Deadline-constrained transmission scheduling and data evacuation in wirelesshart networks

Abstract — Real-time data delivery is a critical issue in Wire-lessHART networks. This paper develops a novel mathematical programming framework for joint routing and link scheduling of deadline-constrained traffic in WirelessHART networks. The general framework explores dynamic network flows in a time-expanded graph model and can provide flexible solutions for a variety of real-time data delivery problems. Data evacuation, an important communication paradigm in WirelessHART net-works, is a special case of this general framework. We establish the lower bound on evacuation time for line, multi-line and binary tree networks. Moreover, we design a novel scheduling algorithm for data evacuation in binary tree networks, and prove that this scheduling algorithm always achieves the lower bound on evacuation time. We evaluate our scheduling algo-rithm through numerical simulations, and the results verify that our algorithm minimizes the evacuation time with the least number of channels. I