Road test: Does WiMax work in the real world?

Just a couple short years ago, many people were abuzz over metro Wi-Fi experiments in Philadelphia, Houston, and San Francisco, only to see those efforts largely collapse as slow speeds, expensive deployments, and economic tussles between carriers and municipalities resulted in low adoption. But waiting in the wings for several years has been the promise of WiMax technology to deliver broadband connectivity wirelessly across entire cities with less equipment to deploy than metro Wi-Fi. After nearly two years of uncertainty, Sprint and its partner Clearwire are now starting to set up WiMax networks in several cities.

WiMax promises users a wireless connection that rivals wired DSL or cable links in speed and reliability. Does it actually deliver on those claims? To find out, I tested the Clearwire Mobile High Speed Internet service for about a month in one of the first deployment areas: Reno, Nev. The results were mixed: The WiMax service provided good connectivity and performance when I was working in a fixed location, whether at my home office or at a café. But I could not get it to work when I was on the move, such as when being driven in a car. (To be completely accurate, the Clearwire service is not officially WiMax but OFDM, the underlying technology behind the WiMax standard. Clearwire deployed the Reno network before the WiMax standard was final, but it is practically the same technology.)

[ WiMax  is in for a fight with 4G cellular networks. See "The looming battle over wireless broadband." ]

Setup was straightforward: Run the installation CD and pop the PC Card into your laptop. I did have an issue with my company laptop because of security measures that disabled installation of unapproved applications, but that had nothing to do with the Clearwire product. If you're considering equipping your laptop users with Sprint or Clearwire WiMax service, be sure to work out the security issues on a test system first. Although Clearwire tried to help, the issue was beyond its scope, and the corporate security staff also couldn't figure out how to authorize the service on my company-issued laptop. The service installed with no problem on a personal laptop that didn't have such security measures applied to it.

WiMax performance is decent but not always consistent

With the software and PC Card installed on that personal laptop, I was good to go. The network connection established itself right after I inserted the PC Card. I was now able to connect wirelessly pretty much everywhere in Reno. A nice touch was that when you start up the PC, the Clearwire software lets you choose between connecting via WiMax or Wi-Fi; Wi-Fi is typically faster when it's available.

To see if the WiMax service truly met broadband speeds, I took speed tests throughout the day from my home office. I got consistent performance much of the time, with download speeds between 1.5Mbps and 2.0Mbps, and upload speeds between 275Kbps and 325Kbps. Sometimes, speeds dropped to less than 1Mbps down and 125Kbps up, but not for long, so they didn't affect my use. It's not clear what caused these occasional slowdowns, and they occurred both when the laptop was stationary and when it was in motion.