Using my 3G iPad in the UK

I spent several days at the beginning of the month visiting my family in England. Since I was staying with my mother in Oxford, and she doesn’t [yet] have any kind of broadband, I had to decide how to stay connected. I elected to take my new 3G iPad with me, and to replace the AT&T SIM with one for a UK-based pay-as-you-go service. I thought about using my iPhone 4 instead, but I wanted to keep my US number “live”, and iPads are shipped unlocked, so I wouldn’t have to do any hacking.
A couple of hours after I arrived at Heathrow, I went into central Oxford to get a SIM. It’s tough: there are mobile phone stores every few yards, and most electronics stores are also carrying the 3G iPad. I eventually picked Vodafone, and was enthusiastically greeted by a young staff member who explained that they’d only just received the iPad data plan kits, and that I would be their first customer. I thought about leaving, but decided not to….
The basic scheme was very simple: 250MB for £10. No alternatives. I wasn’t sure that 250MB would be enough, and asked if I could get an immediate top-up. The answer was “no”; I would have to wait until I’d used most of that allowance before I could apply a top-up. I was pretty sure that other companies were offering better deals, but I decided to stick with it. (As it turned out, 250MB was plenty: I used less than 200MB during the five days I was there.)
Since this was the first time they’d handled this particular transaction, the two Vodafone representatives used it as a training opportunity, and worked through a checklist to get everything registered. Once they had done this, I asked them to replace the SIM while I waited. This was a prudent move, because it turns out that the documentation in the SIM package did not include the username and password corresponding to the APN. Fortunately the training checklist did include the necessary data, and 20 minutes after I arrived I was online. And it was completely anonymous: I paid in cash, and never provided my name or address. (Presumably they could trace my iPad, but even so….)
With my 3G-enabled iPad, I headed off to a nearby pub for beer, food, and email. All three worked perfectly. Unfortunately, when I got back to my mother’s house on the western outskirts of Oxford, I discovered that I was in a Vodafone “dead zone”. Coverage flickered from 3G to EDGE and (most ofter) GPRS. Async email was OK, because the iPad client was quite good at detecting moments of good connectivity and grabbing any pending messages. Twitter was hit-or-miss. Web surfing was horrible, though. (And to rub things in, my iPhone proceeded to roam to Orange, and showed five bars of 3G connectivity the whole time. Obviously I had data roaming turned off….)
During my visit, I used the iPad up and down the country, from Newcastle-under-Lyme to Heathrow, and apart from west Oxford it worked fine. I didn’t test the bandwidth (I wasn’t sure how much traffic a speed test would generate), nor did I try using Skype. When I returned to the US on Wednesday, I replaced the AT&T SIM and was about to check online to see what APN I should configure. I needn’t have worried: it looks as if the iPad remembers the APN for each SIM that it’s seen.
Before I return to Oxford, I hope that BT will have installed a Home Hub, so that I can get WiFi broadband access. And then I need to find a voice-dial phone for my mother – not a mobile, but a voice-activated desktop phone, preferably with a speaker.