INTEGRATED SIGNAL RECEIVER
A signal receiver having: an input for receiving radio signals; a clock; a receiving section for processing signals received at the input, the receiving section being configured to operate in: (a) a first mode for processing the received signals in accordance with a first protocol and in dependence on the state of the clock, and (b) a second mode for processing the received signal in accordance with a second protocol by steps including storing a sample of data received in accordance with the second protocol together with a representation of the state of the clock when that data was received, and subsequently comparing a timing indicated by the content of the stored sample of data with the timing indicated by the stored state of the clock.