MIMO technology boosts the throughput and range of wireless networks. We test six router/PC Card pairs to see which makes the most of it.
Edited by Sean PortnoyOctober, 2005
Are you disappointed with the range of your current 802.11b or 802.11g wireless network? Are you ready to start a home network and want today's cutting-edge technology? Either way, you'll want to take a serious look at wireless-networking equipment using multiple input, multiple output (MIMO) technology. MIMO routers broadcast multiple wireless streams of data, using multiple antennae, on a single channel. The result is less interference than with routers that send out only a single stream, as well as fewer "dead spots" and better throughput at long range.
Many 802.11b/g Wi-Fi networks barely work at an indoor distance of 200 feet, but MIMO equipment can still go strong at that range. Even at a 300-foot distance indoors, MIMO equipment may be able to pump out a usable signal. Plus, MIMO products are backward-compatible with 802.11b/g gear, so you don't necessarily need to throw away your older Wi-Fi products. We looked at paired MIMO solutions—a router and a wireless PC Card—from six different manufacturers to see which delivers the best performance.
Although a wireless card from one company can work with another company's router if both use the same underlying MIMO technology, there's no guarantee of 100 percent interoperability. And speaking of interoperability, with the exception of the Linksys unit, all the routers in this roundup are Mac-compatible. Of the PC Cards, only Belkin's and Netgear's models currently work with Macs. Finally, it's unclear if today's MIMO equipment will be firmware-upgradable to the upcoming 802.11n Wi-Fi standard, due to launch next year.
What's next for Wi-Fi? MIMO technology is one of the features that will be part of the upcoming 802.11n standard, which is expected to be ratified by the Institute for Electrical and Electronics Engineers (IEEE) late next year or early in 2007. Products using the 802.11n protocol won't be available until 2007, but they are expected to outperform today's 802.11g devices by a factor of four or five in throughput. (Compatibility with 802.11a, 802.11b, and 802.11g products is planned.) The incorporation of MIMO technology promises to extend range, too. In the meantime, Airgo is targeting laptops for its MIMO chips, according to Dave Borison, the company's director of product management.
In June, Samsung announced that an Airgo MIMO mobile chip will be available as an option on its X20 and X25 notebooks. (Samsung does not sell laptops directly in the United States.) Airgo has also recently released TrueG and TrueAG MIMO chipsets that will be sold in less-expensive networking products.
In addition, the company is working with consumer-electronics manufacturers to bring networked devices with MIMO technology to market for streaming video, possibly by the end of 2005. Further out, Borison says, MIMO technology could be used to improve the performance of Voice over Internet Protocol (VoIP) services over wireless networks, as well as cellular networks. Another company, Video54, employs a MIMO solution that builds smart-antenna technology on top of already existing Wi-Fi chips.
The company says it can be used with 802.11n products whenever they become available. In the meantime, it is also working on improving the quality of service in wireless video streaming. —S.P.
Source: http://shopper.cnet.com/4002-7409_9-6329640.html?tag=fnav
