US Patent 10492120 User apparatus and base station

A user apparatus that is used in a mobile communication system that supports D2D communication, and that includes a capability for becoming a relay apparatus for relaying data communication between a remote user apparatus and a base station, including: a transmission unit configured to transmit a measurement resource that is used for the remote user apparatus to select a relay apparatus from among candidates of relay apparatuses, and a layer 2 address of the user apparatus; and a response unit configured to receive, from the remote user apparatus, an assignment request of an address for data communication by the relay, and to transmit information of the address to the remote user apparatus.