US-12628238-B2 - Small data transmission procedure termination

US12628238B2US 12628238 B2US12628238 B2US 12628238B2US-12628238-B2

Abstract

Devices, methods and computer programs for small data transmission, SDT, transaction termination are disclosed. A client device determines whether an ongoing small data transmission, SDT, transaction comprising one or more uplink, UL, small data transmissions with a control plane network node device is to be terminated. If yes, a radio resource control, RRC, message comprising termination information related to the determined termination of the ongoing SDT transaction is forwarded from the client device to the control plane network node device.

Inventors

Philippe Godin
Daniela Laselva
Subramanya CHANDRASHEKAR

Assignees

NOKIA TECHNOLOGIES OY

Dates

Publication Date: 20260512
Application Date: 20211202
Priority Date: 20201216

Claims (3)

1 . A client device, comprising: at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the client device to at least perform: determining whether an ongoing small data transmission (SDT) transaction comprising one or more uplink (UL) small data transmissions with a control plane network node device is to be terminated, wherein the determining is based on: buffer status information of an uplink buffer of the client device, information related to applications running on the client device, historical information related to the SDT, a power saving objective of the client device, and a latency objective for the one or more UL small data transmissions; in response to determining that the ongoing SDT transaction is to be terminated: transmitting, to the control plane network node device, a radio resource control (RRC) message for terminating the ongoing SDT transaction, wherein the RRC message is a UEAssistanceInformation message that includes termination information indicating a preference to terminate the SDT transaction, wherein the transmitting comprises one of: transmitting the RRC message with a last UL SDT of the ongoing SDT transaction; or transmitting the RRC message independently as a UL SDT that excludes any user data payload; receiving, from the control plane network node device, an RRC release message in response to the transmitted RRC message; and initiating, based on the RRC release message, a transition of the client device to an RRC_INACTIVE state; and in response to determining that the ongoing SDT transaction is not to be terminated, transmitting, to the control plane network node device, a subsequent UL SDT without including the RRC message.
2 . The client device according to claim 1 , wherein the termination information comprises one of an SDT termination preference and an SDT termination indication.
3 . A control plane network node device, comprising: at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the control plane network node device to at least perform: receiving, from a client device; a radio resource control (RRC) message included within an uplink (UL) small data transmission (SDT), the RRC message comprising termination information indicating a preference of the client device to terminate an ongoing multi-shot SDT transaction, wherein the RRC message is a UEAssistanceInformation message; in response to receiving, from the client device, the RRC message, initiating a termination procedure to terminate the ongoing SDT transaction, and wherein the termination procedure comprises one of: transmitting, to a network node device distributed unit associated with the control plane network node device, an RRC release message comprising suspend information within a CU-DU interface message that indicates a UE context release command or a termination of the ongoing SDT transaction; or triggering a last serving control plane network node device to generate and transmit the RRC release message to the client device upon the termination of the ongoing SDT transaction, wherein the triggering of the last serving control plane network node device comprises one of: transmitting to the last serving control plane network node device an inter-CU-CP message including the RRC message received from the client device; or transmitting to the last serving control plane network node device an inter-CU-CP message including an indication of the termination of the ongoing SDT transaction; and in response to receiving, from the client device, the UL SDT that does not include the RRC message, continuing the ongoing SDT transaction by refraining from initiating the termination procedure.

Description

RELATED APPLICATION This application claims priority to PCT Application No. PCT/EP2021/083872, filed on Dec. 2, 2021, which claims priority from FI application No. 20206308, filed on Dec. 16, 2020, each of which is incorporated herein by reference in its entirety. TECHNICAL FIELD The disclosure relates generally to communications and, more particularly but not exclusively, to small data transmission procedure termination. BACKGROUND In cellular communication networks, a radio access network (RAN) architecture can nowadays be split into centralized baseband units and distributed radio units, allowing both performance and cost benefits. Fifth generation (5G) new radio (NR) wireless networks allow so called small data transmissions (SDTs) to convey packet data transmissions while a client device is in a radio resource control (RRC) inactive state. Furthermore, it is possible for a user equipment (UE) to send multiple uplink and/or downlink small data transmissions subsequent to a first uplink small data transmission without transitioning the UE to an RRC connected state, i.e. as part of a same SDT procedure or transaction. However, for a radio access network architecture split into centralized baseband units and distributed radio units, at least in some situations it may not be possible to terminate an ongoing SDT transaction comprising one or multiple small data transmissions. SUMMARY The scope of protection sought for various example embodiments of the invention is set out by the independent claims. The example embodiments and features, if any, described in this specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various example embodiments of the invention. An example embodiment of a client 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 client device to at least perform: determining whether an ongoing small data transmission, SDT, transaction comprising one or more uplink, UL, small data transmissions with a control plane network node device is to be terminated; andin response to determining that the ongoing SDT transaction is to be terminated, forwarding to the control plane network node device a radio resource control, RRC, message comprising termination information related to the determined termination of the ongoing SDT transaction. In an example embodiment, alternatively or in addition to the above-described example embodiments, the termination information comprises one of an SDT termination preference or an SDT termination indication. In an example embodiment, alternatively or in addition to the above-described example embodiments, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the client device to perform the sending of the RRC message by one of: sending the RRC message with the last UL small data transmission of the ongoing SDT transaction or sending the RRC message on its own. In an example embodiment, alternatively or in addition to the above-described example embodiments, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the client device to at least perform differentiating the RRC message sent to indicate the termination of the ongoing SDT transaction via a message type used for the RRC message or via inclusion of additional termination information in the RRC message. In an example embodiment, alternatively or in addition to the above-described example embodiments, the RRC message comprises a UEAssistanceInformation message. In an example embodiment, alternatively or in addition to the above-described example embodiments, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the client device to perform the determining of whether the ongoing SDT transaction is to be terminated based on at least one of: buffer status information, running applications information, or small data transmissions historical information. In an example embodiment, alternatively or in addition to the above-described example embodiments, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the client device to at least perform: receiving an RRC release message from the control plane network node device after sending the RRC message comprising the termination information; andinitiating a transition of the client device to an inactive state of RRC. An example embodiment of a client device comprises means for performing: determining whether an ongoing small data transmission, SDT, transaction comprising one or more uplink, UL, small data transmissions with a control plane network node device is to be terminated; a