Cost-efficient placement of communication connections for transmission line monitoring

For overhead transmission line monitoring, wireless sensor networks offer a low-cost solution to connect sensors on towers with the control center. However, these networks cannot meet stringent quality of service (QoS) requirements, in terms of packet delivery ratio and delay. Also, it is necessary to ensure robustness such that data can be delivered when a tower fails. In view of the QoS and robustness requirements, wide area network (WAN) connections, such as cellular and satellite network are needed, on top of wireless sensor networks. Different WAN connections have different characteristics in terms of availability, performance, and cost. We have proposed a novel scheme, called optimal placement for QoS and robustness (OPQR), which uses the canonical genetic algorithm to determine the numbers, locations, and types of WAN connections to be deployed to minimize cost while satisfying the QoS and robustness requirements. Evaluation results confirm that OPQR can indeed fulfil the desired requirements at minimum cost, and it is a very useful tool in cost-efficient communication network planning for transmission line monitoring. Specifically, OPQR can maintain cost below USD50 per day for a transmission line that has 80 towers spanning across 32 km, while maintaining the packet delay below 100 ms, packet delivery ratio above 99.99%, and each flow has two node-disjoint paths to the control center.