In sensornets with heterogeneous duty cycles, the heterogeneity of duty cycles and unreliable links collectively impact the network performance in terms of path delay, delivery ratio, and energy efficiency, in a sophisticated way.
EoR [4] is an opportunistic routing metric for sensornets with heterogeneous duty cycles.
In a fundamental way, ORW has not well defined the "opportunity" in opportunistic routing with heterogeneous duty cycles.
In the sensornets with heterogeneous duty cycles, a node needs different expected wait times for different potential forwarders.
For different senders, however, their forwarders easily render much different distributions of active times in sensornets with heterogeneous duty cycles.
In this paper, we present the EOF protocol (Efficient Opportunistic Forwarding) for sensornets with heterogeneous duty cycles.
Even though ORW is a prominent opportunistic routing protocol, it does not consider the heterogeneous duty cycles and especially the network throughput in its routing metric.
For sensornets with heterogeneous duty cycles, sensor nodes wake up with different sleeping periods, which combined with unreliable links, making it very challenging to enhance the network performance.
Different from previous opportunistic routings for sensornets, EOF comprehensively considers the effect of heterogeneous duty cycles and link unreliability on the overall network performance.
When the heterogeneity of duty cycle becomes more significant in scenarios with duty cycle ranges 5∼600% and 5 ∼80%, EOF and ORW lead to almost similar path delay, which means that EOF is more adaptive for sensornets with heterogeneous duty cycles.
In a heterogeneous duty-cycled sensornet, sensor nodes can schedule their different duty cycles independently according to their different functions, energy supplies, and positions in the sensornet [3, 4].
