News

WiFi Alliance acts firmly on compatibility - 11g tests to start

by Guy Kewney | posted on 25 February 2003


There is still no final date announced for when the IEEE will finally ratify the new, high-speed wireless LAN standard, 802.11g - but the WiFi Alliance has now spoken out, insisting that interoperability testing is an essential part of getting a certificate - and that compatibility with the previous 11b standard is an important part of the process.

Guy Kewney

The Alliance announced that WiFi certification testing of IEEE 802.11g products will begin after the IEEE has approved the final standard.

Sources close to the Alliance have expressed fears that the controversy over the various pre-11g standard chips could delay final approval, perhaps as far as October. Others, more optimistic, say it could be tied up as early as March.

At this point, if the Alliance knows when the finalisation will go through, it isn't saying. However, it has made it clear that full compatibility with the original WiFi standard is essential before anybody gets a certificate.

"Wireless LAN product interoperability is fundamental to a good user experience," said Dennis Eaton, Chairman of the Alliance. "That is why the Alliance is committed to providing users with an indicator of quality for wireless LAN technology as it evolves."

Eaton's organisation believes that it has enough technical information to start work on the tricky subject of what the tests have to established, and has started work. "We need to work on new interoperability tests ahead of time. Therefore, we have already started development of the certification program for IEEE 802.11g products - even though the standard is not finalised."

Eaton concluded: "In fact, the need for a proven interoperability certification program is increasing. As more products include wireless LAN technology, users are often not able to choose which vendor's product is used in their laptop at work, at a favourite public access venue or even in consumer electronics devices. Although the Alliance expects products based on the 802.11g draft amendment to be used in these and other applications, we will only certify products after the standard amendment is approved."

The IEEE 802.11g draft amendment currently includes both mandatory and optional components. The WiFi Alliance intends to certify all mandatory features, including backward interoperability with WiFi certified 802.11b products, and simultaneous operation of IEEE 802.11b and 802.11g devices in a mixed network.

Optional elements of the standard to be certified include support for the 54 Mbps data rate in addition to other selected optional IEEE 802.11g features that will optimize performance and network utilisation.

The bare words are, in fact, a diplomatic phrasing of the Alliance's unhappiness with a situation where products have been launched, without any compatibility being done, before it is even known what degree of compatibility will be required.

Wi-Fi certified IEEE 802.11g products will be identified by a new element on the capabilities label. A new line indicating support for 54 Mbps in the 2.4 GHz band will be added to the label. The new label will be released for use when 802.11g certification commences.

Currently, the leading pre-11g standard products are based on the Broadcom chip set, which doesn't allow the 11g standard to run at the full 54 megabit speeds if an 11b standard product is broadcasting in the area. There is strong lobbying for a standard which overcomes this problem. From this announcement, it would seem likely that the Alliance wants to see that as a definite requirement for certification.

This will be the fourth Wi-Fi certification test that has been developed for 802.11 standards since the program began in March of 2000, says the organisation.

To date, over 600 products from 100 companies have received WiFi certification.