International Journal of Engineering Trends and Technology (IJETT) – Volume 6 Number 1- Dec 2013 An Empirical Model of cooperative communication Model in Mobile Adhoc Networks M.V.Rajesh1,LovaGangadhar Kandula2 Sr. Assistantprofessor ,2M.Tech Scholar 1,2 Dept of CSE, Aditya Engineering College, Aditya Nagar, Surampalem, Andhra Pradesh 1 Abstract:Cooperative communication is the one of the current interesting research issue in the field of wireless sensors, various topology architectures defined for data transmission and cooperative communication in MANET, In this paper we are introducing an empirical model for cooperative communication with one of the evolutionary algorithm(i.e genetic algorithm),In this approach we consider the factors of signal strength and channel capacity for calculating the communication cost, then we generates the chromosomes for data transmission between source and destination through relay nodes. I.INTRODUCTION Cooperative communication in mobile ad hoc networks is basic characteristic while communication between the nodes and apart from the peer to peer connections, these nodes indirectly does not connect to the destination nodes in these architectures of cooperative communications, various topology structures defined for the cooperative communication between the nodes in mobile ad hoc networks, every topology architectures has their individual advantages and vulnerabilities with their architectures or structures . Wireless sensor networks (WSNs) area special class of ad hoc networks. Ina WSN, the interconnected units arebattery-operated microsensors, each ofwhich is integrated in a single package with lowpower signal processing, computation, and a wireless transceiver. Sensor nodes collect the data of interest (e.g., temperature, pressure, soil makeup, etc.),and transmit them, possiblycompressed and/or aggregated with those of neighboring nodes, to the other nodes. In this way, every node in the network acquires global view of the monitored area that can be accessed by the external user connected to the WSN through one or more gateway nodes (see Figure 1). Potential applications of sensor networks abound; they can be used to monitor remote and/or hostile geographical regions, to trace animals movement, to improve weather forecast, and so on. Examples of scenarios where WSN can be used are described in Estrin et al. [1999], Heinzelman et al.[1999], Khan et al. [2000], Mainwaring al. [2002], Pottie and Kaiser [2000],Sadler et al. [2004], Schwiebert et al.[2001], Srivastava et al. [2001], Steereet al. [2000], and Szewczyk et al. [2004].The following aspects that have to ISSN: 2231-5381 be carefully taken into account in the design stage are peculiar to wireless ad hoc networks. II.RELATED WORK In mobile ad hoc networks Cooperative communication usually refers to a system where users share and coordinate their Resources to improve the information quality of transmission and it is a generalization of the depended Communication, where multiple sources also serve as relays for each other and previously study of relaying problems appears in the informationtheory community to enhance communication Between the source and destination [7].Recent tremendous interests incooperative communications are due to the increased understanding of the benefits of multiple antenna systems [1].Although multiple-input multiple-output(MIMO) systems have been widely acknowledged, it is difficult for some wireless mobile devices to support multiple antennas due to the size and cost constraints. Recent studies show that cooperative communications allow singleantennadevices to work together to exploit thespatial diversity and reap the benefits of MIMOsystems such as resistance to fading, highthroughput, low transmitted power, and resilientnetworks [1].In a simple cooperative wireless networkmodel with two hops, there are a source, a destination, and several relay nodes. The basic idea of cooperative relaying is that some nodes, whichoverheard the information transmitted from thesource node, relay it to the destination node instead of treating it as interference. Since thedestination node receives multiple independently faded copies of the transmitted information from the source node and relay nodes, cooperative diversity is achieved. Relaying could beimplemented using two common strategies, • Amplify-and-forward • Decode-and-forward In amplify-and-forward, the relay nodes simply boost the energy of the signal received from the sender and retransmit it to the receiver. In decode-and-forward, the relay nodes will perform physical-layer decoding and then forward the decoding result to the destinations. If multiple nodes are available for cooperation, their antennas can http://www.ijettjournal.org Page 25 International Journal of Engineering Trends and Technology (IJETT) – Volume 6 Number 1- Dec 2013 employ a space-time code in transmitting the relay signals. It is shown that cooperation at the physical layer can achieve full levelsof diversity similar to a MIMO system, and the connectivity of wireless networks. Most existing works about cooperative communications are focused on physical layer issues, such as decreasing outage probability and increasing outage capacity, which are only linkwidemetrics. However, from the network’s point of view, it may not be sufficient for the overall network performance, such as the whole network capacity. Therefore, many upper layer network-wide metrics should be carefully studied, e.g., the impacts on network structure and topology control. Cooperation offers a number ofadvantages in flexibility over traditional wireless networks that go beyond simply providing amore reliable physical layer link. Since cooperation is essentially a network solution, the traditionallink abstraction used for networkingdesign may not be valid or appropriate. Fromthe perspective of a network, cooperation canbenefit not only the physical layer, but the wholenetwork in many different aspects. Genetic Algorithm is an evolutionary algorithmuses genetic operators to generate the offspring of the existing population. This section describes three operators of Genetic Algorithms that were used in GA algorithm: selection, crossover and mutation. Selection: The selection operator chooses a chromosome in the current population according to the fitness function and copies it without changes into the new population.GA algorithm used route wheel selection where the fittest members of each generation are more chance to select. Crossover: The