Abstract: AS-B (810) measures a telephone call time from a time point when a telephone call, which is audio-originated by UE (100), starts. When a time obtained by subtracting the telephone call time from a time for which the UE (100) can telephone-call becomes a predetermined time, the AS-B (810) issues a multiplex instruction to FAP (200). When having received the multiplex instruction, the FAP (200) multiplexes a sound, which is based on a sound source file stored in advance, with audio data to be transmitted to the UE (100), and transmits the audio data, with which the sound has been multiplexed, to the UE (100).

Abstract: The present invention enables communication between different communication networks. The communication system 1 according to the present invention has: an SMSC 14 which is provided in a mobile network 10 over which a user terminal 2 performs communication through a wireless base station, and transmits a message to the user terminal 2; a GW 21 which is provided in an autonomous distributed network 20 over which a plurality of user terminals performs direct communication, and communicates with at least one of the plurality of user terminals 2; and a relay device 32 (32a) which, upon receiving a message transmitted using a predetermined protocol from one device of the SMSC 14 and the GW 21, performs communication, which corresponds to a message received from the other device, using a protocol that is used for communication with the other device and is different from the predetermined protocol.

Abstract: When a mobile terminal currently performing a voice communication or currently initiating a call by use of a VoLTE function moves from an LTE network to 3G femto-network, a GW (100) is connected to an MME (200) disposed on an access network in the LTE network and to an FAP (300) having an IMS-femtocell area as a communication area to be handed over the voice communication or the initiation of the call. When the mobile terminal currently performing the telephone communication or currently initiating the call moves from the communication area of the LTE network to the IMS-femtocell area, a call processing of the mobile terminal is caused to be handed over from the MME (200) to the FAP (300).

Abstract: AS-B (810) measures a telephone call time from a time point when a telephone call, which is audio-originated by UE (100), starts. When a time obtained by subtracting the telephone call time from a time for which the UE (100) can telephone-call becomes a predetermined time, the AS-B (810) issues a multiplex instruction to FAP (200). When having received the multiplex instruction, the FAP (200) multiplexes a sound, which is based on a sound source file stored in advance, with audio data to be transmitted to the UE (100), and transmits the audio data, with which the sound has been multiplexed, to the UE (100).