Preface
Why This Book
In the late 1990s, I was engineering manager at the switching department in a mobile telecom operator. The mobile switches we dealt with were based on circuit-switched technology. They were big, complex, and proprietary pieces of hardware and software involved almost exclusively in the provision of voice service. By that time, ATM (Asynchronous Transfer Mode), a packet-switched technology that followed the virtual circuit approach, started to gain maturity as a suitable way for carrying media traffic with QoS requirements. Media transport was only part of the problem. The other part, signaling, did not have, by then, a mature candidate. The industry response was to strip the existing circuit switches off their switching matrix ...
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