Performance Model and Multi-Hour-Optimization of Circuit Switched Networks Driven by Optimized Dynamic Routing Networks Driven by Optimized Dynamic Routing

摘要

The subject of this paper is a highly precise and numerically efficient Erlang fixed-point model of nonhierarchical networks that are driven by Siemens' event-dependent Optimized Dynamic Routing (ODR). Based on extensive simulation it is shown that the calls alternatively routed by the dynamic routing automata arrive at links approximately as Poisson processes with the calls on average having access to an effective number M~* of statistically independent two-link paths. The phenomenological parameter M~* can easily be determined by simulation. M~* is generally non-integer and differs considerably from the nominal M currently used by many models. When incorporated into the Erlang fixed-point model it leads to excellent precision. Simulations also indicate applicability to least-busy-alternative (LBA) routing. Explicit numerical solution of the full set of link-state equations is avoided making the model very efficient. This efficiency allows for direct use of general purpose programming methods on top of the performance model to solve the multi-hour problem. Design results for asymmetric networks are presented and checked by simulation. An extension to IPP (Interrupted Poisson Process) external offers is described and first analysis results are also shown for the IPP case.