Typical 2-Mbps radios use only a fraction of the available bandwidth in the 2.4-GHz spectrum. These 2-Mbps r adios have user-selectable frequency ranges--generally six overlapping ranges--that enable the user to operate multiple radios in a small geographical area. The Clarion radio uses the entire FCC allotted 2.4-GHz Industrial Science and Medicine (ISM) band to carry its 10-Mbps signal. The result is a single, faster channel--but you're subject to more interference from other wireless technologies that may be in the area.

Another trade-off when using the entire 2.4-GHz band is in the area of standards-based networking. The IEEE 802.11 wireless LAN standard has no provisions for 10-Mbps networking. Therefore, interoperability with future standards-based products isn't in the cards. However, because these units generally are sold as a complete package for building-to-building wireless LANs, interoperability is generally not an issue.

When we began our testing, the FCC imposed stringent regulations on the amount of power that devices like the Clarion radio were allowed to transmit. This power restriction limited the distance that most products could traverse. In par ticular, Solectek Corp.'s unit had a huge distance advantage--most products were limited to 10 miles, while Solectek's custom-engineered solution could go up to 25 miles.

Recently, the FCC relaxed its power restrictions for wireless bridges, and many vendors can now offer distances of 25 miles or more. The trade-off is in antenna size--vendors that offer longer distances without newer hardware have to use a bigger antenna. For vendors like Solectek, distance suddenly became less of a selling point, but, at the same time, its solution is more compact and within the old FCC standards.