| 摘要 |
Narrowband subscriber terminals (40, 52, 58) of different narrowband networks are interconnected via a broadband network (48) that supports dissimilar signalling protocols to those maintained on the respective narrowband networks (40, 52, 58). A call server in a first narrowband network (40), in response to a call (100) from a first subscriber terminal (12) to a second subscriber terminal (68) in a second but different narrowband network (52), selects a phantom trunk (202) between the two networks. The phantom trunk has a unique circuit identity, which circuit identity is used in a first instance to relay to the second network an address of the second subscriber terminal (68). Then, in a second instance, the unique circuit identity is used to relay to the second network an address of the first subscriber terminal (68). By recognising that two connection requests have been received at opposite ends of the same phantom trunk, a processor in the second network is able to determine that a direct connection between the first and second subscriber terminals is required through the broadband network (48). |
