This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.
Now days the wireless communication is a basic need in all over the world. Whatever the conditions bad or good, we need wireless communication. In good conditions, we use infrastructure networks for wireless or wired communication like, ROF (Radio over Fibre). But, where we are in the condition of WAR or Natural Disaster like, Earthquakes, Tsunamis and Hurricanes even though Terrorist activities where all infrastructures in wiped out, to cope up with these scenarios we use Mobile Ad Hoc Networks - MANETs.
Mobile Ad Hoc Networks (MANETs) is very useful in National Emergency and Alert situation. Specially design for emergency services like; Police, Fire brigades and Ambulance. Ad Hoc network is an infrastructure less network. In Ad Hoc network each device (node) acts as a router and as an end host. Work without any centralised access point, which is suitable in emergencies.
In this particular project I will discuss my views on Performance Analysis of AODV, OLSR and ZRP routing protocols in MANETs. I will do research with the help of different parameters in MANETs .The performance evaluation of these protocols will carried out with respect of parameters such as delays and network load. I will simulate these parameters with the help of OPNET Modeler/Simulator and evaluate from the results that which protocol is best for MANETs.
AD HOC NETWORKS:
Ad Hoc means " for this ", Ad Hoc networks is a network, which is created for a particular purpose. Ad Hoc networks do not use any central access point like infrastructure network for example, in an office networks we use server as a central access point to connect all the workstations to receive and send information/data. But in Ad Hoc networks there is no server/hub as a central access point, the nodes is connected to each other and act as a router as well as end host. There is no restriction for on these nodes to join or leave the network. There are two types of Ad Hoc networks, which is as follows,
Static Ad Hoc Network - SANET
Mobile Ad Hoc Network - MANET
OVERVIEW OF MOBILE AD HOC NETWORK - MANET:
Mobile Ad Hoc Network is a self-configurable wireless network, which operates independently. MANET sometimes called mobile mesh network. It is operates without any base station infrastructure, each device (node) is free to move independently in any direction, and each device (node) act as a router as well as end host. The term node referred to as, which are free to move randomly in every direction.
MANET consists of wireless node, a router with multiple hosts and a wireless communication device. The wireless communication devices are transmitter, receiver and antennas, which enable the mobile nodes to communicate with each other. The nodes can be anything, desktop computers, laptops and mobile phones, and all other devices, which have WiFi enable. In beginning the MANET is design for military use but now the MANET is used in many areas, such as, emergency/rescue operations and disaster relief areas. As I said earlier in MANET nodes act as router, so that why they maintain routing table using different Routing Protocols.
USAGE AREAS OF MANET:
Mobility and Multihop
Students on Campus
Figure 1.1: CONCEPTUAL MODEL OF MANET:
There are two types of routing, which is as follows,
1. STATIC ROUTING:
In Static Routing administrator does the routing table manually to forward the data packets in network. So, that means routers do not have make any routing table itself.
2. DYNAMIC ROUTING:
In Dynamic Routing software application running in a routing device (router), which dynamically learn, network destination and also advertise their routing table to other routers as well. The dynamic routing is more flexible and better than static routing.
MANET ROUTING PROTOCOLS:
The main purpose of developing the routing protocols is to cope up with the dynamic nature of MANET. The routing protocols efficiency can be determined by the battery power consumption. There is lot of research work has been done on the performance analysis and evaluation of routing protocols in MANET. Different methods and simulation environments give different results for MANET routing protocol performance. There are several kinds of routing protocols in wireless ad hoc network. These routing protocols categorized as follows,
Reactive Routing Protocol (On-Demand)
Proactive Routing Protocol (Table-Driven)
Hybrid Routing Protocol (Combination of both Reactive and Proactive)
REACTIVE ROUTING PROTOCOL: (RRP)
In Reactive Routing the route is only calculated when it is needed that is why it is also called bandwidth-efficient On-Demand Routing. Reactive routing not tries to keep routing information every time to all nodes.
Advantages of Reactive Routing Protocols:
No over head from periodic updates
Bandwidth-efficient On-Demand routing
Disadvantage of Reactive Routing Protocols:
High latency time to searching the network
Excessive flooding can lead to network clogging
The best-known protocols in Reactive Routing is,
2. PROACTIVE ROUTING PROTOCOL: (PRP)
In Proactive Routing a routing table can be maintain at every node from which a route can be determined with less delay. That is why it is also called Table-Driven protocol. In order to maintain correct route information, a node must periodically send control message.
Advantages of Proactive Routing Protocol:
Host can quickly obtain route information and quickly establish a session.
Low route latency
Disadvantages of Proactive Routing Protocol:
High overhead (periodic table updates)
Waste bandwidth control message sent out unnecessarily when there is no data traffic.
The best-known protocols in Proactive Routing is
3. HYBRID ROUTING PROTOCOL: (HRP)
In Hybrid Routing they combine all the advantages of Reactive routing and Proactive routing. The hybrid routing adjusts its routing strategies according to the network characteristics and thus provides an attractive method for routing in MANETs.
