Top of the Chips: Marvell, Atheros

By Eric Griffith

July 20, 2004

The Linley Group, an analyst firm tracking the makers of Wi-Fi silicon, pegs the best available today in its second 'Guide to Wireless LAN Chip Sets.'

There are a lot of names in the wireless LAN chip world, but apparently two stand out: Atheros Communications and Marvell Technology Group .

That according to the technical analysis and comparison of today's existing Wi-Fi chipsets as set forth in the report, "A Guide to Wireless LAN Chip Sets," the second such guide from the Linley Group, an analyst firm out of Mountain View, Calif.

According to Bob Wheeler, a senior analyst there and co-author of the report (along with Linley Gwennap), the firm looked at the specifications and information on products used in client-side Wi-Fi in two categories specifically -- 802.11g-only and dual-band 802.11a/g chips.

"In 11g, we looked at production level products from seven vendors," says Wheeler. "Atheros, Broadcom, Conexant, Intel's miniPCI module, Marvell, Philips, and Texas Instruments -- we put Intel in even though they don't sell actual chips, just the modules used for Centrino [laptops]. In looking at the combination of integration, how that impacts cost, the ease of manufacturing, radio performance, power consumption, all these factors -- we liked Marvell's latest Libertas."

The Libertas 88W8310 baseband/MAC and 88W8000G RF Receiver chips have an external power amplifier (PA) which Wheeler says is unique -- even single chip solutions from other vendors have the PA outside, and thus the Libertas isn't far behind in the number of components.

"It also has some performance features that Atheros and Broadcom don't, like per-packet antenna diversity. Instead of picking an antenna to use at boot time, it changes antennas as it needs, which helps with multipath interference," says Wheeler.

In the dual-band 11a/g world, he says it's "no surprise" that Atheros is the leader. The report marks the Atheros AR5004X chip as a leader because of factors like worldwide frequency coverage -- it handles channels in Japan and Europe, for example, that aren't available in the U.S. -- and for having the fastest turbo mode available today.

The turbo modes of chip makers are controversial with some after last year's reports by Broadcom that Atheros' Super G using channel bonding caused interference, a charge Atheros denies. Atheros changed channel bonding to eliminate any problems anyway. Just yesterday the Wi-Fi Alliance said that if interoperability testing shows a proprietary speed extension causing interference, it would not allow a product with that extension to get official Wi-Fi Certification.

There are 40 total companies mentioned in the report as developing some type of 802.11 chip.

Linley Group did not do any benchmark testing on the chips -- the comparisons are based on the specifications, the architecture, and design of the chips as provided by the vendors. This report doesn't include all chips for access points, just those on the client side -- they say a trend of note is the growing segmentation of chips for markets like access points, routers, and handhelds. They examined some 802.11b single-chip solutions targeting handhelds, but did not make a final estimation on what was best since few of the chips are in final production.

"When you get into handhelds," says Wheeler, "you have to look at other products they offer -- Broadcom, Philips, and TI all have Bluetooth and cellular baseband, not just 802.11." He says the lack of that diversity could hold back companies like Atheros and Marvell as they try to get a share of the handheld pie. Atheros also hasn't released full specifications to Linley Group on its single-chip product.

"Companies with multiple technologies have a better position," says Wheeler.

Linley Group says the shipments of Wi-Fi chips will grow to 100 million in 2005, double what it was in 2003.

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