CN111213335A

CN111213335A - Unlicensed hybrid automatic repeat request

Info

Publication number: CN111213335A
Application number: CN201780095856.3A
Authority: CN
Inventors: 张元涛; 张延冀; 张翼; 郝楠
Original assignee: Nokia Solutions and Networks Oy; Alcatel Lucent SAS
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Alcatel Lucent SAS
Priority date: 2017-10-11
Filing date: 2017-10-11
Publication date: 2020-05-29
Also published as: WO2019071463A1

Abstract

In a license-free environment, various communication systems may benefit from improved retransmission of data packets. For example, certain communication systems may benefit from enhanced license-free hybrid automatic repeat request. In some embodiments, a method may include receiving, at a network entity, an unlicensed transmission from a user equipment. The transmission may include multiple transport blocks, each associated with a logical identification, and the logical identification may be included within or received with the received transport block. The method may also include determining, at the network entity, that one of the plurality of transport blocks is missing based on the logical identification. Furthermore, the method may include scheduling retransmission of a missing one of the plurality of transport blocks from the user equipment to the network entity.

Description

Unlicensed hybrid automatic repeat request

Technical Field

Various communication systems may benefit from improved retransmission of data packets in an unlicensed environment. For example, certain communication systems may benefit from enhanced hybrid automatic repeat request in an unlicensed environment.

Background

The third generation partnership project (3GPP) fifth generation (5G) or New Radio (NR) technologies are designed to allow for ultra-reliable low-latency communication (URLLC). URLLC provides strict latency, reliability and availability requirements for data transmission. Latency refers to the time delay between when data is generated and properly transferred from one device to another. Reliability refers to the guarantee of successful message transmission within a defined delay period, while availability refers to the ability of the URLLC to withstand interruptions.

To meet the stringent delay requirements of 5G URLLC, some communication systems may use uplink grant-free transmission. In uplink grant-free transmission, the user equipment can immediately send data when it is received in the user equipment buffer without waiting for an uplink grant from the network. Thus, the user equipment does not have to send a scheduling request and wait for an acknowledgement including an uplink grant as required in conventional grant-based transmission. Instead, the user equipment may utilize the unlicensed transmission to send data immediately upon arrival at the user equipment buffer. To further improve the reliability of the unlicensed URLLC transmission, repeated K transmissions may occur.

Disclosure of Invention

According to some embodiments, an apparatus may comprise: at least one memory including computer program code and at least one processor. The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to receive an unlicensed transmission from a user equipment at a network entity. The transmission may include a plurality of transport blocks that are each associated with a logical identification, and the logical identification may be included within or received with the received transport block. The at least one memory and the computer program code may also be configured to, with the at least one processor, cause the apparatus at least to determine, based on the logical identification, that one of the plurality of transport blocks is lost. Further, the at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to schedule a retransmission of a lost one of the plurality of transport blocks from the user equipment to the network entity.

In some embodiments, a method may include: an unlicensed transmission is received at a network entity from a user equipment. The transmission may include a plurality of transport blocks that are each associated with a logical identification, and the logical identification may be included within or received with the received transport block. The method may also include determining, at the network entity, that one of the plurality of transport blocks is lost based on the logical identification. Further, the method may include scheduling a retransmission of a lost one of the plurality of transport blocks from the user equipment to the network entity.

In certain embodiments, an apparatus may include means for receiving, at a network entity, an unlicensed transmission from a user equipment. The transmission may include a plurality of transport blocks that are each associated with a logical identification, and the logical identification may be included within or received with the received transport block. The apparatus may also include means for determining, at the network entity, that one of the plurality of transport blocks is lost based on the logical identification. Further, the apparatus may include scheduling a retransmission of a lost one of the plurality of transport blocks from the user equipment to the network entity.

According to certain embodiments, a non-transitory computer-readable medium encodes instructions that, when executed in hardware, perform a process. The process may include receiving, at a network entity, an unlicensed transmission from a user device. The transmission may include a plurality of transport blocks that are each associated with a logical identification, and the logical identification may be included within or received with the received transport block. The process may also include determining, at the network entity, that one of the plurality of transport blocks is lost based on the logical identification. In addition, the process may include scheduling a retransmission of a lost one of the plurality of transport blocks from the user equipment to the network entity.

