Processing of cellular radio data, in particular by a SIM card of a terminal in a mobility situation, said SIM card receiving a current cell identifier and comparing the current identifier with an identifier previously stored in memory, in order to generate a notification intended for a remote server when there is a difference between the current identifier and an identifier previously stored in memory. More particularly, the SIM card stores in memory a list of current identifiers of respective cells in which the terminal is successively located, and the sending of a notification to the server occurs only if the current identifier is absent from this list.