| 摘要 |
<p>The invention provides apparatus (27, 28 and 29) for, in use, transmitting calls generated by a first communication network over a second communication network (22) to a third communication network, the first communication network operating in accordance with a first communication protocol which enables call services, the third communication network operating in accordance with a communication protocol which enables at least one of the call services enabled by the first communication protocol and the second communication network (22) operating according to a second communication protocol different to the first, which apparatus (27, 28 and 29) comprises means to determine (40) whether a call to be routed from the first communication network to the third communication network by means of the second communication network (22) requires a call service; means (40, 41) to produce a data message compatible with the second communication protocol indicative of the required service and means (41) to transmit the call and data message over the second communication network (22) to the third communication network, where the data message is read by further apparatus (27, 28 and 29) and an appropriate call service established to the third communication network. By providing means (40, 41) to produce a data message compatible with the second protocol to carry the call service information it is possible to establish a call service over a communications network (22) even though that network does not explicitly support the call service. The invention also provides a communication method.</p> |
