Multi-hop aided wireless data collection based on flow priority

In traditional power grid, Data Aggregator (DA) and Distribution Box (DB) send the data collected by sensors to Base Station (BS) through cellular interface, which is called Single-hop Communication Mode (SCM). There are too many nodes with different data packets which need to be delivered to BS. But BS can't satisfy the delay requirements of different data because of limited resources through SCM. In order to meet the QoS requirements of different priority data, we introduce Multi-hop Communication Mode (MCM) into this scenario to improve the network's performance by adding another wireless interface on each node (DA or DB), such as wifi or zigbee. We present a framework in which a relay node is chosen according to the node's energy consumption and its residual energy, and DB equipped with large capacity battery is chosen as the cluster header, which helps to forward DAs' data to BS. Our main idea is that each node decides which communication mode the packet should use based on its priority and Residual Life Time (RLT). According to packet's RLT, one node can decide whether it should send it right now through single-hop, or put it into the corresponding queue and then send it to the next hop (multi-hop), or drop the packet. In a node, different priority data packets are put into different priority queues. In each queue, packet is sorted according to its RLT. When the first packet needs to be sent out, the node combines the first few packets in the same queue into a large packet, and then sends it out. The simulation shows our scheme can satisfy the performance requirement of smart grid.