A survey of selfish nodes behaviour in Mobile Adhoc network

 

 International Journal Trends and Technology Technology (IJCTT) (IJCTT) – volume 4 Issue Issue 6–June 2013 2013  Journal of Computer Trends

A survey of selfish nodes behaviour in Mobile Adhoc network 1

2

M.Manjula M.C.A , P.Elango MCA, M.Phil   1

 Mphil Scholar, Scholar, Department Department of Computer Computer Science, Gobi Gobi Arts and Science Co College, llege, Gobi, T Tamil amil nadu, nadu, India.

2

 Associate professor, professor, D Department epartment of Compu Computer ter Science, Gobi Gobi Arts an and d Scienc Sciencee College, Go Gobi, bi, Tamil nadu, nadu, India

 Abstract— MOBILE ad hoc networks (MANETs) have attracted  Abstract— a lot of attention due to the popularity of mobile devices and the advances in wireless communication technologies. A MANET is a peer-to-peer multi hop mobile wireless network that has neither a fixed infrastructure nor a central server. Every node in a MANET acts as a router, and communicates with each other. The mobility and resource constraints of mobile nodes may lead to network partitioning or performance degradation. From literature we can observe several data replication techniques have been proposed to minimize performance degradation. In which most of them assume that all mobile nodes collaborate fully in terms of sharing their memory space. But in reality, however, some nodes may selfishly decide only to cooperate partially, or not at all, with other nodes. These kinds of selfish nodes could then reduce the overall data accessibility in the network. Due to such problem the overall process of MANET got affected. In this work, we examine the impact of selfish nodes in a mobile ad hoc network from the perspective of replica allocation. We name this as selfish replica allocation. This work was motivated by the fact that a selfish replica allocation could lead to overall poor MANET data accessibility. The strategies are inspired by the real-world observations in economics in terms of credit risk and in human friendship management in terms of choosing one’s friends completely at one’s own circumspection. The notion of credit risk from economics is to detect nodes that behave selfishly. Each and every node in a MANET calculates credit risk information on other connected nodes individually to measure the degree of selfishness. The following work is analysis over the selfish node detection mechanism available in literature. 

only limited memory space, there is often a trade-off between query delay and data accessibility. For example, a node may hold a part of the frequently accessed data items locally to reduce its own query delay. As there is only limited memory space and many of the nodes hold locally the same replica which results in replacement and missing of some data items. Therefore, the overall data accessibility would be reduced. Thus, to maximize data accessibility, a MANET node should not hold the same replica that is also held by many other nodes which avoids duplication. Consequently, this will increase its own query delay. Certain node may behave selfishly as it is using its limited resource only for its own benefit, as each node in a MANET has resource constraints such as battery and storage limitations. Also these nodes would like to enjoy the benefits  provided by their sources of other nodes, it may not make its own resource available to help others. This selfish behavior can potentially lead to a wide range of problems for a Mobile Adhoc Networks. A selfish node will typically not cooperate in the transmission of packets leading to degrade network  performance. Although less frequent, nodes may also fail to cooperate either intentionally (a malicious behavior) or due to faulty software software or hardware. W Wee perform analysis of these selfish behaviour of literature in the following paper. II. 

MOBILE ADHOC NETWORKS MANET

 A.  Selfishness and Payments Energy-efficiency is a must for routing protocols in However, r, energy-eff energy-efficiency iciency is only desirable In Mobile Adhoc Networks, Network Network partitions partitions can occur ad hoc networks. Howeve frequently, since nodes move freely in a MANET, this in turn from a global point of view, but not from the point of view of causes some data to be often inaccessible to some of the an individual and selfish node: if a network node gets chosen nodes. Hence, accessibility of data is often an important as an intermediate node with the duty of forwarding packets  performance metric to be considered in a MANET. MANET. To very often, the knowledge that it is on the most energyincrease data accessibility and to cope with frequent network efficient route is all but comforting since the forwarding  partitions, data are usually replicated at nodes, other than the actions drain its battery; the reasonable thing to do for this original owners. A significant amount of research has been node is to play dead as soon as it realizes that its battery level r efusing to forward messages.  proposed in literature for replica allocation in a MANET. MANET. keeps decreasing, thus simply refusing This non-cooperative behavior is a very basic problem in Generally, replication of data can simultaneously improve data accessibility and reduce query delay (query response any ad hoc network in which the nodes are owned by different time), when the MANET mobile nodes altogether have  profit-maximizing entities. It might even be the root cause sufficient memory space to hold both all the replicas and the why the deployment of ad hoc networks has not been as projected a few ye years ars back. The ad hoc original data. If the query accesses a data item that has a  progressive as projected network community has recognized this issue and several locally stored replica then the response time of a query can be substantially reduced. Since most nodes in a MANET have  protocols that stimulate cooperation among nodes have been

I. 

