Optimal bandwidth guaranteed routing and time slot assignment for broadband PLC access networks

High infrastructure availability, easy installation, and low device cost make PLC become one of the promising technologies for broadband communication. In PLC based access network, relay nodes are deployed to extend network coverage and enhance communication quality. In this paper, we consider the bandwidth guaranteed routing and time slot assignment problem in multi-hop PLC networks. Spatial reuse is considered in our system so multiple communication pairs can work at the same time if they do not interfere each other. In particular, our design takes channel quality into consideration in determining the optimal routing. Depending on the receiver node, the sender node uses the best modulation scheme to maximize transmission rate. We formulate the problem as an integer linear programming (ILP) problem. The objective is to minimize the time usage for total data delivery. The output includes optimal routing and collision free slot assignment for each node. To reduce the computation time, we propose a multi-section based algorithm to resolve the problem. We have carried out extensive numerical experiments on several network topologies. Numerical results reveal that the proposed approach obtains significant performance improvement on network resource usage compared to those without taking spatial reuse, routing, and rate adaptation into account.