ตัวอย่างที่ 6 Consider a cellular system in which an average call lasts two minutes, and the probability of blocking is to be no more than 1%. Assume that every subscriber makes one call per hour, on average. If there a total of 395 traffic channels per cell. Assume that blocked calls are cleared so the blocking is described by the Erlang B distribution. Describe the reason why decreases the trunking efficieny so that system can serve less than users