Book excerpt: This practical book provides an extremely comprehensive, up-to-date, and easy-to-understand treatment of the entire GSM network and the signaling methods of its terrestrial interfaces. You learn how to analyze network problems, what measurements you have to take to solve them, and where in a scenario you will find the desired information or parameter. The book introduces you to all the interfaces between the GSM subsystems, starting with the Abis- and Air- Interface and continuing on to VLR's, HLR's and MSC's within the Network Switching Subsystem (NSS). You learn about the various signaling standards or methods used in GSM, including TCAP and MAP and how to apply this knowledge when working with GSM networks.