MIMO technology is used in broadband routers and cell phones. Lately, you hear the term in reference to 802.11N which is the wireless standard the industry is trying to finalize. The standard isn't ratified, but companies have been offering routers based on the draft specification.
MIMO (pronounced my mo) is an acronym. The letters stand for Multiple Input Multiple Output. These routers use multiple transmitters and receivers. Instead of sending one data stream, multiple data streams are sent in parallel thereby improving the data rate. You might think of a MIMO router as a multi-lane highway rather than a double lane road. Instead of having one car or transmitter (radio), you have many.
One characteristics sign of a MIMO router is multiple antennae. In some cases, you can't see the antennas as they are internal and enclosed in the router. Other devices have prominent external antennae that look like they'd fit on the set of a science fiction movie.
Benefits of MIMO Routers
There are some clear benefits to using MIMO routers. These include:
- Faster speeds
- Greater distances between your paired devices
- More simultaneous users
- Less signal fading and dead spots
- Better resistance to interference
Disadvantages of MIMO Routers
There are disadvantages with MIMO, but these may be temporary. The first disadvantage is that MIMO routers have a premium associated with them. You can expect prices to fall as the products mature, but for the short term these routers cost more than the ubiquitous 802.11g routers.
The second concern is the pending 802.11 N standard. Most people are anxiously waiting for the 802.11N routers since they offer much better distance and throughput. Router manufacturers have been releasing equipment with various labels like Pre-N or Draft N.
Although the speed and distance improvements are appealing, the standard may not be ratified till June 2007 or even later. You need to balance your need for speed and distance with the fact your Pre-N router may not have an upgrade path or work with all your equipment.
Despite 802.11N being in draft mode, there are current MIMO wireless routers that use the 802.11G standard. This option may be a more practical for people who are having connection issues caused by distance. Companies such as Belkin, Linksys, Netgear and others offer wireless router solutions with MIMO. You'll see labels such as RangeMax, Wireless G Plus, and SRX (Speed and Range eXpansion) appear as part of the model name. Each term reflects a specific company's implementation. When you factor in antennae technology, chip sets and other technical specifications, you can have substantial differences between manufacturers.
Most people I know who tried these MIMO routers had favorable opinions. Although the results varied, the people who paired devices from the same manufacturer and same technology fared well. Friends who tried to mix and match devices had more problems, but this could be because they had to deal with two different companies for support.
I can relate to this last point as I once returned a wireless notebook card so I would have the same manufacturer for my router and wireless card. Before my switch, each company claimed my problem was caused by the other company. It's best to research what type of equipment can be paired to the MIMO router and how it will impact performance.
Another item to note is the stated data speed and distance claims. It's easy to get seduced by claims of a product being up to X times faster. Certainly there will be gains, but I've not met anyone whose results were as positive as the manufacturer stated. This is one area where you might want to find a good comparative review by some of the computer magazines or websites.
The bottom line is I believe the 802.11N MIMO routers will provide much needed advances. Until the standard is made final, I would defer a purchase and look at the current crop of MIMO routers with 802.11G.
Last Updated (Friday, 06 April 2007 14:02)