US Patent No. 9,143,992

HANDOVER METHOD OF TERMINAL, AND BASE STATION THEREOF


Patent No. 9,143,992
Issue Date September 22, 2015
Title Handover Method Of Terminal, And Base Station Thereof
Inventorship Bin Li, Shenzhen (CN)
Na Liang, Shenzhen (CN)
Assignee ZTE CORPORATION, Shenzhen, Guangdong Province (CN)

Claim of US Patent No. 9,143,992

1. A handover method of a target base station, comprising:
a source base station to which a terminal belongs transmitting a handover request message to one or more alternate target
base stations;

each of the one or more alternate target base station calculating an parameter of load, and
when the parameter of load is larger than a threshold set by a system, returning a handover request response message including
the parameter of load to the source base station directly or to the source base station through a mobility management entity
to notify the source base station;

when the parameter of load is smaller than or equal to the threshold set by the system, returning the handover request response
message including the parameter of load and wireless resource configuration information required in terminal handover to the
source base station directly or to the source base station through the mobility management entity to notify the source base
station;

after transmitting the handover request message, the source base station starting a timer module,
after receiving the handover request response message in a timing period of the timer module, the step of determining the
target base station comprising: when parameters of load of the alternate target base stations are all larger than the threshold
set by the system, the source base station determining an alternate target base station corresponding to a minimal one of
the parameters of load of the alternate target base stations as the target base station,

the indicating step comprising: the source base station obtaining the wireless resource configuration information required
in the terminal handover from the target base station, and indicating the terminal to perform handover to the target base
station according to the wireless resource configuration information;

each of the one or more alternate target base stations notifying the source base station of the parameter of load respectively;
the source base station determining a target base station according to the parameter of load of the one or more alternate
target base stations and indicating the terminal to perform handover to the target base station;

wherein the parameter of load is one of following values: a value of a load quantity of an alternate target base station,
a percentage value of the load quantity to a fixed load quantity of an alternate target base station set by the system, and
a level of the load quantity of an alternate target base station; wherein the levels corresponding to the load quantity from
small to large are level 1, level 2, level 3 and level 4 in sequence, and the threshold set by the system is a level threshold
larger than level 2 and smaller than level 3.