E-Week reports that Broadcom may be taking a giant leap forward with a proprietary, non-standard “802.11n” product in the 2nd half of 2004.
The IEEE 802.11n committee is working on 108 Mbps and faster standards for wireless LANs. The 802.11n spec will reportly handle speeds of 108mbps and above on a single channel. It will use packet bursting to enhance actual throughput and may standardize on some form of MIMO antennas to enhance speed and range. But it won’t be ratified before late 2005. Airgo, for example, claims a range of up to 300 feet using MIMO antennas.
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It wouldn’t be the first time Broadcom has jumped the gun on standards to get an early market lead. All the major chipset vendors with 802.11g products currently use speed enhancement called packet bursting based on the upcoming 802.11e specification (for Quality of Service). It may also be used in 802.11n.
Broadcom currently uses a proprietary feature called Xpress, based on packet bursting, to increase performance beyond the standard 54 Mbps. Intersil promotes PRISM Nitro and Atheros Super G adapts packet bursting (WME) along with the ability to bond two channels, instead of one.
Although packet bursting (WME) is apparently part of a proposed 802.11e/n extension, none of these features is standardized (yet) so vendor interoperability is nil.
Broadcom recently called Atheros chips an “802.11g jammer”. But replicating Broadcom’s test, with two totally separate Broadcom-based wireless networks side by side, running in standard G mode on Channel 1 and Channel 11 “saw significant performance degradation—as low as 1.2Mbps — “simply because they were right next to each other”.
Investigation by Tim Higgins revealed:
- A Super-G WLAN running at full speed will seriously interfere with some 11g WLANs running 2Mbps streaming video even at 30 feet. The interference is essentially gone at 50 feet.
- Dynamic Super-G-based wireless LANs do not interfere with all 802.11g and 802.11b wireless LANs operating on Channels 1 or 11, even at ranges under 10 feet
- Super-G Interoperability problems appear to be most severe with Broadcom-based 802.11g products.
Broadcom’s “802.11n” is no standard at all, of course. It’s just an attempt to get an early market share - at the expense of compatibility and a “real” standard.
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