WO2023159648A1

WO2023159648A1 - Small data transmission

Info

Publication number: WO2023159648A1
Application number: PCT/CN2022/078497
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: 2022-02-28
Filing date: 2022-02-28
Publication date: 2023-08-31

Abstract

Devices and methods for small data transmission (SDT) are provided. According to embodiments of the present disclosure, a first device receives at least one configuration from a second device and the at least one configuration comprises a first timer and a second timer associated with a SDT procedure. The first timer is associated with a first duration of the SDT procedure, and the second timer is associated with a second duration of initial transmission of the SDT procedure. The first device further performs the SDT procedure based on the at least one configuration. In this way, with the second timer associated with the initial transmission of the SDT procedure, the first device is enabled to perform the SDT procedure more efficiently.

Description

SMALL DATA TRANSMISSION

FIELD

Embodiments of the present disclosure generally relate to communication techniques, and more particularly, to methods, devices and computer readable medium for small data transmission (SDT) .

BACKGROUND

For a terminal device in a radio resource control (RRC) idle mode or a RRC inactive mode, signals for transitioning to a RRC connected mode and maintaining the RRC connected mode could cause large overheads (e.g., power consumption and delay) when it has small amount of data (small data) to transmit.

With developments of communication systems, SDT technologies have been proposed to avoid the signalling overhead and delay associated with the transition to the RRC connected mode. Recently, random access channel (RACH) based SDT (i.e., RA-SDT) and configured grant (CG) based SDT (i.e. CG-SDT) are supported. During a RA-SDT procedure, the terminal device is enabled to transmit small data in the RRC inactive mode using an uplink grant received via a random access (RA) procedure for SDT. During a CG-SDT procedure, the terminal device is enabled to transmit small data in the RRC inactive mode using pre-configured uplink resources.

SUMMARY

Generally, embodiments of the present disclosure relate to a method for small data transmission and corresponding devices.

In a first aspect, there is provided a first device. The first device receives at least one configuration from a second device, the at least one configuration comprising a first timer and a second timer associated with a small data transmission (SDT) procedure, the first timer being associated with a first duration of the SDT procedure, the second timer being associated with a second duration of initial transmission of the SDT procedure. The first device further performs the SDT procedure based on the at least one configuration.

In a second aspect, there is provided a second device. The second device transmits at least one configuration to a first device, the at least one configuration comprising a first timer and a second timer associated with a small data transmission (SDT) procedure, the first timer being associated with a first duration of the SDT procedure, the second timer being associated with a second duration of initial transmission of the SDT procedure. The at least one configuration is used for performing the SDT procedure by the first device.

In a third aspect, there is provided a method. The method comprises receiving at least one configuration, the at least one configuration comprising a first timer and a second timer associated with a small data transmission (SDT) procedure, the first timer being associated with a first duration of the SDT procedure, the second timer being associated with a second duration of initial transmission of the SDT procedure; and performing the SDT procedure based on the at least one configuration.

In a fourth aspect, there is provided a method. The method comprises transmitting at least one configuration to a first device, the at least one configuration comprising a first timer and a second timer associated with a small data transmission (SDT) procedure, the first timer being associated with a first duration of the SDT procedure, the second timer being associated with a second duration of initial transmission of the SDT procedure. The at least one configuration is used for performing the SDT procedure by the first device.

In a fifth aspect, there is provided an apparatus. The apparatus comprises means for receiving at least one configuration from a second device, the at least one configuration comprising a first timer and a second timer associated with a small data transmission (SDT) procedure, the first timer being associated with a first duration of the SDT procedure, the second timer being associated with a second duration of initial transmission of the SDT procedure; and means for performing the SDT procedure based on the at least one configuration.

In a sixth aspect, there is provided an apparatus. The apparatus comprises means for transmitting at least one configuration to a first device, the at least one configuration comprising a first timer and a second timer associated with a small data transmission (SDT) procedure, the first timer being associated with a first duration of the SDT procedure, the second timer being associated with a second duration of initial transmission of the SDT procedure. The at least one configuration is used for performing the SDT procedure by the first device.

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 the above third or fourth aspect.

