| 摘要 |
<p>The invention relates to an interworking function apparatus (IWF), a method and an arrangement for establishing a mobile-terminating call in a mobile communications network when the call is received from a calling party via a fixed network without any signalling support which provides information on the protocol employed by the calling party. In the invention, a service is assigned only one directory number, which is common to all the protocols employed by the service. The protocol identifier in a service definition linked with this directory number has a neutral (undefined) value or may be interpreted as neutral. The IWF, upon receiving the neutral RA parameter (Step 2), is switched onto the line and monitors a traffic channel received from the fixed network in order to identify the protocol employed by the calling terminal equipment (Steps 54-57). After identifying the protocol, the IWF is configured according to the identified protocol (Steps 58-60 or 61-63), and data transfer may begin (Step 64).</p> |
