Having set up a network for a UK based outpost (40 office based staff) of a N American company (1500+) we would have frequent visitors from the US. Working with companies on adjacent floors for AP channels we had 13 in use and there was never an issue with any visitors. We also had Ch5 in a different past of te office

When that was set up we ran tests in conjunction with the neighbours, using channels 1, 5, 9, 13 and were getting data rates at over 95% of the channel maximum.

Edited by MHC (Thu 19-Jun-14 09:09:29)

None of his APs will be on auto, they will be manually configured. Yes there is overlap between 1 and 5 but it in minimal and interference weaker. Even when 1 & 6 or even 1 & 8 are used there are sidelobes which cause interference - they don't occur between 1& 6. That interference can be a lot worse that caused by the small overlap.

It is the APs that have the channel defined and not the PC. And if there is one, then it is the user who has incompatible equipment.

One main reason that locations in te UK use 1, 6, 11 is that those installing them do not understand what is actually happening on the RF side.

A lot of laptops sold in pc world even in the UK will not work on channel 13 out of the box.

It's not the AP it's the drivers installed being American and often for that particular card there's only usa drivers available online.

Why does a card driver even need to know which channels can be used? It should listen across the whole band for any WAPs in use and then connect to those.

Wireless cards can setup adhoc networks between devices that don't require WAPs. USA ban the use of channel 13 due to it not being licensed. I believe the USA therefore require that it be disabled on the cards to ensure the radio does not use that channel.

It is because in the USA you are not allowed to use channel 13. As such the drivers will disable the card even seeing any AP on channel 13.

Often you can buy a PC in PCworld and by default 13 will not work. Updating the drivers to UK ones will make it see channel 13. A lot of cards however only have USA drivers available. As well as this some tablets and other devices will not work on channel 13 and updates do not fix this.

Likewise most devices do not see channel 14. Apart from a few Japanese devices operating on 802.11b I believe.

Edited by ukhardy07 (Thu 19-Jun-14 13:58:31)

In reply to a post by ukhardy07:

It is because in the USA you are not allowed to use channel 13. As such the drivers will disable the card even seeing any AP on channel 13.

Often you can buy a PC in PCworld and by default 13 will not work. Updating the drivers to UK ones will make it see channel 13. A lot of cards however only have USA drivers available. As well as this some tablets and other devices will not work on channel 13 and updates do not fix this.

Likewise most devices do not see channel 14. Apart from a few Japanese devices operating on 802.11b I believe.

This is what 802.11d is supposed to sort out. Some drivers in Windows have a setting to enable this.

Listening on channels that the USA doesn't allow is fine, but in the case of hidden SSIDs an active probe is done which breaks FCC regs.

My previous Android phones only did passive WiFi scanning, I was very surprised when I discovered that my Nexus 5 does active scans. As my job involves measuring radio systems I now keep the WiFi off entirely at work and have disabled Google's WiFi enable override too.