Distributed communication system

The conventional multi-user audio communication system and an IM system each require a server for managing a conference or a terminal having functions of the server. Thus, an environment without a server cannot be implemented. A specific terminal broadcasts an online or offline command for indicating an online or offline state with respect to an ad hoc network to all other terminals. In an online state, resources such as buffers used by a plurality of channels consenting in advance are allocated, a participation-expressing command including a number of a channel, which the terminal itself desires to participate in, is multicasted to a pre-assigned address, and audio as well as IM data is transmitted to the address at the same time. If other terminals are participating in the channel, a plurality of pieces of audio and IM data is received from the other terminals. In the case of audio data, a plurality of pieces of audio data are mixed and the mixed data is reproduced. When a terminal leaves the channel, a departure command is transmitted to the address.