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Wi-Fi Routers - The Differences for Each Region?
Wi-Fi Wonderer asks: "I've been wondering what the difference is between the different regions that can be set on a Wi-Fi router? I know the region determines which channels are available, but I can't find any concrete information on anything else. Do regional settings also determine power output, bandwidth, and/or encryption mechanisms? If you are in a Wi-Fi dense area does it make sense (legal ramifications aside) to choose a different regional setting so as to avoid interference? Will one region give a greater broadcast range than another? Is there any documented information on exactly what configuration settings go with each region?"
United States uses channels 1-11, Europe uses 1-13, and Japan uses 14. Changing it won't get you anything, as most people use 1, 6, and 11, and 13 isn't far enough from 11 to save you from other user inteference.
Google is your friend.
Unlicensed means there is no one who pays a license for exclusive use of the space. That is not the same as restricted, wherein the unlicensed use must conform to certain specifications.
Rex is 09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0
If you mess with your WAP to operate outside of legal bands, there is an excellent chance a local ham radio operator will track you down and submit a couple of pounds of evidence to the FCC (or other regulatory body if you are outside of the US) which could (and sometimes does) result in a nice fat fine.
Your access point has limits for a reason. Please respect them. If you start pissing all over someone else's hobby with your computer junk, they're licensed and you're not, you're the one in the wrong.
The channel bandwidths all overlap, but every fifth starts a new piece... So 1, 6, and 11 are all completely disjoint bandwidths and will not interfere with one another. If you use 8 and 6 in the same area, they will interfere.
Products sold in the U.S. will generally fix the behavior to conform to U.S. rules, and if the Country Code can be changed at all, it probably won't change the operation to add more channels or more power. APs from countries other than US and Japan are usually more flexible.
Some differences:
FCC(US) limits average tx power to 27dBm on 1-11
ETSI(Europe) has a limit of 20dBm on 1-13, although individual countries could add further restrictions.
MKK(Japan) 20dBm on 1-14
In 11a, there are greater differences:
FCC - 17dBm on 36,40,44,48, 23dBm on 52,56,60,64, 30dBm on 149,153,157,161,165
ETSI - 20dBm on 36-64 and 27dBm on 100-140
MKK - 23dBm on 34,38,42,46 and possibly 20dBm on 100-140 plus a few other odd lower channels.
The actual rules are too extensive to list and they're constantly changing. If you have an older 11a Access Point, you might only see channels 36, 40, 44, and 48 available. Another big factor to consider is DFS. DFS applies to channels 52-64 and 100-140. It requires the AP to switch channels immediately when it detects a radio signal that might be Radar, and the user is not allowed to return to that channel for 30 minutes. Client devices must passively scan for APs and APs must scan the channel for radar for 1 minute before starting operation on that channel. The US is adding DFS requirements in July 2006. Fortunately they're adding the 100-140 channel range at the same time, so it's not all bad.
You might think that the upper channels (149-165) are ideal for higher power and no DFS, but I think that is the range that get interference from 5.8GHz cordless phones. I'd go with 52-64 pre-DFS rules. 11a has less range, but that also means less neighbor interference. There is less channel overlap. No microwave oven interference. There are no 11b stations to trigger 11b protection modes, or God forbid, a concurrent 11b user on the same AP as you. Most importantly, there are still fewer users of 11a. Where I live, I have neighbors across all of the 11b/g channels, but just a couple on 11a, so I can find an unused channel all to myself. This is much more important than any B.S. Speedburning, RangeMaxing, Super features which have always under-delivered with performance.
Anyway, I think you can see that the U.S. rules are pretty good, so there's not much reason to set the wrong country and violate FCC rules... unless you like that sort of thing.
Controlling complexity is the essence of computer programming. -Brian Kernigan
The country codes are related to the 802.11d addendum. 802.11d is for International Regulatory Domains. It provides a mechanism to allow subscriber stations to automatically detect the country that they are operating in and limit their maximum transmit power accordingly. Each country's regulating body (like the FCC) sets limits on transmit power for different operating bands. If you look around, you'll discover very little consistency from country to country. It's a regulatory nightmare, really. An AP that supports 802.11d will include the country code in its Beacon and Probe Response messages. A subscriber station that has 802.11d enabled shall not transmit at all until it discovers the country code from at least one AP beacon. When it discovers the country code, it looks up in its own regulatory table (eeprom or flash) the maximum transmit power for that country. Once it determines max power, it may begin its normal transmit operations. So, the intention of the feature is to allow subscriber stations to be certified for operation in multiple countries. For those countries, it would know the maximum transmit power in advance and be able to transmit. However, the spec is not all that clear on its operation, and specifies no regulatory requirements itself, so it's really just a feature that enables operation, but isn't necessarily widely used and implemented. Most mobile station solutions support 802.11d by now, but most have it disabled by default. When 802.11d is disabled, it just uses a home country profile that is programmed in eeprom or flash. Also, there is no requirement to not transmit until discovering the country, so the mobile station can transmit probe requests right away.