Effect of Channel Asymmetry on Reputation Based Cooperation Mechanisms in Mobile Ad-Hoc Networks

Enforced cooperation among MANET nodes is an active research issue. One proposed class of protocols to enforce cooperation is based on reputation systems. In Reputation systems, nodes maintain reputation of other nodes. A node after sending a packet to its neighbour to forward further, increases reputation of neighbour if it overhears the same packet from the neighbour. If it does not overhear the packet, reputation of neighbour is reduced. This method of updating reputation requires that wireless channel must be symmetric. Even when two nodes are in range of each other, channel may become asymmetric due to fast fading effects. We have examined the probability of channel asymmetry as a function of ratio r (of inter node distance and transmission range), for given values of relative average velocity of nodes V and Ricean parameter K. Ricean parameter K represents type of the environment i.e. obstructed or unobstructed. An enhancement of existing reputation system ROBUST (7) is also proposed. In the enhanced protocol, observing node probabilistically updates reputation of neighbour when it does not overhear. This probabilistic update takes into account probability of channel asymmetry. Proposed scheme results in reduction of false positives, and even false negatives remain in control. As a result, packet delivery ratio is increased.

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

[2]  Refik Molva,et al.  Core: a collaborative reputation mechanism to enforce node cooperation in mobile ad hoc networks , 2002, Communications and Multimedia Security.

[3]  Dirk Westhoff,et al.  Context aware detection of selfish nodes in DSR based ad-hoc networks , 2002, Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE.

[4]  Haitao Wu,et al.  PARS: stimulating cooperation for power-aware routing in ad-hoc networks , 2005, IEEE International Conference on Communications, 2005. ICC 2005. 2005.

[5]  Mike Burmester,et al.  Cooperation in Mobile Ad Hoc Networks , 2009, Guide to Wireless Ad Hoc Networks.

[6]  Charles E. Perkins,et al.  Ad Hoc Networking , 2001 .

[7]  Mary Baker,et al.  Observation-based Cooperation Enforcement in Ad Hoc Networks , 2003, ArXiv.

[8]  Qi He,et al.  SORI: a secure and objective reputation-based incentive scheme for ad-hoc networks , 2004, 2004 IEEE Wireless Communications and Networking Conference (IEEE Cat. No.04TH8733).

[9]  Jean-Yves Le Boudec,et al.  Performance analysis of the CONFIDANT protocol , 2002, MobiHoc '02.

[10]  Sheng Zhong,et al.  Sprite: a simple, cheat-proof, credit-based system for mobile ad-hoc networks , 2003, IEEE INFOCOM 2003. Twenty-second Annual Joint Conference of the IEEE Computer and Communications Societies (IEEE Cat. No.03CH37428).

[11]  D. Djenouri,et al.  New approach for selfish nodes detection in mobile ad hoc networks , 2005, Workshop of the 1st International Conference on Security and Privacy for Emerging Areas in Communication Networks, 2005..

[12]  Jean-Yves Le Boudec,et al.  Nodes bearing grudges: towards routing security, fairness, and robustness in mobile ad hoc networks , 2002, Proceedings 10th Euromicro Workshop on Parallel, Distributed and Network-based Processing.

[13]  Mary Baker,et al.  Mitigating routing misbehavior in mobile ad hoc networks , 2000, MobiCom '00.

[14]  Jean-Yves Le Boudec,et al.  Performance analysis of the CONFIDANT protocol , 2002, MobiHoc '02.

[15]  Daniel D. Stancil,et al.  Efficient simulation of Ricean fading within a packet simulator , 2000, Vehicular Technology Conference Fall 2000. IEEE VTS Fall VTC2000. 52nd Vehicular Technology Conference (Cat. No.00CH37152).

[16]  S. Buchegger,et al.  A Robust Reputation System for Mobile Ad-hoc Networks , 2003 .

[17]  J.-P. Hubaux,et al.  Enforcing service availability in mobile ad-hoc WANs , 2000, 2000 First Annual Workshop on Mobile and Ad Hoc Networking and Computing. MobiHOC (Cat. No.00EX444).