Abstract Routing is an important functional aspect in wireless ad-hoc networks that handles discovering and maintaining the paths between nodes within a network. Due to nodes mobility, the efficiency of a dynamic ad-hoc routing protocol depends highly on updating speed of network topology changes. To achieve continuous updated routing tables, the nodes periodically broadcast short hello messages to their neighbors. Although benefits of these messages have been proven, many studies show some drawbacks for these messages. In this paper, we adaptively optimize the frequent needs of those messages using a fuzzy logic system. The proposed fuzzy algorithm used to model the uncertainty measurements for updating local connectivity successfully in time. Extensive performance analysis via simulation proves the effectiveness of the proposed method to improve the accuracy of neighborhood information and hence the overall network performance.

References

[1] Abolhasan M., Wysocki T., and Dutkiewicz E., A Review of Routing Protocols for Mobile Ad Hoc Networks, Elsevier s Ad Hoc Networks, vol. 2, no. 1, pp.1-22, 2004.

[2] Boukerche A., Performance Evaluation of Routing Protocols for Ad Hoc Wireless Networks, Mobile Networks and Applications, vol. 9, no. 1, pp. 333-342, 2004.

[3] Broch J., Maltz D. A., Johnson D. B., Hu Y., and Jetcheva J., A Performance Comparison of Multi-Hop Wireless Ad Hoc Network Routing Protocols, in Proceedings of the 4th Annual ACM/IEEE International Conference on Mobile Computing and Networking (MOBICOM'98) , USA, pp. 85-97, October 1998.

[4] Chakeres I. D. and Royer E. M., The Utility of Hello Messages for Determining Link Connectivity, in Proceedings of the 5th International Symposium on Wireless Personal Multimedia Communications (WPMC) , Honolulu, Hawaii, pp. 504-508, October 2002.

[5] Fussler H., Widmer J., Kasemann M., Mauve M., and Hartenstein H., Contention-Based Forwarding for Mobile Ad-Hoc Networks, Elsevier s Ad Hoc Networks, vol. 1, no. 4, pp. 351-369, 2003.

[6] Galluccio L., Leonardi A., Morabito G., and Palazzo S., Tradeoff Between Energy- Efficiency and Timeliness of Neighbor Discovery in Self-Organizing Ad Hoc and Sensor Networks, in Proceedings of the 38th Annual Hawaii International Conference on System Sciences (HICSS'05) , USA, vol. 9, no. 9, pp. 286.1-286.10, 2005.

[7] Gerharz M., De Waal C., Frank M., and Martini P., Link Stability in Mobile Wireless Ad Hoc 199 Adaptive Optimizing of hello Messages in Wireless Ad-Hoc Networks Networks, in Proceedings of the 27th Annual IEEE Conference on Local Computer Networks , USA, pp. 30-42, November 2002.

[8] Hanemann S., Jansen R., and Freisleben B., Reducing Packet Transmissions in Ad Hoc Routing Protocols by Adaptive Neighbor Discovery, in Proceedings of the International Conference on Wireless Networks (ICWN'2003) , Las Vegas, USA, pp. 369-375, 2003.

[9] Heissenb ttel M. and Braun T., Optimizing Neighbor Table Accuracy of Position-Based Routing Algorithms, in Proceedings of IEEE INFOCOM'2005 , Miami, USA, March 2005.

[10] Heissenb ttel M., Braun T., Bernoulli T., and W chli M., BLR: Beacon-Less Routing Algorithm for Mobile Ad-Hoc Networks, Elsevier's Computer Communications Journal, vol. 27, no. 11, pp. 1076-1086, 2004.

[11] Jiang S., He D. and Rao J., A Prediction-Based Link Availability Estimation for Mobile Ad Hoc Networks, in Proceedings of IEEE INFOCOM' 2001 , Alaska, USA, vol. 3, pp. 1745-1782, April 2001.

[12] Lundgren H., Nordstr m E., and Tschudin C., Coping with Communication Gray Zones in IEEE 802.11b Based Ad Hoc Networks, in Proceedings of the 5th ACM International Workshop on Wireless Mobile Multimedia (WoWMoM'2002) , Atlanta, Georgia, USA, pp. 49-55, 2002.

[13] McGlynn M. J. and Borbash S. A., Birthday Protocols for Low Energy Deployment and Flexible Neighbor Discovery in Ad Hoc Wireless Networks, in Proceedings of MobiHoc'2001, Long Beach, , USA, pp. 137-145, October 2001.

