International Journal of Scientific & Engineering Research, Volume 5, Issue 4, April-2014 415 ISSN 2229-5518 IJSER © 2014 http://www.ijser.org Selfish nodes handling in replica allocation by clustering over MANET D.Kanimozhi , Dr.S.Varadhaganapathy Abstract—A mobile ad hoc network (MANET) is a infrastructure-less network with self configuring capability of mobile nodes connected by wireless. Each node moves freely in any direction, and will therefore change its links to other devices frequently. Since mobile hosts move freely, disconnections occur frequently and this causes frequent network division. So, the data sharing in network play a vital role. For effective data sharing, the data replication is needed. Many data replication techniques have been proposed to minimize performance degradation. In most cases it is assumed that all mobile nodes collaborate fully in terms of sharing their memory space. Some nodes decide not to cooperate. Performance of the network and data accessibility is affected by these selfish nodes. The proposed work examines the impact of selfish nodes in a mobile ad hoc network from the perspective of replica allocation. It is termed as selfish replica allocation. The work includes developing a selfish node detection algorithm that considers a replica allocation technique for effective selfish replica allocation. Index Terms — accessibility, availability, MANET, partition, replica allocation, selfish nodes, and topology. ——————————  ———————— 1 INTRODUCTION A MANET is a type of ad hoc network that can change locations and configure itself, Because MANETS are mobile, and they use wireless connections to connect to various networks. Some MANETs are restricted to a local area of wireless devices (such as a group of laptop computers). An ad hoc network typically refers to any set of networks where all devices have equal status on a network and are free to associate with any other ad hoc network device in link range. Ad hoc network often refers to a mode of operation of IEEE 802.11 wireless networks. Each must forward traffic unrelated to its own use, and therefore be a router. The primary challenge in building a MANET is equipping each device to continuously maintain the information required to properly route traffic. Such networks may operate by themselves or may be connected to the larger Internet. MANETs are a kind of Wireless ad hoc network that usually has a routable networking environment on top of a Link Layer ad hoc network. Different types of MANETs include, • InVANET – Intelligent vehicular ad hoc networks make use of artificial intelligence to tackle unexpected situations like vehicle collision and accidents. • Vehicular ad hoc network (VANET) – Enables effective communication with another vehicle or helps to communicate with roadside equipments. • Internet Based Mobile Ad hoc Network (iMANET) – helps to link fixed as well as mobile nodes. Quick configuration and easy deployment make ad hoc networks suitable for emergency situations like natural disasters, military conflicts, emergency situations etc. 1.1 Data Replication In ad hoc networks, since mobile hosts move freely, disconnections occur frequently, and this causes frequent network partition. If a network is partitioned into two networks due to the migrations of mobile hosts, mobile hosts in one of the partitions cannot access data items held by mobile hosts in the other. Thus, data accessibility in adhoc networks is lower than that in conventional fixed networks. In ad hoc networks, it is very important to prevent the deterioration of data accessibility at the point of network partition. A possible and promising solution is the replication of data items at mobile hosts which are not the owners of the original data. Since mobile hosts generally have poor resources, it is usually impossible for them to have replicas of all data items in the network. 1.2 Selfishness in MANET ———————————————— • D.Kanimozhi, PG Scholar, Kongu Engineering College, Perundurai, Erode, Tamilnadu, India. 638052. Email: kanimozhid.12cce@kongu.edu • Dr.S.Varadhaganapathy, Professor, Kongu Engineering College, Perundurai, Erode, Tamilnadu, India. 638052. Email: svg@kongu.ac.in IJSER