802.11n: A Survival Guide

Preface

People still move. Networks still don’t.

A decade ago, I first wrote that people moved, and networks needed to adapt to the reality that people worked on the go. Of course, in those days, wireless LANs came with a trade-off. Yes, you could use them while moving, but you had to trade a great deal of throughput to get the mobility. Although it was possible to get bits anywhere, even while in motion, those bits came slower. As one of the network engineers I worked with put it, “We’ve installed switched gigabit Ethernet everywhere on campus, so I don’t understand why you’d want to go back to what is a 25-megabit hub.” He underestimated the allure of working on the go.

In the rubble of the early 2000s Internet bust, wireless LANs were one of the first new technologies to cut through the gloom. As they gained in popularity, they morphed from an expensive toy to show off and became a must-have technology. My apartment had a wireless LAN very early, and I remember when I showed it off with pride. In the days of 2 Mbps 802.11 networks (or, if you were rich, an 11 Mbps 802.11b network!), all you had to do was beat the speed of your Internet link, which was not particularly hard.

What made 802.11n the next big step in the wireless revolution is that it was the first time that a wireless LAN delivered reasonable performance. Wireless LANs first took root in industries with highly mobile employees: hospital medicine, logistics, and education. Trading speed for mobility is a good exchange ...