Cross-Layer and Path Priority Scheduling Based Real-Time Video Communications over Wireless Sensor Networks

This paper addresses the problem of real-time video streaming over a bandwidth and energy constrained wireless sensor network (WSN). Considering the compressed video bit stream is extremely sensitive to transmission errors, and the constraints in bandwidth and energy in WSNs and delay in video delivery, we exploit the construction of an application-specific number of multiple disjoint paths to enlarge the aggregate bandwidth and facilitate load balancing and fast packet delivery. For efficient multi-path routing of real-time video frames, we propose a path priority scheduling algorithm to satisfy the delay constraint of video frames while balancing energy and bandwidth usage among all the available paths. In the case that the aggregate bandwidth is still not enough to satisfy the required coding rate, we further exploit a cross-layer technique for adaptive coding according to path status. The effectiveness of the proposed scheme is evaluated and demonstrated by simulations.