Diversity Reception and Dual Antennas

'Dual-Mode' Access Points and Gateways

In the fall of 2002, several manufacturers began shipping 'dual-mode' Wi-Fi gear. This means that in a single access point or gateway, you have entirely independent 2.4 GHz 802.11b and 5 GHz 802.11a data radios, capable of connecting to clients using either 802.11b or 802.11a technology.

With a dual-mode access point or gateway as the central wireless hub of your network, your laptop can communicate with your network using an 802.11b client adapter, while the desktop computer in the den can use a faster (if shorter range) 802.11a client adapter. The downside to dual-mode is that it currently costs a lot more than 802.11b. Unexpectedly, dual-mode gear is about as expensive as 802.11a gear, so if you need to use 802.11a, you can get 802.11b compatibility 'for free' by using dualmode instead of 'straight' 802.11a.

Note well that only access points and gateways are dual-mode. Client adapters are (at least for now) either 802.11b or 802.11a. Dual mode clients will appear eventually, but having two modes on a client is much less useful than in an access point.

Dual-mode gear hasn't been out for very long, and although my first tests have been promising, I'd like to see how it works for a few more months before giving it my unreserved recommendation.