![and reactive protocols in the outside zone. Each node
periodically broadcasts control packets in the inside
zone to
build a routing table for all MNs in the inside zone.
When a
node wishes to send data to a destination node that
resides in
the outside zone, it uses a reactive protocol. Thus, a
route
discovery phase is invoked to establish the route to the
destination MN. An example of Hybrid routing protocols
is
When the routing protocol does not use the location
information of the mobile node, then the routing is
topologybased
routing protocol. If the position information is used in
the routing protocol, then the routing is position-based
routing protocol [15], [16]. There are two methods of
forwarding data packets in position-based routing:
greedy](https://image.slidesharecdn.com/introduction-130312073302-phpapp01/85/Introduction-5-320.jpg)
Introduction
- 1. INTRODUCTION A mobile ad hoc network (MANET) consists of a group of mobile nodes (MNs) that communicate with each other without the presence of infrastructure. MANETs are used in disaster recovery, rescue operations, military communication and many other applications. In order to provide communication throughout the network, the mobile nodes must cooperate to handle network functions, such as packet routing. The wireless mobile hosts communicate in a multihop fashion. In multi-hop wireless ad-hoc networks, designing energy-efficient routing protocols is critical since nodes have very limited energy, computing power and
- 2. communication capabilities. For such protocols to scale to larger ad-hoc networks, localized algorithms need to be proposed that completely depend on local information. The key design challenge is to derive the required global properties based on these localized algorithms. In ad hoc networks, the routing protocols are divided into three categories: Proactive, Reactive and Hybrid. In Proactive routing protocols, each MN maintains a routing table where control packets are broadcasted periodically within the whole network. This means that the routes to destination MNs are computed at a regular time before establishing the connection from source to destination. When a source MN wants to send data to a destination MN,
- 3. it searches the routing table to find a destination MN match. The advantage of such a method is that the route is already known. But the disadvantage is that the control packets overhead is large since they are sent periodically to maintain all routes although not all routes will be necessarily used. Thus, the limited network bandwidth is consumed by controloverhead. In Reactive routing protocols, the routes are discovered only when the source MN needs to transmit data packets. Thus, the control packets are broadcasted just when there are data to be transmitted. So, the broadcast overhead is reduced. In these protocols, there are two phases to establish
- 4. routes to destination. These two phases are route discovery and route maintenance. Since the nature of the ad hoc network is highly mobile, the topology of the network is changed often. When the route to destination is broken, the route maintenance phase is started to keep route available. This method suffers from large end to end delay to have route available before sending data packets in large networks. An example of reactive routing protocol is Hybrid routing protocols include the advantages of both proactive and reactive protocols. Each MN defines two zones: the inside zone and the outside zone. Each node maintains a neighbor table with n MN hops. These MNs are considered to be in the inside zone of the node. Thus, the hybrid protocols act as proactive protocols in the inside zone
- 5. and reactive protocols in the outside zone. Each node periodically broadcasts control packets in the inside zone to build a routing table for all MNs in the inside zone. When a node wishes to send data to a destination node that resides in the outside zone, it uses a reactive protocol. Thus, a route discovery phase is invoked to establish the route to the destination MN. An example of Hybrid routing protocols is When the routing protocol does not use the location information of the mobile node, then the routing is topologybased routing protocol. If the position information is used in the routing protocol, then the routing is position-based routing protocol [15], [16]. There are two methods of forwarding data packets in position-based routing: greedy