crossover operator, according to a certain probability, produces two new chromosomes from two selected chromosomes by swapping segments of genes GA. Genetic algorithm is one of the most efficient evolutionary algorithms for solving the problems like NP hard problem (i.e if a problem can have more than one solution) by applying the process of crossover and mutation Crossover and mutation are two basic operators of GA. Performance of GA very depends on them. Type and implementation of operators depends on encoding and also on a problem. Method of merging the genetic information of two individuals; if the coding is chosen properly, two good parents produces good children. This called Cross over III.PROPOSED WORK In this proposed architecture we introduced an evolutionary algorithm for optimal cooperative communication between the nodes with the parameters channel capacity and signal strength, it leads to the communication cost between the nodes, here genetic algorithm finds the optimal communication cost by applying the process of optimal chromosome or path selection and mutation operators between the nodes, after the mutation again calculate the communication cost between the source and destination nodes followed by relay nodes During the cooperative communication between the nodes, nodes communicate with each other with optimal path, which is generated by evolutionary approach, When a node transmits the data to the receiver, initially request made to evolutionary processing module, it computes all the paths between the source to destination and selects the optimal path and transmits the data. N2 N3 N6 N1 N4 N5 Figure1 ISSN: 2231-5381 http://www.ijettjournal.org Page 26 International Journal of Engineering Trends and Technology (IJETT) – Volume 6 Number 1- Dec 2013 In figure1,it shows the cooperative communication between the nodes ,even though various traditional approaches available , every architecture of topology has their own advantages and drawbacks. In our approach when a node transmits the data from one node to another ,processing module process the request and evaluate the path as follows. IV.EVOLUTIONARY APPROACH Genetic algorithm is an evolutionary algorithm, which gives the optimal solution to the problems like NP hard problem(i.e problem can have more than one solution).Genetic algorithm generates the new chromosomes from the existing chromosomes, by applying the process of crossover and mutation between the parent chromosomes to generate the child chromosome and then calculate the fitness of the chromosome with fitness function. In our approach we are considering our individual nodes as genes and chromosomes as combination of the nodes from source to destination and compute the fitness in terms of signal strength and channel capacity. Consider an example of nodes A,B,C,D,E,F ,if a node(gene) ’A’ wants to transfer the data to the receiver ’F’ , processing module computes the all the available paths from source to destination and applies the fitness function and obtains the optimal path and transmits the data over that path. Evolutionary approach as follows ABCDEF ABEDCF AEDCBF ACDBEF Communicationcost=Signalstrength+channellcapacity Obtains the optimal path which has the best communication cost and transmits the data over the path. Step1: Sourcenodeselectsthedestination to transmit thedata Step2: Request received by processingmoduleandgeneratesthepathsintopology the Step3: Processing module computes the path with their signal strength and channel capacity ISSN: 2231-5381 Step4: Compute communicationcostwith signalstrengthandchannelcapacityforfitness Step5:selectoptimalpath(optimalcommunicationcost)andtra nsmitsthedata. V.CONCLUSION We are concluding our approach with optimal approach with evolutionary algorithm which generates the optimal path based communication cost (signal strength + channel capacity) over the mobile ad hoc networks. Our cooperative communication approach evolves the transmission of data between sender and receiver in an efficient mechanism. REFERENCES 1. J. Laneman, D. Tse, and G. Wornell, “Cooperative Diversity in Wireless Networks: Efficient protocols and Outage Behavior,” IEEE Trans. Info. Theory, vol. 50, no. 12, 2004, pp. 3062–80. 2. P. H. J. Chong et al., “Technologies in Multihop Cellular Network,” IEEE Commun.Mag., vol. 45, Sept. 2007, pp. 64–65. 3. K. Woraditet al., “Outage Behavior of Selective relaying Schemes,” IEEE Trans. Wireless Commun., vol. 8, no. 8, 2009, pp. 3890–95. 4. Y. Wei, F. R. Yu, and M. Song, “Distributed Optimal Relay Selection in Wireless Cooperative Networks with Finite-State Markov Channels,” IEEE Trans. Vehic. Tech., vol. 59, June 2010, pp. 2149–58. 5. Q. Guan et al., “Capacity-Optimized Topology Control for MANETs with Cooperative Communications,” IEEETrans. Wireless Commun., vol. 10, July 2011, pp. 2162–70. 6. P. Santi, “Topology Control in Wireless Ad Hoc and sensor Networks,” ACM Computing Surveys, vol. 37,no. 2, 2005, pp. 164–94. [7] T. Cover and A. E. Gamal, “Capacity Theorems for the Relay Channel,” IEEE Trans. Info.Theory, vol. 25, Sept. 1979, pp. 572–84. [8] Q. Guan et al., “Impact of Topology Control on Capacity of Wireless Ad Hoc Networks,” Proc. IEEE ICCS, Guangzhou, P. R. China, Nov. 2008. [9] P. Gupta and P. Kumar, “The Capacity of Wireless Networks,” IEEE Trans. Info. Theory, vol. 46, no. 2, 2000, pp. 388–404. [10] M. Burkhart et al., “Does Topology Control Reduce Interference?,” Proc. 5th ACM Int’l. Symp. Mobile AdHoc Networking and Computing http://www.ijettjournal.org Page 27 International Journal of Engineering Trends and Technology (IJETT) – Volume 6 Number 1- Dec 2013 BIOGRAPHIES LovaGangadharKandulais a student of Aditya Engineering College, Surampalem. Presently he is pursuing his M.Tech [Computer Science] from this college and he received his M.C.A from SriSaiMadhavi Institute of Engineering Technology, affiliated to Andhra University, Mallampudi in the year 2011. His area of interest includes Computer Networks,Soft wareEngeneeringand all current trends techniques in Computer Science MrM.V.Rajesh, well known and excellent teacher received M.Tech (CSE) from JNTU, Kakinada is working Sr.Associateprofessor ,Dept of CSE at Aditya Engineering College. He has 8.5 years of industrial and teaching experience. To his credit couple of publications both national and international conferences/journals. His areaof interest includes Computer Networks and other Software Engineering. And guided many projects. ISSN: 2231-5381 http://www.ijettjournal.org Page 28