Research On Slot Assignment Algorithm Based On PRIME

The evolution of the power of network technology and the changes of the user demand result in changing of the public power supply’s business model, the electricity sector needs to establish a new technical supported electricity network to adapt to new demands, PRIME (Power-line Intelligent Metering Evolution) is a power line communications (PLC) standard of physical layer and MAC layer in demand.The PRIME standards support two channel allocation mechanisms:TDMA and CSMA/CA. Compared with CSMA, TDMA has the advantages of lower data conflict and smaller transmission delay. This paper studies PRIME channel allocation based on TDMA.To the rational use of channel resources, this paper proposed an Ant-based Coloring Slot Assignment(ACSA). ACSA will change PRIME into a directed graph, and converted the link slot allocation into vertex slot allocation, which will change the slot allocation problem into a graph coloring problem. ACSA slot allocation has two stages. The first stage, use the ant colony algorithm to assign a time slot to each node to get the shortest frame length and the optimal time slot allocation scheme; the second stage, remove the node from the optimal time slot allocation scheme and re-distribution to improve the utilization of the channel.ACSA algorithm increases the transmission delay, so this paper proposed a Staggered Slot Assignment(SGSA) to solve the problem. First, SGSA construct a load-balanced tree, then allocate slot on the basis of the load-balanced tree. The optimization objective of SGSA are transmission delay and channel utilization, it order the total load of tree branch from low to high to get a load set, then select the largest branch in the set to staggered allocation of time slots.