离散时间堆栈系统

The queue can store up to five packets. All packets are processed on a first come – first served basis. Assume that when a packet is serviced all other packets in a queue (if any) are shifted instantaneously towards the output. Each slot departures from the queue are processed before arrivals.-Discrete Time Queue

write a program to produce a discrete time simulation of a queue as shown in Fig. 1. Time is slotted on the input and the output. Each input packet follows a Bernoulli process. In a given time slot the independent probability that a packet arrives in a time slot is p, while the probability that the packet will be serviced is q. One packet fills one time slot.　 The queue can store up to five packets. All packets are processed on a first come – first served basis. Assume that when a packet is serviced all other packets in a queue (if any) are shifted instantaneously towards the output. Each slot departures from the queue are processed before arrivals.