Handover control apparatus, relay router, gateway apparatus, access router base station, mobile communication system, and handover control method

A relay router for transmission and reception of data between a plurality of base stations or a plurality of access routers, and gateway apparatus, said relay router comprising:

• counting means for counting the number of relay routers for every candidate access router for a destination of a radio terminal unit, from the gateway apparatus;
• and
• determining means for determining a COR on the basis of the number of relay routers for every access router, counted by the counting means.

A gateway apparatus connected to access routers, the gateway apparatus comprising:

• counting means for counting the number of relay routers for every candidate access router for a destination of a radio terminal unit, from the gateway apparatus;
• and
• determining means for determining a COR on the basis of the number of relay routers for every access router counted by the counting means.

A handover control method of controlling handover of a radio terminal unit between access routers provided in respective base stations for radio communication with the radio terminal unit, the handover control method comprising:

• a counting step wherein a handover control apparatus counts the number of relay routers for every candidate access router for a destination of the radio terminal unit, from gateway apparatus;
• and
• a determining step wherein the handover control apparatus determines a COR on the basis of the number of relay routers for every access router counted in the counting step.

A handover control apparatus comprising gateway apparatus, relay routers, and base stations having access router apparatus, and adapted to control handover of a radio terminal unit between access routers provided in respective base stations for radio communication with the radio terminal unit, the handover control apparatus comprising:

• counting means for counting the number of relay routers for every candidate access router for a destination of the radio terminal unit, from a relay router;
• and
• determining means for determining a COR on the basis of the number of relay routers for every access router counted by the counting means.

A relay router for transmission and reception of data between a plurality of base stations or a plurality of access routers, and gateway apparatus, said relay router comprising:

• counting means for counting the number of relay routers for every candidate access router for a destination of a radio terminal unit, from the relay router;
• and
• determining means for determining a COR on the basis of the number of relay routers for every access router, counted by the counting means.

A gateway apparatus connected to access routers, the gateway apparatus comprising:

• counting means for counting the number of relay routers for every candidate access router for a destination of a radio terminal unit, from the gateway apparatus;
• and
• determining means for determining a COR on the basis of the number of relay routers for every access router counted by the counting means.

A handover control method of controlling handover of a radio terminal unit between access routers provided in respective base stations for radio communication with the radio terminal unit, the handover control method comprising:

• a counting step wherein a handover control apparatus counts the number of relay routers for every candidate access router for a destination of the radio terminal unit, from a relay router;
• and
• a determining step of determining a COR on the basis of the number of relay routers for every access router counted in the counting step.

A handover control apparatus comprising gateway apparatus, relay routers, and base stations having access router apparatus, and adapted to control handover of a radio terminal unit between access routers provided in respective base stations for radio communication with the radio terminal unit, the handover control apparatus comprising:

• counting means for counting the number of relay routers for every candidate access router for a destination of the radio terminal unit, from a relay router;
• and
• determining means for determining as a COR a relay router with which a sum of the numbers of relay routers for every candidate access router for the destination of the radio terminal unit, counted by the counting means, is minimum, out of candidate relay routers for the COR.

An access router provided in a base station for detecting handover of a radio terminal unit, and connected to relay routers, the access router comprising:

• receiving means for receiving the number of relay routers for every candidate access router for a destination of the radio terminal unit, counted from a relay router, from the relay router;
• and
• determining means for determining as a COR a relay router with which a sum of the numbers of relay routers for every candidate access router for the destination of the radio terminal unit, received by the receiving means, is minimum, out of candidate relay routers for the COR.

A relay router for transmission and reception of data between a plurality of base stations or a plurality of access routers, and gateway apparatus, the relay router comprising:

• transmitting means for transmitting the number of relay routers for every candidate access router for a destination of a radio terminal unit, counted from the relay router, to an old access router before handover.

A gateway apparatus connected to access routers, the gateway apparatus comprising:

• transmitting means for transmitting the number of relay routers for every candidate access router for a destination of a radio terminal unit, counted from the gateway apparatus, to an old access router before handover.

A handover control method of controlling handover of a radio terminal unit between access routers provided in respective base stations for radio communication with the radio terminal unit, the handover control method comprising:

• a counting step wherein a handover control apparatus counts the number of relay routers for every candidate access router for a destination of the radio terminal unit, from a relay router;
• and
• a determining step of determining as a COR a relay router with which a sum of the numbers of relay routers for every candidate access router for the destination of the radio terminal unit, counted in the counting step, is minimum, out of candidate relay routers for the COR.