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:

Figs. 1A-1C illustrate schematic diagrams of small stat transmission (SDT) solutions, respectively;

Fig. 2 illustrates a schematic diagram of a communication system according to according to embodiments of the present disclosure;

Fig. 3 illustrates a schematic diagram of interactions between devices according to according to embodiments of the present disclosure;

Fig. 4 illustrates a flow chart of a method according to embodiments of the present disclosure;

Fig. 5 illustrates a simplified block diagram of an apparatus that is suitable for implementing embodiments of the present disclosure; and

Fig. 6 illustrates a block diagram of an example computer readable medium in accordance with some example 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 example 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 “communication network” refers to a network following any suitable communication standards, such as Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) , New Radio (NR) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the future fifth generation (5G) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

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) , 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 mentioned above, SDT techonologies are now supported to avoid the signalling overhead and delay associated with the transition to the RRC connected mode. Figs. 1A-1C show schematic diagrams of interactions for different kinds of SDT procedures. Fig. 1A shows a schematic diagram of interactions for 4-step RA-SDT. As shown in Fig. 1A, a terminal device 110 can transmit 1010 a message 1 (MSG 1) to a network device 120 when the terminal device 110 is in the RRC inactive mode. The MSG 1 comprises a preamble for the RACH. The network device 120 can transmit 1020 a message 2 (MSG 2) to the terminal device 110. The MSG 2 comprises a random access response. The terminal device 110 can transmit 1030 a message 3 (MSG 3) to the network device 120. The MSG 3 comprises a RRC resume request. A small payload (i.e., the small data) can be transmitted in the MSG 3. For example, the small payload can be multiplexed with the RRC resume request. The network device 120 can transmit 1040 a RRC release message.

Fig. 1B shows a schematic diagram of interactions for 2-step RA-SDT. As shown in Fig. 1B, when the terminal device 110 is in the RRC inactive mode, the terminal device 110 transmits 1110 a message A (MSG A) to the network device 120. The MSG A can comprise a preamble for the RACH. The small data can be transmitted with the MSG A. In particular, the small data can be transmitted on physical uplink shared channel (PUSCH) resources that are pre-configured by the network device 120 and are broadcasted in system information with associated physical transmission parameters. The network device 120 transmits 1120 a message B (MSG B) to the terminal device 110. The MSG B comprises a random access response.

Fig. 1C shows a schematic diagram of interactions for CG-SDT. When the terminal device 110 is in the RRC connected mode, the terminal device 110 can receive 1210 a CG type 1 configuration that indicates specific pre-configured PUSCH resources to be used for UL data transmission in the RRC inactive mode as long as the timing alignment is valid. In other words, UL data can be transmitted on pre-configured PUSCH resources when the time advance (TA) is valid. The network device 120 can transmit 1220 a RRC release message.

Conventionally, the SDT procedure can be terminated based on network signaling. For example, the terminal device 110 may receive RRC messages from the network device 120 and terminates the SDT procedure based on the RRC messages. The RRC messages may comprise a RRC release message or a RRC reject message to direct the terminal device 110 to the RRC idle mode or RRC inactive mode, or a RRC resume message or a RRC setup message to direct the terminal device 110 to the RRC connected mode.

Additionally, a timer is proposed to control the duration of the SDT procedure. The timer may be referred to as a SDT failure dection timer (or a SDT error detection timer) . The SDT failure detection timer determines a time period in which the SDT procedure can be performed. When the SDT failure detection timer expires, the terminal device 110 terminates the SDT procedure and transitions to the RRC idle mode. For example, upon expiry of the SDT failure detection timer, the terminal device 110 may determine SDT failure and transitions to the RRC idle mode.

The SDT failure detection timer is configured by the network device 120 and can be stopped by the RRC messages discussed above. Since the SDT failure detection timer defines how long the SDT procedure can last, the network device 120 preferably configures a high value (e.g., 5 or 10 seconds) for the SDT failure detection timer so as to accomadate subsequent transmissions after the successful initial transmission of the SDT procedure.

However, when the SDT failure detection timer is configured with the high value and the initial transmission of the SDT procedure does not succeed before the SDT failure detection timer expires, the terminal device 110 may perform the RA procedure or retransmissions of the initial transmission for a long time (e.g., 5 or 10 seconds) .

In this case, the terminal device 110 may generate interference to the RACH due to continuous RA attempts with maximum transmission power for most of the time after power ramping. Moreover, the power consumption of the terminal device 110 may be increased.

