Clustering and load balancing in hybrid sensor networks with mobile cluster heads

In this paper, we consider the problem of positioning mobile cluster heads and balancing traffic load in a hybrid sensor network, which consists of two types of nodes: basic static sensor nodes and mobile cluster heads. In such a network, sensor nodes are organized into clusters and form the lower layer of the network. At the higher layer, cluster heads collect sensing data from sensors and forward data to outside observers. Such two-layer hybrid networks are more scalable and energy-efficient than homogeneous sensor networks. We show that the locations of cluster head-s can affect network lifetime significantly. The problem of maximizing network lifetime through dynamically positioning cluster heads in the network (referred to as the CHL problem in this paper) turns out to be NP-hard. We present a heuristic algorithm for positioning cluster heads and balancing traffic load in the network. We show that by moving the cluster head to a better location, the traffic load can be balanced and network lifetime can be prolonged. We conducted simulations on the NS-2 simulator, and the result-s show that our clustering algorithm can increase network lifetime by up to 35% after only three rounds of adjustments, compared to the optimal lifetime of the initial network layout.

[1]  Deborah Estrin,et al.  Adaptive beacon placement , 2001, Proceedings 21st International Conference on Distributed Computing Systems.

[2]  Theodore S. Rappaport,et al.  Wireless communications - principles and practice , 1996 .

[3]  Sandeep K. S. Gupta,et al.  Research challenges in wireless networks of biomedical sensors , 2001, MobiCom '01.

[4]  Ossama Younis,et al.  Distributed clustering in ad-hoc sensor networks: a hybrid, energy-efficient approach , 2004, IEEE INFOCOM 2004.

[5]  Yuanyuan Yang,et al.  Energy efficient multi-hop polling in clusters of two-layered heterogeneous sensor networks , 2005, 19th IEEE International Parallel and Distributed Processing Symposium.

[6]  Stefano Chessa,et al.  Crash faults identification in wireless sensor networks , 2002, Comput. Commun..

[7]  Wendi Heinzelman,et al.  Energy-efficient communication protocol for wireless microsensor networks , 2000, Proceedings of the 33rd Annual Hawaii International Conference on System Sciences.

[8]  Leandros Tassiulas,et al.  Energy conserving routing in wireless ad-hoc networks , 2000, Proceedings IEEE INFOCOM 2000. Conference on Computer Communications. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies (Cat. No.00CH37064).

[9]  Ravi Prakash,et al.  Max-min d-cluster formation in wireless ad hoc networks , 2000, Proceedings IEEE INFOCOM 2000. Conference on Computer Communications. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies (Cat. No.00CH37064).

[10]  Ravindra K. Ahuja,et al.  Network Flows: Theory, Algorithms, and Applications , 1993 .

[11]  Srdjan Capkun,et al.  GPS-free Positioning in Mobile Ad Hoc Networks , 2001, Proceedings of the 34th Annual Hawaii International Conference on System Sciences.

[12]  Andrej Bogdanov,et al.  Power-aware base station positioning for sensor networks , 2004, IEEE INFOCOM 2004.

[13]  Michael J. Rycroft,et al.  Understanding GPS. Principles and Applications , 1997 .

[14]  Yuanyuan Yang,et al.  Energy-Efficient Multihop Polling in Clusters of Two-Layered Heterogeneous Sensor Networks , 2008, IEEE Transactions on Computers.

[15]  G. Asada,et al.  Wireless integrated network sensors: Low power systems on a chip , 1998, Proceedings of the 24th European Solid-State Circuits Conference.