Book excerpt: The Definitive Telecommunications Reference--Fully Updated Understand cutting-edge telecommunication and networking technologies using this straightforward, real-world implementation guide. Fully revised to cover all of the latest transmission protocols, Voice & Data Communications Handbook, Fifth Edition covers all the bases-from analog transmission, VPNs, and LANs to DSL, CATV, WiFi, VoIP, and GSM. This authoritative volume covers the ins-and-outs of each vital topic, supplies practical examples and solutions, and provides helpful self-tests. You'll also find up-to-date information on regulatory standards, switches, routers, frame relay, and security procedures. Use new wireless technologies Understand the building blocks of analog transmission-bandwith, amplitude, and frequency Provide transparent communications using the OSI model and seven-layer architecture Comply with local and federal regulations and RBOCs Transmit information using routers, SS7, PBX, and KTS switches Send and receive data across TCP/IP, wireless, cellular, and optical systems Create a connection using a modem Connect to multiple VPNs and LANs using frame relay, ATM, and MPLS Deploy high-speed broadband access with cable modems, xDSL, and CATV Get details on VoIP, SIP, and voice over data services Increase bandwidth using IP telephony techniques and PBX equipment