Ideal for anyone seeking a complete survey of data communications without being bogged down with excessive detail, this applications-oriented overview covers a wide range of subjects in sufficient depth to provide readers with a basic, working knowledge of the field. Discusses everything from network basics to coax, data link layer duties, high speed LANs, network operating system functions, analog vs. digital signal transmission, ISDN history and types, mobile communication problems, ATM layers, the purpose of the Internet, transport layer protocols, SNA hardware, and more. Explains why there are so many different protocols in data communications, the differences between them, and advantages and disadvantages of each. Illustrates protocols and layers with figures throughout. For those in data communications or computer information systems, or for anyone in electronic technology field.