| 摘要 |
In order to calculate the location of a mobile telephone, three base transmission stations 10,12,14 may transmit signals to a mobile station 16,18,20,22 and the time of arrival (TOA) of the signals at the mobile station may be used to calculate location in a process called hyperbolic trilateration. When a mobile station 16 is very close to a base station 10 it may be unable to receive signals from more distant stations within a low visibility area R, this is known as the doughnut effect. In order to mitigate this, a desired low visibility area Rr is determined within low visibility area R. A selected number of calls are dropped from base station 10 in order to reduce the total transmission power Ps of the base station and reduce the low visibility area to Rr. |
