There are two versions of the Nexus S, one (designated for AT&T in the US) that supports 3G at 850, 1900 and 2100 MHz and the other one (designated for T-Mobile in the US and the only version sold in Europe) that supports 3G at 900, 1700 and 2100 MHz.
Since all British 3G networks primarily run on 2100 MHz, both versions would work on any UK network. Also both versions support all GSM-bands (850, 900, 1800, 1900 MHz).
So you could flawlessly use both versions of the Nexus S in the UK. However more and more operators throughout Europe are also deploying 3G to the 900 MHz-band, which provides higher range and better inbuilding penetration, while the 850 and 1900 MHz bands are not used at all in Europe. In Britain O2 has recently started rolling out 3G coverage at 900 MHz (see http://mobilesociety...-in-london.html
So for Europe (I actually consider the UK being part of Europe
) you would be better off with the T-Mobile version, which is 900MHz-compatible and so future-proof for 3G networks running at 900 MHz.The 850 and 1900 MHz frequencies supported by the AT&T version are only used in the Americas, Australia and New Zealand.
Edited by theInquisitor, 27 July 2011 - 02:11 PM.