Tim Higgins, who writes the definitive WiFi site SmallNetBuilder.com has published an excellent guide to buying WiFi routers called How To Buy a Wireless Router: The Short Version. He notes that by the end of 2009, the 802.11n standard will be finalized.
He reviews the four major types of routers:
- Single-band G
- Single-band N
- Dual-band, single-radio “N”
- Dual-band, two-radio “N”
The two radio, dual band “N” router is best, explains Higgins. You can put your “N” clients on 5 GHz and your “G” clients on 2.4GHz.
The 5 GHz band has more non-overlapping channels than 2.4 GHz. While the 2.4 GHz band has only three usable channels out of 11, the 5 GHz band usually supports eight. With two (Multiple-Input Multiple-Output) channels, “N” routers often run into channel conflicts on the 2.4GHz band.
Whenever there are G and N devices connected to the same N type router, they both will operate at slower speed, but only when both are active. So if you do a lot of long wireless downloads, file transfers or backups or watch a lot of online video via wireless connections, you will want to segregate G and N clients onto separate networks, for optimum performance of both types.
The easiest way to separate the client types, especially if you already have a G type router, is to add an N type router. Another way to separate the client types is to use a dual-band, dual-radio N router.
So when would a single-radio, dual-band N router be a good choice? Actually, not that often.
Higgins warns about buying non-standard “N150″ routers. They don’t use MIMO, they put “N” protocol elements on a single channel. “Single stream N technology” routers are marketed as “N150″ products, but single-stream clients are not draft 11n certifiable. Higgins advises people to stay away from single channel “N150″ products including Cisco/Linksys WRT120N, Cisco Linksys WRT110, NETGEAR WNR1000, D-Link DIR-600, and Belkin N150
As I have said before, these are a marketing experiment aimed at luring unsuspecting shoppers who think they are buying something that will make their G devices work faster and / or go farther (they will do neither). They are pitched as cheaper alternatives to real N routers, but, in the end they aren’t a good deal.