08-16-2017, 09:28 PM
Mobile Communications Book Reviews
Up and Close
[attachment=260]
INTRODUCTION
Here are three books on mobile wireless communications which have come my way recently, and it seemed appropriate to group them and talk about them briefly for readers of antenneX online magazine. The topics are slanted towards cellnet phone technology, but make use of what is called the air interface or the physical layer wireless channel , which is the principal topic of interest to this readership. T
Unlike the experiences of most Ham radio aficionados, the professional communication scene has developed under the influence of computer communications, and there is the ubiquitous idea of the layered protocol which might best be illustrated using the old-fashioned example of sending someone a hand-written letter. The physical layer consists of crafting words on a piece of paper with a pen. The piece of paper is folded up and placed in an envelope, on which is written an address. This is the next layer up in the protocol. The envelope is handed to a postman, who conveys it to a sorting office, where it is grouped by destination with many other letters and the whole group of them conveyed to a remote sorting office. The postman is a protocol layer, the sorting algorithms are another and the bulk transport yet another. If we consider the bulk transport layer for a moment, the content of the original message and the precise details of the destination address are of no consequence to the operation. On the other hand, the recipient of the letter has no interest in the precise method by which the letter arrived in his mailbox, but is only interested in the contents.
MOBILE WIRELESS COMMUNICATIONS
Antennas get only a few pages of mention in this digital communications systems engineering book, which is aimed at University students who are at the interface between undergraduate and postgraduate study. In fact, the term wireless in the title is more a description of an application, and electromagnetics and diversity engineering such as were discussed in the book above, do not feature. I found it an interesting read, as it seems to indicate that there will be a new generation of telecommunications engineers coming out of the Universities who have only the smattering of knowledge of the Physics that underlies their discipline. Another striking point that may be observed is that very little of the subject matter of this book is science-based. Rather, everything is man-made, and if history had turned out differently the systems to achieve the same results might have been designed very differently.