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EP-4395413-B1 - SMALL DATA TRANSMISSION

EP4395413B1EP 4395413 B1EP4395413 B1EP 4395413B1EP-4395413-B1

Inventors

  • KIM, TAEHUN
  • PARK, KYUNGMIN
  • DINAN, ESMAEL
  • RYU, Jinsook
  • TALEBI FARD, Peyman

Dates

Publication Date
20260506
Application Date
20210212

Claims (15)

  1. A method comprising: sending, from a second base station (104) to a first base station, a request for a context of a wireless device (106), wherein the request comprises assistance information for a small data transmission, SDT, procedure of the wireless device in a radio resource control, RRC, inactive state, the assistance information indicating whether: no further data associated with the SDT procedure is expected; or further data associated with the SDT procedure is expected; and sending, by the second base station to the wireless device in the RRC inactive state, downlink data associated with the SDT procedure received from the first base station.
  2. The method of claim 1, wherein the first base station sends, to a wireless device (106), a first radio resource control, RRC, message indicating a suspension of an RRC connection of the wireless device.
  3. The method of claim 2, wherein the first RRC message comprises at least one of: a resume wireless device identity of the wireless device; a next hop chaining count; radio access network, RAN, notification area information; and period RAN-based notification area update timer value.
  4. The method of any of claims 1 to 3, wherein the first base station determines, based on the assistance information, whether to keep the context of the wireless device.
  5. The method of any of claims 1 to 4, further comprising receiving, by the second base station from the first base station and based on determining to keep the context of the wireless device, a second RRC message indicating a release or a suspension of an RRC connection.
  6. The method of any of claims 1 to 5, further comprising receiving, by the second base station from the first base station and based on determining to not keep the context of the wireless device, the context of the wireless device.
  7. The method of any of claims 4 to 6, wherein: the first base station determines to keep the context of the wireless device based on no further uplink or downlink data transmission being expected; and the first base station determines to not keep the context of the wireless device based on more than a single uplink or single downlink data transmission being expected.
  8. The method of any of claims 1 to 7, wherein the assistance information comprises a data radio bearer identity associated with the SDT procedure.
  9. The method of claim 8, wherein: the first base station determines to keep the context of the wireless device based on a data radio bearer associated with the data radio bearer identity being configured for small data transmission; and the first base station determines to not keep the context of the wireless device based on the data radio bearer associated with the data radio bearer identity being not configured for small data transmission.
  10. The method of any of claims 1 to 9, wherein the assistance information comprises application information associated with the SDT procedure.
  11. The method of claim 10, wherein: the first base station determines to keep the context of the wireless device based on an application associated with the application information being configured for small data transmission; and the first base station determines to provide the context of the wireless device based on the application associated with the application information being not configured for small data transmission.
  12. The method of any of claims 1 to 11, wherein the assistance information comprises an amount of expected data.
  13. The method of claim 12, wherein: the first base station determines to keep the context of the wireless device based on the amount of expected data being below a threshold; and the first base station determines to not keep the context of the wireless device based on the amount of expected data being above the threshold.
  14. A second base station (104) comprising one or more processors and memory storing instructions that, when executed by the one or more processors, cause the second base station to perform the method of any of claims 1 to 13.
  15. A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors of a second base station, cause the second base station to perform the method of any of claims 1 to 13.

