Alan Stevens

The march towards high-speed wireless networking continues apace, but it is home and small business buyers who are doing most of the marching. Corporate buyers are proving a lot more hesitant.

Worries over compatibility and delays in the ratification of the new IEEE 802.11n standard are the main reasons for their caution, but there are others, not least the impact that the new wireless-n technology is likely to have on existing network infrastructures.

The latest wireless-n access points can support users at speeds of 100Mbit/s or more and, as such, tend to come with one or more Gigabit Ethernet ports to provide the backhaul connection to the wired network. The supporting wired infrastructure, therefore, needs to have sufficient bandwidth to support those Gigabit links. However, despite all the talk of Gigabit to the desktop, most organisations still only use the technology to connect servers and subnets together, with the rest of the network running at just 100Mbit/s.

Fortunately, upgrading to Gigabit Ethernet isn’t difficult and, if you’re a small business with only a handful of switches to worry about, not that expensive either. However, for larger firms that have many users, it could be a very costly exercise indeed.

On the plus side, faster wireless could make a lot of the wired infrastructure redundant, but there are costs involved even then. Installing new wireless adapters to fixed-wire PCs, for example, or replacing desktops with wireless notebooks are costs that make the ROI calculations far from straightforward.

Then there’s the power angle. To date, Power over Ethernet (PoE) support has been conspicuous by its absence on most high-speed wireless-n access points. That’s mainly because of the lack of corporate demand – the classic chicken and egg situation.

However, the power demands are also much higher, with a lot more than the 15 watts or so provided by the current 802.3af standard required to take full advantage of what wireless-n technology has to offer. And that means giving up on PoE altogether and cabling high-speed access points directly into the mains, which can, again, be costly.
The alternative is to wait until the enhanced 802.3at specification – PoE Plus – gets ratified.

Companies that have gone for wireless switch solutions may also find they need to upgrade their firmware or even their switch hardware to cope. And lastly, even where the necessary infrastructure changes have been made, slower wireless clients can still act as a brake on overall bandwidth. And that means making sure that as many clients are updated together as possible, as quickly as possible to maximise the ROI involved.