Inspired by the structure composed of edge nodes without routing voids, a routing protocol based on virtual coordinates is proposed in this letter. The basic idea of the proposed protocol is to transform a random structure composed of edge nodes into a regular one by mapping edge nodes to virtual nodes on a virtual circle. The virtual circle can prevent greedy forwarding from failing by proposed strategies, so that control overhead and the average length of routing paths can be reduced. Simulations show the proposed protocol has higher delivery ratio, shorter path length, and less control packet overhead and energy consumption.