Peer To Peer File Sharing For Social Networks Using Ambassador And Coordinator Relationship For Disconnected MANETs

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1 Peer To Peer File Sharing For Social Networks Using Ambassador And Coordinator Relationship For Disconnected MANETs Priyadharshini.A #1 and Uvaraj Arutkumaran.S, *2 # ME, Information Technology, Sri Venkateswara college of Engineering,India * Assistant Professor, Information Technology, Sri Venkateswara college of Engineering,India Abstract Current peer-to-peer (P2P) file sharing methods in mobile ad hoc networks (MANETs) can be classified into three groups: flooding-based, local broadcasting based advertisement and contact-based. The first two techniques can simply be high overhead and low scalability. They are mainly developed for associated MANETs, in which end-to-end connectedness among nodes is ensured. The third group of method,the social contact-based method adapt to the opportunistic nature of disconnected MANETs. A P2P content based file sharing system, namely Social network based P2P content file sharing system in disconnected Mobile adhoc Networks (SPOON) is used to derive a node s interests from its files for content-based file searching using interest extraction algorithm. For competent file searching, SPOON gathered common-interest nodes that frequently meet with each other as communities. It takes the benefit of node mobility by designating constant nodes, which have the most frequent contact, with neighborhood members, as community coordinators for searching within the community, and hugely mobile nodes tat visit other communities frequently as community ambassadors for search in other community. The Work proposes Gossiping algorithm based on pull and push mechanism, so that it gives time slot to each individual node to achieve good relation between ambassadors and coordinators and to avoid transmission overhead and also get efficient file sharing. Keywords MANETs, content-based file sharing, Mobility, Coordinator, Ambassador, Community. I. INTRODUCTION In the past few years, personal mobile devices such as laptops, PDAs and smart phones have been more popular. so, the number of smart-phone users increased by 118 million across the world in 2007 [1], and expected to reach around 300 million by 2013 [2]. The rapid growth of mobile users is leading to a promising future, in which they can share files between each other whenever and wherever. The mobile searching users (through smart phones, tablets, etc.) is estimated to reach million in 2013 [3]. Nowadays, mobile users interact with each other and share 18 files via an infrastructure formed by geographically distributed base stations. However, users has find themselves in an area without wireless service (e.g., mountain areas and rural areas). Moreover, They may hope to reduce the cost on the expensive infrastructure network data. A Mobile Ad-hoc Network(MANET) have received significant attention in recent years.it has usually consists of wireless mobile nodes that communicate with each other, in the absence of a stable infrastructure. hence, it is suitable for use in situations where an infrastructure is unavailable or to deploy one is not cost effective. Current applications of MANETs include outdoor business meeting, disaster relief operations, battlefield, and so on. Mobile and wireless, each of these two words enforces a list of requirements, and the difficult task is to fulfill them to their best. The mobility means that nodes I the networks moves at any time, which implies the short duration of neighbor-hood and topology information received at any moment. In order to handle mobility correctly, the information need to be updated regularly for efficient file sharing. The P2P file sharing model makes large-scale networks a blessing, in which nodes share files directly with each other without a centralized server. Wired P2P file sharing systems (e.g., BitTorrent [4] and Kazaa [5]) have already become a popular and success-ful paradigm for file sharing among millions of users. II. RELATED WORK Peer to Peer System: P2P systems may be categorized into centralized, brokered, and decentralized systems. Centralized systems require peers to connect to a server, which coordinates and manages all communication.in Brokered systems,it require peers to connect to a server to discover other peers, but peers manage communication between themselves. In decentralized

