Mobile wireless communication system and method of carrying out handover in the system

A method of carrying out handover in a mobile wireless communication system comprising:

• a network;
• a retrieval server connected in wireless communication to said network;
• a plurality of wireless stations connected in wireless communication to said network;
• and a mobile communication terminal device making communication, keeping a first wireless link comprising a pair of uplink and downlink with one of said wireless stations,
• said method comprising:
• a first step of, by said mobile communication terminal device, transmitting, when a strength of an electric field for receiving wireless signal in said downlink is equal to or smaller than a predetermined strength, a retrieval request to said retrieval server through a wireless station through which said mobile communication terminal device is making wireless communication, to cause said retrieval server to start selecting a new wireless station, changing at least one of profiles (UTP) for transmitting wireless signal in said uplink, and notifying said wireless station of the changed profile(s);
• a second step of, by said wireless station, changing a profile or profiles (URP) for receiving wireless signal in uplink, corresponding to the changed profile(s) (UTP) for transmitting wireless signal in said uplink, received from said mobile communication terminal device, changing at least one of profiles (DTP) for transmitting wireless signal in said downlink, and notifying said mobile communication terminal device of the changed profile(s) (DTP) for transmitting wireless signal in said downlink;
• a third step of, by said mobile communication terminal device, changing, until said mobile communication terminal device establishes a second wireless link with said new wireless station notified from said retrieval server, a profile or profiles (DRP) for receiving wireless signal in downlink, corresponding to the changed profile(s) (DTP) for transmitting wireless signal in said downlink, received from said wireless station, to maintain said first wireless link with said wireless station;
• and
• a fourth step of, by said mobile communication terminal device, establishing a second wireless link with said new wireless station notified from said retrieval server.

A wireless station to be used in a mobile wireless communication system comprising:

• a network;
• a retrieval server connected in wireless communication to said network;
• a plurality of wireless stations connected in wireless communication to said network;
• and a mobile communication terminal device making communication, keeping a first wireless link comprising a pair of uplink and downlink with one of said wireless stations,
• the wireless station comprising:
• a first unit that receives, from said mobile communication terminal device, at least one of profiles (UTP) for said mobile communication terminal device transmitting wireless signal in said uplink, the at least one of the profiles being changed by said mobile communication terminal device when a strength of an electric field for receiving wireless signal in said downlink is equal to or smaller than a predetermined strength, said mobile communication terminal device transmits a retrieval request to said retrieval server through a wireless station through which said mobile communication terminal device is making wireless communication, to cause said retrieval server to start selecting a new wireless station, changes at least one of profiles (UTP) for transmitting wireless signal in said uplink;
• and
• a second unit that changes a profile or profiles (URP) for receiving wireless signal in uplink, corresponding to the changed profile(s) (UTP) for transmitting wireless signal in said uplink, received from said mobile communication terminal device, changes at least one of profiles (DTP) for transmitting wireless signal in said downlink, and notifies said mobile communication terminal device of the changed profile(s) (DTP) for transmitting wireless signal in said downlink.

A mobile communication terminal device in a mobile wireless communication system comprising:

• a network;
• a retrieval server connected in wireless communication to said network;
• a plurality of wireless stations connected in wireless communication to said network;
• and said mobile communication terminal device,
• said mobile communication terminal device making communication, keeping a first wireless link comprising a pair of uplink and downlink with one of said wireless stations,
• said mobile communication terminal device comprising:
• a first unit that transmits, when a strength of an electric field for receiving wireless signal in said downlink is equal to or smaller than a predetermined strength, a retrieval request to said retrieval server through a wireless station through which said mobile communication terminal device is making wireless communication, to cause said retrieval server to start selecting a new wireless station, changes at least one of profiles (UTP) for transmitting wireless signal in said uplink, and notifies said wireless station of the changed profile(s);
• a second unit that receives, when said wireless station changes a profile or profiles (URP) for receiving wireless signal in uplink, corresponding to the changed profile(s) (UTP) for transmitting wireless signal in said uplink, received from said mobile communication terminal device, and changes at least one of profiles (DTP) for transmitting wireless signal in said downlink, the changed profile(s) (DTP) for transmitting wireless signal in said downlink;
• a third unit that changes, until said mobile communication terminal device establishes a second wireless link with said new wireless station notified from said retrieval server, a profile or profiles (DRP) for receiving wireless signal in downlink, corresponding to the changed profile(s) for transmitting wireless signal in said downlink, received from said wireless station, to maintain said first wireless link with said wireless station.

A non-transitory computer-readable storage medium storing therein a program for causing a computer mounted in a wireless station to carry out a method of carrying out handover in a mobile wireless communication system comprising:

• a network;
• a retrieval server connected in wireless communication to said network;
• a plurality of wireless stations connected in wireless communication to said network;
• and a mobile communication terminal device making communication, keeping a first wireless link comprising a pair of uplink and downlink with one of said wireless stations,
• wherein the program causes said computer to execute:
• a step of receiving, from said mobile communication terminal device, at least one of profiles (UTP) for said mobile communication terminal device transmitting wireless signal in said uplink, the at least one of profiles being changed by said mobile communication terminal device when a strength of an electric field for receiving wireless signal in said downlink is equal to or smaller than a predetermined strength, and said mobile communication terminal device transmits a retrieval request to said retrieval server through a wireless station through which said mobile communication terminal device is making wireless communication, to cause said retrieval server to start selecting a new wireless station;
• a step of changing a profile or profiles (URP) for receiving wireless signal in uplink, corresponding to the changed profile(s) (UTP) for transmitting wireless signal in said uplink, received from said mobile communication terminal device, changing at least one of profiles (DTP) for transmitting wireless signal in said downlink, and notifying said mobile communication terminal device of the changed profile(s) (DTP) for transmitting wireless signal in said downlink.

A non-transitory computer-readable storage medium storing therein a program for causing a computer mounted in a mobile communication terminal device to carry out a method of carrying out handover in a mobile wireless communication system comprising:

• a network;
• a retrieval server connected in wireless communication to said network;
• a plurality of wireless stations connected in wireless communication to said network;
• and a mobile communication terminal device making communication, keeping a first wireless link comprising a pair of uplink and downlink with one of said wireless stations,
• wherein the program causes said computer to execute:
• a first step of transmitting, when a strength of an electric field for receiving wireless signal in said downlink is equal to or smaller than a predetermined strength, a retrieval request to said retrieval server through a wireless station through which said mobile communication terminal device is making wireless communication, to cause said retrieval server to start selecting a new wireless station, changing at least one of profiles (UTP) for transmitting wireless signal in said uplink, and notifying said wireless station of the changed profile(s);
• a second step of receiving, when said wireless station changes a profile or profiles (URP) for receiving wireless signal in uplink, corresponding to the changed profile(s) (UTP) for transmitting wireless signal in said uplink, received from said mobile communication terminal device, and changes at least one of profiles (DTP) for transmitting wireless signal in said downlink the changed profile(s) (DTP) for transmitting wireless signal in said downlink;
• a third step of changing a profile or profiles (DRP) for receiving wireless signal in downlink, corresponding to the changed profile(s) (DTP) for transmitting wireless signal in said downlink, received from said wireless station, to maintain said first wireless link with said wireless station;
• and
• a fourth step of establishing a second wireless link with said new wireless station notified from said retrieval server.