Description

BACKGROUND With regards to the relevant prior art, reference is made to the patent publication WO2018/142207 A1. Further reference is made to the 3GPP Technical Specification TS 38.300, RAN WG2 V16.0.0, Jan. 8, 2020 and the 3GPP Technical Report TR 23.724, SA WG2. V16.1.0, June 11, 2019, as well as to the publications Huawei, HiSilicon, "Small data transmission with RA-based schemes", in: 3GPP draft R2-2101214, 3GPP TSG-RAN WG2 #113-e, E-meeting, Jan. 25-Feb 5, 2021; Huawei, HiSilicon, "SDT aspects common for RACH-based and CG-based SDT scheme", in: 3GPP draft R2-2009930, 3GPP TSG-RAN WG2 #112-e, Online, Nov. 2-13, 202; and LG Electronics Inc., "Consideration on small data transmission with and without anchor relocation", in: 3GPP draft R3-210880, 3GPP TSG-RAN WG3 #111-e, Jan. 24-Feb.4, 2021. SUMMARY In accordance with the present invention, there is provided a method as defined in claims 1 to 13 of the accompanying claims. In accordance with the present invention, there is provided a second base station as defined in claim 14 of the accompanying claims. In accordance with the present invention, there is provided a non-transitory computer-readable medium as defined in claim 15 of the accompanying claims. BRIEF DESCRIPTION OF THE DRAWINGS Examples of several of the various embodiments of the present disclosure are described herein with reference to the drawings. FIG. 1A and FIG. 1B illustrate example mobile communication networks in which embodiments of the present disclosure may be implemented.FIG. 2A and FIG. 2B respectively illustrate a New Radio (NR) user plane and control plane protocol stack.FIG. 3 illustrates an example of services provided between protocol layers of the NR user plane protocol stack of FIG. 2A.FIG. 4A illustrates an example downlink data flow through the NR user plane protocol stack of FIG. 2A.FIG. 4B illustrates an example format of a MAC subheader in a MAC PDU.FIG. 5A and FIG. 5B respectively illustrate a mapping between logical channels, transport channels, and physical channels for the downlink and uplink.FIG. 6 is an example diagram showing RRC state transitions of a UE.FIG. 7 illustrates an example configuration of an NR frame into which OFDM symbols are grouped.FIG. 8 illustrates an example configuration of a slot in the time and frequency domain for an NR carrier.FIG. 9 illustrates an example of bandwidth adaptation using three configured BWPs for an NR carrier.FIG. 10A illustrates three carrier aggregation configurations with two component carriers.FIG. 10B illustrates an example of how aggregated cells may be configured into one or more PUCCH groups.FIG. 11A illustrates an example of an SS/PBCH block structure and location.FIG. 11B illustrates an example of CSI-RSs that are mapped in the time and frequency domains.FIG. 12A and FIG. 12B respectively illustrate examples of three downlink and uplink beam management procedures.FIG. 13A, FIG. 13B, and FIG. 13C respectively illustrate a four-step contention-based random access procedure, a two-step contention-free random access procedure, and another two-step random access procedure.FIG. 14A illustrates an example of CORESET configurations for a bandwidth part.FIG. 14B illustrates an example of a CCE-to-REG mapping for DCI transmission on a CORESET and PDCCH processing.FIG. 15 illustrates an example of a wireless device in communication with a base station.FIG. 16A, FIG. 16B, FIG. 16C, and FIG. 16D illustrate example structures for uplink and downlink transmission.FIG. 17 illustrates an example of an RRC connection reestablishment procedure.FIG. 18 illustrates an example of an RRC connection resume procedure.FIG. 19 illustrates an example of an RRC connection resume procedure with anchor relocation.FIG. 20 illustrates an example of an RRC connection resume procedure without anchor relocation.FIG. 21 illustrates an example of a control plane early data transmission procedure.FIG. 22 illustrates an example of a user plane early data transmission procedure with anchor relocation.FIG. 23 illustrates an example of optimal path for data transmission in mobility of a wireless device.FIG. 24 illustrates an example of diagram showing an enhanced procedure for an anchor relocation determination in RRC inactive state.FIG. 25 illustrates an enhanced procedure for mobile originated data transmission without anchor relocation in RRC inactive state.FIG. 26 illustrates an example of an enhanced procedure for mobile terminated data transmission without anchor relocation in RRC inactive state.FIG. 27 illustrates an example of diagram showing an enhanced procedure for an anchor relocation determination in RRC idle state.FIG. 28 illustrates an example of an enhanced procedure for mobile originated data transmission without anchor relocation in RRC idle state.FIG. 29 illustrates an example of an enhanced procedure for mobile originated data transmission with anchor relocation in RRC idle state.FIG. 30 illustrates an example of an enhanced procedure wi