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I NTRODUCTION 

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 International Journal Trends and Technology Technology (IJCTT) (IJCTT) – volume 4 Issue Issue 6–June 2013 2013  Journal of Computer Trends  proposed. These protocols are either based on repudiation In fact, making exaggerated claims with respect to the models, where nodes are punished for non-cooperation, or emission signal strength will result in a higher payment that  based on monetary incentives, where nodes are awarded the node receives if it is on the shortest or most energy payments for forwarding forwarding messages. In payment-based models, efficient path. Even more obvious: a node that exaggerates its the question arises how much a node should be paid for cost-of-energy    will receive a larger payment if it is chosen forwarding messages. An obvious answer would be the cost it to be on the shortest path. Similarly, a node may profit from incurs when forwarding the message. sending false information regarding received signal strength. The cost of forwarding messages could be defined and Of course, we could make the assumption that no node has determined in various ways taking into account factors such as any information with respect to the current network structure, cost of energy used to forward messages, cost of energy when  but that assumption is unrealistic if several communicatio communication n recharging the battery, current battery level, as well as other sessions take place: a node might have partial knowledge of factors. A model should consider cost through: the cost-of- the underlying weighted graph and make a bet based on its energy parameter    of dollars per watt is individual for each knowledge. In reality, the aamounts mounts of money that we are node in the network. A node covers its true costs for dealing with are certainly small for a single transmission; forwarding a unit-size packet requiring an emission signal however, cheating is very attractive over a long time horizon, strength of    watts, if it receives a payment of  .    when small amounts add up to considerable sums. The app roach should deal with this problem is to make dollars for forwarding. On the other hand, if a node does not  proposed approach get a payment that is sufficient to cover its costs, it will simply the payments attractive enough such that the nodes will not try to cheat. Their goal is to design a protocol that causes all refuse to forward. i. e., to reveal their true costs. Thus, in a model, a node cannot be forced to participate nodes to act truthfully, i.e., protocols of M MANET ANET (which is different in repudiation-based protocols). C.  Routing protocols In [1] author introduced a game-theoretic setting for routing Participation is always voluntary in this sense. The cost-ofin a MANET that consists of greedy selfish agents that accepts energy parameter can be a complex function functi on of several factors forwarding arding data for other agents if th thee payments (mentioned above) and also of time. For example, a node  payment for forw might have a cost-of-energy that depends inversely on some cover their individual costs incurred by forwarding data  power of its current battery level. Given the complexity of utilizing Ad hoc-VCG, a reactive routing protocol that these we parameter do not pretend to other know nodes. them, but a nodefunctions, declare the to the In rather terms let of implementation, we could imagine that a device user can set the function for parameter   according to t o her preferences.  B.  Attractive Cheating Cheating Ad hoc-VCG routing protocol consists of two distinct phases that roughly work as follows: In a first phase namely the route discovery  phase, the underlying weighted graph is computed with vertices representing network nodes and weighted directed edges representing the payments an emitting node has to receive if it transmits a packet along this edge in order to cover its costs. The nodes determine the emission energy levels to reach their neighbors by first sending a packet with high emission energy indicating their emission signal strength in a packet header and receiving a  packet back from their neighbors which contains the signal strength at which they received the packet. pa cket. The nodes also communicate their cost-of-energy cost-of-energy    to their neighbors. The destination node collects all edge weights and then computes the shortest path in this graph from source to destination, which corresponds to the most energy-efficient  path. In a second phase namely n amely the th e data transmission  phase,  packets are forwarded along the shortest path route and  payments are made to the intermediate nodes. However, there is a big caveat in the route discovery phase: the nodes have ha ve to indicate the signal strength at which they emit and they also need to forward information regarding their neighbors’ received signal strengths. This opens the door to cheating: it may not be in a node’s best interest to reveal the emission signal strength correctly.

