To simulate the communication network of a metro railway line and develop a detailed traffic model to meet the system design of all of the sub-systems to make an assessment of:
The overall railway communication network is composed of four rings, which was simulated and analyzed.
Traffic models were created for:
All traffic was modeled was unicast traffic flowing from Control Center to STATIONS per the rates provided.
The following assumptions have been made for simulation purposes:
NetSim simulation was run during about 2 million packets and 22 million events were processed.
The result of the performed simulation showed that the worst case scenario caused traffic loaded to cross 1 Gbps and hence the original link dimensioning had to increase to factor this in.
These results were based on simulation of unicast traffic. If the path between server and client traverses h3 router hops and h2 switch hops, the "unicast" video would consume 1.5 x n x h3 Mbps of router bandwidth, plus 1.5 x n x h2 Mbps of switch bandwidth, where n is the number of unicast clients. However in a multi cast environment, a single video stream is replicated as required by the network's multi cast routers and switches to allow an arbitrary number of clients to subscribe to the multi cast address and receive the broadcast. Within the network, the multi cast transmission would consume only 1/nth of the bandwidth of the unicast solution.