In order to solve at least part of the above problems and other potential problems, solutions on small data transmission are proposed. According to embodiments of the present disclosure, a first device receives at least one configuration from a second device and the at least one configuration comprises a first timer and a second timer associated with a SDT procedure. The first timer is associated with a first duration of the SDT procedure, and the second timer is associated with a second duration of initial transmission of the SDT procedure. The first device further performs the SDT procedure based on the at least one configuration.

In this way, with the second timer associated with the initial transmission of the SDT procedure, the first device is enabled to perform the SDT procedure more efficiently. For example, when the second timer expires, the first devie can terminate the SDT procedure without waiting until the first timer expires or is stopped, thereby reducing the interference and power consumption.

Fig. 2 illustrates a schematic diagram of a communication system in which embodiments of the present disclosure can be implemented. In the communication environment 200, a plurality of communication devices, including a first device 210 and a second device 220, can communicate with each other.

In the example of Fig. 2, the first device 210 is illustrated as a terminal device while the second device 220 is illustrated as a network device serving the terminal device. The serving area of the second device 220 may be called a cell 202.

It is to be understood that the number of devices and their connections shown in Fig. 2 are only for the purpose of illustration without suggesting any limitation. The environment 200 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 200. It is noted that although illustrated as a network device, the second device 220 may be other device than a network device. Although illustrated as a terminal device, the first device 210 may be other device than a terminal device.

In some example embodiments, if the first device 210 is a terminal device and the second device 220 is a network device, a link from the second device 220 to the first device 210 is referred to as a downlink (DL) , while a link from the first device 210 to the second device 220 is referred to as an uplink (UL) . In DL, the second device 220 is a transmitting (TX) device (or a transmitter) and the first device 210 is a receiving (RX) device (or a receiver) . In UL, the first device 210 is a TX device (or a transmitter) and the second device 220 is a RX device (or a receiver) .

Communications in the communication system 200 may be implemented according to any proper communication protocol (s) , comprising, 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, comprising but not limited to: Code Divided Multiple Address (CDMA) , Frequency Divided Multiple Address (FDMA) , Time Divided Multiple Address (TDMA) , Frequency Divided Duplexer (FDD) , Time Divided Duplexer (TDD) , Multiple-Input Multiple-Output (MIMO) , Orthogonal Frequency Divided Multiple Access (OFDMA) and/or any other technologies currently known or to be developed in the future.

Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Reference is now made to Fig. 3, which illustrates a signaling flow 300 according to example embodiments of the present disclosure. Only for the purpose of illustrations, the signaling flow 300 involves the first device 210 and the second device 220.

The second device 220 transmits 3005 at least one configuration to the first device 210. The at least one configuration comprises a first timer and a second timer associated with a SDT procedure. The first timer is associated with a first duration of the SDT procedure and the second timer is associated with a second duration of initial transmission of the SDT procedure.

The term “initial transmission” used herein can refer to one or more transmissions to the second device 220 and the first receipt of a response from the second device 220. For example, the first device 210 may perform the initial transmission comprising transmitting UL small data via Msg 3/MsgA and receiving DL small data via Msg 4/MsgB. After receiving the Msg 4/Msg B, the first device 210 may stay in the SDT procedure and continues the subsequent transmission.

In some embodiments, the initial transmission may comprise the RA procedure duiring the RA-SDT procedure. Alternatively or in addition, the initial transmission may comprise an initial CG transmission during the CG-SDT procedure.

In some embodiments, the first timer associated with the first duration of the SDT procedure may be the SDT failure detection timer as discussed above. The first duration may be the time period for the entire SDT procedure comprising the initial transmission and the subsequent transmission (s) . Alternatively, the first duration may be the time period only for the subsequent transmission (s) of the SDT procedure, as will be described below.

In some embodiments, the values for the first duration may be set as {ms100, ms200, ms300, ms400, ms600, ms1000, ms2000, ms3000, ms6000, ms10000, spare6, spare5, spare4, spare3, spare2, spare1} .

In some embodiments, the second timer may be a newly defined timer. The second timer may be comprised in the same configuration for the SDT procedure. Alternatively, the second timer may be an existing timer used for one of a RRC resume procedure, a RRC setup procedure, or a RRC reestablishment procedure.

