Broadcom ships draft 802.11n chipsets

Pre-ratification headache


Broadcom has shipped its first consignments of its draft 802.11n chipsets to vendors. Called Intensi-fi wireless LAN technology, the silicon will be used in kit from Buffalo Technology, Netgear and US Robotics among others. The company claims real-world throughput of more than 180Mbps, though we look forward to getting our hands on some of the kit to see just how 'real-world' that actually is...

Draft 802.11n ‘causes interference’

Spanner in the works

According to Airgo, the draft version of the new 802.11n wireless standard will cause interference with legacy 802.11b and g networks. Airgo, maker of the True MIMO chipsets featured in kits including those from Belkin, Netgear and Buffalo, has made an incredible statement about version 1.0 of draft IEEE standard, approved by the IEEE 802.11 working group on March 10 in Denver. The timing is designed to be devastating for the standard. Netgear has publicly declared it’s intention to release draft 802.11n kit in the first half of this year, while others will be similarly timed. In a statement released to us, Airgo claims that if draft 1.0 kits are released “they will severely degrade – or even disable – nearby 802.11b and 802.11g networks.” Airgo is clearly hoping to start a fight with the release of this statement, which comes despite an 87 per cent approval rate for the draft at the meeting. “A few chipset companies are attempting to develop chip designs based on early, less stable versions of the draft and are resisting all proposed improvements to the specification because they do not wish to ‘respin’ their chips,” the statement continues.

The problem centres around a 40MHz channel bonded mode of the draft standard which uses MIMO technology. Think of this as a turbo mode that may not be on all the routers being released. 40GHz has a problem since there are just three channels in the 2.4Ghz band that don’t already have a problem with overlapping. Craig Reid, Product Specialist for Buffalo Technology explains the draft: “It is mandatory to have 20MHz channels and 40MHz is optional. Only if the chipset vendors like Atheros, Broadcom and Marvell use this 40MHz option…[the draft will] inhibit the 802.11b/g networks that currently exists. The truth is that if you use a 40MHz channel bonded solution then there is simply no room available for anything else in the channel spectrum.” Buffalo isn’t planning to go this route. “As Buffalo is a Japanese company we are pushing for 20MHz channel bonding because in Japan it is not legal to use 40MHz channels in the 2.4GHz frequency,” explains Reid.

Atheros’ CTO Bill McFarland told us that changes to the 1.0 draft are possible, but unlikely: “Any new changes will have to receive 75 per cent approval. Additionally, companies have already been discussing the best techniques for the 802.11n standard for several years now. It’s very unlikely that a new technique would be introduced at this stage….” An ad-hoc group, led by Motorola and Cisco, has been created to look at the 40MHz issue, something that Airgo refers to in its statement as a ‘deficiency’ in the draft standard. This group will report in May. “Atheros’ position is that the implementation of avoidance technologies should be clearly defined and mandatory,” says McFarland. His company is clearly planning to release channel-bonded kit but says this will not cause interference problems.

“Atheros-based devices intelligently select 40 MHz mode only when adjacent channels are free. Silicon based on the 1.0 draft does contain elements to mitigate interference with legacy devices. Atheros will guarantee that its chips include avoidance technologies,” he says. It’s known that the third generation of Airgo’s MIMO chipset, as featured in products including the Netgear RangeMax 240 and Linksys SRX 400 range does have the ‘bad neighbour’ syndrome that Airgo is referring to. “Don't forget, the first company that launched product with the unsocial 40MHz channel bonding technology was Airgo,” continues Reid.

McFarland looks ready for a fight. “We find it rather ironic that Airgo is on one hand promoting its third-generation chipsets, which do cause interference with legacy devices, and on the other hand warning the public regarding the 1.0 draft specification,” he states. “It is a fact that Airgo’s third-generation chipsets are not upgradeable to the 1.0 draft. As a result, one could assume that Airgo is trying to slow down the momentum for the 802.11n standard or otherwise cast doubts on the 1.0 draft specification. In a desperate attempt to preserve MIMO market share, Airgo is trying to create confusion in the market so they can continue to sell their own proprietary third-generation chipsets while creating FUD about competitors’ chipsets.”