2 systems, there are no servers; peers operate independently and perform both discovery and communication in a decentralized manner. Peer to Peer (P2P) networks are increasingly popular and their uses vary over many different types of applications, such as file sharing, Voice over IP, video streaming,gaming and instant messaging. A. Peer To Peer File Sharing in MANET We have mention the former approach of the P2P file sharing algorithms designed for connected MANETs Fig.1 Data transmission in Connected MANETs 1) Flooding Based Method: In flooding-based methods, 7DS [6] is one of the first approaches to port P2P technology to mobile environments. It utilize the mobility of nodes within a geographic area to disseminate web content among neighbors. Passive distributed indexing (PDI) [8] is a general-purpose distributed file searching algorithm. It uses local broadcastin for content searching and sets up content indexes on nodes along the reply path to guide subsequent searching. Klemm et al. [7] implemented a special-purpose on-demand file searching and transferring algorithm based on an application layer overlay network.hereby, the algorithm transparently aggregates query results from other peers to eliminate redundant routing paths. Hayes [9] extended the Gnutella system to mobile environments and proposed the use of a set of keywords to represent user interests. Anyways, these flooding-based methods produce high overhead due to broadcasting. 2) Advertisement Based Method: Tchakarov and Vaidya [10] proposed GCLP for efficient content discovery in location-aware ad hoc networks. It disseminates the contents and requests in crossed directions to ensure their encountering. P2PSI [11] combines both advertisement (push) and discovery (pull) processes. It acquires the idea of swarm intelligence by regarding shared files as food sources and routing tables as pheromone. Each file holde regularly broadcasts an advertisement message to inform surrounding nodes about its files. Repantis and Kalogeraki [12] proposed a file sharing mechanism in which nodes use the Bloom filter to build content synopses of their data and adaptively disseminate them to other nodes to guide queries. Though the advertisement-based methods reduces the overhead of flooding-based methods, they still generating high overhead for advertising and cannot guarantee the success of file searching due to node mobility. B. Peer To Peer File Sharing in Disconnected MANET: The disconnected MANETs are featured by sparse node density and intermittent node connection, which make previously introduced methods infeasible in such networks.then,we further introduce two categories of P2P file sharingmethods for disconnected MANETs. 1) Cache/Replication-Based Methods: Huang et al. [13] proposed a method that considers multiple factors (e.g., node mobility, file popularity, and file server topology) in which creating file replicas in file servers to realize optimal file availability in content distribution community. Gao et al. [14] implemented cooperative caching in disruption tolerant networks. It replicas each files to network central locations which are frequently visited by nodes in the system, to ensure efficient data access. QCR [15] uses file caching to realize effective multimedia content dissemination in opportunistic networks.thereby in addition to node mobility and file popularity, it also considering the impatience of users when creating replicas. Though these methods improve file availability, In these methods, nodes passively wait for contents they are interested in rather than actively search files, which may leads to search delay. 2) Social Network-Based Methods: Currently,social networks have been utilized in content publishing/dissemination algorithms [18], [19], [20], [21] in opportunistic networks. MOPS [18] provides content-based sub/pub service by utilizing the long-term neighboring relationship between nodes.thereby,it groups nodes with frequent contacts and selects nodes that connect different groups as brokers which are responsible for intercommunity communication. Then the contents and subscriptions are relayed through brokers to reach different communities. MOPS only considers node mobility, while SPOON is advantageous by considering both node interest and mobility as described previously. Unlike MOPS that only depends on the meeting of brokers for intercommunity search, SPOON escalates the efficiency of intercommunity search by 1) assigning one ambassador for each known foreign community, which assists to forward a query directly to the destination community, and 2) utilizing stable nodes (coordinator) to receive messages from ambassadors.therefore, these methods cannot be applied to file searching directly. III. DESIGN OF SPOON 19

