Clearwire 4G USB Modem (Motorola USBw 25100 WiMax Adapter)

The Clear 4G USB Modem, a Clearwire-branded Motorola USBw 25100 WiMax adapter, is basically a 4G radio on a USB stick. The modem is relatively easy to set up, and Clear includes a USB elbow adapter to help you face the antenna in the optimal direction (typically out a window). The modem costs $70 from Clear without a contract, or you can lease it for $4 per month with a two-year contract. For people who plan on never needing to connect outside the range of a 4G network, the Clear 4G USB Modem might be a fine choice. But anyone who travels, or who lives in one of the many non-4G cities in the United States, would be better off looking for a dual-mode 3G/4G modem.

The good news is that the drivers are clean and simple to use and install. On my wife’s Dell Mini 10, the Clear Connection Manager starts the instant she plugs in the USB modem; on my MacBook Pro and my Debian Linux machine, however, I have to start it manually. (One piece of advice: Take a bit of time to tinker with which way the USB elbow points, in order to get the Connection Manager displaying as many bars as possible.)

Credit goes to Clearwire for opting to go well beyond Windows-only driver support for the device. Mac OS X support is available on the Clear download site, and Linux drivers are easily found in places such as SourceForge.

In pre-WiMax days, Clear handed out real address space with its modems. Real addresses allow you to set up a home Web server that you can reach from outside, making gaming, videoconferencing, Voice over IP, and many other Internet services work much better. As Clear made the move to WiMax, however, it succumbed to the siren song of NAT (Network Address Translation). The company is now giving out real addresses only to customers willing to spend more money for a professional account, which includes one or more static/permanent addresses depending on how much cash you hand over. Too bad.

I ran five speed tests from each of two WiMax markets--Honolulu and Las Vegas--and found throughput numbers that were scattered all over the map, as well as high signal-latency numbers in many of the tests. In my (admittedly limited) Honolulu tests, I saw average download speeds of 2.1 megabits per second and upload speeds of 1.8 mbps; download speeds ranged from 1.2 mbps to 3.9 mbps. In my Las Vegas tests, I saw average download speeds of 3.2 mbps and average upload speeds of 1.7 mbps; download speeds ranged from 3.1 mbps to 4.3 mbps.

Naturally, you'll see performance differences between a USB-connected device like this Clear modem and devices that are internal cards connected on the high-speed PCI bus.

To get comfortable with WiMax, you need to keep in mind that the technology is more related to your cell phone than to your Wi-Fi access point. It might be nearly as fast, but it is a wireless service that is shared by an ever-increasing number of subscribers, making your slice of the bandwidth pie thinner and thinner.

Clearwire will need some time to enhance and tune its networks in all markets. Like all wireless providers, though, Clear will make changes faster if and when enough customers complain. If you notice sagging performance in your WiMax service, take a bit of time to tell the company.

Clearwire’s WiMax network is running in 36 cities currently, but the company will be turning it on in many more locations in the near future. Before buying this modem, make sure that 4G WiMax service is available not only where you live but also but also in the areas you travel to most (see Clearwire’s coverage map). If the service isn't ready in those locations, you might want to opt for a 3G/4G dual-mode device, which you can buy from Clearwire or Sprint.