According to some other embodiments, a computer program product may encode instructions for performing a process. The process may include receiving, at a network entity, an unlicensed transmission from a user device. The transmission may include a plurality of transport blocks that are each associated with a logical identification, and the logical identification may be included within or received with the received transport block. The process may also include determining, at the network entity, that one of the plurality of transport blocks is lost based on the logical identification. In addition, the process may include scheduling a retransmission of a lost one of the plurality of transport blocks from the user equipment to the network entity.

According to some embodiments, an apparatus may comprise: at least one memory including computer program code and at least one processor. The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to transmit an unlicensed transmission from a user equipment to a network entity. The transmission may include a plurality of transport blocks each associated with a logical identification, and the logical identification may be included within or transmitted with the transport block. The at least one memory and the computer program code may also be configured to, with the at least one processor, cause the apparatus at least to receive a request to retransmit a lost one of the plurality of transport blocks to a network entity. The request may be based on a logical identification. Further, the at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to retransmit the lost one of the plurality of transport blocks from the user equipment to a network entity.

In some embodiments, a method may include transmitting an unlicensed transmission from a user equipment to a network entity. The transmission may comprise a plurality of transport blocks, each transport block being associated with a logical identification, and the logical identification being included within or transmitted with the transport block. The method may also include receiving a request to retransmit the lost one of the plurality of transport blocks to a network entity. The request may be based on a logical identification. Further, the method may include retransmitting a lost one of the plurality of transport blocks from the user equipment to the network entity.

In some embodiments, an apparatus may include means for transmitting an unlicensed transmission from a user equipment to a network entity. The transmission may include a plurality of transport blocks each associated with a logical identification, and the logical identification may be included within or transmitted with the transport block. The apparatus may also include means for receiving a request to retransmit the lost one of the plurality of transport blocks to a network entity. The request may be based on a logical identification. Further, the apparatus may include means for retransmitting a lost one of the plurality of transport blocks from the user equipment to the network entity.

According to certain embodiments, a non-transitory computer-readable medium encodes instructions that, when executed in hardware, perform a process. The process may include transmitting an unlicensed transmission from the user equipment to the network entity. The transmission may include a plurality of transport blocks each associated with a logical identification, and the logical identification may be included within or transmitted with the transport block. The process may further include: a request to retransmit a lost one of the plurality of transport blocks to a network entity is received. The request may be based on a logical identification. Further, the process may include retransmitting a lost one of the plurality of transport blocks from the user equipment to the network entity.

According to some other embodiments, a computer program product may encode instructions for performing a process. The process may include transmitting an unlicensed transmission from the user equipment to the network entity. The transmission may include a plurality of transport blocks each associated with a logical identification, and the logical identification may be included within or transmitted with the transport block. The process may also include receiving a request to retransmit the lost one of the plurality of transport blocks to a network entity. The request may be based on a logical identification. Further, the process may include retransmitting a lost one of the plurality of transport blocks from the user equipment to the network entity.

Drawings

For a proper understanding of the invention, reference should be made to the accompanying drawings, in which:

fig. 1 illustrates an example of a hybrid automatic repeat request in accordance with certain embodiments.

Fig. 2 illustrates an example of a hybrid automatic repeat request in accordance with certain embodiments.

FIG. 3 illustrates an example of a flow chart in accordance with certain embodiments.

FIG. 4 illustrates an example of a flow chart in accordance with certain embodiments.

FIG. 5 illustrates an example of a system according to some embodiments.

Detailed Description

In some embodiments utilizing unlicensed transmission, one or more hybrid automatic repeat request (HARQ) processes may be used to allow for continuous transmission of transport blocks. HARQ may be a combination of high speed forward error correction coding and automatic repeat request (ARQ) error control. The use of one or more HARQ processes may help reduce retransmission delay of transport blocks from the user equipment to a network entity, such as a 5G/NR NodeB (gNB). The number of HARQ processes for the unlicensed transmission may be configured by the gNB. As will be seen in the embodiments of fig. 1 and 2, the gNB may configure three HARQ processes.

In view that some embodiments may utilize multiple HARQ processes, the manner of identification for each of the transport blocks should be determined for the network entity and/or the user equipment. The identity may be, for example, a HARQ process identity. Using the identification of the transport block, the network entity may transmit an indication, such as an acknowledgement, to indicate that the transport block corresponding to the HARQ process was correctly detected. The indication may also include an uplink grant to the user equipment for refraining from granting retransmission of the transport block.

