A couple of months ago I purchased an O2 Mobile Broadband USB dongle so that I could continue working during an ADSL outage. Once the ADSL was back on I had no further use for it. Seeing as I also had a 3G-enabled Samsung Galaxy Tab 10.1 without a SIM, I thought it would make sense to use the remaining data allowance on that. However I was initially unable to find the right settings to make the tablet connect to O2’s network.
Having given it another shot before the unused data expires, I have eventually stumbled upon the correct settings, which I’ll document here for anyone who might need to achieve the same. Previously I was trying the device’s default O2 access point configurations and the APN settings I found on the web. The problem with these is that they are for pay-monthly and pay-as-you-go SIMs sold specifically for use in phones and tablets. The settings for the mobile broadband SIMs are different. You need to use the m-bb.o2.co.uk APN rather than payandgo.o2.co.uk or mobile.o2.co.uk. The full working settings from my Galaxy Tab are shown to the right (the obscured password is, predictably, ‘password’).
Update (30/1/2013): After the remaining data had expired, I didn’t use the 3G functionality of the tablet for a while, during which time I updated the tablet to Android 4.0.4. For whatever reason, the settings shown here no longer worked after adding more credit to the SIM. Eventually I discovered that the “APN type” field had to be set to “default” rather than “internet”. I also switched to using the “o2bb” username that the OS X connection manager software uses with the dongle.