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achievesbest the interest design objectives of truthfulness it is in the agents’ to reveal their true costs (i.e., for forwarding data) and cost-efficiency (i.e., it guarantees that routing is done along the most cost-efficient path) in a game-theoretic sense by paying to the intermediate nodes a premium over their actual costs for forwarding data packets. They have shown that the total overpayment (i.e., the sum of all  premiums paid) is relatively small by giving a theoretical upper bound and by providing experimental evidence. MANETs operate on the basic underlying assumption that all participating nodes fully collaborate in self-organizing functions. Yet, performing network functions consumes energy and other resources. As a result, some network nodes may decide against cooperating with others. In [2], author  proposed two network-lay n etwork-layer er ackn acknowledgme owledgment-based nt-based schemes, namely the TWOACK and the S-TWOACK schemes that can  be simply added-on to any source routing protoco protocol. l. This TWOACK scheme detects such misbehaving nodes and then seeks to alleviate the problem by notifying the routing  protocol to a void th them em in future routes. They have found that in a network of where up to 40% of the nodes are misbehaving, the TWOACK scheme results in 20% improvement in packet delivery ratio with a reasonable additional routing overhead. The TWOACK scheme can be implemented on top of any source routing protocol such as DSR. This follows from the fact that a TWOACK packet derives its route from the source route established for the corresponding data packet. The TWOACK scheme uses a special type of acknowledgment packets called TWOACK packets that are

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 International Journal Trends and Technology Technology (IJCTT) (IJCTT) – volume 4 Issue Issue 6–June 2013 2013  Journal of Computer Trends assigned a fixed route of two hops (or three nodes) in the direction opposite to that of data packets. The TWOACK scheme described above gives rise to two hops of TWOACK  packets for every hop of data packet being forw forwarded. arded. Considering that each TWOACK packet is a unique entity and has to contend for the medium just like any other packet, the TWOACK packets packets may contribute to t o the traffic congestion on the routing path. Therefore, we further propose the STWOACK (Selective-TWOACK) scheme, a derivative of the TWOACK scheme, to reduce this extra traffic due to

network of selfish servers by means of theoretical analysis and simulation. In this author modelled selfish sel fish caching as a nonnon cooperative game. Payment model was elaborated and defined in this paper. Pay Payment ment model defines that each bids for having an object replicated at another site. In this each site has an option of replicating an object and collecting the related bids. After choosing a strategy by all servers, each game specifies a configuration(i.e., the set of servers that replicate the object, and the corresponding costs for all servers).In this [5],the solution for the following constraints has been addressed.