An identification, such as a HARQ process identification, may be associated with the slot index. If a network entity (e.g., a gNB) detects a user equipment transmission from a time slot, it may implicitly know the identity associated with the time slot. In some embodiments, the identification may be referred to as an absolute identification or an absolute HARQ process identification.

Fig. 1 illustrates an example of a hybrid automatic repeat request in accordance with certain embodiments. In particular, fig. 1 illustrates the association between the HARQ identity 110 and the slot index 120. The network entity may implicitly know the identity if it detects a user equipment transmission from a time slot. As shown in the example of fig. 1, a network entity (e.g., a gNB) may be configured with three HARQ processes for an unlicensed transmission. This means that HARQ can be used to retransmit three different unlicensed transmissions if required. In other words, the identity or HARQ process identity may have a value or number of 1,2 or 3. The configured slots for the unlicensed transmission may be represented by m, m + N, m +2N, …, and m +7N, where m represents the first slot and N represents the configured period of the unlicensed transmission.

In fig. 1, a data packet may be received by or may arrive at a buffer of the user equipment between time slots m and m + N. In an unlicensed environment, the user equipment may begin transmission of data packets in time slot m + N after receiving the data packets in the buffer. The network entity may then use the

HARQ process identity

2,3, 1 to identify the

unlicensed transport block

1,2,3, respectively. Fig. 1 illustrates that another data packet is received by or arrives at the buffer of the user equipment between m +4N and m + 5N. The user equipment then transmits two transport blocks in slots m +5N and m +6N, with associated

HARQ identities

3 and 1, respectively.

As seen in the example shown in fig. 1, the HARQ process corresponding to the unlicensed transport block is variable. As such, in certain embodiments in which the first one or more transport blocks are not detected by the network entity, the network entity may not immediately be aware that a transport block was lost. Higher layers may reside in network entities. In some embodiments, the network entity may have lost a transport block due to high inter-cell interference that causes data sent within the transport block to be incorrectly received.

Conventional Radio Link Control (RLC) retransmissions may not meet the strict user plane delay requirements of URLLC. Therefore, performing retransmissions in URLLC may rely on higher layer applications (such as the application layer) to perform retransmissions, which implies higher retransmission delays. In some embodiments, the user equipment may retransmit the transport block using an unlicensed transmission after a predefined backoff time. However, waiting until a predefined back-off time may translate into even higher latency. In other embodiments, the retransmission may be based on a schedule that may exclude unlicensed transmissions.

Thus, certain embodiments help reduce the latency of the unlicensed retransmission. In doing so, two different identifiers associated with the same unlicensed transport block may be associated. As mentioned above, the first identifier may be an absolute identifier, also referred to as an absolute identity, e.g. an absolute HARQ process identifier. The absolute identifier may be associated with a slot index, as shown in fig. 1, and may be determined by a slot, mini-slot, or subframe index. The second identifier may be a logical identifier, also referred to as a logical identity, e.g. a logical HARQ process identifier. The logical identifier may be associated with a grant-free transport block index of the incoming packet. Thus, the logical identifier may be included in or sent with a transmission received by the network entity from the user equipment.

Based on the logical identifier and/or the absolute identifier received or detected by the network entity, the network entity may determine or decide whether there is a missing transport block or blocks in the previous time slot. A lost transport block may mean that the network entity fails to receive the data packet transmitted from the user equipment in the transport block. If the network entity determines that one or more transport blocks are lost, the network entity may schedule retransmission of the one or more lost transport blocks without having to rely on higher layer checks or timers.

In some embodiments, the absolute identifier may be included in downlink control information transmitted to the user equipment. The user equipment may then use the absolute identifier to identify the transport blocks that need to be retransmitted. The absolute identity may be included in downlink control information sent from the network entity to the user equipment. Since the absolute identity is known to both the user equipment and the network node by the slot index, the absolute identity is not transmitted by the user equipment as is the case with the logical identity.

The network entity may configure a single number or a single value of the unlicensed HARQ processes, which is applicable to both HARQ processes. For example, a network entity such as the gNB may configure the number of HARQ processes or a value for the unlicensed transmission, and the number may apply to both absolute and logical HARQ processes. The logical HARQ process may be associated with a logical identification. In the embodiment shown in fig. 2, the network entity may configure three HARQ processes for both absolute and logical processes. Each unlicensed HARQ process may be associated with a particular absolute identifier and/or logical identifier. As described above, the logical identifier may be included in, or transmitted with, the associated transport block. When a new packet is received or arrives in the user equipment buffer, the user equipment transmits a first transport block with a first logical identifier from the latest available slot. The next transport block may then be transmitted from the next available time slot along with the second logical identifier. In some embodiments, a data packet may be divided into multiple transport blocks.

