WO2022198624A1

WO2022198624A1 - Selective rach overload control

Info

Publication number: WO2022198624A1
Application number: PCT/CN2021/083202
Authority: WO
Inventors: Samuli Heikki TURTINEN; Jussi-Pekka Koskinen; Chunli Wu
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy; Nokia Technologies Oy
Priority date: 2021-03-26
Filing date: 2021-03-26
Publication date: 2022-09-29
Also published as: CN115413422A

Abstract

Embodiments of the present disclosure relate to selective RACH overload control. The first device transmits a random access preamble to a second device. Then the first device receives a response message from the second device. The response message includes first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type. The first device determines a first backoff value of the random access procedure for the first device based on the response message and performs the random access procedure based on the first backoff value. This solution allows indicating backoff for a specific device type (e.g., a REDCAP UE) or access attempt type (e.g., SDT), while conventional/normal devices (e.g., non-REDCAP UEs) or access attempt type (e.g., non-SDT) may not perform backoff (or perform backoff with a conventional solution).

Description

SELECTIVE RACH OVERLOAD CONTROL

FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to a method, a device, an apparatus and a computer readable storage medium for selective random access channel (RACH) overload control.

BACKGROUND

In some communication systems, a terminal device can transition between an inactive state and a connected state. In the inactive state, the terminal device may not have a connection established with a network device for communications. To avoid unnecessary signaling overhead and power consumption for establishing or reestablishing a connection, it has been agreed to support small data transmission (SDT) for a terminal device in the inactive state, without requiring the terminal device to establish a connection with a network device.

Further, reduced capability user equipment (REDCAP UE) , which was originally known as new radio-light (NR-light) is introduced to communication systems. The REDCAP UE is a low cost and power efficient UE with reduced capability.

SUMMARY

In general, example embodiments of the present disclosure provide a solution for selective random access channel (RACH) overload control.

In a first aspect, there is provided a first device. The first device comprises at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, with the at least one processor, cause the device to transmit a random access preamble to a second device; receive a response message from the second device, the response message comprising first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type; determine a first backoff value of the random access procedure for the first device based on the response message; and perform the random access procedure based on the first backoff value.

In a second aspect, there is provided a second device. The second device comprises at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, with the at least one processor, cause the device to receive a random access preamble from a first device; and transmit a response message to the first device, the response message comprising first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type.

In a third aspect, there is provided a method. The method comprises transmitting, at a first device, a random access preamble to a second device; receiving a response message from the second device, the response message comprising first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type; determining a first backoff value of the random access procedure for the first device based on the response message; and performing the random access procedure based on the first backoff value.

In a fourth aspect, there is provided a method. The method comprises receiving, at a second device, a random access preamble from a first device; and transmitting a response message to the first device, the response message comprising first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type.

In a fifth aspect, there is provided a first apparatus. The first apparatus comprises means for transmitting, at a first apparatus, a random access preamble to a second apparatus; means for receiving a response message from the second apparatus, the response message comprising first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type; means for determining a first backoff value of the random access procedure for the first apparatus based on the message; and means for performing the random access procedure based on the first backoff value.

In a sixth aspect, there is provided a second apparatus. The second apparatus comprises means for receiving a random access preamble from a first apparatus; and means for transmitting a response message to the first apparatus, the response message comprising first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type.

In a seventh aspect, there is provided a computer-readable medium comprising program instructions for causing an apparatus to perform at least the method according to any one of the above third to fourth aspects.

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

Some example embodiments will now be described with reference to the accompanying drawings, where:

Fig. 1 illustrates an example communication network in which example embodiments of the present disclosure can be implemented;

Fig. 2 illustrates a signaling flow for selective RACH overload control according to some embodiments of the present disclosure;

Fig. 3A illustrates a diagram of a medium access control (MAC) protocol data unit (PDU) according to some embodiments of the present disclosure;

Fig. 3B illustrates a diagram of a MAC PDU according to some embodiments of the present disclosure;

Fig. 3C illustrates a diagram of a MAC subheader according to some embodiments of the present disclosure;

Fig. 3D illustrates a diagram of a MAC subheader according to some embodiments of the present disclosure;

Fig. 3E illustrates a diagram of a MAC PDU according to some embodiments of the present disclosure;

Fig. 4 illustrates a flowchart of a method implemented at the first device according to some embodiments of the present disclosure;

Fig. 5 illustrates a flowchart of a method implemented at a second device according to some embodiments of the present disclosure;

Fig. 6 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

Fig. 7 illustrates a block diagram of an example computer readable medium according to some embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example 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 can be implemented in various manners other than the ones described below.

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 embodiment, ” “an example embodiment, ” and the like indicate that the embodiment 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 are not necessarily referring to the same embodiment. 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” etc. 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. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example 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 used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) :

(i) a combination of analog and/or digital hardware circuit (s) with software/firmware and

(ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a NR NB (also referred to as a gNB) , a remote radio unit (RRU) , a radio header (RH) , a remote radio head (RRH) , an integrated access and backhaul (IAB) node, a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology.

The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a subscriber station (SS) , a portable subscriber station, a mobile station (MS) , or an access terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device and applications (e.g., remote surgery) , an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. In the following description, the terms “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

As used herein, the term “resource, ” “transmission resource, ” “resource block, ” “physical resource block” (PRB) , “uplink resource, ” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other resource enabling a communication, and the like. In the following, a resource in both frequency domain and time domain will be used as an example of a transmission resource for describing some example embodiments of the present disclosure. It is noted that example embodiments of the present disclosure are equally applicable to other resources in other domains.

Fig. 1 shows an example communication environment 100 in which example embodiments of the present disclosure can be implemented. In the communication environment 100, a plurality of communication devices, including a first device 110 and a second device 120 can communicate with each other.

