[2] In coverage the strength of the signal is measured using test equipment and this can be used to estimate the size of the cell.
The audio quality considers monitoring a successful call for a period of time for the clarity of the communication channel.
This means that two users of the circuit group out of a hundred will encounter a call refusal during the busy hour at the end of the planning period.
The grade of service standard is thus the acceptable level of traffic that the network can lose.
GoS is calculated from the Erlang-B formula, as a function of the number of channels required for the offered traffic intensity.