The Wi-Fi Alliance plans to begin interoperability and certification testing of new wireless-LAN products based on the evolving 802.11g standard this summer.

Atheros Communications and Intersil have both developed 802.11g - which offers 54Mbs data in the 2.4GHz band - chip sets. Manufacturers such as Cisco Systems and Proxim plan to sell WLAN access points and cards incorporating the standard. Several hardware vendors are already selling 802.11g products, including Apple, NetGear and D-Link. Those products are out, even though ratification of the standard by the Institute of Electrical and Electronics Engineers (IEEE) has not occurred.

The IEEE decision is expected between June and August, according to Dennis Eaton, chairman of the Wi-Fi Alliance.

But analysts wonder whether 802.11g is ready for prime time this year.

Products integrating the standard must be backward compatible with the 802.11b standard and support simultaneous operation of both 802.11b and 802.11g clients, Eaton said. That presents manufacturers with a tough technical challenge, he explained, since the "b" and "g" standards use entirely different modulation schemes - Complementary Code Keying for "b" and Orthogonal Frequency Division Multiplexing for "g".

Since a "g" access point cannot hear a "b" client due to the different modulations, the "g" protocol includes technology that allows the access point to determine whether there is a clear channel in the 2.4GHz band.

Ray Martino, vice president of the network systems group at Symbol, said the forced sharing by "b" and "g" clients of the same frequency band means enterprise customers with a large installed base of 802.11b WLANs will pass on installing 802.11g access points.

Martino also cited potential conflicts between older "b" clients and the new "g" gear in environments where enterprises also use Bluetooth short-range communications devices, which operate in the 2.4GHz band. In such installations - for example, United Parcel Service sorting hubs where UPS uses Bluetooth scanners and 802.11b WLANs - the conflicts in the 2.4GHz band could be difficult to manage.

Phil Redman, an analyst at Gartner, said his company recommends that enterprises stick with the 802.11b standard due to its maturity and the wide variety of interoperable products.

Eaton said the Wi-Fi Alliance could certify 802.11g products within a matter of weeks after the IEEE approves the standard.