In the example of Fig. 1, the first device 110 is illustrated as a terminal device while the second device 120 is illustrated as a network device serving the terminal device. The serving area of the second device 120 may be called a cell 102.

It is to be understood that the number of devices and their connections shown in Fig. 1 are only for the purpose of illustration without suggesting any limitation. The environment 100 may include any suitable number of devices adapted for implementing embodiments of the present disclosure. Although not shown, it would be appreciated that one or more additional devices may be located in the cell 102, and one or more additional cells may be deployed in the environment 100. It is noted that although illustrated as a network device, the second device 120 may be other device than a network device. Although illustrated as a terminal device, the first device 110 may be other device than a terminal device.

In some example embodiments, if the first device 110 is a terminal device and the second device 120 is a network device, a link from the second device 120 to the first device 110 is referred to as a downlink (DL) , while a link from the first device 110 to the second device 120 is referred to as an uplink (UL) . In DL, the second device 120 is a transmitting (TX) device (or a transmitter) and the first device 110 is a receiving (RX) device (or a receiver) . In UL, the first device 110 is a TX device (or a transmitter) and the second device 120 is a RX device (or a receiver) .

Communications in the communication environment 100 may be implemented according to any proper communication protocol (s) , including, but not limited to, cellular communication protocols of the first generation (1G) , the second generation (2G) , the third generation (3G) , the fourth generation (4G) and the fifth generation (5G) and on the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and/or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, including but is not limited to: Code Division Multiple Access (CDMA) , Frequency Division Multiple Access (FDMA) , Time Division Multiple Access (TDMA) , Frequency Division Duplex (FDD) , Time Division Duplex (TDD) , Multiple-Input Multiple-Output (MIMO) , Orthogonal Frequency Division Multiple (OFDM) , Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and/or any other technologies currently known or to be developed in the future.

As mentioned above, REDCAP UEs have been introduced to the communication networks. However, it is being considered that a REDCAP UE identification would be done from message 3 (MSG3) of the random access (RA) procedure. That is, a physical random access channel (PRACH) would be shared between normal UEs and REDCAP UEs, which is why the random access response (RAR) is common.

Further, there is currently no means to make only certain UEs to backoff in a RA procedure. Whereas, a network might want to have REDCAP UEs to backoff while the normal UEs would not. There is no solution on selective RACH overload control (i.e., selectively backoff certain UEs during RACH for overload control) . Furthermore, even with 2-step RACH, in case the network does not receive the physical uplink shared channel (PUSCH) part of message A (MSGA) or neither (PRACH preamble + PUSCH) , it cannot deduce the UE attempting is a REDCAP UE.

Furthermore, in case the usage of common RACH resources for SDT and non-SDT gains traction, there is no mechanism to effectively prioritize UEs, for example, who don’t access for SDT. In general, in resource consumption wise, it is always more beneficial to bring the UE into CONNECTED mode to send the data as proper link reporting and management can be performed.

As a result, a solution on selective RACH overload control is needed, such that backoff during a random access procedure for one device type (e.g., REDCAP UE) can be differentiated with that of normal/conventional device type (e.g., non-REDCAP UE) , and backoff of a random access procedure for a certain access attempt type (e.g., SDT) can be differentiated with a further access attempt type (e.g., non-SDT) , such that, for example, it allows indicating backoff for a specific device type (e.g., a REDCAP UE) or access attempt type (e.g., SDT) , while conventional/normal devices (e.g., non-REDCAP UEs) or access attempt type (e.g., non-SDT) may not perform backoff (or perform backoff with a backoff value indicated with a conventional solution) . For example, there may be a REDCAP UE device type supporting 1Rx (single receiver chain) and another REDCAP UE device type supporting 2Rx (two receiver chains) .

In order to solve at least part of the above mentioned problems, solutions on selective RACH overload control is provided. In this solution, the first device 110 transmits a random access preamble to a second device 120. Then, the first device 110 receives a response message from the second device 120. The response message includes first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type. Accordingly, the first device 110 determines a first backoff value of the random access procedure for the first device 110 based on the response message and performs the random access procedure based on the first backoff value.

Through this solution, a selective RACH overload control is provided. It allows indicating backoff for a specific device type (e.g., a REDCAP UE) or access attempt type (e.g., SDT) , while conventional/normal devices (e.g., non-REDCAP UEs) or access attempt type (e.g., non-SDT) may not perform backoff (or perform backoff with a conventional solution) .

Specifically, the solution is able to allow backoff for a specific use when common RACH is applied for different device types (e.g., REDCAP UEs or non-REDCAP UEs) . Further, even in case the usage of common RACH resources for SDT and non-SDT gains traction, a solution is provided to effectively prioritize devices (e.g., UEs, e.g., who don’t access for SDT) . In general, in resource consumption wise, it is always more beneficial to bring the UE into CONNECTED mode to send the data as proper link reporting and management can be performed.

Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Reference is now made to Fig. 2, which shows a signaling flow 200 for selective RACH overload control according to some example embodiments of the present disclosure. For the purpose of discussion, the signaling flow 200 will be described with reference to Fig. 1. The signaling flow 200 involves the first device 110 and the second device 120 as illustrated in Fig. 1.

As shown in the signalling flow 200, the first device 110 transmits 205 a random access preamble to a second device 120. Accordingly, upon receiving 210 the random access preamble, the second device 120 transmits 220 a response message to the first device 110. The response message includes first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type. For example, the response message may be for a RA preamble transmitted from another device (e.g., another UE) .

In some embodiments, the at least one device type indicates a REDCAP device. In some embodiments, the at least one access attempt type indicates an access attempt related to a SDT.

Upon receiving 225 the response message, the first device 110 determines 235 a first backoff value of the random access procedure for the first device 110 based on the response message. Then, the first device 110 performs 245 the random access procedure based on the determined first backoff value.

