US 11,968,573 B2
Handover method and device in mobile communication system
Kisuk Kweon, Suwon-si (KR); Haneul Ko, Suwon-si (KR); Sangheon Pack, Suwon-si (KR); Jaewook Lee, Suwon-si (KR); Joonwoo Kim, Suwon-si (KR); and Yujin Tae, Suwon-si (KR)
Assigned to Samsung Electronics Co., Ltd., Suwon-si (KR); and Korea University Research And Business Foundation, Seoul (KR)
Appl. No. 17/250,640
Filed by Samsung Electronics Co., Ltd., Suwon-si (KR); and Korea University Research And Business Foundation, Seoul (KR)
PCT Filed Aug. 13, 2019, PCT No. PCT/KR2019/010328
§ 371(c)(1), (2) Date Feb. 15, 2021,
PCT Pub. No. WO2020/036424, PCT Pub. Date Feb. 20, 2020.
Claims priority of application No. 10-2018-0094628 (KR), filed on Aug. 13, 2018.
Prior Publication US 2021/0168681 A1, Jun. 3, 2021
Int. Cl. H04W 36/00 (2009.01); H04L 1/08 (2006.01); H04W 36/02 (2009.01); H04W 36/08 (2009.01)
CPC H04W 36/00837 (2018.08) [H04L 1/08 (2013.01); H04W 36/02 (2013.01); H04W 36/08 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A handover method performed by a source base station in a wireless communication system, the handover method comprising:
receiving, from an access and mobility management function (AMF), a general packet radio service (GPRS) tunneling protocol user plane (GTP-U) sequence number indicating a start of packet duplication transmission of a user plane function (UPF);
receiving, from the UPF, at least one packet being transmitted duplicately and assigned the GTP-U sequence number;
distinguishing the received at least one packet and at least one redundant packet based on the GTP-U sequence number;
transmitting, to a target base station, the at least one redundant packet; and
transmitting, to the target base station, an end-mark indicating that transmission of the redundant packet is completed after transmitting all of the at least one redundant packet to the target base station, or along with a last redundant packet;
wherein the packet duplication transmission includes transmitting, to the target base station, a packet that is identical to a packet transmitted by the UPF;
wherein the at least one redundant packet is received from the UPF before the start of the packet duplication transmission but is not transmitted to a User Equipment (UE) and stored.