Sprint's promotion of super-speed wireless Internet has taken an important step with the release of a plug-in modem that can work with WiMAX and the slower but more widespread 3G network.

Xohm, the name for its service employing the small but growing WiMax wireless network, is also dubbed 4G (following on from the 3G network used by devices such as the iPhone) and aims to provide wireless data speeds comparable to fixed-line broadband.

Like the 3G network, users don't have to be near a WiFi 'hotspot' (such as a cafe or airport): the data comes over the mobile phone network. At the moment, the service is only available across Baltimore; however, Sprint says a Portland, Oregon launch is set for January and several other major cities are in the works.

Those who've used the service say it's pretty reliable and even works well with online gaming, which can trip up some high-speed connections. One test achieved a speed of 3.4MBps (which is slower than some home broadband services but still impressive). (Source: informationweek.com)

The biggest stumbling block at launch (apart from being limited to one market) was that users needed a dedicated modem to use the WiMax network. That meant that if they were in a part of the city where the WiMax reception was patchy for any reason, they could lose access completely and have no back-up.

However, Sprint is now selling a plug-in modem that automatically switches between the 3G and WiMax networks depending on coverage. It costs $149.99, compared with $59.99 for the WiMax-only modem. The firm is also offering a combined data subscription to both network for $79.99 a month (each network costs $49.99 by itself). (Source: pcmag.com)

While these deals offer some savings, the prices remain high. We'll have to see if they prove tempting enough for early adopters to establish the service until it becomes a mainstream option.