US Patent No. 9,872,208

DATA FORWARDING METHOD AND DEVICE


Patent No. 9,872,208
Issue Date January 16, 2018
Title Data Forwarding Method And Device
Inventorship Yi Yang, Beijing (CN)
Dajun Zhang, Beijing (CN)
Wei Bao, Beijing (CN)
Assignee CHINA ACADEMY OF TELECOMMUNICATIONS TECHNOLOGY, Beijing (CN)

Claim of US Patent No. 9,872,208

1. A method for forwarding data, wherein the method comprises:
obtaining, by a source macro base station, sequence number transmission status information of uplink and downlink Packet Data
Convergence Protocol (PDCP) data packets of a source local base station currently accessed by a User Equipment (UE), wherein
a control plane of the UE is only connected with the source macro base station, a user plane of the UE is connected with the
source local base station, and all or a part of bearers of the user plane of the UE are separated from all bearers of the
control plane of the UE; and

transmitting, by the source macro base station, the sequence number transmission status information to a target base station
to which a handover of the UE is to be effectuated from the source macro base station to enable the target base station to
set up a user plane connection with the UE according to the sequence number transmission status information such that the
UE is connected with the target base station through at least one of the bearers of the user plane and is connected with the
source local base station after the handover and such that the control plane of the UE is only connected with the target base
station after the handover, the target base station is a macro base station providing underlying coverage in another layered
network adjacent to the source macro base station, or a base station in another non-layered network;

wherein obtaining, by the source macro base station, the sequence number transmission status information of uplink and downlink
PDCP data packets of the source local base station currently accessed by the UE comprises:

obtaining, by the source macro base station, the sequence number transmission status information according to a sequence number
status report transmitted by the source local base station;

or
obtaining, by the source macro base station, the sequence number transmission status information from the PDCP data packets,
for which no acknowledgement indicator of successful transmission is available from the source local base station, among PDCP
data packets locally stored in the macro source base station.