Efficient Multirate Teletraffic Loss Models Beyond Erlang

6The Engset Multirate Loss Model

We start with quasi‐random arriving calls of fixed bandwidth requirements and fixed bandwidth allocation during service. Before the study of multirate teletraffic loss models, we begin with the simple case of a loss system that accommodates calls of a single service‐class.

6.1 The Engset Loss Model

6.1.1 The Service System

Consider a loss system of capacity b.u. which accommodates calls of a single service‐class. A call requires 1 b.u. to be connected in the system. If this bandwidth is available, then the call is accepted in the system and remains for an exponentially distributed service time, with mean value . Otherwise (when all b.u. are occupied), the call is blocked and lost without further affecting the system. What is important is that a call comes from a finite source population , then the arrival process is smoother than the Poisson process and is known as quasi‐random [1]. The mean arrival rate of the idle sources is given by:

(6.1)

where is the number of in‐service calls, is the number of idle sources in state , while is the arrival ...