As such, a selective RACH overload control is provided, allowing to indicate backoff for a specific device type (e.g., a REDCAP UE) or access attempt type (e.g., SDT) , while conventional/normal devices (e.g., non-REDCAP UEs) or access attempt type (e.g., non-SDT) may not perform backoff (or perform backoff with a conventional solution) .

In some embodiments, the response message includes a first indication of a second backoff value for the at least one device type or the at least one access attempt type. In such embodiments, for example, the second backoff value for the certain device type or the access attempt type may be used when the type of the first device 110 is the at least one device type. In addition, the first indication may indicate to the first device 110 about the second backoff value in a variety of ways which will be introduced in a latter part.

In some embodiments, the first device 110 may determine a backoff time for the random access procedure based on the determined first backoff value, and may perform the random access procedure with the backoff time. In some examples, the backoff time may be randomly selected between 0 and the first backoff value. In one example, the first device 110 may select a random backoff time according to a uniform distribution between 0 and the first backoff value.

In the following part, the ways on how to determine the first backoff value for the first device 110 will be introduced. In some embodiments, if it is determined that the type of the first device 110 is one of the at least one device type (e.g., the REDCAP UE type) , the first device 110 may determine the first backoff value based on the second backoff value. If it is determined that the type of the first device 110 is different from the at least one device type (e.g., the first device 110 is of the normal/conventional UE type) , the first device 110 may determine the first backoff value based on a third backoff value configured for the device type different from the at least one device type.

In some examples, the device different from the at least one device type may be a conventional/normal device (e.g., a normal Non-REDCAP UE) . Accordingly, the third backoff value configured for the device may be the backoff value for the normal device which may be obtained as in conventional solutions. It should be appreciated that the type of the device different from the at least one device type may also be other device type (as long as it is different from the at least one device type) and the scope of the present disclosure is not limited in this regard.

For example, the third backoff value configured for a device type different from the at least one device type may also be indicated in the response message. In such example, the device type different from the at least one device type may be a normal UE type. Accordingly, the third backoff value may be indicated via a current MAC subheader with a backoff indicator (BI) . As such, the third backoff value may be indicated by the BI according to the following Table. 1. For scenarios in which the index of the backoff parameter value corresponds to “reserved” , the third backoff value will be set to zero.

Table. 1 Backoff Parameter values

Index	Backoff Parameter value (ms)
0	5
1	10
2	20
3	30
4	40
5	60
6	80
7	120
8	160
9	240
10	320
11	480
12	960
13	1920
14	Reserved
15	Reserved

In some embodiments, if it is determined that an access attempt type of the first device 110 is one of the at least one access attempt type, the first device 110 may determine the first backoff value based on the second backoff value. If it is determined that an access attempt type of the first device 110 is different from the at least one access attempt type, the first device 110 may determine the first backoff value based on a third backoff value configured for a device type different from the at least one device type.

In such embodiments, when the at least one access attempt type indicates an access attempt related to a SDT, the first device 110 may determine whether the first device 110 is performing SDT. If it is determined that the first device 110 is performing SDT, the first device 110 may determine the first backoff value based on the second backoff value. If it is determined that the first device is not performing SDT (i.e., non-SDT) , the first device 110 may determine the first backoff value based on a third backoff value configured for a device type different from the at least one device type. The third backoff value may be obtained via the method mentioned above which will not be repeated here.

In some examples, as mentioned above, the device different from the at least one device type may be a conventional/normal device (e.g., a normal Non-REDCAP UE) . Accordingly, the third backoff value configured for the device may be the backoff value for the normal device which may be obtained as in conventional solutions. It should be appreciated that the type of the device different from the at least one device type may also be other device type (as long as it is different from the at least one device type) and the scope of the present disclosure is not limited in this regard.

It should be appreciated that there may also be other ways for determining the first backoff value of the random access procedure for the first device 110 based on the response message and the scope of the present disclosure is not limited in this regards.

As mentioned above, the second backoff value may also be indicated by the first indication to the first device 110 in a variety of ways. In the following part, what the first indication may indicate will be introduced in the following part with reference to Figs. 3A-3E. Figs. 3A-3E illustrates diagrams of a MAC PDU and/or MAC subheader according to some embodiments of the present disclosure. It should be appreciated that, MAC PDU for RAR illustrated in Figs. 3A-3E are only shown as examples, MAC PDU for message B (MSGB) may also be used similarly and the scope of the present disclosure is not limited in this regard.

In some embodiments, the first indication may indicate a position of a BI including the second backoff value. Now, reference will be made to Figs. 3A-3B to illustrate such embodiments.

Fig. 3A illustrates a diagram of a medium access control (MAC) protocol data unit (PDU) according to some embodiments of the present disclosure. In such embodiments, for example, as shown in Fig. 3A, the first indication may be R bit 312, and/or R bit 313 of a current E/T/R/R/BI MAC subheader, and/or the reserved value in the BI field 314 (e.g., for conventional/normal device type (e.g., a non-REDCAP UE) or a non-SDT access attempt type) , which may be used to indicate that a separate BI follows in the end of the MAC PDU (e.g., BI’ 316) (i.e., after all the MAC RARs) . Such separate BI may include the second backoff value.

Currently in the MAC subheader, E/T/R/R/BI are used to as in the following Table 2.

Table. 2 E/T/R/R/BI in MAC subheader

It should be appreciated that any one of the R bit in the E/T/R/R/BI MAC subheader or both may be used to indicate that a separate BI follows in the end of the MAC PDU. The scope of the present disclosure is not limited in this regard.

As such, in some examples, as mentioned above, when the first device 110 determines that it is a REDCAP UE, it may determine the first backoff value based on the second backoff value indicated in this BI’ 316. While, for example, when the first device 110 determines that it is a non-REDCAP UE, it may determine the first backoff value based on the third backoff value indicated in BI 314.

