Exploiting heterogeneity in sensor networks

TLDR

The presence of heterogeneous nodes—those with enhanced energy or communication capabilities—improves network reliability and lifetime, yet the optimal number, placement, and types of such nodes remain largely unexplored. The study aims to investigate how energy and link heterogeneity can be leveraged in ad hoc sensor networks through resource‑aware MAC and routing protocols. The authors analyze, simulate, and test on a real testbed the impact of the number and placement of heterogeneous resources across networks of varying sizes and densities. The study shows that although optimal deployment is computationally hard, deploying a modest number of reliable long‑range backhaul links and line‑powered nodes can triple delivery rates and increase network lifetime fivefold.

Abstract

The presence of heterogeneous nodes (i.e., nodes with an enhanced energy capacity or communication capability) in a sensor network is known to increase network reliability and lifetime. However, questions of where how many, and what types of heterogeneous resources to deploy remain largely unexplored. We focus on energy and link heterogeneity in ad hoc sensor networks and consider resource-aware MAC and routing protocols to utilize those resources. Using analysis, simulation, and real testbed measurements, we evaluate the impact of number and placement of heterogeneous resources on performance in networks of different sizes and densities. While we prove that optimal deployment is very hard in general, we also show that only a modest number of reliable, long-range backhaul links and line-powered nodes are required to have a significant impact. Properly deployed, heterogeneity can triple the average delivery rate and provide a 5-fold increase in the lifetime (respectively) of a large batten-powered network of simple sensors.