An energy-delay model for a packet coalescer

Newer link-layer protocols - including Energy Efficient Ethernet (EEE) - support a sleep mode to save energy during idle periods. Bursting or coalescing of packets can be used to reduce the overhead from sleep-wake transitions for such links. We develop an energy-delay model for a coalescing queue given deterministic interarrival and service times. We also model the delay of a downstream queue. The model shows that there is a burst size beyond which only little energy savings can be achieved while the packet delay increases linearly. By a simulation study, we show that the results from our model approximate that of an EEE-enabled Ethernet link connected to an uplink.