In one example, the BI’ 316 may use indexes to indicate respective backoff parameter values as shown in Table. 1 mentioned above. Alternatively, the BI’ 316 may also use other ways to indicate backoff parameters and the scope of the present disclosure is not limited in this regard. For example, another set of backoff parameter values may be defined that may be different to those as shown in Table. 1.

Accordingly, in such examples, the BI 314 may be set to the reserved value such that backoff for conventional/normal devices or access attempt type in this case can be avoided. As a result, only a certain type of device (e.g., REDCAP UEs) or a certain access attempt type (e.g., SDT) may perform RACH with backoff while conventional/normal ones would not. That is, conventional BI (314) is able to be reused as an indication for the a certain type of device (e.g., REDCAP UEs) or a certain access attempt type (e.g., SDT) , while the other device type or access attempt type may still perform backoff for RACH based on the conventional solution, without affecting the conventional device’s operation. Meanwhile, network resources are saved.

It should also be appreciated that although in the above example, the separate BI following in the end of the MAC PDU (thus may have less impact on the current MAC PDU) , the position of BI indicating the second backoff value may be at different positions of the MAC PDU and the scope of the present disclosure is not limited in this regard.

Fig. 3B illustrates a diagram of a MAC PDU according to some embodiments of the present disclosure. As shown in Fig. 3B, the first indicator may be the E field 324 after the last MAC RAR. For example, when the E field 324 is set, a “normal” type device (e.g., a normal non-REDCAP UE) would determine padding to start (thus, without affect the conventional device’s operation) , while the certain type of devices (e.g., REDCAP UEs may also decode the T field 326 of the last MAC RAR (i.e., the one that indicates to conventional UEs no MAC RARs follow) . In such examples, for example, the T field 326 of the last MAC RAR may be encoded to indicate that an additional backoff indication follows the last MAC RAR, and the additional backoff indication may include the second backoff value.

Accordingly, the RAR MAC PDU will include at least a conventional BI (e.g., the BI for the normal device (e.g., non-REDCAP UE) ) as shown in Fig. 3B or a single MAC RAR so that the T field in the MAC subPDU may be used for the purpose.

For example, if the first device 110 is a REDCAP UE, based on the T field 326, it will determine that there is an additional backoff indication 328. However, if the first device 110 is a conventional/normal device (e.g., non-REDCAP UE) , it may determine that the bits after the E filed 324 are padding bits, thus without affecting the conventional device’s operation.

In some embodiments, the first indication may indicate using a predetermined backoff value as the second backoff value. In the following part, examples for the first indication indicating using a predetermined backoff value as the second backoff value will be introduced with reference to Fig. 3C, which illustrates a diagram of a medium access control (MAC) subheader according to some embodiments of the present disclosure.

In some examples, as shown in Fig. 3C, a reserved value in BI 332 may be the first indication and it may be used to indicate a predetermined backoff value for the first device 110 applying it. That is, the reserved value in BI 332 is used to indicate to the first device 110 that a predetermined backoff value will be used when the first device 110 is the certain type of device (e.g., a REDCAP UE) . Meanwhile, when the first device 110 is not the certain type of device (e.g., a non-REDCAP UE) , the reserved value in BI 332 is used to indicate to the first device 110, for example, a zero backoff value will be used as in the conventional solution.

It should be appreciate that using the predetermined backoff value as the second backoff value may also be indicated by the first indication via other information elements and the scope of the present disclosure is not limited in this regard.

In such examples, the predetermined backoff value may be obtained in a variety of ways. In one example, the predetermined backoff value may be obtained via a system information block (SIB) . In another example, the predetermined backoff value may be obtained via a dedicated signaling (e.g., a RRC release message) . Alternatively, the predetermined backoff value may also be predefined in specifications (e.g., the third generation partnership project (3GPP) specification) . There may also be other ways for obtaining the predetermined backoff value and the scope of the present disclosure is not limited in this regard.

In some embodiments, the first indication may indicate whether a third backoff value for a second device type may be determined as the second backoff value. In the following, reference will be made to Fig. 3D illustrates a diagram of a medium access control (MAC) subheader according to some embodiments of the present disclosure.

For example, as shown in Fig. 3D, the first indication may be the R bit 342 and/or R bit 343 of the E/T/R/R/BI MAC subheader. This first indication may be used to indicate if the backoff in the BI field with conventional values (e.g., applied by the conventional/normal UEs) may be applied by the certain type of UEs of the certain access attempt type (e.g., a REDCAP UE or a UE performing SDT access) . It should be appreciated that any one of the R bits in the E/T/R/R/BI MAC subheader or both may be used to indicate such information. The scope of the present disclosure is not limited in this regard.

In such example, for example, if the R bit 342 is set, it may indicate the backoff value in the BI field with conventional values (e.g., applied by the conventional/normal UEs) may be applied by the certain type of UEs of a certain access attempt type. In such case, for example, when the first device 110 is a non-REDCAP UE, it may use the BI field in conventional solutions.

However, if the

R bit

342 or 343 is not set, it may indicate the backoff value in the BI field with conventional values (e.g., applied by the conventional/normal device or non-SDT) may not be applied by the certain type of device (e.g., the REDCAP UE) . In such case, the MAC RARs may follow an additional BI for the certain type of device, and the additional BI include the second backoff value. Alternatively, in such case, the backoff may not be applied by the certain type of device (e.g., the REDCAP UE) in the Random Access procedure.

In some other embodiments, the first indication may also indicate whether the second backoff value is determined based on the third backoff value and a scaling factor for backoff. In such embodiments, for example, still referring to Fig. 3D, the

R bit

342 or 343 of the E/T/R/R/BI MAC subheader may be used to indicate if the backoff in the BI field (applied by the conventional/normal devices, e.g., UEs) should be applied by the certain type of device (e.g., the REDCAP UE) or the certain type of access attempt type (e.g., SDT) as such or whether the certain type of device/the certain type of access attempt type may apply scaling to the indicated backoff value.

