Mobile phone signals mapping app appeal for help

Technology correspondent Rory Cellan-Jones explains an ambitious BBC project which aims to map mobile coverage across the UK.

Members of the public can download an app which will record the signal on their phone and feed the data back to the research project.

The aim is to plot the findings on a map which will be searchable by postcode.

Rory Cellan-Jones says "the more people that help with the project, the better it will be".