Apple’s Airport Extreme upgrade to 802.11n may prove to be illegal to operate in the UK, thanks to how it’s implemented.
Whereas many manufacturers of the latest specification of 802.11 wireless networking use the 2.4GHz wireless spectrum, Apple has apparently chosen to implement both the 2.4GHz and 5GHz spectrum. This means it can work seamlessly across all types of 802.11 network (a, b, g, and n), plus it has the advantage that the 5GHz spectrum is less prone to interference.
However, it could limit the unit’s theoretical 5 times speed improvement over 802.11g, because in the UK (amongst other countries including Japan, Germany, Spain, and Austria), a government regulation prohibits wide-channel operation on the 40MHz channel that’s found in the 5GHz frequency. The 20MHz frequency isn’t restricted, but offers only a 2.5 times improvement in speed.
As if that weren’t enough, HDTVUK reports on an expert prediction that the 802.11n’s speed in general may be throttled if there are any 802.11g systems in the same area. Joy.