In some examples, when scaling to the indicated BI is applied, the value for scaling may be provided by the second device 120 via a variety of ways. In some embodiments, the second device 120 may provide the value for scaling via SIB. In some other embodiments, the second device 120 may provide the value for scaling via a dedicated signaling. For example, the value for scaling may be provided over a RRC Release message to the certain type of devices performing SDT or over a RRC Reconfiguration message.

In such embodiments, there is no need to provide additional BI (i.e., backoff value) for the certain type of device or the certain access attempt type, thereby saving network overhead.

In some embodiments, the first indication may indicate a BI including the second backoff value. In the following, reference will be made to Fig. 3E, which illustrates a diagram of a medium access control (MAC) protocol data unit (PDU) according to some embodiments of the present disclosure.

As shown in Fig. 3E, there is an additional MAC subheader 352 (i.e., the first indication) encoded for the certain type of devices (e.g., SDT or REDCAP UEs) after all the MAC RARs and/or BI MAC subheader to provide additional backoff indication. In such example, normal/conventional devices (e.g., non-REDCAP UE) may determine padding to start –E field set to “0” , thus without affecting the conventional device’s operation.

As shown in Fig. 3E, the additional MAC subheader 352 may include fields such as E, T, R, BI, and the like, as they are provided in the current E/T/R/R/BI MAC subheader in conventional solution mentioned above, and the BI may include the second backoff value. In this example, the additional MAC subheader 352 is encoded when the BI MAC subheader 351 is encoded for the conventional/normal devices (e.g., non-REDCAP UE) in the beginning of the RAR MAC PDU. As a result, a separate MAC subhead is able to be used for the certain type of device or the certain access attempt type, thus providing flexibility for the solution.

In the above part, what the first indication may indicate has been introduced with reference to Figs. 3A-3E. It should be appreciated that the first indication may also indicate others for obtaining the second backoff value, and the scope of the present disclosure is not limited in this regard.

In some embodiments, the network device 120 may transmit, to the first device 110, a message indicating the at least one device type includes a reduced capability device, and/or a type of reduced capability device.

As such, the second device 120 is able to configure the first device 110 which device type (e.g., REDCAP UEs) should apply the new backoff behavior (i.e., applying backoff with the first information related to a backoff of a random access procedure for at least one device type) . Otherwise, the conventional backoff mechanism applies.

In some other embodiments, the network device 120 may transmit to the first device 110, the message indicating that the at least one access attempt type includes a SDT, a SDT for a signaling radio bearer (SRB) , or a SDT for a data radio bearer (DRB) . Accordingly, the first device 110 may receive the message, and determine the first backoff value based on both the response message and this message. In some examples, the message may be sent via system information or via dedicated signaling.

As such, the second device 120 is able to configure the first device 110 which access attempt types (e.g., SDT, or SDT for SRB/DRB data, and the like) should apply the new backoff behavior (i.e., applying backoff with the first information related to a backoff of a random access procedure for at least one access attempt type) . Otherwise, the conventional backoff mechanism applies.

Accordingly, only the certain type of device or access attempt type configured by the network device 120 will apply the new backoff behavior, thus providing flexibility for the backoff mechanisms.

In one example, the network device 120 may transmit, to the first device 110, a message indicating that the at least one access attempt type includes SDT for DRB. Accordingly, the first device 110 which receives the message may apply backoff with the first information for the SDT for DRB. Meanwhile, the first device 110 may still apply backoff with, for example conventional BI, for the SDT for SRB. As a result, SDT for SRB and SDT for DRB may be configured with different BI, such that they can be provided with different priorities while accessing a cell.

In another example, the network device 120 may transmit, to the first device 110, the message indicating that the at least one device type includes a specific type of REDCAP UEs. Accordingly, the first device 110 which receives the message may apply backoff with the first information for the specific type of REDCAP UE. Meanwhile, the first device 110 may still apply backoff with, for example conventional BI, for the other REDCAP UEs. As a result, different types of REDCAP UEs may perform RACH with different backoff values, such that they can be provided with different priorities when they access a cell.

Accordingly, for example, when REDCAP UE type (s) are defined in the REDCAP work item which could have different priorities when it comes to accessing the cell (e.g., industrial sensor vs. wearables vs. non-REDCAP UEs) , the at least one device type may include the specific REDCAP type (s) which should apply the new backoff behavior.

In some embodiments, the second device 120 may transmit, to the first device 110, a message including a plurality of sets of BIs, and each of the plurality of sets may be for a SRB, DRB, a logical channel (LCH) , a priority of the LCH, and the range of the priority of the LCH.

Accordingly, the first device 110 receives the message, and may determine the first backoff value based on the response message and at least one of the plurality of sets of BIs. As such, the second device 120 may configure different/new (i.e., different values from conventional/normal devices type (e.g., non-REDCAP UEs) backoff parameter values for the SDT procedure in the RRC Release message suspending the UE or for REDCAP UEs. Further, the configuration is able to be provided on a per SRB basis, DRBs basis, or LCH priority basis, or LCH priority range basis, thus increasing the configuration flexibility.

In some embodiments, different backoff value table (s) may also be specified and the second device 120 may configure which table (the conventional or the new one (s) ) applies for the SDT or for certain LCH/DRB/SRB or for REDCAP UE. For example, the second device 120 may configure which table applies in an RRC Release or RRC Reconfiguration message. In this way, the backoff indication can be the same for the conventional/normal devices (e.g., non-REDCAP UEs) and the new devices (e.g., the certain type of UE, i.e., REDCAP UEs) .

