In this paper, an effort is made to represent the military access area grade of service (i.e., probability of blocking) in a more realistic way than before. The circuit switching process is structured into three representative contention phases. The three phases are analytically tractable and are rather typical in existing military networks. All three phases apparently have service properties not accurately described by the conventional Engset, Erlang, and other classical models. Their blocking probabilities also differ from those predicted by the classical models. Given an access area network, the three blocking models may be applied individually or in a variety of combinations. The paper demonstrates several applications to typical access area telephony.