Wi-Fi Alliance cracks down on ‘standards-plus’ kit

For those that are worried about the Alliance policies, the body says it will withhold or even revoke certification if is sees any interference issues during testing, or during subsequent investigations as a result of vendor or user complaints. The problem is likely to increase as chipmakers start to launch pre-802.11n products. Atheros says it is considering such a product, and Broadcom and Conexant hinted at the same course of action earlier this year. Atheros’ moves:

Last November, Broadcom claimed that it had test results to prove that Atheros’ Super G Turbo Mode, which extends the rate and range of 802.11g, interfered with nearby Wi-Fi networks and dramatically degraded their performance. Atheros denied this but did adjust its channel bonding technique, the supposed cause of the problem, to make it dynamic and eliminate the risk.

But it certainly has not pulled back from its attempts to make up for being caught offguard last year by Broadcom’s early leap into 802.11g. Its latest leap is to promise pre-standard 802.11e functionality using smart antennas, targeting the buoyant digital home market.

The forthcoming 802.11e specification adds quality of service features to Wi-Fi and is vital for voice over WLan and video applications. This makes it important to the most buoyant growth market for Wi-Fi chips, the digital media home. This is the area Atheros will target with its AR50005VA chipset, which is claims is the first “standards compliant” silicon to incorporate the fashionable MIMO (Multiple In Multiple Out) smart antenna technique.

The dual-band 802.11a/b/g device will support multiple DVDquality links of 6-8Mbps each, or a combination of HDTV (19- 24Mbps) and DVD links, over homes up to 550 square meters in area. It will also offer support for the draft specification of 802.11e, though any changes in the standard before finalization could make kit based on the current silicon immediately obsolete, or non-interoperable with newer products.

Signal intent

Atheros’ implementation of smart antennas, which it calls VLocity, is based on up to four antennas. It uses beam forming techniques for transmission – using dual OFDM baseband processors and radios to focus an intense burst of energy towards the receiver, extending data rate and range. At the receiver end, ‘receive combining’ processes signals from up to four antennas to extend range and improve message quality. Atheros claims these two approaches combined “increase the effective signal up to tenfold”.

VLocity is compatible with legacy WLAN devices and with Atheros’ own Super-G and Super-AG technologies, the company claims. It also says that there will be a performance benefit even if AR5005VA products are used at only one end of the link. The chipmaker stated these claims repeatedly, clearly sensitive about the charges that its proprietary Super-G silicon used to cause interference with standard Wi-Fi kit.

The new chipset is available in two- and four-antenna configurations and volume production will start in autumn. Atheros and NEC are demonstrating an Audio Video wireless module, which incorporates the AR5005VA chipset and NEC Electronics' MPEG2 encoder/decoder boards. It supports guidelines from the Digital Living Networking Alliance, a body focused on digital home standards, in areas such as digital rights management. Atheros has recently become very interested in MIMO. It is leading one of two main groups battling it out within the IEEE to control the upcoming 802.11n standard for 100Mbps-plus Wi-Fi.

Its proposal rests on MIMO combined with wide 40MHz bands, while the rival group, which includes Broadcom, is also focused on smart antennas, but using advanced coding rather than doublewidth bands to boost performance. A third proposal has been entered by Agere, using MIMO with either single or double bands and a larger number of antennas.

Analysts at the Linley Group says shipments of Wi-Fi chips will grow to 100m in 2005, double the 2003 figure.

Copyright © 2004, Wireless Watch

Wireless Watch is published by Rethink Research, a London-based IT publishing and consulting firm. This weekly newsletter delivers in-depth analysis and market research of mobile and wireless for business. Subscription details are here.

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