For example, the second timer may be T319 as used in the RRC resume procedure, T300 as used in RRC setup procedure, or T301 as used in RRC re-establishment procedure. In this case, the second timer may be comprised in a different configuration than the configuration for the SDT procedure. For example, the second timer may be configured in a system information, SIB1. In other words, the first timer and the second timer may be comprised in the same configuration or different configurations of the at least one received configuration.

In some embodiments, the second timer may be configured over system information, such as SIB1 or others. Alternatively, the second timer may be configured through dedicated RRC signaling. For example, the second timer may be configured through the RRC release message before the transition to the RRC inactive mode.

In some embodiments, the second timer may be configured to be operated in media access control (MAC) layer. Alternatively, the second timer may be configured to be operated in RRC layer.

In some embodiments, the second timer may be configured for both the RA-SDT procedure and the CG-SDT procedure. In this case, the second timer may be configured with a first value for the RA-SDT procedure and a second value different from the first value for the CG-SDT procedure.

Based on the at least one configuration comprsing the first timer and the second timer, the first device 210 performs the SDT procedure. The SDT procedure may comprise the RA-SDT procedure and/or the CG-SDT procedure.

In some embodiments, the CG-SDT procedure is prioritized compared to the RA-SDT procedure. The first device 210 may first perform several evaluations to check if the CG-SDT procedure is selectable and if the CG-SDT procedure is not selectable, the first device 210 may continue to determine whether a 2-step RA-SDT procedure or 4-step RA-SDT procedure could be selected instead.

In some embodiments, the first device 210 performs the SDT procedure by initiating 3010 the SDT procedure and starting 3015 the second timer upon the initiation of the SDT procedure.

In some embodiments, the initiation of the SDT procedure may comprise the initiation of the RA procedure during the RA-SDT procedure. In this case, the first device 210 may start 3015 the second timer upon the initiation of the RA procedure. Alternatively, in the RA-SDT procedure, the first device 210 may start 3015 the second timer upon transmission of the RRC resume request. For example, the transmission point for the RRC resume request may refer to the time point when RRC submits RRCResumeRequest message to lower layers for transmission or upon the MsgA/Msg3 has been transmitted.

Alternatively or in addition, the initiation of the SDT procedure may comprise the initiation of the initial CG transmission during the CG-SDT procedure. In this case, the first device 210 may start 3015 the second timer upon the initiation of the initial CG transmission.

In some embodiments, the first device 210 may start the second timer upon initiation of another RA procedure for requesting uplink resources during the CG-SDT procedure. For example, the first device 210 may need to perform a RA procedure during the CG-SDT procedure to request UL resources for some of the beams without a CG grant.

In some embodiments, the first device 210 may start the first timer at the same time as the second timer (not shown in Fig. 3) .

After the SDT procedure is initiated, the first device 210 performs 3020 attempts of the initial transmission of the SDT procedure. In the case of the RA-SDT procedure, the attempts may comprise RA attempts over the SDT RACH resources. Alternatively or in addition, in the case of the CG-SDT procedure, the attempts may comprise CG attempts over the CG-SDT resources.

Note that, when the first device 210 performs 3020 the RA attempts of the initial transmission during the RA-SDT procedure, the number of preamble transmissions may exceed the threshold preambleTransMax. In this case, the first device 210 may continue the RA attempts because the second timer can be used for terminating the RA procedure.

In some embodiments, the second device 220 may respond 3025 to the attempts. The second device 220 may respond 3025 to the first device 210 by transmitting a response comprising a RRC message. Examples of the RRC message may comprise a RRC Resume message, a RRC Release message, a RRC Setup message, or a RRC Reject message. Upon receipt of the response comprsing the RRC message, the first device 210 may stop 3030 the second timer.

Alternatively or in addition, in the case of the RA-SDT procedure, the second device 220 may respond 3025 to the first device 210 by transmitting an indication of the successful completion of the RA procedure as a response. For example, the indiction may comprise a contention resolution. For example, the indication for contention resolution may comprise a UE Contention Resolution Identity. For example, the UE Contention Resolution Identity may be a MAC CE and may be identified by MAC subheader with LCID (Logical Channel Identity) . For example, the UE Contention Resolution Identity contains the UL CCCH SDU and if the UL CCCH SDU is longer than 48 bits, this field contains the first 48 bits of the UL CCCH SDU. The UL CCCH SDU may be the message transmitted in MsgA/Msg3 by the first device 210 or the initial CG-SDT transmission. Hence, the UL CCCH SDU may comprise the RRC resume request message by the first device 210 and may comprise also SDT data. Hence, for example, when the first device 210 receives MAC PDU as a response from the second device 220 and the MAC PDU contains a UE Contention Resolution Identity MAC CE, the first device 210 may determine contention resolution successful. Alternatively or additionally, the first device 210 may determine the RA procedure as successful in this case.

