Linksys' Next-Generation Wireless LAN: Blazing Speed, Many Questions

Suddenly, you can't throw a rock in a Circuit City or Best Buy store without hitting a box of Wi-Fi equipment with Multiple Input-Multiple Output (MIMO) technology. Vendors claim this intelligent antenna technology provides faster wireless speeds over a wider area than regular Wi-Fi equipment.

I tested Linksys' new Wireless-G router and PC Card with Speed and Range Expansion (SRX), which uses MIMO technology, and found that it's the real deal. If you need your wireless LAN to cover an area larger than regular Wi-Fi equipment can handle, or if you have high-bandwidth needs such as streaming media or voice-over-WLAN, this equipment is worth a serious look.

However, there are some significant 'yes-buts.' These don't relate specifically to Linksys' MIMO equipment but rather to first-generation MIMO equipment in general. Bottom line: Despite the startlingly fast performance of the Linksys Wireless-G equipment with SRX, MIMO isn't for everybody.

Speed Matters

First a word about MIMO, which stands for Multiple In, Multiple Out. In simple terms, it uses multiple antennas and radios for sending and receiving data, which enables it to perform those tasks faster and over greater range. MIMO will be part of the 802.11n standard, which will eventually replace the 802.11g standard. However, final approval of that standard could take as long as two years.

That hasn't stopped vendors of WLAN equipment aimed at homes and small offices from releasing MIMO equipment now. For instance, I recently reviewed MIMO equipment from Belkin. In addition, a host of other vendors, such as D-Link and Netgear, have said they will release MIMO equipment in the coming months.

Linksys' MIMO equipment works as advertised. I found typical data throughput speeds at close range -- that is, the router and adapters were in the same room -- of between 40 Mbps and 42 Mbps. This was only marginally slower than speeds using a standard Ethernet network.

When one laptop used a Linksys SRX adapter and the other used regular 802.11g equipment, typical speeds were about 20 Mbps. When both endpoints used standard 802.11 equipment, speeds slowed down to about 16 Mbps. I used the Qcheck program from Ixia to test throughput.

Linksys also promises a 4X speed increase when the MIMO devices are "two rooms away." Again, I found this claim to be true. From a distant corner of the house with a brick fireplace in between the laptop and the router, speeds using the Linksys SRX system dropped off only to about 38 Mbps. Speeds using standard 802.11g equipment varied widely but averaged around 8 Mbps and, sometimes, the signal was dropped altogether.

While not directly related to MIMO technology, I also found the equipment to be stable. For instance, I didn't have to reset the router during almost two weeks of continuous use. Other routers I've used, including Belkin's Pre-N MIMO router, had to be reset periodically.

I only had two minor quibbles with the Linksys equipment. First, Linksys should put a bit more focus on making the equipment less clumsy to install, particularly since it's aiming at the home market. For instance, the installation program never tells you when to insert the PC Card into the laptop. I installed the Linksys software and, later, plugged in the card. Windows detected a new card made me go through the driver installation process yet again. Most other vendors have greatly simplified this process.

Second, one of the primary target markets for this equipment is home users who need to stream media among various devices throughout the home, the lack of adapters that work with PCs is a serious omission. A spokesman for Linksys said the company will release a USB 2.0 or PCI by the end of the second quarter of 2005. The Yes-Buts

Before forking over your dough, there are some factors to consider and those factors may discourage you. The first is that, at about $200 for the router and $129 for the PC Card, Linksys is charging two to three times the price of plain-Jane Wi-Fi equipment. As a result, it's hard to recommend this equipment unless you specifically have a big area to cover or have high bandwidth needs such as streaming media.

The Linksys spokesman said the price premium is due to the fact that MIMO equipment costs more to produce since it requires multiple antennas and multiple radios. In addition, it requires greater on-board processing power to intelligently manage the signals from those multiple antennas and radios. That's undoubtedly true, but it also should be pointed out that the Linksys MIMO equipment is significantly more expensive than similar equipment from Belkin that I previously tested although, as I mentioned, the Linksys router and PC Card were more reliable.

The second issue relates to compatibility. This issue cuts two ways: short-term compatibility with other Wi-Fi equipment and compatibility with future equipment based on MIMO and the 802.11n standard.

I tested the Linksys SRX equipment with a variety of routers and adapters from Netgear and D-Link and found no incompatibilities. Plus, the Linksys SRX equipment passed my Starbucks test. Belkin's Pre-N MIMO equipment couldn't find the T-Mobile wireless network in Starbucks while the Linksys PC Card had no difficulty at all.

Even though I found no incompatibilities with the Linksys equipment, however, remember that there is no officially ratified MIMO standard. Your neighbor could potentially be using a router that I didn't test that would be incompatible with the Linksys SRX equipment. As a result, it would be best to purchase this equipment from a retailer that allows returns if the equipment proves incompatible.

A potentially bigger problem is compatibility with future equipment. MIMO standards are still evolving and, in fact, vendors of MIMO equipment are getting tetchy with each other about specific implementations of the technology. At the recent Consumer Electronics Show, most vendors I spoke with badmouthed their competitors' MIMO implementations.

The problem is this: Say you install MIMO equipment now and two years from now, after the 802.11n standard is ratified, you buy an expensive media server based on the official standard. Even the Linksys spokesman I spoke with acknowledged there's a good chance that any MIMO equipment you buy now from any vendor won't be compatible with that future equipment.

That's not to say that you should ignore MIMO equipment now. If your immediate need for MIMO is so compelling that it is relatively unimportant that the equipment will be outdated in a couple years, the Linksys Wireless-G SRX is highly recommended.

But make sure your eyes are wide open -- and not blinded by the speed -- before you buy.

Linksys Wireless-G With SRX; Linksys; http://www.linksys.com/SRX/; Router: $199; PC Card: $129