Patent ID: 6983163

Claim:
A multipoint communication method, in which voice communication takes place among mobile stations via communication control devices, having a transcoder provided with a codec which performs encoding and decoding of voice signals, and a rate control unit which determines the encoding rate in the codec and employs the unit's own rate specifier to specify the encoding rate for the transcoder; comprising: in two-point communication, connecting a rate control unit of the communication control device of one of the points to a rate control unit of the communication control device of the other point, without passing through a transcoder, exchanging between the two rate control units rate control information which is the correspondence relations between rate specifiers and encoding rates, and replacing at a rate control unit a rate specifier which is sent by the rate control unit at the other point together with voice data by its own rate specifier, referring to said rate control information, and transmitting the voice data with said rate specifier to the mobile station; when making a transition from two-point communication to three-point communication, inserting transcoders in the communication path between the two points. While maintaining the communication, starting a transcoder for the third point to establish paths between the transcoders of different points, and controlling the transcoders at each point to acquire the rate control information for all points, thereafter a transition to three-point communication is performed; and, in the transcoders at each point, transmitting encoded voice data for transmission which is made to the transcoders at the plurality of other points, and in addition, processing encoded voice data received from other points for the purpose of multipoint communication, referring to the rate control information, and transmitting the processed encoded voice data to the mobile station.