The logical identifier may be transmitted from the user equipment to the network entity in various ways. For example, the logical identification may be included as part of a Medium Access Control (MAC) Protocol Data Unit (PDU). A new MAC control element (MAC CE) may be defined in the MAC PDU to indicate the logical identification. In another example, the logical identification may be included in a MAC subheader corresponding to a medium access control Service Data Unit (SDU). In yet another example, the logical identification may be transmitted from the user equipment to the network entity as part of the uplink control information.

Fig. 2 illustrates an example of a hybrid automatic repeat request in accordance with certain embodiments. Unlike the example shown in fig. 1, the example in fig. 2 employs both absolute identification 220 and logical identification 210. In fig. 2, the network entity may configure three HARQ processes for the unlicensed transmission. The configured slots for unlicensed transmissions (also referred to as slot indices 230) may be m, m + N, m +2N, …, m + 7N. The user equipment may start transmission from slot m + N when a data packet may reach the user equipment buffer between slots m and m + N. The logical identification for the three unlicensed transport blocks may be {1,2,3} and the absolute HARQ for the three unlicensed transport blocks may be {2, 3, 1 }. The absolute HARQ process identification may be determined by a slot, mini-slot, and/or subframe index. The logical identification may be included in the transport block as one MAC CE in the MAC PDU and/or in a MAC subheader corresponding to the MAC SDU.

In the example of fig. 2, a network entity (such as the gNB) may not detect the first unlicensed transport block (e.g., a transport block in m + N), but may detect the remaining two transport blocks in m +2N and m + 3N. In some embodiments, the failure to detect the first unlicensed transport block may be caused by high inter-cell interference experienced in slot m + N, while m +2N and m +3N experience lower levels of interference.

Once the network entity detects the second transport block, m +2N, the network entity may also receive logical identification 2. In other words, the transport blocks received by the network entity may be associated with an absolute identity of 3 instead of a logical identity of 2. Based on the logical identification of the first received transport block that does not have a value of 1, the network entity may then determine or know that a previous transport block has been lost. In other words, determining, by the network entity, that one of the plurality of transport blocks is lost may occur when the value of the logical identification received at the network entity is not less than the available value. The value is the first value, the last value, or an intermediate value that falls between the first value and the last value. When the value is a first value of the logical identification received at the network entity, the network entity may determine that one of the plurality of transport blocks is lost when the first value is not a minimum available value.

For example, in fig. 2, the logical identification may not be 1, and the network entity may determine that a transport block has been lost based on the logical identification. In another example, the value of the logical identification may be 3. If the network entity does not receive logical identification 2 before receiving logical identification 3 and logical identification 2 is an available value, the network entity may determine that one transport block of the plurality of transport blocks is lost.

The network entity may then schedule retransmission of the lost transport blocks between time slots m +2N and m + 3N. The above example allows the network entity to schedule transport block retransmissions without having to use higher layer inspection and signaling. This may allow for lower latency.

FIG. 3 illustrates a flow diagram in accordance with certain embodiments. In particular, fig. 3 illustrates an embodiment of a method performed by a network entity (such as a gNB). At step 310, the network entity receives an unlicensed transmission from the user equipment. The transmission may include a plurality of transport blocks that are each associated with a logical identification, and the logical identification may be included within or received with the received transport block. For example, the logical identification is included as part of a medium access control protocol data unit. In particular, the logical identification is included as part of a medium access control protocol data unit. In another example, the logical identification may be included in a media access control subheader corresponding to the media access control service data unit. In yet another example, the logical identification is transmitted as part of uplink control information.

In step 320, the network entity may determine that one of the plurality of transport blocks is lost based on the logical identification. In some other embodiments, the network entity may determine that one of the plurality of transport blocks is lost based on an absolute identification associated with a slot index of the transport block. The absolute identification may be determined by a slot, mini-slot or sub-frame index of the transport block. The absolute identity may be included in downlink control information sent from the network entity to the user equipment. As shown in fig. 1 and 2, the absolute identification may be known to both the user equipment and the network node by the slot index. In some embodiments, the network entity may configure a single value for the number of HARQ processes, which may apply to both absolute and logical HARQ processes. The logical HARQ process may be associated with a logical identification.

