Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: A scalable multi-sink gradient-based routing protocol for traffic load balancing | Yoo et al. EURASIP Journal on Wireless Communications and Networking 2011 2011 85 http content 2011 1 85 o EURASIP Journal on Wireless Communications and Networking a SpringerOpen Journal RESEARCH Open Access A scalable multi-sink gradient-based routing protocol for traffic load balancing Hongseok Yoo1 Moonjoo Shim1 and Dongkyun Kim2 Abstract Wireless sensor networks have been assumed to consist of a single sink and multiple sensor nodes which do not have mobility. In these networks sensor nodes near the sink dissipate their energy so fast due to their many-to-one traffic pattern and finally they die early. This uneven energy depletion phenomenon known as the hot spot problem becomes more serious as the number of sensor nodes . their scale increases. Recently multi-sink wireless sensor networks have been envisioned to solve the hot spot problem. Gradient routing protocols are known to be appropriate for the networks in that network traffic is evenly distributed to multiple sinks to prolong network lifetime and they are scalable. Each node maintains its gradient representing the direction toward a neighbor node to reach one of the sinks. In particular existing protocols allow a sensor node to construct its gradient using the cumulative traffic load of a path for load balancing. However they have a critical drawback that a sensor node cannot efficiently avoid using the path with the most overloaded node. Hence this paper introduces a new Gradient routing protocol for LOad-BALancing GLOBAL with a new gradient model to maximize network lifetime. The proposed gradient model considers both of the cumulative path load and the traffic load of the most overloaded node over the path in calculating each node s gradient value. Therefore packets are forwarded over the least-loaded path which avoids the most overloaded node. In addition it is known that assigning a unique address to each sensor node causes much communication overhead. Since the .
