Voice Mail System in our GSM network has 150,000 subscriber as on date and the traffic carried is 104Erlangs. We want to upgrade the exsisting system.One of the vendors specification says that their system can handle 100,000BHCA at 4.26mErlangs/Subscriber. My question is:1) Can anybody tell me how many customers the new system can handle.
Generally vendor specifications include BHCA and Total Traffic Handling capacity of system.However in this case vendor has specified only Traffic per subscriber only.
You may need to know average Holding Time of a connection if you don’t know Total Traffic Handling capacity.Assuming Average Holding Time of 30 seconds.
Traffic Handling Capacity of proposed system is 100000×30/3600
ie 833E app.
Total Traffic = (BHCA x Avg. Holding Time in sec)/ 3600
Traffic / Sub in your case is 0.69mE
Number of Subscribers supported in proposed system will be 833/0.00069
ie Around 12 Lac
That was a convincing one, the average holding time in case the call is forwarded to Voice mail system is 30sec and in case of message retrieval it is 35sec.