Cross layer load balanced forwarding schemes for video sensor networks

In this paper, we propose two cross layer geographic forwarding schemes which address congestion in wireless video sensor networks (VSN) to provide reliable video delivery. The first scheme Load Balanced Reliable Forwarding (LBRF) introduces the notion of local load balancing where a sensor dynamically determines the next hop among the alternative neighbors providing positive advancement towards the sink by considering the balance of their buffer occupancy levels at the time of delivery. LBRF utilizes a modified version of SMAC where the packet structure as well as the operation of SMAC is modified for the accurate monitoring of the buffer occupancy conditions of the neighbors. The second scheme Directional Load Balanced Spreading (DLBS) combines local and direction-based (spatial) load balancing approaches to provide more reliable and faster video delivery by benefiting from the advantages of both approaches. The performance of the forwarding schemes are compared using simulation with two geographic routing schemes where one applies no load balancing and the other applies spatial load balancing. The results show that both LBRF and DLBS provide more reliable video delivery as compared to other schemes, whereas DLBS is more reliable and faster as compared to LBRF. In addition, DLBS provides more energy efficient video delivery in terms of energy expenditure per successfully delivered frame to the sink as compared to LBRF and the other two schemes.