802.11n: A Survival Guide

Wireless has finally come of age. With a significant jump in throughput over previous standards, 802.11n is the first wireless technology that doesn’t trade speed for mobility, and users have stormed onto wireless networks with a passion. In this concise guide, Matthew Gast—chair of the IEEE group that produced revision 802.11-2012—shows you why wireless has become the default method of connecting to a network, and provides technical details you need to plan, design, and deploy 802.11n today.

Building a network for the multitude of new devices is now a strategic decision for network engineers everywhere. This book gives you an in-depth look at key parts of 802.11n, and shows you how to achieve an Ethernet-free wireless office.

• Learn how MIMO’s multiple data streams greatly increase wireless speed
• Discover how 802.11n modifications improve MAC efficiency
• Examine advanced PHY features such as beanforming and space-time code block
• Use advanced MAC features to maintain interoperability with older devices
• Plan an 802.11n network by determining traffic demand, key applications, power requirements, and security
• Choose the architecture, select hardware, and plan coverage to design and build your network

Author Interview with Matthew Gast

What made you write the book?

When I first started writing about 802.11, wireless networks were cool and promising. The first time I held a Wi-Fi LAN party, the equipment cost several thousand dollars, and we all needed to spend time installing the right software and drivers. Fast forward a decade, and 802.11n has come along. Wi-Fi has grown up. Every computing device you want to interact with just has Wi-Fi built in‚ and some devices, like the iPad, don’t even give you the option not to use it. In the middle of the ’00s, I would talk about Wi-Fi and say that everybody was going to have two Wi-Fi devices: A laptop and a phone. I was wrong. It’s a laptop, tablet, smartphone, and maybe another device or two. Supporting all these devices requires a fast network, and right now, that means 802.11n.

Why is your book especially important now?

It’s only a slight joke to say that there are only two kinds of users. There are those who have iPads, and there are those who want them. Building a robust network to support tablet computing and its rich interactive experience blending text, audio, and video is a challenge. This book teaches you how to do that.

What is the single most important thing readers will be able to do after reading your book?

Readers will understand the trade-offs involved in building a large-scale wireless network, and how 802.11n’s protocol features help them build the network they want.

What do you think is on the horizon for your readers?

Wireless LANs touch everything in networking. A key enabler of the mobile computing revolution is that small devices can access data and applications stored elsewhere on the network. Providing a solid network connection is the first step towards enabling any network service, whether it is hosted applications, videoconferencing and screen sharing, or electronic learning.

Table of Contents

Chapter 1. Introduction to 802.11n-2009
Part I. The PHY
Chapter 2. MIMO and the 802.11n PHY
Chapter 3. Channels, Framing, and Coding
Chapter 4. Advanced PHY Features for Performance
Part II. The MAC
Chapter 5. MAC Basics
Chapter 6. Advanced MAC Features for Interoperability
Part III. Using 802.11n to Build a Network
Chapter 7. Planning an 802.11n Network
Chapter 8. Designing and Installing an 802.11n Network