Bandwidth-Power Aware Cooperative Multipath Routing for Wireless Multimedia Sensor Networks

Cooperative communication is becoming an attractive technology as it can greatly improve the spatial diversity without additional antennas. This novel communication paradigm can effectively reduce power consumption via multi-node cooperation and resource allocation. This paper studies the energy-efficient node-disjoint multi-path routing for a given source-destination pair by joint route construction, relay assignment and power allocation methods. We first define a new bandwidth-power aware cooperative multi-path routing (BP-CMPR) problem, and formally prove its NP-hardness. The paper then presents a polynomial-time heuristic algorithm CMPR to solve the above problem. The algorithm adopts the Suurballe's method to find k minimal-weight node-disjoint paths from source to destination on a weighted graph. Then, dynamic programming is used to implement relay assignment and power allocation. The theoretical analysis shows that CMPR can reach approximation factors of 2 and \frac{4}{3} for BP-CMPR under the amplify-and-forward and decode-and-forward schemes respectively. The distributed version of the algorithm DCMPR is also presented for this problem. We also prove that both CMPR and DCMPR construct the same cooperative multi-path routing, and show via simulations that the performance of the proposed scheme is more than 15% better than that of a traditional multi-path routing scheme, and close to the optimal result for BP-CMPR in variety of situations.