International Journal of Engineering Trends and Technology (IJETT) – Volume 6 Number 7- Dec 2013 ISSN: 2231-5381 http://www.ijettjournal.org Page 380 A Complete Study on Unipath Routing Protocols in MANETs D.Ganesh Kumar 1 , N.Kumar 2 , M.Ramesh Kumar 3 Assistant Professor 1, 2, 3 1, 2, 3 Vel Tech Multi Tech Dr.Rangarajan Dr.Sakunthala Engineering College, Avadi, Chennai, Tamil Nadu, India. . Abstract - Mobile Ad hoc network is a cluster of wireless mobile nodes making a network with dynamically changing topology without using any permanent access point as a base station. To create connectivity among nodes more than single hop is needed due to low transmission range. Increasing of mobile nodes enhances this overhead. Many standards have been developed for transmission and to find effective routes from a source to some destination. In this paper, we have analyzed the main protocols and issues of routing in MANETs. Keywords: adhoc networks, routing protocol, unipath. 1. Introduction Mobile Ad hoc network is a cluster of wireless mobile nodes making a network with periodically changing topology without any permanent access point as a base station. To create connectivity among nodes more than single hop is needed due to low transmission range. Increasing of mobile nodes enhances this overhead. Many standards have been developed for transmission and to find effective routes from a source to destination. Wireless network has issues like low power, unreliable nodes, unstable path dynamic protocols, low bandwidth, and security [6]. Because of the very vast features of the MANET, the research for the routing protocol has been one of the concerns in the MANET. The traditional routing algorithms for fixed networks are not efficient for the changes. Many protocols have been developed a lot for routing which can be used in MANET, and here some typical protocols are analyzed. Section 2, reactive, proactive and hybrid routing are discussed. Most of them is developed from one of the uni-path routing protocols described in the final section 2. Uni-path Routing Protocol To identify the routes and maintain the path till the end of communication from source and destination. In MANET, there are two main kinds of the routing protocol: on- demand protocols (also called reactive protocols) and table-based protocols (also called proactive protocols)[1] ~ [5].In reactive routing the nodes updates the routing path when they are needed. [1][2][4]. In proactive protocols every node maintains a table for updating of the entire node’s location. Messages with routing information are exchanged using heart sync method to keep routing tables up-to-date. The advantages of both reactive and proactive protocols are taken for hybrid protocol. This always has an edge over the two protocols and definitely handles better. 2.1. Reactive Routing This routing technique uses the dynamic approach to update the routing path whenever necessary so it is mostly suited for large network where scalable is always an issue. When a node wants to identify the destination to another node, it triggers a route discovery process to find the destination path. It consists of two main phases [6]: Route discovery: It is the process of seeking a path between two nodes which is established either directly or through any other nodes using n number of hopes through other hosts. Route maintenance: It is the process of repairing a broken route or finding an alternate route in case of a route failure. It examines the operation of the route and informs the sender