摘要 |
An integrated services digital network (ISDN) (62) connection is maintained between a wireless office environment (40) type private cellular telephone system and a public access cellular telephone system (12). In particular, an mB+D ISDN connection (where m=2, 23 or 30) is maintained between the ISDN network and each of a wireless office environment mobile switching center (WOEMSC) (42), a public land mobile network mobile switching center (PLMN-MSC) (14) and a home location register (PLMN-HLR) (22). A protocol converter (72) is provided in each of these nodes to convert between the Transaction Capabilities Applications Part (TCAP) message Signaling Connection Control Part (SCCP) supported signaling system no. 7 (SS7) message formats and the ISDN format. During registration, call delivery and hand off, an ISDN call (108, 118, 202, 302) communication is established between the wireless office environment type private cellular telephone system and the public access cellular telephone system. The SS7 messages are then exchanged between the systems over the D channel. Any necessary speech connection is then carried over one of the m available B channels.
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