Input buffer requirements for round robin polling systems

Abstract

A packet switched network that can be modeled as a round robin polling system with nonzero switchover times is considered. The input traffic is assumed to obey the (σ, ϱ) regularity conditions recently proposed by Cruz [ IEEE Trans. Inform. Theory 37(1) (1991) 114–141]. These conditions are particularly applicable to traffic from open loop flow control mechanisms, such as the leaky bucket. For partially gated service, upper and lower bounds are provided for buffer requirements to insure no data loss. The bounds are extended to gated and exhaustive service and are modified to provide bounds on guaranteed network delays. Using the bounds, it is demonstrated that partially gated service requires nearly minimal buffering when incoming traffic approaches the capacity of the network. It is also demonstrated that open loop flow control can improve the buffer requirements and guaranteed delays of the network significantly.