Wireless MIMO shootout Round II
Our old friend Tim Higgins is at it again with this massive MIMO face-off and he looks at the second generation of "pre-N" MIMO products. Tim looks at a wide range of products and I highly recommend anyone looking for high-performance long-range Wi-Fi gear to read Tim's review before you even think about buying anything.
Five months ago, a young rebel startup Airgo Networks was ripping up the competition in wireless range and performance and an incumbent leader in the Wi-Fi market Atheros Communications was coughing dust. But could we now be seeing the "Empire Strikes Back" in Round II of the MIMO wars? That really depends. Atheros was one of the early leaders in the dual-band 802.11 a/b/g market and still has a successful line of dual-band Wi-Fi chipsets that's commonly used. However, its first MIMO product was such a disappointment that D-Link - a user of Atheros MIMO chipsets - refused to be benchmarked in Tim Higgins' first MIMO report. Now with the new Atheros VLocity technology used, Atheros seems to have taken back the speed crown in raw throughput and range. Unfortunately, the competition isn't standing still.
The first problem for the Atheros MIMO products is that the speed attained isn't stable. Atheros MIMO based products use a controversial cheat called "channel-bonding" where two Wi-Fi channels are bonded together to attain the higher speeds. The minute there is another 802.11 b or g Access Point in range, the throughput takes a nosedive because the Atheros channel-bonding products have to stop hogging the spectrum and fall back to a single channel of operation. Because there are only 3 channels in North America allocated for 802.11 b/g 2.4 GHz Wi-Fi, there isn't any room to spare. I can personally see 4 of my neighbor's Access Points in my home so I don't stand a chance running in channel-bonding mode. Airgo's MIMO technology is the only technology that can achieve full double throughput on a single Wi-Fi channel using a technology called "Spatial Multiplexing" so it can operate at maximum speeds even if there are two Access Points using the other two channels nearby.
The second problem for Atheros is that the "Return of the Jedi" has come early. While everyone else is releasing their second generation MIMO products, Airgo has already come out with its third generation of MIMO products which not only make use of Spatial Multiplexing but also channel-bonding. Products like the Linksys WRT54GX4 Router with SRX400 are already available now. The end result is a product that is nearly quadruple the speed of standard 802.11g devices and double the speed second generation MIMO products. (Note that Tim Higgins did not cover the newer third generation Airgo products but I'm hoping that he'll add that soon.) For the first time, Wi-Fi can break the 100 mbps barrier and actually sustain those kinds of high speeds.