Dave Bailey

If the Institute of Electrical and Electronics Engineers’ (IEEE) 802.11n wireless standard was a car, what car would it be? Well, considering that it could take over five years for the standard to move from conception to ratification, it should be one of those arthritic road-going steam traction engines you see on repeats of Fred Dibnah – Steeplejack documentaries.

Hang on a minute, when 802.11n finally gets ratified in March 2009, it’s predicted to be the fastest mass-market wireless technology on the planet. So shouldn’t it be a really fast car? Well, maybe it should, but one chained to a caravan full of wireless chipset vendors who keep stopping every five minutes to argue about which way to go.

When 802.11n eventually jettisons the caravan of discontent, its speed will still be an issue. The problem is that the initial data transfer rates will be around 100Mbit/s, but will increase to 300Mbit/s later on. This means that the access points (APs) running this standard will need a Gigabit Ethernet connection and a powerful processor onboard to dish out data over this network link. With an AC adaptor that’s not a problem, but what about firms wanting to use Power over Ethernet (PoE) to provide the APs with juice?

There are fears that the current standard for PoE, 802.3af, which can theoretically dispense around 15 watts over a standard network cable, may not be able to supply enough power. Firms wanting to power these APs over a LAN cable may have to wait for ratification of the newer standard for PoE, 802.3at, before such a capability exists.

The good news is that so far the 802.3at standard looks like it could be ratified before 802.11n, and at the Interop show in Las Vegas last week, vendors including Phihong were demonstrating systems that could supply enough juice over a LAN cable to power a workstation.

Currently, the 802.3at standard is on course for ratification before the end of 2009. It is hoped that the 802.3at chipset vendors, and remember some of these vendors have their fingers in both 802.11n and 802.3at pies, can bury the hatchet, but preferably not in each other’s heads.

Enterprises are being asked to postpone the deployment of any 802.11n kit until the standard is finally ratified, even though the Wi-Fi Alliance has certified Draft 2.0 of the standard for interoperability. The bigger problem for enterprises is that they may need to completely upgrade their network if they want to deploy 802.11n. Although gigabit network interface cards have been available for desktops and laptops for a while, firms may need to install new gigabit switches and new structured cabling to cope with aggregated 802.11n wireless traffic.

Still, there’s another 18 months to go before 802.11n finally parks itself on your drive.