假设目前的情况是one imcoming line, one toll gate. 我们要比较目前的状况与one imcoming line, several toll gates. 找到最优的number of toll gates so that the average waiting time (or queuing length) of the system is minimized.
这个问题与UE没有关系.这个问题做到深处就太深了, 是一个多到达,多服务台,到达池与离开池有能力限制的问题.