In some embodiments, a backoff scaling may be applied based on the data priority that triggered the SDT procedure or based on the UE type (e.g., different REDCAP UE type which may be 1Rx REDCAP UE type or 2Rx REDCAP UE type) . In some examples, a scaling factor value used for the backoff procedure may be determined based on the priority of data the SDT procedure is initiated for. In some examples, the scaling factor value may be configured per LCH/SRB/DRB/priority basis. For example, the priority of data may be determined based on the highest priority data in the UE buffer or based on the lowest priority data in the UE buffer –e.g., based on the configured LCH priority.

In some examples, only the SDT data may be accounted for the priority determination. In some examples, the non-SDT data may also be accounted. In some examples, the non-SDT data may always be determined to be the highest priority regardless of the priority of the LCH/DRB the non-SDT data is available.

In some examples, the scaling factor may be determined to be 0/zero for the highest priority data or SRB data. In some examples, the second device 120 may configure a threshold priority (ies) which is (are) used to determine the scaling factor. For example, any priority >2 may use scaling factor 0/zero, priorities between 2=<X<4 scaling factor 0.25 and so on.

In some examples, the second device 120 may configure the used scaling factor for the SDT procedure in the RRCRelease message suspending the first device 110. In some examples, the configuration may be provided on a per first device (e.g., UE) , per SRB/DRB basis, SRBs/DRBs basis, or LCH priority basis, or LCH priority range basis.

In some examples, the scaling factor may be determined based on the establishment cause used for the SDT. In some examples, the second device 120 may configure the scaling factor on a per establishment cause basis.

In some examples, the configured backoff parameter/scaling factor may be applied for all the attempts for SDT, or only applied for re-attempts. In some examples, the configured scaling factor may only be applied if the received BI value in RAR is above a threshold value.

In some embodiments, a scaling factor value used for the backoff procedure is determined based on the UE type. In some examples, the second device 120 may configure the scaling factor per UE type. In some examples, the configuration may be carried over dedicated signaling (e.g., RRC signaling) or via system information broadcast. In some examples, the scaling factor value may be above 1 based on the UE type (i.e., scaling the backoff value higher than the one indicated in the RAR/MSGB) .

Fig. 4 illustrates a flowchart of a method 400 implemented at a first device 110 according to some embodiments of the present disclosure. For the purpose of discussion, the method 400 will be described from the perspective of the first device 110 with reference to Fig. 1.

At block 410, the first device 110 transmits a random access preamble to the second device 120. At block 420, the first device 110 receives a response message from the second device 120. The response message includes first information related to a backoff of a random access procedure for at least one device type (e.g., REDCAP UE type) or at least one access attempt type (e.g. SDT) . At block 430, the first device 110 determines a first backoff value of the random access procedure for the first device 110 based on the response message. At block 440, the first device 110 performs the random access procedure based on the first backoff value.

In some embodiments, the at least one device type may indicate a reduced capability device, and the at least one access attempt type indicates an access attempt related to a small data transmission.

In some embodiments, the response message may include a first indication of a second backoff value for the at least one device type or the at least one access attempt type.

In some embodiments, the first device 110 may determine the first backoff value by: in accordance with a determination that a type of the first device 110 is one of the at least one device type, determining the first backoff value based on the second backoff value; and in accordance with a determination that the type of the first device 110 is different from the at least one device type, determining the first backoff value based on a third backoff value configured for a device type different from the at least one device type.

In some embodiments, the first device 110 may determine the first backoff value by: in accordance with a determination that an access attempt type of the first device 110 is one of the at least one access attempt type, determining the first backoff value based on the second backoff value; and in accordance with a determination that an access attempt type of the first device 110 is different from the at least one access attempt type, determining the first backoff value based on a third backoff value configured for a device type different from the at least one device type.

In some embodiments, the first indication may indicate at least one of: a position of a backoff indicator comprising the second backoff value, using a predetermined backoff value as the second backoff value, whether a third backoff value for a second device type is determined as the second backoff value, whether the second backoff value is determined based on the third backoff value and a scaling factor for backoff, and the backoff indicator comprising the second backoff value.

In some embodiments, the predetermined backoff value may be obtained via one of: a system information block, SIB, a radio resource control, RRC, release, and a medium access control-control element.

In some embodiments, the first device 110 may receive, from the second device 120, a further message indicating the at least one device type comprising at least one of: a reduced capability device, and a type of reduced capability device, and the at least one access attempt type comprising at least one of: a small data transmission, a small data transmission for a signaling radio bearer, and a small data transmission for a data radio bearer, and the first device 110 may determine the first backoff value by: determining the first backoff value based on both the response message and the further message.

In some embodiments, the first device 110 may receive, from the second device 120, a further message comprising a plurality of sets of backoff indicators, each of the plurality of sets is for at least one of: a signaling radio bearer, a data radio bearer, a logical channel, a priority of the logical channel, and a range of the priority of the logical channel; and the first device 110 may determine the first backoff value by: determining the first backoff value based on the response message and at least one of the plurality of sets of backoff indicators.

In some embodiments, the first device 110 may perform the random access procedure by: determining a backoff time for the random access procedure based on the first backoff value, and perform the random access procedure with the backoff time.

In some embodiments, the first device 110 comprises a terminal device, and the second device 120comprises a network device.

Fig. 5 illustrates a flowchart of a method 500 implemented at a second device 120 according to some embodiments of the present disclosure. For the purpose of discussion, the method 500 will be described from the perspective of the second device 120 with reference to Fig. 1.

At block 510, the second device 120 receives a random access preamble from a first device 110. Then, at block 520, the second device 120 transmits a response message to the first device 110. The response message includes first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type.

In some embodiments, the at least one device type may indicate a reduced capability device, and the at least one access attempt type indicates an access attempt related to small data transmission.

In some embodiments, the first indication may indicates at least one of: a position of a backoff indicator comprising the second backoff value, using a predetermined backoff value as the second backoff value, whether a third backoff value for a second device type is determined as the second backoff value, whether the second backoff value is determined based on the third backoff value and a scaling factor for backoff, and the backoff indicator comprising the second backoff value.