3 The Trace data analysis to verify the social network properties in a real MANET. A P2P MANET file sharing system usually consists of 1) a method to represent contents, 2) a node management structure, and 3) a file searching method A. Interest Extraction Without loss of generality, we assume that node contents can be classified to different interest categories. It was found that users usually have a few file categories that they query for files frequently in a file sharing system. Specifically, for the majority of users, 80% of their shared files fall into only 20% of total file categories. Like other file sharing systems we consider that a node s stored files can reflect its file interests. Thus, SPOON derives the interests of a node from its files. coordinator in the community finds that the home community cannot satisfy a request,then, it launches the inter-community searching and forwards the request to an ambassador that will travel to the foreign community that matches the request s interest. A request is deleted when its TTL (Time To Live) expires. During the search, a node sends a message to another node using the interest-oriented routing algorithm (IRA), in which a message is always forwarded to the node that is likely to hold or to meet the queried keywords. The received file is routed along the search path or through IRA if the route expires. B. Community Construction Social network theory reveals that people with the same interest tend to meet frequently. By exploiting this property, SPOON classifies nodes with common interests and frequent contacts into a community to facilitates interest based file searching, as introduced. Nodes with multiple interests belong to multiple communities. The community construction can easily be conducted in a centralized manner by collecting node interests and contact frequencies from all nodes to a central node. However, considering that the proposed system is for distributed disconnected MANETs, in which timely information collection and distribution is non-trivial, we further propose a decentralized method to ensure the adaptivity of SPOON in real environment. C. Node Role Assignment It defines Community coordinator and ambassador nodes in the view of a social network. A community coordinator is popular and important node in the community. It keeps the indexes of all files in its community. Each and every community has one ambassador for each known foreign community, which act as a bridge to the community. A Community coordinator maintains the of foreign communities and corresponding ambassador to map queries to ambassador for intercommunity searching. A number of ambassadors and coordinators can be adjusted based on the network size and workload to avoid overloading these nodes. Thereby. ambassadors and coordinators take more responsibility. Fig.2 File Searching in SPOON E. Push Pull Gossipping Technique To facilitate an efficient gossiping operation, The Distributed Discovery algorithm,it first identifies highly influential peers (called seers) in a community. Then, A Push Phase multicasts information to these seers so that peers can easily and quickly retrieve this information via a pull phase. The gossip information to only a small number of seers allows a large percentage of peer members to obtain (pull) the information within just two hops. The work proposes Gossiping algorithm based on Push and Pull Mechanism and uses TDMA,It gives time slot to each individual node to achieve good relation between ambassadors and coordinators. It avoids transmission overhead and packet loss and also get efficient file sharing. Architecture Diagram D.. File Searching In SPOON The interest-oriented file searching has two steps: Intra- Community and Inter-community searching.firstly, A node first searches files in its home community. If the 20

4 The PDR(Packet Delivery Ratio) is calculated using following formula, Throughput is the number of packet that is passing through the channel in a particular unit of time. This performance metric shows the total number of packets that have been successfully delivered from source node to destination node. The Factors that affect throughput include frequent topology changes, unreliable communication, limited bandwidth and limited energy. Fig.3 Architecture Diagram IV. RESULT The Results are based on the implementation of the SPOON Technique with Gossiping Push and Pull Mechanism. The Result shown is packet loss graph. A. Input Specifications The simulation employs IEEE MAC. The nodes move with a random speed. The simulation parameters are shown in table below A specific packet is transmitting from source to destination node and calculates the difference between send times and received times. This metric describes the packet delivery time. Delays due to Queueing, route discovery, propagation and transfer time are included metric TABLE I SIMULATION PARAMETERS PARAMETER SPECIFICATION Simulator NS-2 (version 2.34) Traffic type Constant Bit Rate (CBR) Number of nodes 20 Area 670m*670m Packet Size 512 Channel data rate 0.02 Mbps Speed 20 m/s Routing protocol SPOON The Packet Loss Ratio Graph is shown below B. Output Analysis The proposed system was executed and the results are analyzed using Network Simulator The number of nodes is 20 and there is one malicious node. The nodes move randomly with a speed of 20m/s. 21

5 Fig 5. Electing Ambassador and Coordinator V. CONCLUSION AND FUTURE WORK Fig.4 Packet loss Ratio graph Figure 4.4 shows the packet loss ratio in the graph, it achieves 83% packet delivery effectively.in that packet loss,delay,time are used as parameters in it. Here coordinate x axis as packet loss and y axis is time. This project explored a Social network based P2P content file sharing system in disconnected Mobile adhoc Networks(SPOON) with Gossiping Pull and Push Mechanism. SPOON considers both node interest and contact frequency for efficient file sharing.hereby, We introduce four main components of SPOON: Interest extraction identifies nodes interests; Community construction builds common-interest nodes with frequent contacts into communities. The node role assignment component utilizes nodes with tight connection with community members for intra-community file searching and highly mobile nodes that visit external communities frequently for inter-community file searching. In interestoriented file searching scheme,it selects forwarding nodes for queries based on interest similarities. Using Gossiping Pull and Push Mechanism it allots time slot to each individual node to achieve good relation between ambassadors and coordinators and to avoid transmission overhead and also get efficient file sharing. 22 The propose scheme enhances good relationship between ambassadors and Coordinators relationship with allotted time slot for each individual node. This proposed schemed extended to implement in Decentralized approach for intra and inter community phases, mobility enhancement and also providing simple node prevention scheme. This

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