| 摘要 |
<p>When the user lifts the receiver, the termial of a wireless local loop telephone system detects this and generates a dial tone as normally. The user starts dialing. But instead of waiting for completion of dialing, the terminal immediately sends a channel request message to the network. This triggers the exchange of normal messages with the result that a signaling channel is assigned, an authentication procedure is performed and the ciphering mode is set up during the time when the user is pressing keys to give a called subscriber's telephone number. Because dialing is still in process and the called subscriber's number is not yet available, the terminal puts a predetermined pseudonumber into a message which normally carries the called subscriber's number. The pseudonumber informs the network that the terminal will send the telephone number of the called subscriber later. The number will arrive as DTMF digits on the assigned signaling channel.</p> |
