Preventing mobile phone transmissions in prohibited areas

摘要

A mobile communication apparatus calculates its location based upon radio control signals received from at least three different base stations 104,102, 112. A plurality of transmission inhibition areas are stored as data and the transceiver is controlled depending on whether the location of the mobile communication apparatus is within one of the transmission inhibition areas. Signal transit time and/or Doppler shift of the received control signals is used to determine the location of the mobile apparatus relative to the base stations. Location data, relating to the base stations, may either be stored at the mobile or transmitted in the control signals and this may then be used in conjunction with the relative location calculation to determine the exact location of the mobile, for subsequent comparison with a look-up table (fig.4) of prohibited transmission areas. One of the base stations 102 (fig.1) used in the location calculation may belong to a wide area, one-way communications system, whilst the other base stations 104 (fig.1) may be part of a two-way cellular communications system.