In some embodiments, the second device 120 may transmit, to the first device 110, a further message indicating the at least one device type comprising at least one of: a reduced capability device, and a type of reduced capability device, and the at least one access attempt type comprising at least one of: a small data transmission, a small data transmission for a signaling radio bearer, and a small data transmission for a data radio bearer.

In some embodiments, the second device 120 may transmit, to the first device 110, a further message comprising a plurality of sets of backoff indicators, each of the plurality of sets is for at least one of: a signaling radio bearer, a data radio bearer, a logical channel, a priority of the logical channel, and a range of the priority of the logical channel.

In some embodiments, the first device 110 may include a terminal device, and the second device 120 may include a network device.

In some embodiments, the first apparatus capable of performing any of the method 400 (for example, the first device 110) may comprise means for performing the respective steps of the method 400. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the first apparatus comprises: means for transmitting, at a first apparatus, a random access preamble to a second apparatus (e.g., the second device 120) ; means for receiving a response message from the second apparatus, the response message comprising first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type; means for determining a first backoff value of the random access procedure for the first apparatus based on the message; and means for performing the random access procedure based on the first backoff value.

In some example embodiments, the at least one device type indicates a reduced capability device, and the at least one access attempt type indicates an access attempt related to a small data transmission.

In some embodiments, the response message comprises a first indication of a second backoff value for the at least one device type or the at least one access attempt type.

In some embodiments, means for determining the first backoff value comprises means for in accordance with a determination that a type of the first apparatus is one of the at least one device type, determining the first backoff value based on the second backoff value; and means for in accordance with a determination that the type of the first apparatus is different from the at least one device type, determining the first backoff value based on a third backoff value configured for a device type different from the at least one device type.

In some embodiments, means for determining the first backoff value comprise means for in accordance with a determination that an access attempt type of the first apparatus is one of the at least one access attempt type, determining the first backoff value based on the second backoff value; and means for in accordance with a determination that an access attempt type of the first apparatus is different from the at least one access attempt type, determining the first backoff value based on a third backoff value configured for a device type different from the at least one device type.

In some embodiments, the first indication indicates at least one of: a position of a backoff indicator comprising the second backoff value, using a predetermined backoff value as the second backoff value, whether a third backoff value for a second apparatus type is determined as the second backoff value, whether the second backoff value is determined based on the third backoff value and a scaling factor for backoff, and the backoff indicator comprising the second backoff value.

In some embodiments, the predetermined backoff value is obtained via one of: a system information block, SIB, a radio resource control, RRC, release, and a medium access control-control element.

In some embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, a further message indicating the at least one device type comprising at least one of: a reduced capability device, and a type of reduced capability device, and the at least one access attempt type comprising at least one of: a small data transmission, a small data transmission for a signaling radio bearer, and a small data transmission for a data radio bearer, means for determining the first backoff value comprises means for determining the first backoff value based on both the response message and the further message.

In some embodiments, the first apparatus further comprises means for receiving, from the second apparatus, a further message comprises a plurality of sets of backoff indicators, each of the plurality of sets is for at least one of: a signaling radio bearer, a data radio bearer, a logical channel, a priority of the logical channel, and a range of the priority of the logical channel; and means for determining the first backoff value comprise: means for determining the first backoff value based on the response message and at least one of the plurality of sets of backoff indicators.

In some embodiments, means for performing the random access procedure comprises means for determining a backoff time for the random access procedure based on the first backoff value, and means for performing the random access procedure with the backoff time.

In some embodiments, the first apparatus comprises a terminal device, and the second apparatus comprises a network device.

In some embodiments, the second apparatus capable of performing any of the method 500 (for example, the second device 120) may comprise means for performing the respective steps of the method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some embodiments, the second apparatus comprises: means for receiving a random access preamble from a first apparatus; and means for transmitting a response message to the first apparatus, the response message comprising first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type.

In some embodiments, the at least one device type indicates a reduced capability device, and the at least one access attempt type indicates an access attempt related to small data transmission.

In some embodiments, the first indication indicating indicates at least one of: a position of a backoff indicator comprising the second backoff value, using a predetermined backoff value as the second backoff value, whether a third backoff value for a second apparatus type is determined as the second backoff value, whether the second backoff value is determined based on the third backoff value and a scaling factor for backoff, and the backoff indicator comprising the second backoff value.

In some embodiments, the second apparatus further comprises means for transmitting, to the first apparatus, a further message indicates the at least one device type comprises at least one of: a reduced capability device, and a type of reduced capability device, and the at least one access attempt type comprising at least one of: a small data transmission, a small data transmission for a signaling radio bearer, and a small data transmission for a data radio bearer.

In some embodiments, the second apparatus further comprises means for transmitting, to the first apparatus, a further message comprising a plurality of sets of backoff indicators, each of the plurality of sets is for at least one of: a signaling radio bearer, a data radio bearer, a logical channel, a priority of the logical channel, and a range of the priority of the logical channel.

Fig. 6 is a simplified block diagram of a device 600 that is suitable for implementing embodiments of the present disclosure. The device 600 may be provided to implement the communication device, for example the first device 110, the second device 120 as shown in Fig. 1. As shown, the device 600 includes one or more processors 610, one or more memories 620 coupled to the processor 610, and one or more communication modules 640 coupled to the processor 610.

The communication module 640 is for bidirectional communications. The communication module 640 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.

The processor 610 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 600 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

The memory 620 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 624, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 622 and other volatile memories that will not last in the power-down duration.

A computer program 630 includes computer executable instructions that are executed by the associated processor 610. The program 630 may be stored in the ROM 624. The processor 610 may perform any suitable actions and processing by loading the program 630 into the RAM 622.

