The concept of multi-band wireless is a fairly simple one; you only need multiple radios broadcasting on different frequency ranges to achieve it. These bands are most commonly 2.4GHz and 5GHz. With 2.4GHZ your highest supported wireless type is going to be 802.11n which means that less and less systems will be using this as we move forward. 2.4GHz also has a smaller range to choose from which makes it much easier to get congested and show degraded performance. 5GHz, by comparison has much better performance and a higher saturation point that your average 2.4GHz radio. Having both in a single device allows you to service each and if your device is sophisticated enough to can automatically shift clients between the radios to ensure the best performance this protocol is usually known as dynamic load balancing.
Dynamic load balancing between 2.4GHz and 5GHz was (and still is) not typically available on consumer devices though… at least it was not until companies started noticing degraded performance on their 5GHzs devices due to saturation. This impact lead to the adoption of MUMIMO (Multi-User Multiple Input Multiple Output). If you are not familiar with this protocol, I will give you a very basic explanation. In normal MIMO wireless any connection will occupy all of the antenna that the radio has available. So if you only have one antenna on your 5GHz adapter you are still going to all of the ones your access point has available. With MUMIMO the system will allow you to use the number of antenna that you need. In the above example you would only use one antenna on the radio leaving two open for additional connections. You get more potential connections with the same hardware.
Now someone came up with the idea of extending that and using an existing technology to expand the 5GHz availability in the consumer market. They took MUMIMO and combined it with dynamic load balancing and a second 5GHz radio (complete with its own antenna bank). This lets you shift existing or new connections between the two radios to ensure the best performance. So you do have three radios in your new access point, but you do not have three radio frequency bands which is what would be required for true tri-band devices.
Again, the term Tri-Band is not new, multiple radios with load balancing is not new, nor are the channel plans needed to make all of this work without interference. We just wanted to take a few minutes to explain what the term meant (in simple language) and also to highlight how progress in wireless performance is starting to use multiple existing technologies from the corporate space to enhance what is available to the consumer.
We hope to get a few “tri-band” products in the lab in the next few months to put them through their paces. We will also be working on a comparison between what the consumer has available and wave2 802.11ac devices available to corporate networks.