It's been about a year since the debut of dual-band routers, those that support both the ever-popularly used 2.4Ghz and the newer, less busy 5Ghz frequencies. This was very exciting news at first, but after having worked with a few of them, I wonder if they are really worth it.
If you turn on a wireless network scan in a neighborhood of a big city (like where we are right now in downtown San Francisco), chances are you'll find multiple existing wireless networks.
Wireless routers are so popular now. Up till about a year ago, they all operated in the 2.4ghz frequency, which is shared by many other home appliances, such cordless phones or Bluetooth devices. This, in crowded areas, could potentially create interference that adversely affects your wireless network's performance.
For you to take advantage of the 5Ghz frequency, the receivers (client machines/adapters) also needs to support this frequency. Most of the existing wireless adapters, however, are made to support only the 2.4Ghz. For this reason, the new routers that support the 5Ghz frequency are generally those that can also support the 2.4Ghz, in most case, simultaneously.
And that is all good. What is not, however, is the problem I have found in all of the dual-band routers I've worked with: the range of the 5Ghz frequency is shorter than that of the 2.4Ghz frequency. Often, the 5Ghz throughput performance is not much faster that of the 2.4Ghz, either.
Also, though the dual-band routers have been out there for a year, there are still very few adapters/clients that support the 5Ghz frequency. And those that do tend to also support the 2.4Ghz frequency. This means, it doesn't matter how much you want it; so far the 5Ghz frequency has been more of an option than a transition.
I find this very much like the ongoing change from the 32-bit Windows operating system to the 64-bit one. As the 64-bit Windows supports 32-bit software applications and there aren't many 64-bit-only software applications, there aren't that many compelling reasons to switch. After a while, your excitement wanes and you wonder why you should even worry about the 64-bit OS at all.
One more thing: Wireless-N routers' radio spectrum consists of 11 channels. This means if they are all set up to use one channel each, there needs to be 12 or more routers/access points in an area to create a considerable amount of interference. Most Wireless-N routers offer the option of scanning and picking the unused channel by themselves.
When it comes to wireless routers, the two most important factors are range and throughput performance. Personally, I find that 2.4Ghz Wireless-N routers are still the best for this. Case in point: our only Editors' Choice award for wireless routers this year is the Belkin N+, a router that doesn't offer any 5Ghz support at all.
Last but not least, 5Ghz or 2.4Ghz, wireless networking to me has always been a mystery. With the same router, it works differently from one location to another, from one Internet service to another, and so on. There are so many unknown factors that could affect your wireless signal.
The only way to ensure the consistency of a LAN is relying on something you can put your finger on. This is where the network cable or a pair of powerline adapters come into play.