discard is associated with at least one PDU set to which the FEC is to be applied, and the configuration further comprises at least one sequence number of the at least one PDU set; and

wherein:

the discard ratio is for the at least one PDU set,

the maximum discard ratio is for the at least one PDU set,

the minimum discard ratio is for the at least one PDU set,

the list of discard ratios is for the at least one PDU set,

the list of maximum discard ratios is for the at least one PDU set,

the list of minimum discard ratios is for the at least one PDU set,

the third number of PDUs to be discarded is for each of the at least one PDU set,

the maximum number of PDUs to be discarded is for each of the at least one PDU set,

the minimum number of PDUs to be discarded is for each of the at least one PDU set, or

the list of numbers of PDUs to be discarded is for each of the at least one PDU set,

the list of maximum numbers of PDUs to be discarded is for each of the at least one PDU set, or

the list of minimum numbers of PDUs to be discarded is for each of the at least one PDU set.
The UE of claim 1, wherein the processor is configured to discard the at least one PDU in the PDU set based on the configuration, the at least one FEC parameter of the PDU set and at least one discard rule, the at least one discard rule indicates at least one of the following:

discarding a third number of PDUs in the PDU set which arrive at an access stratum (AS) layer of the UE last,

discarding the third number of PDUs in the PDU set in an ascending order of remaining time of discard timers for PDUs in the PDU set,

prioritizing to discard a first PDU in the PDU set, wherein the first PDU comprises padding bits,

prioritizing to discard a second PDU in the PDU set, wherein the second PDU carries a repair symbol of a block of source data, or

starting a discard timer for each of the third number of PDUs in the PDU set which arrive at the AS layer of the UE last and discarding a third PDU among the third number of PDUs based on determining that a third discard timer for the third PDU expires.
The UE of claim 10, wherein the processor is configured to discard the at least one PDU in the PDU set by:

determining the third number based on a total number of PDUs in the PDU set and one of the following: the discard ratio, the maximum discard ratio, or the minimum discard ratio; or

determining the third number based on one of the following: the third number of PDUs to be discarded for each of at least one PDU set, a maximum number of PDUs to be discarded for each of the at least one PDU set, or a minimum number of PDUs to be discarded for each of the at least one PDU set; and

discarding the third number of PDUs in the PDU set which arrive at the AS layer of the UE last.
The UE of claim 10, wherein the processor is configured to discard the at least one PDU in the PDU set by:

determining the third number based on a total number of PDUs in the PDU set and one of the following: the discard ratio, the maximum discard ratio, or the minimum discard ratio; or

determining the third number based on one of the following: the third number of PDUs to be discarded for each of at least one PDU set, a maximum number of PDUs to be discarded for each of the at least one PDU set, or a minimum number of PDUs to be discarded for each of the at least one PDU set; and

discarding the third number of PDUs in the PDU set in the ascending order of remaining time of discard timers for PDUs in the PDU set.
The UE of claim 10, wherein the processor is configured to discard the at least one PDU in the PDU set by:

determining the third number of PDUs to be discarded for the PDU set based on a total number of PDUs in the PDU set and one of the following: the discard ratio, the maximum discard ratio, or the minimum discard ratio; or

determining the third number based on one of the following: the third number of PDUs to be discarded for each of at least one PDU set, a maximum number of PDUs to be discarded for each of the at least one PDU set, or a minimum number of PDUs to be discarded for each of the at least one PDU set; and

prioritizing to discard the first PDU in the PDU set, wherein the first PDU comprises the padding bits, the third number of the PDUs comprises the first PDU.
The UE of claim 10, wherein the processor is configured to discard the at least one PDU in the PDU set by:

determining the third number based on a total number of PDUs in the PDU set and one of the following: the discard ratio, the maximum discard ratio, or the minimum discard ratio; or

determining the third number based on one of the following: the third number of PDUs to be discarded for each of at least one PDU set, a maximum number of PDUs to be discarded for each of the at least one PDU set, or a minimum number of PDUs to be discarded for each of the at least one PDU set; and

prioritizing to discard the second PDU in the PDU set, wherein the second PDU carries the repair symbol of the block of source data, the third number of the PDUs comprises the second PDU.
The UE of claim 10, wherein the processor is configured to discard the at least one PDU in the PDU set by:

determining the third number based on a total number of PDUs in the PDU set and one of the following: the discard ratio, the maximum discard ratio, or the minimum discard ratio; or

determining the third number based on one of the following: the third number of PDUs to be discarded for each of at least one PDU set, a maximum number of PDUs to be discarded for each of the at least one PDU set, or a minimum number of PDUs to be discarded for each of the at least one PDU set; and

discarding a third PDU among the third number of PDUs which arrive at the AS layer of the UE last based on determining that a third discard timer for the third PDU expires.
The UE of any of claims 11 to 15, wherein the processor is further configured to:

receive a medium access control control element (MAC CE) comprising an indication via the transceiver from the network entity, wherein the indication indicates whether to activate or deactivate the FEC based discard; and

activate or deactivate the FEC based discard based on the indication.
The UE of claim 16, wherein the processor is configured to activate or deactivate the FEC based discard based on the indication by:

activating or deactivating the FEC based discard for one of the following to which the FEC based discard is to be applied:

at least one quality of service (QoS) flow,

at least one data radio bearer (DRB) ,

at least one protocol data unit set importance (PSI) value, or

at least one PDU set.
The UE of claim 1, wherein the processor is further configured to:

receive a first indication or a second indication via the transceiver from the network entity, wherein the first indication indicates to activate the FEC based discard and the second indication indicates to deactivate the FEC based discard; and

activate the FEC based discard based on the first indication; or

deactivate the FEC based discard based on the second indication.
A network entity, comprising:

a processor; and

a transceiver coupled to the processor,

wherein the processor is configured to:

transmit, via the transceiver to a user equipment (UE) , a configuration for forward error correction (FEC) based discard.
The network entity of claim 19, wherein the processor is further configured to:

receive, via the transceiver from the UE, first FEC information about at least one quality of service (QoS) flow, wherein the first FEC information comprises at least one of the following:

an indication indicating whether the FEC is to be applied to the at least one QoS flow,

an FEC encoding type which is to be applied to the at least one QoS flow,

a redundant ratio for the at least one QoS flow, or

an identifier of the at least one QoS flow.