Netgear to use Marvell

Netgear is to use Marvell chipsets in its new Draft N kit....

"Marvell, today announced that Netgear has deployed its Marvell TopDog™ branded family of 802.11n IEEE draft compliant silicon products, Netgear’s new PC client and wireless routers based on the Marvell TopDog family are the first available 802.11n IEEE compliant Wireless LAN consumer products in the market."

D-Link also coming to market

D-Link has also announced it will be one of the first manufacturers to market with draft 802.11n kit.

"D-Link's new RangeBooster N 650 router (DIR-635) and optional adapters will be available later this month but can be pre-ordered at the D-Link online store (www.dlinkshop.com) with manufacturer's suggested retail prices (MSRP) set at $159.99 for the router, $119.99 each for the RangeBooster N Desktop Adapter (DWA-547) and RangeBooster N USB 2.0* Adapter (DWA-142), and $99.99 for the RangeBooster N CardBus Adapter (DWA-645)."

Netgear to release draft 802.11n kit

Netgear has announced it will be among the first to ship draft 802.11n kits. Release below...

"NETGEAR’s new products based on 802.11n draft specification will surpass the performance of 802.11g, the current interoperable standard, and will support wirelessly a variety of applications requiring high-quality and advanced data throughput speeds, such as high-definition video streaming and network storage, and will deliver more stable connections at greater range with higher degrees of security including AES (Advanced Encryption Standard).

Highly acclaimed for its innovative product designs, NETGEAR’s new line of wireless networking products will again deliver cutting edge style. The new form factor for NETGEAR’s 802.11n draft specification products will be specially constructed to optimise for maximum stability, speed, range, and security extending data rates up to 600Mbps using spatial multiplexing MIMO technology. NETGEAR will debut the new design and form factor at CeBIT (hall 13, stand C58).

By actively collaborating with leading wireless networking chipset suppliers and working as a member of both the IEEE and WiFi Alliance, NETGEAR is promoting the industry need for multi-vendor interoperability at the new higher speeds and for maintaining reliable backwards-compatibility with existing wireless products.

“The rapid adoption of bandwidth-intensive applications that support high-quality data, voice and video traffic in the consumers and SOHO environments is driving the demand for a network infrastructure that delivers increased stability, faster data throughput speeds, and greater range,” explained Vivek Pathela, Senior Director of Product Marketing – Consumer Products. “NETGEAR commends the progress of the IEEE Task Group in drafting the 802.11n specifications and in accelerating the ratification of the standardised 802.11n specification for sometime in 2007. NETGEAR’s technology suppliers assure that we will have ample supply of chipsets based on a draft 802.11n specification, and we are confident of our ability to commit quantities of products to our channel partners worldwide to meet customer demands.”

He went on to add, “With the new innovative design we have engineered to be optimised for the new wireless standards, NETGEAR’s customers will benefit from products that deliver the maximum speeds and stability that are promised by the 802.11n specification, while providing backwards compatibility with existing 11b/g networks and interoperability with other manufacturers’ products.”

Following the unanimous vote by Task Group N of the IEEE 802.11 committee on January 19, 2006, the Joint Proposal for high-throughput wireless networking up to 600Mbps with spatial multiplexing MIMO is being formatted into an IEEE draft document and further developed in preparation for issuance of a letter ballot. As the standardisation process advances, issues relating to maintaining reliable backwards compatibility with 802.11a/b/g products without degrading the performance of the existing products in the market as well as ensuring multi-vendor interoperability will need to be addressed. As a member of the Wi-Fi Alliance (WFA), NETGEAR supports the WFA initiative to certify products for 802.11n compliance aligned with the ratification of the standard in 2007. In the meantime, NETGEAR is actively working with technology chipset suppliers to ensure the incorporation of those features in the specification that promise reliable backwards-compatibility and channel-friendly behavior with existing wireless networks."