CLAIMS
1. A mobile communication system comprising a movable user equipment device, a plurality of base station devices configured to perform radio comrnunicalion with said user equipment device, and a relay device movably configured to relay radio communications between said user equipment device and said base station devices,
wherein in a handover process of switching a base station device to be connected with said relay device from a base station device being a moving source to a base station device being a moving destination along with moving of said relay device, said base station device being a moving destination rejects a connection request from said relay device in a case where the own base station device does not have a function supporting said relay device.
2. The mobile communication system according to claim 1, wherein
said handover process is activated by said base station device being a moving source, and
when activating said handover process, said base station device being a moving source notifies said base station device being a moving destination that an object to be subjected to said handover process is the relay device.
3. A mobile communication system comprising a movable user equipment
device, a plurality of base station devices configured to perform radio communication
with said user equipment device, and a relay device movably configured to relay radio
communications between said user equipment device and said base station devices,
wherein in a handover process of switching a base station device to be connected with said relay device from a base station device being a moving source to a

base station device being a moving destination along with moving of said relay device, said base station device being a moving source selects said base station device being a moving destination from base station devices other than a base station device that does not have a function supporting said relay device, and performs said handover process such that said relay device is connected to the selected base station device.
4. The mobile communication system according to any one of claims 1 to 3, comprising a plurality of said relay devices,
wherein between said plurality of relay devices, different subframes are used for subframes of a communication frame for use in an access link from said user equipment device to said relay device and for subframes of a communication frame for use in a backhaul link from said relay device to said base station device.