Repeater Coordination in Attenuating Weak Signals on a Circular Flat Area Based on Queuing Theory

Abstract

A repeater is able to amplify attenuating weak signals, as a consequence, transmission distance was greatly elongated. Plus, CTCSS avoid interference among repeaters to some extent, thus providing more channels to accommodate increasing number of users. The problem is, how to coordinate the repeaters in a certain area, flat or mountainous, to suit the users’ demands about communication. Queuing Theory was introduced to solve the problem, the optimum answer is not a constant but is given based on the probability of waiting before served. In our model, the statistic parameter “Arrival Rate” is given by steps, thus forming a series of trails. Different isolines of user performances (especially probability of waiting) are selected and fit the curve to get approximate solutions. If 1000 users are in the flat area, mean number of users who are expected to communicate is 400, the number of repeaters required goes to 42, when waiting probability is set 10–5. If 10000 users, of which 4000 user couples are expected to communicate, the number of repeaters required goes to 224, under the waiting provability of 10–5. In the model, the results are plotted on a 3-dimensional coordinate system, a visual view of parameter flexibility was given.