for the local use provides an interface between the bsc 200 and the pbx 212 on the other hand the radio packet interface board 228 connected to the pdsn 204 is allocated for public use while the radio packet interface board 230 connected to the intranet 216 is allocated for a local use namely the radio packet interface board 228 provides an interface between the bsc 200 and the pdsn 204 and the radio packet interface board 230 provides an interface between the bsc 200 and the intranet 216 the control board 222 controls a public network originating call a call originating from ms 210 and utilizing the public communications network from the ms 210 by interworking with the msc 202 if there is a public network originating call process request transmitted through the bts 206 or 208 from the ms 210 further the control board 222 controls a private network originating call a call originating from ms 210 and utilizing the private communications network from the ms 210 by interworking with the pbx 212 if there is a private network originating call process request transmitted from the ms 210 through the bts 206 or 208 on the other hand the control board 222 controls respective public network and private network terminating call processes calls to ms 210 utilizing the public communications network and the private communications network respectively requested from the msc 202 and pbx 212 respectively through the bts 206 or 208 to ms 210 also the control board 222.