[14] Omnetpp, Discreet Event Simulation System, available at: http://www.omnetpp.org/, 2005.

[15] Perkins C. E. and Royer E. M., Ad-Hoc On- Demand Distance Vector Routing, in Proceedings of the 2nd IEEE Workshop on Mobile Computing Systems and Applications , New Orleans, USA, pp. 90-100, February 1999.

[16] Perkins C. E. and Royer E. M., The Ad-Hoc On- Demand Distance Vector Protocol, in Perkins C. E. (Ed), Ad Hoc Networking, Addison-Wesley, pp. 173-220, 2001.

[17] Perkins C. E., Royer E. M., and Das S. R., Ad- Hoc On-Demand Distance Vector (AODV) Routing , available at: http://draft-ietf-manet- aodv-13.txt (work in progress), February 2003.

[18] Tauchi M., Ideguchi T., and Okuda T., Ad-Hoc Routing Protocol Avoiding Route Breaks Based on AODV, in Proceedings of the 38th Annual Hawaii International Conference on System Sciences (HICSS'05) , USA, vol. 9, no. 9, pp. 322.1-322.7, 2005.

[19] Turgut D., Das S. K., and Chatterjee M., Longevity of Routes in Mobile Ad Hoc Networks, in Proceedings of the IEEE VTC, Rhodes, Greece, vol. 4, pp. 2833-2837, May 2001.

[20] Pedrycz W., Why Triangular Membership Functions?, Fuzzy Sets Systems, vol. 64, no. 1, pp. 21-30, 1994.

[21] Rappaport T. S., Wireless Communications: Principles & Practice , Prentice Hall, pp. 70-74, 1996.

[22] Royer E. M. and Toh C. K., A Review of Current Routing Protocols for Ad-Hoc Mobile Wireless Networks, IEEE Personal Communications Magazine , vol. 6, no. 2, pp. 46-55, April 1999.

[23] Samar P. and Wicker S. B., On the Behavior of Communication Links of a Node in a Multi-Hop Mobile Environment, in Proceedings of the 5th ACM International Symposium On Mobile Ad Hoc Networking And Computing , Tokyo, Japan, pp. 145-156, 2004.

[24] Singh J. P., Bambos N., Srinivasan B. and Clawin D., Proposal and Demonstration of Link Connectivity Assessment Based Applications to Routing in Mobile Ad-Hoc Networks, in Proceedings of the IEEE 58th Vehicular Technology Conference , Orlando, Florida, vol. 5, pp. 2834-2838, 2003.

[25] Yager R. R. and Filev D. P., Essentials of Fuzzy Modeling and Control , John Wiley and Sons, 1994. Essam Natsheh obtained the MSc in computer engineering from the Arab Academy for Science and Technology in Egypt in 1999. He subsequently worked as a lecturer at Al-Alamiah Institute for Computer and Technology, Saudi Arabia, from 1999 to 2002. He worked as a lecturer also at the Information Systems Department, King Faisal University, Saudi Arabia, from 2002 to 2003. Since 2003, he has been a member of a research group headed by Dr. Jantan A. at the University Putra Malaysia, which investigates issues related to the design and analysis of ad-hoc wireless networks. Adznan Jantan is an associate professor at the Department of Computer and Communication Systems at the University Putra Malaysia, where he has been conducting research in computer networking, pattern recognition, and digital systems design since 2002. He obtained his MSc in digital systems from Cranfield Institute of Technology, UK, in 1982 and PhD in speech recognition systems from the University College of Swansea, UK, in 1988. The International Arab Journal of Information Technology, Vol. 4, No. 3, July 2007 200 Sabira Khatunreceived her BSc (Hons), MSc in applied mathematics and PhD in hydromagnetic stability from the University of Rajshahi, Bangladesh in 1988, 1990 and 1994, respectively. She received her second PhD in communications and networking from University Putra Malaysia in 2003. She became a lecturer at the Discipline of Computer Science and Engineering, University Khulna, Bangladesh in 1991, assistant professor in 1994. She joined as a senior lecturer the Department of Computer & Communication Systems Engineering, University Putra Malaysia in 1998. She is an active researcher of Teman project and MyREN research community. She is a member of IEEE and her research interest spans broadband and wireless communications, and network management, including software defined radio and IPv6.Shamala Subramaniam completed her PhD from University Putra Malaysia in 2002. Currently, she is a lecturer at the Department of Communication Technology and Networks, Faculty of Computer Science and Information Technology, University Putra Malaysia. Her research interest includes scheduling algorithms, congestion control, real-time systems, modeling and simulation.