802.11g products have been around for about two years now. 802.11g is a backwards-compatible upgrade from 802.11b because (unlike 802.11a) B and G operate on the same radio frequencies. Standard G has a top link speed of 54 Mbps – again, this means throughput of perhaps ~25 Mbps when the station and AP are close, dropping with distance.

Technically, B and G have the same range, but G products can deliver higher throughput at a distance. In practical terms, that means that you’ll communicate more effectively when your station and AP are, say, 100 feet apart, with walls in between them. Also, a new G product is just plain likely to work better than an old B product from the same vendor due to code fixes and hardware improvements unrelated radio standards.

If you have old laptops with built-in B cards, but you’re buying new adapters for new laptops or new APs/routers, it makes good sense to buy G products today. They’re likely to cost the same or very little more than B products, and can interoperate with older B products, albeit no faster than 11 Mbps. When B and G products operate in the same area, the G products must use a compatibility mode that reduces their top speed, but G-to-G connections will still be faster than B-to-G connections at the same distance.

Finally, what is G-plus? You could be asking about any one of MANY vendor extensions to 802.11g. For example, Atheros? Super G bonds two radio channels to get a top link speed of 108 Mbps (60 Mbps throughput) — see http://www.super-g.com. Or you could be thinking of Broadcom’s 54g BroadRange technology, which extends 802.11g’s range without channel bonding. The IEEE is working on an even higher-speed WLAN standard, 802.11n, to be based on some kind of as-yet-unchosen MIMO (multiple input multiple output) technology. Several products labeled “extended G” or “pre N” implement MIMO-related technologies to go faster and reach farther — see http://searchmobilecomputing.com/tip/0,289483,sid40_gci1068451,00.html for several examples.