Use these links to check the network
coverage in your area. 
http://www.t-mobile.co.uk/business/services/uk-coverage/streetcheck/
http://search.orange.co.uk/ouk/portal/coveragechecker.html?channel=direct/
http://www.o2.co.uk/coveragechecker
http://www.vodafone.co.uk/personal/price-plans/network-and-coverage/uk-coverage-map/index.htm