William J Buchanan 
Mastering Global Information Systems [PDF ebook] 

This book provides an excellent foundation in modern information systems and data communications. It has five basic themes:- Digital Information Sources and Multimedia;- The Internet, the World Wide Web and Java;- Local area Networking;- Wide area Networking;- Video Conferencing.The information sources material covers the main standards in digital information on modern computer systems. It includes the conversion of sound and images into a digital format.The networking material introduces the main local area network technologies:- Ethernet;- Token Ring;- FDDI.Modern Wide Area Network technologies like ATM are considered, also the usage of ISDN and Modems for interconnection.