The 54Mbit/s 802.11g wireless LAN (WLAN) equipment currently being sold by many vendors is unsuitable for use in corporate environments due to performance issues, according to Intel, which recently announced it would ship 802.11g technology in its Centrino chipset for notebook PCs.

Andy Greenhalgh, Intel's European mobile marketing director, said last week that low-cost 802.11g Wi-Fi access points and client PC Cards currently on offer from Buffalo, SMC and US Robotics are suitable for low-level usage in the home and small office, but do not provide the bandwidth or reliability needed by roaming corporate users.

Greenhalgh advised firms to invest in dual-mode equipment that supports both 802.11a and 802.11b, or triple-mode kit that also supports 802.11g.

"The future for wireless LANs in the corporate space is 802.11a/b or 802.11a/b/g. In real usage environments where many users connect simultaneously, the performance of 802.11g drops off dramatically," he said. "We fully expect firms to go to 802.11a, although IT departments will have to do their own tests and decide which technology is best for them."

Greenhalgh's comments are borne out by IT Week Labs tests, which show that data rates of 54Mbit/s 802.11g equipment can drop below 10Mbit/s when sharing the network with a single 802.11b client. In contrast, 54Mbit/s 802.11a kit rarely drops below 20Mbit/s, partly because it operates in the relatively clear 5GHz radio frequency waveband - as opposed to the 2.4GHz spectrum used by 802.11b and 802.11g.

Michael Wall of analyst firm Frost & Sullivan said companies should not necessarily ignore 802.11b or g technology, which may be suitable for some environments, depending on the number of users and types of applications being supported.

He also pointed out that the performance of 802.11a can deteriorate if too many access points are used.

"802.11b and 802.11g only have three non-overlapping channels, and the usage planning is limited. 802.11a has eight non-overlapping channels so there is less signal interference, but it depends on how many access points are in one location," said Wall.

Other wireless vendors, including HP and Nortel, are also sceptical of 802.11g's suitability for corporate use. Both have said they will not support 802.11g until a final standard is ratified, if at all.

"The step from 802.11b to a and b is a very logical one [for corporates]. We have yet to understand how 802.11g will fit in with those products," said Peter Kelly, Nortel's president for Europe.

Have your say: reply to IT Week