Accepting more general telephone calls in emergency situations by limiting general call holding time under trunk reservation control

Abstract

We investigated the effect of limiting the holding time of general telephone calls on their acceptance rate during an emergency situation. Simulation using a queuing system model of a telephone exchange showed that limiting the holding time of general calls increased the number of accepted general calls even when their acceptance was threshold-controlled while still enabling the required number of emergency calls to be accepted. An investigation of the relationship between the traffic intensity of accepted general calls and the general call-blocking rate showed that an upper limit on the traffic intensity can be set by using threshold control. Limiting the holding time enables more general callers to share the acceptable traffic intensity, which reduces the general call-blocking rate. Calculation of the call-blocking rate for various numbers of lines in a telephone exchange showed that the effect of a general call holding time limitation on the general call-blocking rate is equivalent to that obtained by adding a certain number of lines.