Shaping Throughput Profiles in Multihop Wireless Networks: A Resource-Biasing Approach

A fundamental question in multihop wireless network protocol design is how to partition the network\´s transport capacity among contending flows. A classically "fair” allocation leads to poor throughput performance for all flows because connections that traverse a large number of hops (i.e., long connections) consume a disproportionate share of resources. However, naïvely biasing against longer connections can lead to poor network utilization, because a significantly high fraction of total connections are long in large networks with spatially uniform traffic. While proportional fair allocation provides a significant improvement, we show here that there is a much richer space of resource allocation strategies for introducing a controlled bias against resource-intensive long connections in order to significantly improve the performance of shorter connections. Specifically, mixing strongly biased allocations with fairer allocations leads to efficient network utilization as well as a superior trade-off between flow throughput and fairness. We present an analytical model that offers insight into the impact of a particular resource allocation strategy on network performance, taking into account finite network size and spatial traffic patterns. We point to protocol design options to implement our resource allocation strategies by invoking the connection with the well-studied network utility maximization framework. Our simulation evaluation serves to verify the analytical design prescriptions.