Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Conclusions <s> Geographic routing is a useful and scalable point-to-point communication primitive for wireless sensor networks. However, previous work on geographic routing makes the unrealistic assumption that all the nodes in the network are awake during routing. This overlooks the common deployment scenario where sensor nodes are duty-cycled to save energy. In this paper we investigate several important aspects of geographic routing over duty-cycled nodes. First, we extend existing geographic routing algorithms to handle the highly dynamic networks resulting from duty-cycling. Second, we provide the first formal analysis of the performance of geographic routing on duty-cycled nodes. Third, we use this analysis to develop an efficient decentralized sleep scheduling algorithm for reducing the number of awake nodes while maintaining both network coverage and a (tunable) target routing latency. Finally, we evaluate via simulation the performance of our approach versus running existing geographic routing algorithms on sensors duty-cycled according to previous sleep scheduling algorithms. Our results show, perhaps surprisingly, that a network of duty-cycled nodes can have slightly better routing performance than a static network that uses comparable energy. Our results further show that, compared to previous algorithms, our sleep scheduling algorithm significantly improves routing latency and network lifetime. <s> BIB001 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Conclusions <s> This paper focuses on studying the impacts of a duty-cycle based CKN sleep scheduling algorithm for our previous designed TPGF geographical multipath routing algorithm in wireless sensor networks (WSNs). It reveals the fact that waking up more sensor nodes cannot always help to improve the exploration results of TPGF in a duty-cycle based WSN. Furthermore, this study provides the meaningful direction for improving the application-requirement based QoS of stream data transmission in duty-cycle based wireless multimedia sensor networks. <s> BIB002
This paper provides an extensive and novel survey of most of the existing state-of-the-art QoS WMSNs routing protocols. In addition, it provides an overview of the relationship between QoS routing protocols and link/path routing metrics. Furthermore, it emphasizes the importance of blending the number of link/path routing metrics for optimal performance. Routing protocol plays a important role in guaranteeing QoS in WMSNs. This survey introduces a new taxonomy for the classification of QoS WMSNs routing protocols. Existing QoS WMSNs routing protocols are classified based 24 Journal of Computer Networks and Communications (a) CKN BIB001 based TPGF BIB002 (b) CKN BIB001 based TPGF BIB002 Figure 6: Duty cycle based sensor network using NetTopo  simulator (active nodes in blue/maroon, sleeping nodes in black, source node in red, and sink node in green color).