Not Quite a Match Made in Heaven

Review: Declaration of 802.11n interoperability by Broadcom and Atheros may be premature.

In an early salvo to prove that wireless LAN equipment based on Draft 1.0 of the 802.11n standard is not only extremely fast but also interoperable among different vendor implementations, Broadcom and Atheros announced on May 31 the results of a months worth of interoperability testing.

Gear based on each companys chip sets does play nice together—given the right circumstances—but consumers should take that info with a grain of salt.

During a visit to Broadcoms Sunnyvale, Calif., offices last week, I got a look at parameters agreed upon by Atheros and Broadcom testers, as well as at the end results of their combined efforts.

The tests aimed to prove chip-set interoperability given several mandatory elements of the draft standard, as well as one optional element.

Tests were conducted using a single Atheros client adapter associated to a Broadcom access point, and using a single Broadcom client associated to an Atheros access point.

Using Ixias IxChariot, testers gathered full-duplex bandwidth measurements for each testbed, finding each combo able to surpass 100M bps of full-duplex traffic.

It is hard to gauge what these tests mean in the grand scheme of things, since they represent a narrow slice in time with findings for specifically detailed firmware and software revisions.

In the case of the Broadcom gear, the firmware under test was actually an earlier revision than the one eWEEK Labs used for last months review of Linksys draft-802.11n-based WRT300N.

Weve also learned that the Broadcom firmware has revved twice since our review, so these interoperability tests are based on old technology, indeed.

/zimages/3/28571.gifDraft 802.11n standard fails to pass. Click here to read more.

Given the lack of data for more current revisions, not to mention the complete lack of testing of products from another draft-802.11n chip-set vendor—Marvell—users shouldnt expect interoperability to come quite so easily in a multivendor home network.

eWEEK Labs will soon embark on a round of interoperability testing among multiple draft-802.11n products. Stay tuned.

Technical Analyst Andrew Garcia can be reached at

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