In some embodiments, determining, by the network entity, that one of the plurality of transport blocks is lost occurs when the value of the logical identification received at the network entity is not less than the available value. The value may be the first value, the last value, or an intermediate value that falls between the first value and the last value. For example, the logical identification may not be 1. For example, as shown in fig. 2, a network entity may receive a first transport block having a logical identification of 2. Based on both the logical identity and the absolute identity, the user equipment may determine the lost transport block.

In another embodiment, the network entity may determine the loss of a subsequent transport block by the received logical identification and/or buffer status. In the example of fig. 2, a network entity (such as the gNB) may not detect the last unlicensed transport block, e.g., the transport block in m +3N, but may detect the first two transport blocks in m + N and m + 2N. When the buffer status received in m +2N is not null, the network entity may determine that the last grant-free transport block was lost. In other words, the determination by the network entity that one of the plurality of transport blocks is lost occurs when the last value of the logical identification received at the network entity is not the maximum available value and the received buffer status is not empty.

In step 330, the network entity may schedule a retransmission of the lost one of the plurality of transport blocks from the user equipment. In step 340, the network entity may receive a retransmission including the missing one of the plurality of transport blocks.

FIG. 4 illustrates a flow diagram in accordance with certain embodiments. In particular, fig. 4 illustrates an embodiment of a method performed by a user equipment. The embodiment of the user equipment shown in fig. 4 may receive and/or transmit the unlicensed transmission and the retransmission request from the network entity shown in fig. 3. At step 410, the user equipment may transmit an unlicensed transmission to a network entity. The transmission may comprise a data packet. The transmission may include a plurality of transport blocks, each transport block associated with a logical identification. The logical identification may be included within or transmitted with the transport block.

In step 420, the user equipment may receive a request to retransmit a lost one of the plurality of transport blocks to a network entity. The request may be based on a logical identification. The received request may be a hybrid automatic repeat request. In another embodiment, the request may be determined as an absolute identification associated with a slot index of the transport block. The absolute identification may be determined by a slot, mini-slot or sub-frame index of the transport block. In step 430, the user equipment may retransmit the lost one of the plurality of transport blocks to the network entity. The situation of license-free transmission occurs when a data packet arrives in the buffer of the user equipment.

FIG. 5 illustrates a system according to some embodiments. It should be understood that each signal or block in fig. 1-4 may be implemented by various means or combinations thereof, such as hardware, software, firmware, one or more processors, and/or circuitry. In one embodiment, the system may include several devices, such as, for example, a network entity 520 or a User Equipment (UE) 510. The system may include more than one UE510 and more than one network entity 520, although only one access node is shown for purposes of illustration. The network entity may be a network node, an access node, a base station, a 5G/NR NodeB (gNB), a server, a host, or any of the other access nodes or network nodes discussed herein.

Each of these devices may comprise at least one processor or control unit or module, indicated 511 and 521, respectively. At least one memory may be provided in each device and is indicated as 512 and 522, respectively. The memory may include computer program instructions or computer code embodied therein. One or

more transceivers

513 and 523 may be provided, and each device may further include an antenna shown as 717 and 727, respectively. Although only one antenna is shown each, many antennas and multiple antenna elements may be provided for each of the devices. Higher category UEs typically include multiple antenna panels. For example, other configurations of these devices may be provided. For example, in addition to wireless communication, network entity 520 and UE510 may additionally be configured for wired communication, and in

such cases antennas

514 and 524 may illustrate any form of communication hardware, and are not limited to only antennas.

The

transceivers

513 and 523 may each independently be a transmitter, a receiver, or both a transmitter and a receiver, or may be configured as a unit or device for both transmission and reception. In other embodiments, the UAV or network entity may have at least one separate receiver or transmitter. The transmitter and/or receiver (in the case of the radio part) can also be implemented as a remote radio head, which is not located in the device itself, but for example in the mast. The operations and functions may be performed in a flexible manner in different entities, such as nodes, hosts or servers. In other words, the division of labor may vary from case to case. One possible use is for network nodes to deliver local content. One or more functions may also be implemented as virtual application(s) in software that may run on a server. The beamformer may be a transceiver.

