| 摘要 |
<p>Each network handled call (24, 60, 62), including its original leg and all subsequently initiated related call legs, is assigned a single unique identification number (B-1D). When a determination is made that the call (including any leg thereof) is to be monitored by a law enforcement agency, a switch handling the call requests (R1, R2, R3, R4, R5) a trunk connection (34) from a monitoring center (28). This request includes the assigned unique identification number. The monitoring centre then compares the included identification number with previously received identification numbers (52) associated with active call monitoring operations. If the numbers match, this is indicative of the fact that the call at issue is already being monitored, and the request for a trunk connection is accordingly denied (D2, D3, D4, D5) as being redundant. More efficient use of valuable monitoring center communications (trunk (48)) and monitoring (recorder (30)) resources is accordingly made. In a particular embodiment of the present invention, the single unique identification number assigned to a call comprises a cellular telecommunications network assigned billing identification number.</p> |
