Abstract: Communication quality of a terminal device which directly connects to a macro cell base station is guaranteed and communication quality of a terminal device which connects to the macro cell base station via a relay apparatus is guaranteed.

Abstract: A relay apparatus and relay method capable of enhancing communication quality in both transmission and reception when the relay apparatus relays communication between a terminal device and a macro cell base station are provided. A relay apparatus 20 for relaying communication between a terminal device 10 and a macro cell base station includes: an antenna group 25 constituted of a plurality of selectable antennas for receiving a signal from a macro cell base station; and an antenna selection unit 207 that selects a plurality of antennas from among the antenna group 25 to form a beam to transmit the signal to the macro cell base station on the basis of a reception status of the signal received from the macro cell station.

Abstract: Communication quality in both transmission and reception is enhanced when a relay apparatus that communicates with a plurality of base stations in a plurality of different frequency bands relays communication between a terminal device and a macro cell base station.

Abstract: Beamforming for radio communication (uplink) from a relay apparatus to a donor base station is performed accurately.

Abstract: A base station apparatus installed by a general user, wherein a cell ID can be easily set in cases when setting of a cell ID is necessary. In this apparatus, a DHCP message reception unit (105) receives a DHCPACK message from a DHCP server. An IP address extraction unit (107) extracts an IP address stored in the IP address field of the DHCPACK message. A cell ID determining unit (108) sets a unique cell ID for this base station apparatus based on the IP address extracted by the IP address extraction unit (107).

Abstract: A base station apparatus is provided, by which a downlink transmission power can be properly set and frequent handovers of a mobile station (user equipment) can be prevented to occur. The base station apparatus is installed in a base station communicating with a mobile station in a mobile communication network, and provided with control means of controlling so as to decrease a setting of downlink transmission power when changing a setting of offset for handover from the own cell to a neighboring cell so as to advance a hand-out from the own cell to the neighboring cell.

Abstract: Communication quality of a terminal device which directly connects to a macro cell base station is guaranteed and communication quality of a terminal device which connects to the macro cell base station via a relay apparatus is guaranteed.

Abstract: Beamforming for radio communication (uplink) from a relay apparatus to a donor base station is performed accurately.

Abstract: A base station apparatus and a communication system, witch are capable of optimizing a radio transmission path between a mobile station and a base station according to a communication speed of a backhaul link, are provided. The base station apparatus capable of communicating with a mobile station via a radio transmission path comprises information acquisition means of acquiring information on a communication speed of a backhaul link, and parameter adjustment means of adjusting communication parameters of the radio transmission path so that a communication speed of the radio transmission path becomes equal to or lower than the communication speed of the backhaul link, based on the information on communication speed of the backhaul link and a channel bandwidth of the radio transmission path.

Abstract: A relay apparatus is provided which is capable of properly executing beamforming for radio communication from the relay apparatus to a donor base station, while inhibiting occurrence of beam interference in its surrounding area as much as possible. A relay apparatus 20 includes: an amplitude and phase measurement unit 25 that measures an amplitude and phase of radio communication from a donor base station 30 to the relay apparatus 20; a beam adjuster 27 that performs beamforming by adjusting a combination of a plurality of antennas; and a base station judgment unit 29 that judges base stations; wherein the adjustment for the beamforming is made so that a relatively strong beam is directed towards the donor base station 30 and a relatively weak beam is directed towards base stations other than the donor base station 30.

Abstract: A base station apparatus of small-cell base station is provided, by which interference from a small-cell in downlink signals of macro cell can be suppressed without lowering a power of downlink signals from the small-cell base station more than necessary, in state that a macro-cell base station is located neighboring the small cell of small-cell base station. The base station apparatus comprises transmission-power control means of controlling a down link transmission power of downlink in a range between a maximum power and a minimum power which are set in advance, and information acquisition means of acquiring information on electrical field intensity of a transmission signal transmitted from the macro-cell base station located at a periphery of the own base station.

Abstract: A base station apparatus is provided, by which a downlink transmission power (transmission output) can be properly set and frequent handovers of a mobile station (user equipment) can be prevented to occur. The base station apparatus is installed in a small-cell base station communicating with a mobile station in a mobile communication network, and provided with measurement means of measuring a time interval between a timing of receiving a handover request from a macro-cell base station when a mobile station performs a hand-in from a macro cell to a small cell and a timing of receiving information showing a failure of handover from the macro cell to the small cell, from the macro-cell base station, in sate that the small-cell base station is located in the macro cell or neighboring the macro cell and control means of controlling so as to decrease a setting of downlink transmission power based on the time interval measured by the measurement means.

