... better understanding of the book's main topic: Signaling System No. 7. Today, Signaling System No. 7 is the most advanced and widely used signaling system for both cellular and fixed-line ... 23, 19 95, when it was removed from Crawford, Scotland. Strowger sold his patents to his associates for $1, 800 in 18 96 and sold his share in the company for $10 ,000 in 18 98. He died in 19 02. ... and CCS Signaling System No. 7, known more commonly in North America as SS7 and elsewhere as C7, is both a network architecture and a series of protocols that provide telecommunications signaling. ...