Deploying License-Free Wireless Wide-Area Networks
Author: Jack Unger
Publisher: Cisco Press
Don’t expect this book to describe wireless network installations. I’m just saying that the book doesn’t cover actual case studies or, as I expected, usage of Cisco Systems wireless hardware in the process of finalizing the wide area wireless networks. The book does just what the title says, covers the planning and deploying parts related to broadband wireless wide area networks.
About the author
Jack Unger, is the founder and president of Wireless Infonet, Inc., and is a recognized broadband wireless expert with 10 years’ experience in license-free network design, deployment, training, and support. Providing continuous wireless broadband services since 1995, Wireless Infonet, Inc. was the first to deploy license-free public broadband wireless Internet access in Silicon Valley.
Inside the book
From the broadband wireless network user’s point of view there are usually no differences between wireless and wired networks. On the other hand from the technical point of view, planning and designing steps are very different and the start of this book explains those differences. The chart the author presents contains information on the network characteristics for both wireless and wired networks, comes quite useful for the early steps when planning a network. As I usually like to know the historical facts behind the various technological issues, I was happy to see another chart, this one dealing with Wireless developments from 1600 to 1997. Don’t be intrigued by the year 1600 being used in the chart, as the year has a general historical meaning – that was the year when Dr. William Gilbert detected electromagnetic activity inside the human body, and tagged it as “electricity”.
In order to get the best out of your wireless WAN set-up, the author notes some important challenges that should be considered in the deployment step. These include the understanding of wireless fundamentals, overcoming real-world obstacles, maximizing the available bandwidth and last but not least, security. We are talking about physical security in the safety kind of way as some topics like using personal safety equipment, watching the weather and using lightning protection, must be taken care of.
The second, 35 pages long chapter, provides a really nice overview of wireless fundamentals, written in the way that can be understood by both technical and non-technical readers. The information presented in this chapter offers most of the background information reader needs to understand how the wireless networks work. With the perfect amount of descriptive text and with the help of several self-describing diagrams, Unger covers the most important topics like wireless propagation, wavelength and frequency. When a wireless signal encounters an obstruction while travelling between two points, there are several issues that can come in the way: attenuation, reflection, diffraction, precipitation and refraction. If you are math’s fan, you’ll surely enjoy the calculations for the Fresnel zone clearance, which is used to calculate the amount of clearance, a wireless wave needs from an obstacle to ensure that the obstacle does not attenuate the signal. Calculation, description and a sample diagram will help most of the users to understand this term. Author’s tips on planning longer wireless links end this chapter.
Following the chapters containing the needed facts on wireless networks, Unger focuses the third chapter on evaluation of several wireless network architectures. The architectures discussed here include Point-to-Point, Point-to-Multipoint, Mesh and Cellular. All of these architectures are decently covered and the way author guides us through all four concepts by showing us both the advantages and the disadvantages. This makes the architectural choice even easier.
After the preliminary network design process, which finished with the choice of the optimal architecture, it is time for evaluating the possible wireless equipment locations. By doing the site survey there are lots of things to think about. The main parts of this process are divided into physical site survey and radio frequency site survey. These pages are very useful as they deal with the most important issues including the modifications to the network design, checking if the site is 100% perfect for the organization’s network, determining the antenna locations, inspecting the band of frequencies and coverage testing. These issues are self-explaining, but the information presented in this publication, comes really handy when it is time to do the job.
Extending the wireless fundamentals antenna introduction, chapter 5 deals exclusively with antenna systems. I’m interested in wireless communities, and this chapter really came perfect to me as I’m currently building a cantenna. Regardless of the mentioned homemade antenna, the author offers information on all major types of antennas, and additionally presents some guidelines for selecting the perfect antenna type for your needs. A very nice chapter indeed. The following 50 pages are given to the process of evaluating and choosing the optimal wireless equipment.
As the vital part of a reliable productive network is the correct installation of the outdoor wireless system, Unger notes the three successful installation stages. These include planning and preparation of the network, installation of the wireless hardware and network testing. Author goes deep into hardware installation and includes figures showing mounting configurations and flat roof mast base. As with the wireless set-ups, it is quite important that the quality of signal should be on its highest possible level. Therefore, author gives a whole chapter to the topics of solving noise and interference problems. The chapter will sure come handy to the perfectionists our there. For the wireless Internet Service Provider wannabes, the final chapter discusses methods of providing broadband wireless Internet access.
After reading the author’s biography snippet and learning that he started his own wireless concentrated company almost 10 years ago, I expected the book to be an informative guide for deploying wireless Wide Area Networks. I must tell that it is even better, as the author manages to cover various important aspects of wireless networks. On the other hand he introduces the readers with information leveraging from wireless signal technicalities to product evaluation and broadband wireless Internet access providing.
I was really happy to see years of author’s experience, smoothly transformed into text. This can be especially seen from the chapters dealing with physical specifications of wireless networks and site surveys. I was not satisfied with the scope on network security issues, which is just covered via a one-page overview of precautions.
Overall, “Deploying Licence-Free Wireless Wide-Area Networks” is a very good guide aimed to the IT savvy people interested in planning and deploying broadband wireless Wide Area Networks. The publications should also be of interest to anyone who sees the obvious advantages of wireless networking, as it provides must-read information on wireless fundamentals and wire-free network planning.