Flow routing and relay node selection in cooperative multi-hop networks for heterogeneous demand video transmission

Abstract

Much concern is headed to the technologies to improve network performance with support of cooperative communications in multi-hop wireless networks. The most research is about how to optimize physical layer performance. However, studies on multimedia transmission, especially on video transmission, are not active. This paper focuses on how to get higher performance of video transmission in cooperative multi-hop networks. For that, we proposed algorithms for path selection and node assignment. The purpose of the algorithms is to maximize video image quality, total sum of PSNR, for all the selected paths of video sessions, while transmitting video flows requiring various rates in cooperative multi-hop wireless networks. An MINLP is formulated to resolve video rate assignment, relay node selection, path selection, and time resource allocation problems to maximize the total PSNR value. Two algorithms are proposed to solve this NP-hard problem. It is important to acquire high data rate and low delay in video transmission. In the proposed algorithm 1, a path with the highest data rate is selected while satisfying delay bound and hop-count limitation. And then appropriate cooperative relay nodes are selected to improve the link capacity. In algorithm 2, cooperative relays are assigned in the first phase to find a transmission path for each video session. Each algorithm results in better performance in different conditions as shown in the simulation results.