Indoor Wireless Metering Networks

Abstract

Wireless Metering Networks (WMN), a special class of Wireless Sensor Networks (WSN), consisting of a large number of tiny inexpensive sensor nodes are a viable solution for many problems in the field of building automation, especially if the expected lifetime of the network permits to synchronize the network maintenance with the schedule for routine maintenance of the building. In order to meet the resulting energy constraints, the nodes have to operate according to an extremely low duty cycle schedule. The existence of an energy efficient MAC Layer protocol, the adoption of a robust time synchronization mechanism and the implementation of effective network discovery and maintenance strategies are key elements for the success of a WMN project.

The main goal of this work was the development of a set of algorithms and protocols which enable the low energy / low power operation in the considered family of WMNs.The development and validation of a propagation model reproducing the characteristics of the indoor radio environment was a necessary step in order to obtain appropriate instruments for the evaluation of the quality of the proposed solutions.

The author suggests a simple localized heuristic algorithm which permits the integration of all sensor nodes into a tree-like failure tolerant routing structure and also provides some basic continuous adaptation capabilities of the network structure.A subsequent extension of the basic algorithm makes the network able of self healing.

An innovative approach to the solution of the synchronization problem based on a reformulation of the original problem into an estimation problem permitted the development of an efficient time synchronization mechanism. This mechanism, which makes an opportunistic usage of the beacon signals generated by the MAC layer protocol, permits an effective reduction of the synchronization error between directly communicating nodes and, indirectly, introduces a global synchronization among all nodes.

All the proposed solutions have been developed for a specific network class. However, since the presence of a low duty cycle scheduling, the adoption of a beacon enabled MAC protocol and the presence of limited hardware resources are quite general assumptions, the author feels confident about the applicability of the proposed solution to a much wider spectrum of problems.

About the Author

Dr. Nicola Altan received his M.Sc. degree in Computer Engineering from the University of Padova (Italy) in 1996 and in 2009 was awarded a Ph.D. in Computer Science from the University of Duisburg-Essen (Germany). He has worked in a number of positions within research and development throughout Europe covering an extensive range of telecommunication topics. Since 2008, working at CETECOM GmbH HQ, Dr. Altan has been in the FACTSWare department where he participates in the development of the FACTSWare test system with particular focus on LTE protocol aspects. He is currently lecturing a master course on protocols for wireless sensor networks at the university of Essen; he has done this since 2009.

Dr. Altan has made a vast array of contributions to the academic world. From 2003 through 2008, he worked for the University of Essen (Germany) as research associate at the Chair of Computer Networking Technology Group. His research area concerned the development of protocols for Wireless Sensor networks. As a result of Dr. Altan's work, he has a number of publications and patents to his name.