1. A method of predicting future connectivity of a portable electronic device comprising: accessing a query composite signature vector providing an indication of a plurality of radio scenes detected at the portable electronic device at respective predetermined reference times, each radio scene identifying transmitters and associated signal strength of signals received by the portable electronic device at the respective reference time; retrieving one or more connectivity predictions from a corpus of pairs of: a composite signature vector, providing an indication of a plurality of radio scenes detected at one or more different portable electronic device at the predetermined reference times, and associated connectivity information, each of the one or more connectivity predictions retrieved based on a similarity between the associated respective composite signature vector and the query composite signature vector; and providing future connectivity prediction of the portable electronic device based on the one or more retrieved connectivity predictions.