Alternatively or in addition, the second device 220 may respond 3025 to the first device 210 by transmitting a response to indicate a success of the initial CG transmission during the CG-SDT procedure. The response may comprise a dynamic UL grant or a DL assignment.

Upon receipt of responses indicating the successful completion the RA procedure and/or the success of the initial CG transmission, the first device 210 may stop 3030 the second timer. In addtion, the first device 210 may start 3035 the first timer to control the time period for the subsequent transmission (s) . In this way, the first timer may be configured with the high value without much RACH interference and power consumption.

Alternatively or in addition, the first device 210 may stop 3030 the second timer when the first timer is stopped. As discussed above, the first timer may be stopped by the network signaling comprising the RRC messages.

Alternatively or in addition, the first device 210 may stop 3030 the second timer upon occurance of cell reselection. Alternatively, upon occurance of cell reselection, the second timer may be considered as being expired.

If the second device 220 does not respond 3025 to the first device 210 before the second timer expires, the first device 210 may initiate 3040 a failure for the SDT procedure when the second timer expires.

In some embodiments, the first device 210 may initiate 3040 the failure for the SDT procedure by terminating the SDT procedure. The first device 210 may further transition from the RRC inactive mode to the RRC idle mode or trigger a non-SDT RA procedure in the RRC inactive mode. For example, the first device 210 may initiate a RRC resume procedure or RRC setup procedure.

In this way, the RACH interference generated due to the continuous RA procedure and/or the power/resource comsumption of the retransmission of the initial CG transmission can be reduced. Thus the SDT procedure can be performed more efficiently.

Fig. 4 illustrates a flow chart of method 400 according to embodiments of the present disclosure. The method 400 can be implemented at any suitable devices. For example, the method may be implemented at the first device 210.

At block 410, the first device 210 receives at least one configuration from a second device, the at least one configuration comprising a first timer and a second timer associated with a SDT procedure, the first timer being associated with a first duration of the SDT procedure, the second timer being associated with a second duration of initial transmission of the SDT procedure.

In some embodiment, the SDT procedure may comprise at least one of a RA-SDT procedure and a CG-SDT procedure. The initial transmission may comprise at least one of a RA procedure duiring the RA-SDT procedure and an initial CG transmission during the CG-SDT procedure.

In some embodiment, the second timer is configured for at least one of the RACH-based SDT procedure and the CG-based SDT procedure.

In some embodiment, the second timer is configured for both the RA-SDT procedure and the CG-SDT procedure, and the second timer is configured with a first value for the RA-SDT procedure and a second value different from the first value for the CG-SDT procedure.

In some embodiment, the second timer is configured to be operated in media access control (MAC) layer or RRC layer.

In some embodiment, the second timer is configured over system information or through dedicated RRC signaling.

In some embodiment, the second timer is a newly defined timer or an existing timer used for one of a RRC resume procedure, a RRC setup procedure, or a RRC reestablishment procedure.

In some embodiment, the first timer and the second timer are comprised in a same configuration or different configurations of the at least one configuration.

At block 420, the first device 210 performs the SDT procedure based on the at least one configuration.

In some embodiment, the first device 210 may perform the SDT procedure based on the at least one configuration by initiating the SDT procedure and starting the second timer upon initiation of the SDT procedure.

In some embodiment, the first device 210 may start the second timer upon one of:initiation of the RA procedure; transmission of an Radio Resource Control (RRC) Resume Request; or initiation of the initial CG transmission.

In some embodiment, the first device 210 may perform the SDT procedure based on the at least one configuration by stoping the second timer upon one of: successful completion of the RA procedure; a success of the initial CG transmission; the first timer being stopped; receipt of a response from the second device, the response comprising a RRC Resume message, a RRC Release message, a RRC Setup message, or a RRC Reject message; or occurance of cell reselection.

