Abstract: A control apparatus for, and a method of operating, a mobile station in a time division multiplexed access (TDMA) communications system are described. The control apparatus is arranged to determine how many timeslots per TDMA frame are to be or are being employed by the mobile station to transmit data, and to activate an indicator when more than one timeslot per TDMA frame is to be or is being employed. Application to a mobile telephone operating in a GSM/GPRS cellular radio communications system is described.

Abstract: The apparatus is for digitizing demodulated frequency shift key modulated data signals, and comprises a differentiating circuit arranged to receive the demodulated data signal, and produce differentiated pulses at an output thereof. First and second comparators are arranged to receive the differentiated pulses, and compare the pulses with respective reference voltages to generate output pulses when pulses above and below the respective reference voltages are detected. The outputs of the comparators are connected to the set and reset inputs respectively of a flip-flop, causing a digitized form of the input demodulated signal to be generated at an output of the flip-flop.