To conduct communication between an optional radio access subscriber terminal and an optional subscriber terminal on an existing communication network or other optional radio access subscriber terminal.
For example, a terminal signal from a radio access subscriber terminal 7a used between the terminal 7a and a subscriber terminal 3a is converted by a protocol converter 4 into a terminal signal on an existing communication network corresponding to the type of the service, the converted signal is transferred to the existing communication network exchange 1a, converted further by an exchange 1a into a terminal signal corresponding to the type of the service of the terminal 3a and then transferred to the terminal 3a. The terminal signal from the terminal 3a is transferred to the terminal 7a while being inversely converted by the exchange 1a and the converter 4 on a reverse path.
NAGAO MIYAO
NAKAZAWA HIROAKI
NANBA YUKIHIRO
NIPPON TELEGRAPH & TELEPHONE