In some embodiment, the first device 210 may perform the SDT procedure based on the at least one configuration by initiating a failure for the SDT procedure when the second timer expires.

In some embodiment, the first device 210 may initiate the failure for the SDT procedure by terminating the SDT procedure; and transitioning from a RRC inactive mode to a RRC idle mode or triggering a non-SDT RA procedure in the RRC inactive mode.

In some embodiment, the first device 210 may perform the SDT procedure based on the configuration by starting the first timer upon one of successful completion of the RA procedure; or a success of the initial CG transmission.

In some embodiment, the first device 210 may start the second timer upon initiation of another RA procedure for requesting uplink resources during the CG-based SDT procedure.

Fig. 5 is a simplified block diagram of a device 500 that is suitable for implementing embodiments of the present disclosure. The device 500 may be provided to implement the communication device, for example the first device 210, or the second device 220 as shown in Fig. 2. As shown, the device 500 includes one or more processors 510, one or more memories 520 coupled to the processor 510, and one or more communication modules 540 coupled to the processor 510.

The communication module 540 is for bidirectional communications. The communication module 540 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 510 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 500 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 520 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) 524, 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) 522 and other volatile memories that will not last in the power-down duration.

A computer program 530 includes computer executable instructions that are executed by the associated processor 510. The program 530 may be stored in the ROM 524. The processor 510 may perform any suitable actions and processing by loading the program 530 into the RAM 522.

The embodiments of the present disclosure may be implemented by means of the program 520 so that the device 500 may perform any process of the disclosure as discussed with reference to Figs. 3 and 4. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some example embodiments, the program 530 may be tangibly contained in a computer readable medium which may be included in the device 500 (such as in the memory 520) or other storage devices that are accessible by the device 500. The device 500 may load the program 530 from the computer readable medium to the RAM 522 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. 6 shows an example of the computer readable medium 600 in form of CD or DVD. The computer readable medium has the program 530 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 methods as described above with reference to Figs. 3-4. 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 codes;

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

receive at least one configuration from a second device, the at least one configuration comprising a first timer and a second timer associated with a small data transmission (SDT) procedure, the first timer being associated with a first duration of the SDT procedure, the second timer being associated with a second duration of initial transmission of the SDT procedure; and

perform the SDT procedure based on the at least one configuration.
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 SDT procedure based on the at least one configuration by:

initiating the SDT procedure; and

starting the second timer upon initiation of the SDT procedure.
The first device of claim 2, wherein the SDT procedure comprises at least one of a random access channel (RACH) -based SDT and a configured grant (CG) -based SDT procedure, and wherein the initial transmission comprises at least one of a random access (RA) procedure duiring the RACH-based SDT procedure and an initial CG transmission during the CG-based SDT procedure.
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 start the second timer upon one of:

initiation of the RA procedure;

transmission of a Radio Resource Control (RRC) Resume Request; or

initiation of the initial CG transmission.
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 perform the SDT procedure based on the at least one configuration by stoping the second timer upon one of:

successful completion of the RA procedure;

a success of the initial CG transmission;

the first timer being stopped;

receipt of a response from the second device, the response comprising a RRC Resume message, a RRC Release message, a RRC Setup message, or a RRC Reject message; or

occurance of cell reselection.
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 perform the SDT procedure based on the at least one configuration by:

initiating a failure for the SDT procedure when the second timer expires.
The first device of claim 6, 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 initiate the failure for the SDT procedure by:

terminating the SDT procedure; and

transitioning from a RRC inactive mode to a RRC idle mode or triggering a non-SDT RA procedure in the RRC inactive mode.
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 perform the SDT procedure based on the configuration by starting the first timer upon one of:

successful completion of the RA procedure; or

a success of the initial CG transmission.
The first device of claim 3, wherein the second timer is configured for at least one of the RACH-based SDT procedure and the CG-based SDT procedure.
The first device of claim 9, wherein the second timer is configured for both the RACH-based SDT procedure and the CG-based SDT procedure, and wherein the second timer is configured with a first value for the RACH-based SDT procedure and a second value different from the first value for the CG-based SDT procedure.
The first device of claim 1, wherein the second timer is configured to be operated in media access control (MAC) layer or RRC layer.
The first device of claim 1, wherein the second timer is configured over system information or through dedicated RRC signaling.
The first device of claim 1, wherein the second timer is a newly defined timer or an existing timer used for one of a RRC resume procedure, a RRC setup procedure, or a RRC reestablishment procedure.
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, further cause the first device to:

start the second timer upon initiation of another RA procedure for requesting uplink resources during the CG-based SDT procedure.
The first device of claim 1, wherein the first timer and the second timer are comprised in a same configuration or different configurations of the at least one configuration.
A second device comprising:

at least one processor; and

at least one memory including computer program codes;

