The technique for separate but parallel signalling channel is called ________

A. Common channel signalling
B. Forward channel signalling
C. Reverse channel signalling
D. Separate channel signalling

Explanation: During the mid 1980s, the PSTN was transformed into two parallel networks- one dedicated to user traffic, and one dedicated to call signalling traffic. This technique is called common channel signalling.

In North America, the cellular telephone signalling network uses _______

A. Ss7
B. Ixc
C. Is-41
D. Pstn

Explanation: In North America, the cellular telephone signalling network uses No. 7 Signalling System (SS7), and each MSC uses the IS-41 protocol to communicate with other MSCs on the continent.