  This paper studies the Ethernet Passive Optical Network (EPON) with
gated-limited service. The transmission window (TW) is limited in this system
to guaranteeing a bounded delay experienced by disciplined users, and to
constrain malicious users from monopolizing the transmission channel. Thus,
selecting an appropriate TW size is critical to the performance of EPON with
gated-limited service discipline. To investigate the impact of TW size on
packet delay, we derive a generalized mean waiting time formula for M/G/1 queue
with vacation times and gated-limited service discipline. A distinguished
feature of this model is that there are two queues in the buffer of each
optical network unit (ONU): one queue is inside the gate and the other one is
outside the gate. Furthermore, based on the Chernoff bound of queue length, we
provide a simple rule to determine an optimum TW size for gated-limited service
EPONs. Analytic results reported in this paper are all verified by simulations.
