US 12,279,173 B2
Terminal apparatus, base station apparatus, and method
Takako Hori, Sakai (JP); Shohei Yamada, Sakai (JP); and Hidekazu Tsuboi, Sakai (JP)
Assigned to Sharp Kabushiki Kaisha, Sakai (JP)
Appl. No. 17/776,430
Filed by Sharp Kabushiki Kaisha, Osaka (JP)
PCT Filed Nov. 12, 2020, PCT No. PCT/JP2020/042347
§ 371(c)(1), (2) Date May 12, 2022,
PCT Pub. No. WO2021/095825, PCT Pub. Date May 20, 2021.
Claims priority of application No. 2019-205414 (JP), filed on Nov. 13, 2019.
Prior Publication US 2023/0030653 A1, Feb. 2, 2023
Int. Cl. H04W 36/00 (2009.01); H04W 36/30 (2009.01); H04W 76/27 (2018.01)
CPC H04W 36/305 (2018.08) [H04W 36/0079 (2018.08); H04W 76/27 (2018.02)] 3 Claims
OG exemplary drawing
 
1. A terminal apparatus for communicating with a base station apparatus, the terminal apparatus comprising:
a receiver configured to receive, from the base station apparatus, a Radio Resource Control (RRC) reconfiguration message including a parameter indicating a handover; and
a processor, wherein
the processor is configured to, in a case that a first timer expires, that no radio link failure is detected in a source primary cell, and that Dual Active Protocol Stack (DAPS) configuration is configured on any radio bearer,
reset Medium Access Control (MAC) for a target primary cell,
discard all data of a Packet Data Convergence Protocol (PDCP) entity for a Signaling Radio Bearer (SRB) of the source primary cell,
discard all data of a Radio Link Control (RLC) entity for the SRB of the source primary cell,
resume the SRB in the source primary cell, and
transmit, to the base station apparatus, an RRC message to report a DAPS handover failure, and
the first timer starts in a case that the terminal apparatus receives, from the base station apparatus, the RRC reconfiguration message including the parameter indicating the handover, and stops in a case that random access to a Special Cell (SpCell) is successfully completed.