The user equipment or user device 510 may be a Mobile Station (MS), such as a mobile phone or smart phone or multimedia device, a computer provided with wireless communication capabilities, such as a tablet computer, a personal data or digital assistant (PDA) provided with wireless communication capabilities, a portable media player, a digital camera, a camcorder, a navigation unit provided with wireless communication capabilities, or any combination thereof. In other embodiments, the UE may be a Machine Type Communication (MTC) device, which may not require human interaction, such as sensors, meters, or actuators.

In some embodiments, an apparatus (such as a network entity) may include means for performing the embodiments described above with respect to fig. 1-4. In certain embodiments, the at least one memory including the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform any of the processes described herein.

Processors

511 and 521 may be embodied by any computing or data processing device, such as a Central Processing Unit (CPU), Digital Signal Processor (DSP), Application Specific Integrated Circuit (ASIC), Programmable Logic Device (PLD), Field Programmable Gate Array (FPGA), digital enhancement circuit, or the like, or a combination thereof. The processor may be implemented as a single controller, or as multiple controllers or processors.

For firmware or software, the implementation may include modules or units (e.g., procedures, functions, and so on) in at least one chip set. The

memories

512 and 522 may independently be any suitable storage device, such as a non-transitory computer-readable medium. A Hard Disk Drive (HDD), Random Access Memory (RAM), flash memory, or other suitable memory may be used. The memory may be combined with the processor on a single integrated circuit or may be separate therefrom. Furthermore, the computer program instructions may be stored in a memory, and the computer program instructions that may be processed by the processor may be computer program code in any suitable form, such as a compiled or interpreted computer program written in any suitable programming language. The memory or data storage entity is typically internal, but may also be external or a combination thereof, such as in the case when additional storage capacity is obtained from a service provider. The memory may be fixed or removable.

The memory and the computer program instructions may be configured to, with the processor for the particular apparatus, cause a hardware device, such as the network entity 520 or the UE510, to perform any of the processes described above (e.g., see fig. 1-4). Thus, in certain embodiments, a non-transitory computer readable medium may be encoded with computer instructions or one or more computer programs (such as added or updated software routines, applets, or macros) that, when executed in hardware, may perform a process such as one of the processes described herein. The computer program may be coded by a programming language, which may be a high-level programming language, such as objective-C, C, C + +, C #, Java, or the like, or a low-level programming language, such as a machine language or an assembler. Alternatively, some embodiments may be performed entirely in hardware.

Moreover, as illustrated and discussed herein, although fig. 5 illustrates a system including network entity 520 and UE510, certain embodiments may be applicable to other configurations and configurations involving additional elements. For example, there may be multiple user equipment devices and multiple network entities, or other nodes providing similar functionality, such as nodes combining the functionality of user equipment and network entities, such as relay nodes. In addition to the communication network entity 1020, the UE510 may similarly be provided with various configurations for communication. For example, the UE510 may be configured for device-to-device or machine-to-machine transmission.

The features, structures, or characteristics of certain embodiments described throughout this specification may be combined in any suitable manner in one or more embodiments. For example, the phrases "some embodiments," "other embodiments," or other similar language, as used throughout this specification, refer to the fact that: a particular feature, structure, or characteristic described in connection with the embodiments may be included within at least one embodiment of the invention. Thus, appearances of the phrases "in certain embodiments," "in some embodiments," "in other embodiments," or other similar language throughout this specification do not necessarily refer to the same group of embodiments, and the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

One of ordinary skill in the art will readily appreciate that the invention as discussed above may be practiced with steps in a different order and/or with hardware elements in configurations other than those disclosed. Thus, while the invention has been described based upon these preferred embodiments, it would be apparent to those skilled in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of the invention.

Part glossary

3GPP third generation partnership project

5G fifth generation

NR new radio

LTE Long term evolution

gNB NR node B

UE user equipment

URLLC ultra-reliable and low-latency communication

DL downlink

UL uplink

TB transport block

HARQ hybrid automatic repeat request

MAC medium access control

CE control element

Claims

1. A method comprising:

An unlicensed transmission is received at a network entity from a user equipment, wherein the transmission includes a plurality of transport blocks, the plurality of transport blocks are each associated with a logical identity, and wherein the logical identity is included in the received transmission received within a block or with said transport block received;

at the network entity, determining that one of the plurality of transport blocks is missing based on the logical identification; and

A retransmission of the missing one of the plurality of transport blocks from the user equipment to the network entity is scheduled.

