Optimal TDMA Scheduling in Tree-Based Power-Line Communication Networks

The large amount of differentiated quality-of-service traffic generated by modern smart grids necessitates efficient scheduling schemes for the uplink traffic. This paper proposes a cross-layer time-division multiple access scheduling scheme destined for broadband power-line communications (BB-PLC)-access networks. The scheme determines the topology of the smart-grid communications (SGC) PLC trees formed across the power grid, identifies the noninterfering segments in the tree graph, and schedules the uplink transmission. The scheme is based on appropriately adjusting the injected power of the SGC tree nodes following a graph-based distributed approach in the attempt to enhance slot reuse. The scheme has been tested and assessed for typical SGC networks deployed in rural and urban areas, considering both aggregated and nonaggregated SGC traffic. The relevant simulations verify that by reducing the interference due to PLC transmission, the proposed adaptive power-control-based scheme can significantly minimize the injected power, enhance throughput, and reduce delay on an SGC cell basis. The reduction in schedule length depends drastically on the maximum-allowed injected power and the topology of the SGC tree and may reach 70% when combined with data aggregation.