Abstract: A TDMA cellular mobile radio system has at least one network control unit, at least one radio transceiver, and at least one multiplexor for multiplexing and demultiplexing digitally encoded and compressed speech data transmitted between the network control unit and radio transceiver. The bandwidth of the speech data is reduced through compression. The bandwidth of the speech data required on a radio transceiver side of the multiplexor is further reduced by buffering the speech data arriving at the multiplexor at a relatively high modulation rate, retransmitting the buffered speech data at a relatively lower modulation rate, buffering the speech data arriving from the multiplexor at a relatively lower modulation rate, and retransmitting the buffered speech data at a relatively higher modulation rate.

Abstract: A mobile telephony system intended for use by outdoor subscribers, for instance in cars, while affording, at the same time, high traffic capacity and relatively disturbance-free speech transmission to subscribers located within a building, for instance an office building. Signal transmission between mobile stations (MS, MSI) and base stations (BS1, BSI) is effected with radio waves in a first part-system (7), for instance intended for telephony traffic via car telephones, and with light, at least in the area nearest the mobile stations (MSI), in a second part-system (6) intended, for instance, for an office building. Signal transmission with light can also be effected in areas that contain electronic apparatus which is sensitive to radio disturbances, for instance in hospitals and/or in areas in which strong radio disturbances capable of preventing mobile telephony transmission with radio waves occur.

Abstract: The invention relates to a method in connection with handoff from a first base station in a mobile radio communication system, in which method the signal strengths from a set of base stations surrounding a mobile station are measured in the latter. When handoff is considered to be motivated, the signal strength vector formed by the measured signal strengths is correlated with stored characteristic signal strength vectors associated with the first base station. If the correlation between measured signal strength vector and one of said stored characteristic signal strength vectors exceeds a predetermined correlation level, handoff is commanded to a predetermined second base station in the set having acceptable but not the highest signal strength in the measured signal strength vector, or is the handoff procedure interrupted and the connection between the mobile station and the first base station maintained.