The embodiments of the present disclosure may be implemented by means of the program 630 so that the device 600 may perform any process of the disclosure as discussed with reference to Figs. 2 to 5. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some embodiments, the program 630 may be tangibly contained in a computer readable medium which may be included in the device 600 (such as in the memory 620) or other storage devices that are accessible by the device 600. The device 600 may load the program 630 from the computer readable medium to the RAM 622 for execution. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. Fig. 7 shows an example of the computer readable medium 700 in form of CD or DVD. The computer readable medium has the program 630 stored thereon.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the method 400-500 as described above with reference to Figs. 2-5. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A first device, comprising:

at least one processor; and

at least one memory including computer program code;

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

transmit a random access preamble to a second device;

receive a response message from the second device, the response message comprising first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type;

determine a first backoff value of the random access procedure for the first device based on the response message; and

perform the random access procedure based on the first backoff value.
The first device of claim 1, wherein the at least one device type indicates a reduced capability device, and the at least one access attempt type indicates an access attempt related to a small data transmission.
The first device of claim 1, wherein the response message comprises a first indication of a second backoff value for the at least one device type or the at least one access attempt type.
The first device of claim 3, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to determine the first backoff value by:

in accordance with a determination that a type of the first device is one of the at least one device type, determining the first backoff value based on the second backoff value; and

in accordance with a determination that the type of the first device is different from the at least one device type, determining the first backoff value based on a third backoff value configured for a device type different from the at least one device type.
The first device of claim 3, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to determine the first backoff value by:

in accordance with a determination that an access attempt type of the first device is one of the at least one access attempt type, determining the first backoff value based on the second backoff value; and

in accordance with a determination that an access attempt type of the first device is different from the at least one access attempt type, determining the first backoff value based on a third backoff value configured for a device type different from the at least one device type.
The first device of claim 3, wherein the first indication indicates at least one of:

a position of a backoff indicator comprising the second backoff value,

using a predetermined backoff value as the second backoff value,

whether a third backoff value for a second device type is determined as the second backoff value,

whether the second backoff value is determined based on the third backoff value and a scaling factor for backoff, and

the backoff indicator comprising the second backoff value.
The first device of claim 6, wherein the predetermined backoff value is obtained via one of:

a system information block, SIB,

a radio resource control, RRC, release, and

a medium access control-control element.
The first device of claim 1, wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the first device to:

receive, from the second device, a further message indicating the at least one device type comprising at least one of:

a reduced capability device, and

a type of reduced capability device, and

the at least one access attempt type comprising at least one of:

a small data transmission,

a small data transmission for a signaling radio bearer, and

a small data transmission for a data radio bearer,

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to determine the first backoff value by:

determining the first backoff value based on both the response message and the further message.
The first device of claim 1, wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the first device to:

receive, from the second device, a further message comprising a plurality of sets of backoff indicators, each of the plurality of sets is for at least one of:

a signaling radio bearer,

a data radio bearer,

a logical channel,

a priority of the logical channel, and

a range of the priority of the logical channel; and

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to determine the first backoff value by:

determining the first backoff value based on the response message and at least one of the plurality of sets of backoff indicators.
The first device of claim 1, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to perform the random access procedure by:

determining a backoff time for the random access procedure based on the first backoff value, and

performing the random access procedure with the backoff time.
The first device of claim 1, wherein the first device comprises a terminal device, and the second device comprises a network device.
A second device, comprising:

at least one processor; and

at least one memory including computer program code;

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

receive a random access preamble from a first device; and

transmit a response message to the first device, the response message comprising first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type.
The second device of claim 12, wherein the at least one device type indicates a reduced capability device, and the at least one access attempt type indicates an access attempt related to small data transmission.
The second device of claim 12, wherein the response message comprises a first indication of a second backoff value for the at least one device type or the at least one access attempt type.
The second device of claim 14, wherein the first indication indicates at least one of:

a position of a backoff indicator comprising the second backoff value,

using a predetermined backoff value as the second backoff value,

whether a third backoff value for a second device type is determined as the second backoff value,

whether the second backoff value is determined based on the third backoff value and a scaling factor for backoff, and

the backoff indicator comprising the second backoff value.
The second device of claim 15, wherein the predetermined backoff value is obtained via one of:

a system information block, SIB,

a radio resource control, RRC, release, and

a medium access control-control element.
The second device of claim 12, wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the second device to:

transmit, to the first device, a further message indicating the at least one device type comprising at least one of:

a reduced capability device, and

a type of reduced capability device, and

the at least one access attempt type comprising at least one of:

a small data transmission,

a small data transmission for a signaling radio bearer, and

a small data transmission for a data radio bearer.
The second device of claim 12, wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the second device to transmit, to the first device, a further message comprising a plurality of sets of backoff indicators, each of the plurality of sets is for at least one of:

a signaling radio bearer,

a data radio bearer,

a logical channel,

a priority of the logical channel, and

a range of the priority of the logical channel.
The second device of claim 12, wherein the first device comprises a terminal device, and the second device comprises a network device.
A method comprising:

receiving a response message from the second device, the response message comprising first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type;

determining a first backoff value of the random access procedure for the first device based on the response message; and

performing the random access procedure based on the first backoff value.
A method comprising:

receiving, at a second device, a random access preamble from a first device; and

transmitting a response message to the first device, the response message comprising first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type.
A first apparatus, comprising:

means for transmitting, at a first apparatus, a random access preamble to a second apparatus;

means for receiving a response message from the second apparatus, the response message comprising first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type;

means for determining a first backoff value of the random access procedure for the first apparatus based on the message; and

means for performing the random access procedure based on the first backoff value.
A second apparatus, comprising:

means for receiving, at a second apparatus, a random access preamble from a first apparatus; and

means for transmitting a response message to the first apparatus, the response message comprising first information related to a backoff of a random access procedure for at least one device type or at least one access attempt type.
A computer-readable medium comprising program instructions for causing an apparatus to perform at least the method of claim 20 or 21.