Editing Grade of service (section)

{{Short description|Concept in telecommunications engineering}}
In [[telecommunications engineering]], and in particular [[teletraffic engineering]], the quality of voice service is specified by two measures: the '''grade of service''' ('''GoS''') and the '''[[quality of service]]''' ('''QoS''').

'''Grade of service''' is the [[probability]] of a [[telephone call|call]] in a circuit ''group'' being blocked or delayed for more than a specified interval, expressed as a [[vulgar fraction]] or [[decimal fraction]]. This is always with reference to the [[busy hour]] when the [[traffic]] intensity is the greatest. Grade of service may be viewed independently from the perspective of incoming versus outgoing calls, and is not necessarily equal in each direction or between different source-destination pairs.  "Grade of Service" sometimes means a measure of inbound [[call center]] traffic to verify adherence to conditions to measure the success of customers served.

On the other hand, the '''quality of service''' which a ''single'' [[Telecommunication circuit|circuit]] is designed or conditioned to provide, e.g. voice grade or program grade is called the quality of service. Quality criteria for such circuits may include [[equalization (communications)|equalization]] for amplitude over a specified [[band (radio)|band]] of frequencies, or in the case of [[digital data]] transported via analogue circuits, may include equalization for [[phase (waves)|phase]]. Criteria for [[Mobile QoS|mobile quality of service]] in cellular telephone circuits include the probability of abnormal termination of the call.