2. The method of claim 1, further comprising:

The retransmission including the missing one of the plurality of transport blocks is received at the network entity.

3. The method of claim 1, wherein the logical identification is included as part of a medium access control protocol data unit.

4. The method of claim 3, wherein the logical identity is defined using a medium access control control element.

5. The method of claim 1, wherein the logical identification is included in a medium access control subheader corresponding to a medium access control service data unit.

6. The method of claim 1, wherein the logical identification is transmitted as part of uplink control information.

7. The method of claim 1, wherein the network entity determines that a transport block of the plurality of transport blocks is missing based on an absolute identity associated with a slot index of the transport block.

8. The method of claim 7, wherein the absolute identification is included in downlink control information sent from the network entity to the user equipment.

9. The method of claim 7, wherein the absolute identification is determined by a slot, minislot or subframe index of the transport block.

10. The method of claim 1, wherein determining, by the network entity, that of the plurality of transport blocks occurs when the value of the logical identifier received at the network entity is not lower than an available value. A transport block is lost, wherein the value is a first value, a last value, or an intermediate value between the first value and the last value.

11. The method of claim 1, wherein when the last value of the logical identifier received at the network entity is not a maximum available value, and when the received buffer status is not empty, the occurrence of The network entity determines that one of the plurality of transport blocks is missing.

12. The method of claim 1, wherein the network entity configures a single value of the number of HARQ procedures, the single value applicable to absolute HARQ procedures and associated with the logical identification The linked logic mixes the automatic retransmission request process with the two.

13. A method comprising:

An unlicensed transmission is transmitted from the user equipment to the network entity, wherein the transmission comprises a plurality of transport blocks, the plurality of transport blocks are each associated with a logical identity, and wherein the logical identity is included within or with the transport block the transport blocks are transmitted together;

receiving, at the user equipment, a request to retransmit a missing one of the plurality of transport blocks to the network entity, wherein the request is based on the logical identification; and

The missing one of the plurality of transport blocks is retransmitted from the user equipment to the network entity.

14. The method of claim 13, wherein the transmission of the license-free transmission occurs when a data packet arrives in a buffer of the user equipment, wherein the transmission includes the data packet.

15. The method of claim 13, wherein the logical identification is included as part of a medium access control protocol data unit.

16. The method of claim 15, wherein the logical identification is defined using a medium access control control element.

17. The method of claim 13, wherein the logical identification is included in a medium access control subheader corresponding to a medium access control service data unit.

18. The method of claim 13, wherein the logical identification is transmitted as part of uplink control information.

19. The method of claim 13, wherein the request is determined to an absolute identity associated with a slot index of the transport block.

20. The method of claim 19, wherein the absolute identification is determined by a slot, minislot, or subframe index of the transport block.

21. The method of claim 19, wherein the absolute flag is included in downlink control information sent from the network entity to the user equipment.

22. The method of claim 13, wherein determining, by the network entity, that of the plurality of transport blocks occurs when the value of the logical identifier received at the network entity is not lower than an available value. A transport block is lost, wherein the value is a first value, a last value, or an intermediate value between the first value and the last value.

23. The method of claim 13, wherein when the last value of the logical identifier received at the network entity is not a maximum available value, and when the received buffer status is not empty, occurs by The network entity determines that one of the plurality of transport blocks is missing.

24. An apparatus comprising:

at least one processor; and

at least one memory, including computer program code,

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least:

25. An apparatus comprising:

at least one processor; and

at least one memory, including computer program code,

receiving a request to retransmit a missing one of the plurality of transport blocks to the network entity, wherein the request is based on the logical identification;

26. An apparatus comprising:

at least one processor; and

at least one memory, including computer program code,

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to perform at least a process, the process comprising any of claims 2 to 12 and 14 to 23 the method described.

27. A non-transitory computer readable medium encoded with instructions that, when executed in hardware, perform a process comprising the method of any one of claims 1 to 23.

28. An apparatus comprising means for performing a process comprising the method of any one of claims 1 to 23.

29. A computer program product encoded with instructions for performing a process comprising the method of any one of claims 1 to 23.

30. A computer program product embodied in a non-transitory computer readable medium and encoded with instructions that, when executed in hardware, perform a process, the process comprising any one of claims 1 to 23 method described in item.