Abstract: A relay station relays communications between a plurality of home base stations and a switching station via communication interfaces. The relay station sets up a switching station side communication interface for each base station group. The switching station side communication interface is a part of a communication interface used by each home base station belonging to the base station group to communicate with the switching station, where the part is between the relay station and the switching station. The base station group includes the home base stations identified by home base station identifiers, each of which has a first data length, having a common upper segment. The upper segment has a second data length shorter than the first data length and being located sequentially from an uppermost position. The second data length is the same as a data length of a macro base station identifier.

Abstract: A relay station relays communications between a plurality of home base stations and a switching station via communication interfaces. The relay station sets up a switching station side communication interface for each base station group. The switching station side communication interface is a part of a communication interface used by each home base station belonging to the base station group to communicate with the switching station, where the part is between the relay station and the switching station. The base station group includes the home base stations identified by home base station identifiers, each of which has a first data length, having a common upper segment. The upper segment has a second data length shorter than the first data length and being located sequentially from an uppermost position. The second data length is the same as a data length of a macro base station identifier.

Abstract: A radio communication system including: a radio terminal, a first radio base station configured to establish a first connection with the radio terminal, and to store connection information of the first connection to a memory when the radio terminal transits to a dormant state, and the second radio base station configured to obtain the connection information from the first radio base station when the radio terminal returns from the dormant state under the second radio base station, and to establish a second connection with the radio terminal based on the connection information.

Abstract: A radio communications system includes a mobile station, a third generation base station that communicates with the mobile station using a 3G system, and a long time evolution (LTE) base station that communicates with the mobile station using an LTE system. The mobile station includes a communication controller and a 3G communication module. The communication controller determines feasibility of communication with the LTE base station using the LTE system. The 3G communication module notifies the 3G base station that the communication with the LTE base station is not feasible at the time of transmitting a communication request to the 3G base station when the communication controller determines that the communication is not feasible. The 3G base station communicates with the mobile station using the 3G system in response to the communication request without requesting the mobile station to communicate with the LTE base station.