MOBILE RADIO TELEPHONE NETWORK

A mobile radio network comprises a plurality of base stations in a mutual three-dimensional arrangement in the manner of a cellular system. A respective, rigidly prescribed plurality of immediately adjacent, neighboring radio zones forms a radio zone group in which the frequency channels available are repeated. A problem area occurs in the design of radio zones in that the ground-bound radio propagation dependent on terrain and the nature of the built-up area leads to irregular field intensity distributions and radio zone boundaries; however, the radio zones must be designed according to the distributions of the radio traffic density. A solution for the traffic-qualified radio zone boundary is provided which is best suited for the detection of radio zone boundaries. The identificaiton of the radio zone boundary of two mutually-adjacent radio zones as a criterion for the transfer of mobile subscribers into a different radio zone is provided through a relative range measurement as a comparison of the distance of a mobile subscriber from two or more base sections and an evaluation of the phase difference of their signals is carried out. This transit time measurement is executed by way of the organization channels for operationally-ready radio subscriber devices and in the voice channels for radio subscriber devices involved in a call, the latter upon the use of the measurement receiver of the radio base stations.