Wireless-n gear interoperability tested says Linksys

Stuart Corner
Monday, 01 May 2006 12:16

Business IT - Technology

Other readers also enjoyed
First draft of next Wi-Fi standard, 802.12n

Amid claims that current equipment conforming to the still draft 802.11n wireless network standard  will have interoperability problems, Linksys claims to have undertaken extensive interoperability testing of its new range of 802.11n gear.

Agreement was reached on the draft standard only in January but Linksys and Netgear, and others have announced products with immediate availability. Linksys' products announced are a wireless gateway/access point, wireless router, PCI adaptor and Notebook adaptor. A similar range is available from Netgear.

Malachy Moynihan, vice president and general manager, Home Networking for Linksys, said: "A substantial number of products for both homes and businesses will soon depend on compatibility with Wireless-N to reach their full potential. Because of the importance of the technology, we have taken the unique step of conducting extensive testing with multiple vendors to ensure that the greatest possible number of them will perform at peak levels when interacting with our 802.11n products."

However this testing is to existing 802.11g products not other 802.11n products of which there are very few.

All 802.11n products rely on MIMO (multiple input, multiple output) technology: they use multiple radios to simultaneously transmit two streams of data over multiple pathways. This enable each standard 20MHz channel to carry much more data than in 802.11g mode.

The standard also allows transmission over two available channels at the same time, effectively creating a 40MHz channel that doubles the capacity. However industry experts have warned that this mode of operation has the potential to 'hog' the unlicensed spectrum used for all 802.11 systems.

Vendors have made claims for data rates of up to 600Mbps, but it is likely that only 150-170Mbps will be achievable without channel bonding. The Personal Computer World report quoted Paul Senior, vice-president of Airspan Networks, saying that it would not be possible to assess real world performance until certified 802.11n products had been put through interoperability tests.

Two additional key pieces of the 802.11n draft specification are the requirements that products provide both mixed mode operation and backward compatibility with 802.11g and 802.11b. Mixed mode operation designates that, unlike previous proprietary networking technologies, 802.11n networks must maintain optimum speeds when operating with legacy products. Backward compatibility ensures that existing standards-based wireless products are able to work at their respective highest performance levels for that environment.

However with the standard still not finalised and with no large scale deployment s 802.11n gear it remains to be seen whether this level of interoperability will be achieved.