Abstract: The fairness of radio communication between a donor base station and terminal devices is maintained. A relay apparatus 20 for relaying radio communication between one or more terminal devices 10 and a donor base station 30, wherein when the relay apparatus 20 receives a cell restriction instruction from the donor base station 30 to restrict a quantity of terminals capable of existing in a service area of a cell formed by the donor base station 30, the relay apparatus 20 executes processing for avoiding cell restriction operation on itself and transfers the cell restriction instruction received from the donor base station 30 to the terminal devices 10 existing in a service area of a cell formed by the relay apparatus itself.

Abstract: In order to implement a relay apparatus capable of suppressing frequency of handover which may occur between macro cell base stations, a relay apparatus 20 relays communication between a terminal device 10 and a macro cell base station 30 and establishes a connection to a specified macro cell base station 30 on the basis of connection point identification information for identifying the macro cell base station 30 which is a connection point; and even when the relay apparatus 20 receives a connection switching request form a core network side to switch the connection from a macro cell base station 30-1 to another macro cell base station 30-2, the relay apparatus 20 prohibits switching of the connection to the other macro cell base station 30-2 pursuant to the connection switching request.

Abstract: A relay apparatus is a relay apparatus that relays communication between a terminal device and macro cell base station in order to implement a relay apparatus capable of preventing a disconnection between the macro cell base station and the relay apparatus, wherein when starting a new connection for radio communication, the relay apparatus acquires identification information for identifying the other end of the radio communication, checks connectability information for defining whether connection to the other end of the radio communication can be established or not against the identification information, and determines whether the connection for the radio communication can be established or not.

Abstract: A base station apparatus and a communication system, which are capable of optimizing a radio transmission path between a mobile station and a base station according to a communication speed of a backhaul link, are provided. The base station apparatus capable of communicating with a mobile station via a radio transmission path comprises information acquisition means of acquiring information on a communication speed of a backhaul link, and parameter adjustment means of adjusting communication parameters of the radio transmission path so that a communication speed of the radio transmission path becomes equal to or lower than the communication speed of the backhaul link, based on the information on communication speed of the backhaul link and a channel bandwidth of the radio transmission path.

Abstract: A base station apparatus is provided, by which a new base station (cell) can be surely added in a neighboring-cell list even when a maximum value is set for the number of base stations (cells) capable being registered in the neighboring-cell list. The base station apparatus is installed in a base station communicating with a mobile station in a mobile communication network. The base station apparatus comprises memory means of memorizing a list of peripheral base stations located at a periphery of the own base station, list-update means of adding a new peripheral base station in the list when finding the peripheral base station, and delete means of deleting at least one peripheral base station registered at an early timing in the list when the number of peripheral base stations registered in the list reaches to a predetermined maximum value that is set in advance.

Abstract: A base station apparatus capable of ensuring a sufficiently large coverage of a small cell while reducing a power of downlink signals from a small-cell base station so as to be equal to or smaller than an allowable maximum power is provided. The base station apparatus of the small-cell base station comprises measurement means of measuring an interference level from a macro cell located in a periphery of the own base station and transmission-power control means of controlling a downlink transmission power based on a measurement result of the interference level from the macro cell.

Abstract: A mobile communication system 1 for relaying packet communication between a macro cell base station 10 and a mobile unit 30 includes a femto cell base station 20 in which first radio communication is executed with the macro cell base station and second radio communication is executed with the mobile unit, wherein at least one of first frequency used for the first radio communication and second frequency used for the second radio communication is automatically selected so as to make the first frequency and the second frequency different from each other.

Abstract: A base station apparatus is provided, by which a downlink transmission power can be properly set and frequent handovers of a mobile station (user equipment) can be prevented to occur. The base station apparatus is installed in a base station communicating with a mobile station in a mobile communication network, and provided with control means of controlling so as to decrease a setting of downlink transmission power when changing a setting of offset for handover from the own cell to a neighboring cell so as to advance a hand-out from the own cell to the neighboring cell.