Joint Convergecast and Power Allocation in Wireless Sensor Networks

Convergecast is a critical communication paradigm for data collection in wireless sensor networks, where both energy and bandwidth are scarce resources. Previous converge-cast algorithms only focused on minimizing the energy cost without considering the constraint of wireless bandwidth. This article shows that constructing a congestion-free convergecast tree cannot ignore the bandwidth constraint. Considering the adjustable transmission power of sensor nodes, it will affect not only the topology of networks but also the bandwidth of wireless links. In this paper, we formulate the Minimum Total Transmission Power (MTTP) problem, which aims to address the issue of constructing a congestion-free convergecast tree in WSNs with adjustable transmission power of sensor nodes. We transform MTTP to an Integer Linear Programming (ILP) model, by which the optimal solution to MTTP is derived. To strike a balance between scheduling overhead and system performance, we propose a heuristic algorithm called Nearest-to-Sink, which searches viable paths in a greedy way and achieves near optimal performance. We build the simulation model and give a comprehensive performance evaluation, which demonstrates the feasibility and the effectiveness of the proposed algorithm.