A travel velocity detector is installed in a mobile telephone station such as a portable telephone or a car telephone. The travel velocity detector adapts a received power level to a travel velocity of the mobile station. Two receiving circuits receive communication waves via respective antennas and output respective power levels E1 and E2 therefrom. The detected powers E1 and E2 are compared with each other to determine which of the powers is greater. A variation of the comparison result is then detected. The number of detected variations, corresponding to a switching frequency, is then counted during a preset time period. A relative travel velocity between the mobile station and an opposite transmitting station is estimated on the basis of the number of the counted variations.

In a multicellular radio communications network, when a mobile station satisfies a criterion for automatic intercellular handover from a source cell to a target cell, the speed of movement of the mobile station with respect to the base station of the target cell is estimated on the basis of the measured levels of the signal which the mobile station has received from this base station before the handover criterion is satisfied. Depending on the layers of the cells concerned, it is then possible to take account of this speed estimate in order to decide whether or not to trigger intercellular handovers.

A method for identifying a fast speed mobile station (MS) in a radio system, said method comprising measuring the frequency error of radio signals received from a mobile station. In order for a fast speed mobile station to be more reliably identified than before, the method comprises calculating the change (df) in BSC the frequency error from a time interval (t) of predetermined length, and identifying the mobile station as a fast speed mobile station if the change (df) in the calculated frequency error exceeds a predetermined limit value.

A method and apparatus for estimating the speed of relative movement of a transmitter and a receiver which are in communication with each other in a telecommunications system. The transmitter and receiver are in communication via a channel of the telecommunications system by a carrier wave. An analysis is made of the variations of amplitude or power of the signal transmitted by the transmitter and the channel between the transmitter and the receiver. The dopler shift undergone by the carrier wave is deduced from the variations, and the speed of movement is thereby deduced.

A system and method in a wireless communications system enables a preferred frequency hopping (FH) sequence to be determined and instituted in real-time. The average speed of mobile stations within a cell is determined or estimated using a variety of techniques. If the average speed is below a predetermined threshold, then a cyclic FH sequence is instituted to achieve superior frequency diversity and therefore combat small-scale fading dips. If the average speed is above a predetermined threshold, then a random FH sequence is instituted to achieve superior interference averaging and therefore combat co-channel interference. Delay timers and a hysteresis may also be used to enhance stability and to counteract short-term fluctuations. The measuring of the average speed and the comparing of the average speed to the threshold are periodically repeated.