Bandwidth Efficient Collaborative Quality of Service Routing for Real-Time Flow in Wireless Multimedia Sensor Networks

Wireless multimedia sensor networks (WMSN) emerges as an important category of Wireless Sensor Networks, which retrieves real-time information such as video and audio streams, still images etc. One of the prominent characteristics of WMSN is severe bandwidth limitation which has great impact on design of routing algorithm. In traditional routing protocols, path(s) are selected aiming at providing optimal transmission performance for the current flow while little attention is paid to bandwidth efficiency. This greedy strategy results in the existence of large amounts of bandwidth fragments which can´t be fully used so that the networks capability to carry real-time flows is degraded. In this paper, bandwidth efficient Collaborative Quality of service Routing (CQR) is proposed. The defining aspect of CQR is to collaboratively optimize the path selections of multiple flows over the networks. The CQR problem is formulized as linear programming. Resource allocation vector is constructed to decouple the inherently dependent path selections between different flows and sub-gradient based searching algorithm is proposed to get the optimal solution. Simulation results show that CQR achieves higher call admission rate for real-time flow comparing to existed algorithm, under heavy load CQR outperforms traditional algorithms about 40% in call admission rate and has similar transmission cost.