TWOACK packets. In the S-TWOACK scheme, instead of 1. Existence of pure strategy Nash equilibria in the caching sending back a TWOACK packet every time when a data game.  packet is received, a node waits until a certain number of data 2. If there is an existence of pure strategy Nash equilibria in  packets (through the th e same triplet) arrive. The node n ode then sends the caching game then it defines how  back one TWOACK packet acknowle acknowledging dging multiple data Efficient are they in terms of the price of anarchy, or its  packets that have been been received so far.  optimistic counterpart ) under different network topologies, demand distributions , and placement costs.  D.  Caching as replica in Adhoc networks Adhoc Network is a collection of wireless mobile nodes 3.Nash equilibria improvement and effectiveness of dynamically forming a temporary infrastructure-less network adopting payments were described. without any centralized administration. As because of the limited transmission range of wireless network interfaces, III.  PEER-TO-PEER (P2P) SYSTEM there is a need of multiple network "hops" for one node to exchange data with another across the network. An array of  A.  Peer to peer file sharing new routing protocols targeted specifically at this thi s environment Peer-to-peer Peer-to-pe er (P2P) system share information among a have been developed in recent years, but little performance large number of users without the assistance of explicit information on each protocol and no realistic performance servers. Peer-to-pe Peer-to-peer er file-sharing systems works mostly on comparisonthe between currentlypacket-level available. In simulation [3] author wired networks. In this [6]author presented, five peer-torouting  presented resultsthem of ais detailed approaches with different complexity for enabling comparing four multi-hop wireless ad hoc network routing  peer file-sharing over MANET. The complexity of [6] is  protocols that cover a range of design choices:, TORA, evaluated and compared. It defined and proved that the crossDSDV, AODV and DSR. layer protocols performance acts better than simply overlaying peer-to-peer searching protocol on MANET. In  E.  Cooperative caching In [4] author author presented caching techniques techniques such as [6] P2P protocols co-ordinates by the cross-layer design at CachePath, CacheData, and Hybrid Cache which uses the application layer and routing protocols at network layer, underlying routing protocols to overcome problems and which offers offers better performance improve improvement ment in DHT improves performance by the data can be caught locally approach and Broadcast Broadcast.. For MA MANETs NETs o off small ssize, ize, The otherwise the path to the data can be caught to save spaces. Broadcast approach can be implemented i mplemented easily. Accessibility of data can be increased by caching  B.  Free-Riding Behavior in Peer-to-Peer Systems different data items than their neighbours by mobile nodes. The fundamental premise of peer-to-peer (P2P) Even though mobile nodes nodes increases data accessibility, accessibility, it also systems is that of individual peers are shared by voluntary increases query delays. The reason is that instead of accessing resources .Then there is an inherent tension betwee between n its own nodes it might might have to access data from its neighbour neighbour collective welfare welfare and individual rationality that thre threatens atens the node also .In addition, data replication from the server might viability of these systems. systems. In [7] aauthor uthor pres presents ents at the create security problems. intersection of computer science and economics ,targets the F.  Game-theoretic approach: selfish server’s network design of distributed systems which consisting of rational  participants with selfish and diverse interests. In particular, caching In Game theoretic approach, Server nodes acts major findings and open questions related to free-riding in selfishly by replicating its resources. This can be referred as P2P systems such as challenges in the design of incentive selfish caching problem. In this research, the relative cost of mechanisms for P2P systems, factors affecting the degree of the lack of coordination can be shown by existence of pure free-riding and incentive mechanisms to encourage user strategy Nash equilibria and investigate the price of anarchy. cooperation were discussed in [7]. The undersupply problem causes the price of anarchy to be high in this research. But certain topologies have better  bounds. With the help h elp of payment scheme the best case social optimum was implemented by the game by giving servers incentive to replicate. In [5],the author presented a gametheoretic approach for analyzing the problem of caching in

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 International Journal Trends and Technology Technology (IJCTT) (IJCTT) – volume 4 Issue Issue 6–June 2013 2013  Journal of Computer Trends IV. 

DISTRIBUTED SYSTEM

 A.  Distributed Selfish Selfish Cach Caching ing In [8] author has not covered tthe he susceptibility of nodes which is participating in a distributed on-demand caching group which is being mistreated. Two causes of mistreatments, were identified namely, mistreatment due to the use of a common scheme for cache management across all members of the group and mistreatment due to cache state interactions between various members of the group.

Distributed Network and usage of these related techniques were discussed. Based on Survey as discussed above, Ad hocVCG is truthful with respect to a single cheating node, but not robust against coalitions of cheating nodes. The protocols such as DSDV, TORA, DSR, and AODV covered a range of design choices which includes periodic advertisement Vs on demand route discovery d iscovery.. Each of the protocols studied performs well in some cases at the same time it has certain drawbacks in others. Cooperative caching uses multi nodes to share and coordinate

