* Check local rules before deploying global 5GHz Wi-Fi
A few years ago, 5GHz spectrum rules were so inconsistent all over the world that it would have been difficult to develop a global strategy for 802.11a networking, even if client devices and handsets had been widely available. Ditto for 802.11h, the derivative of 802.11a that avoids interference with military radar, especially used in Europe.
At this juncture, however, global harmonization is fairly complete, with all but a few Middle Eastern countries and Russia allowing 5GHz networking in at least one of the four 5GHz networking spectrum bands:
* 5.15 – 5.25GHz (four channels).
* 5.25 – 5.35GHz (four channels).
* 5.470 – 5.725GHz (11 channels).
* 5.725 – 5.825/5.850GHz (four or five channels).
Having some harmony among the rules is extremely helpful to worldwide equipment rollouts and will be particularly important as 802.11n enters the picture. 802.11n will be depending on the 5GHz band for its high throughput, because of a characteristic called channel bonding, which combines two radio channels for aggregate bandwidth. Channel bonding is difficult to do in the 2.4GHz range of 802.11b and 11g networks, because only three channels total are available for cell site planning that avoids interference.
So the good news is that 5GHz has become fairly open around the world. As you create your global Wi-Fi plan to include it, however, keep in mind that some countries have their own rules about operation. They might require you to have a permit, for example. Some countries prohibit the use of 5GHz networking in hospitals. Others have restrictions about running it outside, which certainly has implications for muni/metro Wi-Fi networking.
If you are planning to run 5GHz Wi-Fi globally, be sure the chipsets in the wireless products you buy can accommodate all the channels in all the countries where you will be deploying. From there, most vendors’ product guides will inform you of the idiosyncratic rules that vary from country to country.
