Tips for American Visitors to The Uk: Check Your Cell Phone Will Work

If you plan on bringing your cell phone to the UK (note we call them mobile phones in Britain) then it is best to check in advance that it will work over here to avoid being stuck with a seemingly dead phone when you desperately need to be able to contact someone.

Why might your phone not work? Well a cell phone is basically a two-way radio connecting you to one of the network masts dotted around towns and the countryside. To be able to make that radio link, the phone and the network must both be operating in the same radio band (frequency) and they must be using the same modulation/protocol scheme (the way the call and supporting messages are turned into a radio signal).

An analogy: to hold a conversation with someone, you must both be able to hear them and you must be talking the same language.

Problem #1: modulation/protocol (or language in my analogy)

Some networks in the USA use the European GSM protocol and its third generation follow-on called UMTS, but many use the American IS95/cdma2000 protocols. There are simply no IS95 or cdma2000 networks at all in Britain. If you have a cdma2000 phone then even if it can work in the same frequency bands that we use in Britain, our networks will simply be talking a language it doesn’t understand, so it won’t work at all – it will show no signal coverage.

This is not something you can fix with upgraded software – the protocol in use is built into the very silicon chips of the phone. And since I know of no phones at the time of writing which support both GSM/UMTS and cdma2000 don’t rely on finding a phone that will do both. If you are a customer of one of the cdma2000 networks in the USA you are simply stuck.

You can find out if your home cell phone operator is a cdma2000 one or a GSM/UMTS one by looking at the table on Wikipedia here, but basically AT&T uses GSM/UMTS so their phones are potentially compatible with British and European networks (if they also cover the right frequency – see problem #2 below), whereas Verizon uses cdma2000 and phones issued by them are simply incompatible with British networks (they just don’t talk the same radio ‘language’).

Problem #2: different frequency bands

The USA and Britain use slightly different frequency bands. For example GSM networks operate in the 900 MHz (mega hertz) and 1800 MHz bands in Britain and Europe, but 850 MHz and 1900 MHz in the USA. Your phone needs its own little radio within it for each band it is to work in, but many phones have several and so the good news is that you can get phones which will operate in both the UK/Europe and the USA. Those are called tri-band phones (one with three radio bands: the two in your home area plus one of the two in the other area) or quad-band phones (one that covers all four GSM bands).

You can find out which frequency bands your phone covers from its specification (so a web search or look in the manual if it came with a decent one), but it’s pretty safe to say that of newish phones all but the very cheapest budget models will be at least tri-band nowadays.

But then again it is probably simpler to call up your cell phone provider or take your phone to a shop and just ask if your phone will work in the UK. You don’t need to understand the technical details, really, just that there are physical reasons why your phone might not work here and that it’s worth checking in advance. Though if you’ve read this far at least you have a chance of understanding what they are on about if they try to baffle you with terminology!

Author’s credentials: Bruce Officer is an electronic engineer with many years experience of radio systems and of UMTS cell phone protocols.