CPC H04W 36/00837 (2018.08) [H04L 1/08 (2013.01); H04W 36/02 (2013.01); H04W 36/08 (2013.01)] | 12 Claims |
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.
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