Marvell Rings In New Year with 3x3 802.11n Silicon

Marvell's latest TopDog-450 802.11n chipset boasts the highest performance available in the market and represents a taste of things to come as 802.11n matures in 2008. Found in numerous consumer-oriented wireless routers and Cisco's modular 1250 series AP, Marvell's current 802.11n Draft 2.0 chipset uses 2x3 MIMO and supports only two distinct spatial streams. In contrast, Marvell's forthcoming TopDog-450 leverages 3x3 MIMO technology with three distinct spatial streams supporting a maximum data rate of 450Mbps. Although effective application-layer throughput will likely be close to half that number because of overhead, that's still over 200Mbps and improvement over currently available ~150Mbps 802.11n Draft 2.0 performance. Like previous wireless technologies, this solution only achieves its maximum performance when paired with a technically homogenous client and will automatically 'downshift' to 300Mbps rates when communicating with today's 802.11n Draft 2.0 chipsets. In addition, 450Mbps can be seen as a best-case performance peak, achievable only with a double-wide channel (40MHz), when AP to client distance is low and environmental multipath conditions are sufficient to support three distinct spatial streams.

One of Marvell's main silicon competitors, Atheros, still has yet to announce a 3x3 MIMO chipset supporting three spatial streams (one supporting two spatial streams is currently shipping) but this will probably occur sooner than later. In addition, Atheros' chipsets can be found in enterprise-class APs including Aruba's AP-124/5 and Trapeze's MP-432. Although this is an exciting development for next generation wireless networks, don't expect its benefits to trickle into the enterprise just yet. According to the press release, volume shipments aren't expected to begin until next quarter and it's likely that consumer oriented access points will utilize Marvell's new chipset well before it is found in anything considered enterprise-grade.