  The next generation of electric grid has a scalable and reliable
bi-directional communication infrastructure known as Advanced Metering
Infrastructure (AMI) to allow monitoring and controlling of grid resources. In
this kind of communication system, comprising thousands of resource-constrained
nodes such as smart meters, the routing protocol plays a critical role to
guarantee reliability and low latency for data delivery. The Routing Protocol
for Low Power and Lossy Networks (RPL) currently is standardized by IETF which
is expected to meet the requirements of AMI networks as the standard routing
protocol. On the other hand, cooperative routing has gained a lot of attention
recently. Cooperative routing improves performance over traditional routing by
exploiting the broadcasting nature of wireless channels. Our objective in this
paper is to propose a cooperative approach to RPL for application in AMI
networks. Our proposed protocol, termed as Coop-RPL, is specially designed for
the challenges of AMI networks. Coop-RPL ensures reliable packet transmission
by selecting an optimal relay node. Performance evaluation demonstrates the
efficiency of Coop-RPL for AMI networks with the aim of achieving increased
PDR, and reduced number of retransmissions and end-to-end delay.
