What is Grade of service?
Grade of service: In a loss system, the traffic carried through the network is usually lower than the actual traffic offered to the network through the subscribers. The overload traffic is rejected and therefore this is not carried by the network. The amount of traffic discarded by the network is an index of the quality of the service offered through the network and is known as grade of service (GOS) and is described as the ratio of lost traffic to offered traffic. The offered traffic is the product of the average number of calls produced by the users and the average holding time per call. GOS is specified by
GOS = A-A0 / A0
Here A= offered traffic; A0 = carried traffic; A-A0= lost traffic