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

transmit, at the second device, at least one configuration to a first device, the at least one configuration comprising a first timer and a second timer associated with a small data transmission (SDT) procedure, the first timer being associated with a first duration of the SDT procedure, the second timer being associated with a second duration of initial transmission of the SDT procedure, and

wherein the at least one configuration is used for performing the SDT procedure by the first device.
A method, comprising:

receiving, at a first device, at least one configuration from a second device, the at least one configuration comprising a first timer and a second timer associated with a small data transmission (SDT) procedure, the first timer being associated with a first duration of the SDT procedure, the second timer being associated with a second duration of initial transmission of the SDT procedure; and

performing the SDT procedure based on the at least one configuration.
The method of claim 17, wherein performing the SDT procedure based on the at least one configuration comprises:

initiating the SDT procedure; and

starting the second timer upon initiation of the SDT procedure.
The method of claim 18, wherein the SDT procedure comprises at least one of a random access channel (RACH) -based SDT and a configured grant (CG) -based SDT procedure, and wherein the initial transmission comprises at least one of a random access (RA) procedure duiring the RACH-based SDT procedure and an initial CG transmission during the CG-based SDT procedure.
The method of claim 19, wherein starting the second timer comprises starting the second timer upon one of:

initiation of the RA procedure;

transmission of a Radio Resource Control (RRC) Resume Request; or

initiation of the initial CG transmission.
The method of claim 19, wherein performing the SDT procedure based on the at least one configuration comprises stoping the second timer upon one of:

successful completion of the RA procedure;

a success of the initial CG transmission;

the first timer being stopped;

receipt of a response from the second device, the response comprising a RRC Resume message, a RRC Release message, a RRC Setup message, or a RRC Reject message; or

occurance of cell reselection.
The method of claim 19, wherein performing the SDT procedure based on the at least one configuration comprises:

initiating a failure for the SDT procedure when the second timer expires.
The method of claim 22, wherein initiating the failure for the SDT procedure comprises:

terminating the SDT procedure; and

transitioning from a RRC inactive mode to a RRC idle mode or triggering a non-SDT RA procedure in the RRC inactive mode.
The method of claim 19, wherein performing the SDT procedure based on the configuration comprises starting the first timer upon one of:

successful completion of the RA procedure; or

a success of the initial CG transmission.
The method of claim 19, wherein the second timer is configured for at least one of the RACH-based SDT procedure and the CG-based SDT procedure.
The method of claim 25, wherein the second timer is configured for both the RACH-based SDT procedure and the CG-based SDT procedure, and wherein the second timer is configured with a first value for the RACH-based SDT procedure and a second value different from the first value for the CG-based SDT procedure.
The method of claim 17, wherein the second timer is configured to be operated in media access control (MAC) layer or RRC layer.
The method of claim 17, wherein the second timer is configured over system information or through dedicated RRC signaling.
The method of claim 17, wherein the second timer is a newly defined timer or an existing timer used for one of a RRC resume procedure, a RRC setup procedure, or a RRC reestablishment procedure.
The method of claim 19, further comprising:

starting the second timer upon initiation of another RA procedure for requesting uplink resources during the CG-based SDT procedure.
The method of claim 17, wherein the first timer and the second timer are comprised in a same configuration or different configurations of the at least one configuration.
A method, comprising:

transmiting, at a second device, at least one configuration to a first device, the at least one configuration comprising a first timer and a second timer associated with a small data transmission (SDT) procedure, the first timer being associated with a first duration of the SDT procedure, the second timer being associated with a second duration of initial transmission of the SDT procedure, and

wherein the at least one configuration is used for performing the SDT procedure by the first device.
A computer readable storage medium comprising program instructions stored thereon, the instructions, when executed by an apparatus, causing the apparatus to perform the method of any one of claims 17-31 or claim 32.
An apparatus comprising means for performing a process according to any one of claims 17-31 or claim 32.