Nippon Telegraph and Telephone Corporation

Haruka Eitoku

Koji Tanida

Kodai Yamamoto

A terminal not equipped with a SIM is authenticated properly by a mobile core network. A communication systemincludes a relay deviceincluded in a fixed core networkand an HSSincluded in a mobile core network. The relay deviceincludes an issuing unitthat issues IMSI information corresponding to a subscriber identifier of a non-SIM terminaland authentication information corresponding to the IMSI information, and transmits the subscriber identifier and the IMSI information to the mobile core network, and a termination unitthat transmits the IMSI information and the authentication information of the non-SIM terminalto the mobile core network. The HSSholds the subscriber identifier and the IMSI information in association with each other, and authenticates the IMSI information and the authentication information of the non-SIM terminal.

Communication method, communication system, relay device, and relay program

Unexpected call disconnection during normal time is prevented. When a gateway deviceinstalled on a POI border receives RTP packets even though reception of RTCP packets is stopped, the gateway devicegenerates RTCP packets and sends out the RTCP packets to the gateway device's own network side or the gateway devicegenerates a call control signal showing that media transfer is continued and sends out the call control signal to the gateway device's own network side. Thereby, even in the case of performing interruption monitoring of RTCP packets within the gateway device's own network, it is possible to prevent unexpected call disconnection during normal time accompanying change in RTCP packet sending-out conditions.

Growing community of inventors

Tokyo, Japan

Haruka Eitoku