Analysis of the probability of interference during a telephone interconnect call

This paper develops a means of estimating the probability of call interference for telephone interconnect calls placed on mobile radio systems with reuse. Two classes of systems are treated: (1) those in which the channel is monitored for occupancy prior to placing a call and (2) those in which the channel is not monitored. An example of a class (1) system is the recently proposed personal radio communications system (FCC PR Docket No. 83- 26). Traditional cell system designs fit into class (2) as there reuse cell spacings are engineered so as to achieve some desired "static" interference probability. Our analysis accounts for the temporal variations of average signal powers with both desired and interference sources moving and is thus "dynamic". We take as the definition of call interference, the probability that during the first T seconds of successfully established calls the desired-to-interference power ratio falls below a reference value of x dB at least once.