The result of [8] analysis and evaluate the suggested cached data for improving web performance in wired network. that as long as proxying (L2 caching) is not enabled and as A non-cooperative game model in survey is to categorize the long as intragroup access costs do not include outliers, on- caching problem in selfish servers without using any central demand distributed caching is fairly resilient.. In [8], author author coordination. Based on survey non cooperative caching is focused on distributed caching as an instance of an online more realistic than cooperative caching in Internet.P2P file  protocol for the management of a distributed resource, the sharing over MANET were discussed. the comparison of five limited storage available at each node. different protocols in terms of complexity, scalability,  B.  Distributed Selfish Selfish Replication maintenance complexity, implementation complexity, shortest short est In [9] author has described two algorithms and an  path , energy efficiency and the cross layer property were efficient distributed protocol for implementing equilibrium surveyed. Trust management in distributed systems showed object placement strategies. when replication nodes cater to how to minimize the risk and ensures network activity. their local utilities, these placement strategies become Among all surveyed techniques our work can be enhanced by meaningful, as is the case with some content distribution collaborative watchdog based on contact dissemination to applications which run under multiple authorities (e.g., P2P, detected selfish nodes. distributed web web caching). In In these applications, following following a R EFERENCES EFERENCES   socially optimal placement strategy might causes mistreatment of some nodes. node On nodes the other strategies strategie guarantee thats. all arehand, betterthe o ff equilibrium   participating in thes group by opposing to operating in isolation isolation iin n a greedy local manner. While forbidding the mistreatment of any one of the nodes, excessive excessive gain for for all can be be created for for keeping a distributed group from splitting .  C.  Trust Management in Distributed Systems Peer-to-Peer networks, the Internet, and mobile ad hoc networks are said to be Distributed Distributed systems. systems. Risk minimization and ensuring the network activity of benign entities in distributed systems were helped by Trust management. Trust management remains an active research area. Internet applications( e-commerce), e-commerce), which uses databases to store users’ trust values, and updating updating them regularly to show show the trustworthiness of of users in the sy system. stem. Another potential area in [10] is combining the trust values of different applications. an ad hoc network, might involve several different applications, such as file sharing, packet forwarding, and mobile e-commerce. In [10] author discussed about how should we use a different trust value for each application, or to use the same trust value for all applications? And, if each of any application has its own trust value, then how can we combine their trust values? discussed in [10]. V. 

CONCLUSION

MANETS are used in various contexts like mobile social networks, emergency deployment; intelligent transportation systems etc.We discussed a lot of techniques to improve selfish node detection in MANET in this survey. The  problem in different network such as Peer-to-Peer Peer-to-Peer networks,

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[1].  L. Anderegg and S. Eidenbenz, “Ad Hoc-VCG: A Truthful and Cost-Efficient Routing Protocol for Mobile Ad Hoc Networks with Selfish Agents,” Proc. ACM MobiCom, pp. 245-259, 2003. [2].  K. Balakrishnan, J. Deng, and P.K. Varshney, “TWOACK: Preventing Selfishness in Mobile Ad Hoc Networks,” Proc. IEEE Wireless Comm. and Networking, pp. 2137-2142, 2005. [3].  J. Broch, D.A. Maltz, D.B. Johnson, Y.-C. Hu, and J. Jetcheva, “A Performance Comparison of Multi-Hop Wireless Ad Hoc Network Routing Protocols,” Proc. ACM MobiCom, pp. 85-97, 1998. [4].  G. Cao, L. Yin, and C.R. Das, “Cooperative Cache-Based Data Access in Ad Hoc Networks,” Computer, vol. 37, no. 2, pp. 32-39, Feb. 2004. [5].  B.-G. Chun, K. Chaudhuri, H. Wee, M. Barreno, C.H. Papadimitriou, and J. Kubiatowicz, “Selfish Caching in Distributed Systems: A Game-Theoretic Analysis,” Proc. ACM Symp. Principles of Distributed Computing, pp. 21-30, 2004. [6].  G. Ding and B. Bhargava, “Peer-to-Peer File-Sharing over Mobile Ad Hoc Networks,” Proc. IEEE Ann. Conf. Pervasive Computing and Comm. Workshops, pp. 104-108, 2004. [7].  M. Feldman and J. Chuang, “Overcoming Free-Riding Behavior in Peer-to-Peer Systems,” SIGecom Exchanges, vol. 5, no. 4, pp. 4150, 2005. [8].   N. Laoutaris, G. Smaragdakis, A. Bestavros, I. Matta, and I. Stavrakakis, “Distributed Selfish Caching,” IEEE Trans. Parallel and Distributed Systems, vol. 18, no. 10, pp. 1361-1376, Oct. 2007. [9].   N. Laoutaris, O. Telelis, V. Zissimopoulos, and I. Stavrakakis, “Distributed Selfish RepLication,” IEEE Trans. Parallel and Distributed Systems, vol. 17, no. 12, pp. 1401-1413, Dec. 2006. [10].  H. Li and M. Singhal, “Trust Management in Distributed Systems,” Computer, vol. 40, no. 2, pp. 45-53, Feb. 2007.

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