The best known protocols in Hybrid Routing is,
OVERVIEW OF AODV: AD HOC ON-DEMAND DISTANCE VECTOR:
In November 2001 the MANET working group for routing of the IEFT ( Internet Engineering Task Force) community has publish the first version of the AODV Routing Protocol (Ad Hoc On Demand Distance Vector).
AODV is an on-demand routing protocol. AODV is a Reactive routing protocol, meaning that it establishes to the destination only on demand. AODV is capable of both unicast and multicast routing. AODV works on three types of messages (1) Route Request (RREQs) (2) Route Replies (RREPs) and the (3) Route Error (RERRs). In AODV, route request is flooded through the network and route reply activates forward route and link failure generate route error.
AODV use Destination Sequence Number (DSN) to avoid counting the infinity that is why it is loop free. This is the characteristic of this algorithm. When a node send request to the destination, it send its DSNs together with all routing information. It also select the best route based on the destination sequence number.
Advantages of AODV:
Bandwidth-Efficient because work only on-demand
Supports both unicast and multicast routing.
Routing table selects shortest path
Loop free because of Destination Sequence Number (DSNs)
No overhead on data packets
Link breakage efficiently repaired
Disadvantages of AODV:
No special security so attacks can easily do.
High latency due to the route discovery only being reactive.
OVERVIEW OF OLSR: OPTIMIZED LINK STATE ROUTING:
Optimized Link State Routing (OLSR) protocol is developed by INRIA (France). OLSR is specially design for MANET but also can use for other wireless ad hoc networks. OLSR is a Proactive routing protocol and it is also called a table driven protocol because it permanently stores and regularly update its routing table. It is link state protocol means, only send connectivity information, and do not send full routing table in the network. Compare to distance vector, which is send all the information in the routing table to the neighbour node in the network. In OLSR, just Multipoint Relay (MPR) nodes broadcast the route packet. Only node that is selected for the multipoint relay is responsible to forwarding the control traffic in the network. Each node in the network keeps the list of the MPR nodes. MRP is efficient mechanism for flooding control traffic by reducing the number of transmission required. Nodes in the network send HELLO messages to their neighbours. These messages are sent at a predetermined interval in OLSR to determine the link status.
Advantages of OLSR:
Optimization: Multipoint Relay (MPR)
Suitable for large and dense network
Do not send full routing table
Calculate the best logical path
Disadvantages of OLSR:
Lack of security
No support for multicast
Overhead problem: maintaining rotes to all nodes is often unnecessary
OVERVIEW OF ZRP: ZONE ROUTING PROTOCOL:
Zone Routing Protocol (ZRP) is invented by Zygmunt Haas of Cornell University in 1997. In ZRP they combine the advantages of Reactive routing protocol and Proactive
routing protocol in hybrid scheme. Inside the zone we use Proactive routing protocol and outside or between the zones we use Reactive routing protocol. Each node individually creates its own neighbourhood, which is called a routing zone. The zone is defined as a collection of nodes whose minimum distance (in hops) from the node. Each zone has a different size. ZRP it is not itself a protocol its provide the framework from the protocols. It is a loop free protocol. ZRP is developed by mainly two sub protocols,
IARP - Intra-Zone Routing Protocol
IERP - Inter-Zone Routing Protocols
It is also have some more routing protocols for purpose of Neighbour Discovery and Bordercast Resolution, which is as follows,
NDP - Neighbour Discovery Protocol
BRP - Bordercast Resolution Protocol
Intra-Zone Routing Protocol - IARP:
Supports Proactive Routing Protocol
Local route discovery is very efficient and route to local destination is fast available.
Use for inside zone
Source and destination in the same zone
Work with Neighbour Discovery Protocol - NDP
Hello message send in order to ensure that neighbour are still present, this helps to detect link failures.
Inter-Zone Routing Protocol - IERP:
Use between routing zone
If the IARP cannot find the destination, means, the destination is out of the zone, and then IERP starts its work.
Work with Bordercast Resolution Protocol - BRP
Reactive approach enables the discovery of the destination.
3. INITIAL RESEARCH:
In this particular project I start my basic search in need of relevant matter corresponding to MANET using AODV, OLSR and ZRP protocols and go through of different articles with the help of internet and visiting some local libraries. I research includes different search engines, such as Google, Wikipedia and some video tutorials from Youtube. After collecting sufficient amount of information I made up my Proposal.
4. AIMS AND OBJECTIVES:
To find out Performance Analysis of AODV, OLSR and ZRP in MANETs.
In this project I will compare three routing protocols AODV, OLSR and ZRP. The performance of these routing protocols is analysed by Delay and Network Load. And I will use OPNET Modeler version 16 as a simulation tool. The comparison analysis will be carrying out about these protocols and in the last the conclusion will be presented, that which routing protocol is the best one for mobile ad hoc networks.
Following the study of routing protocols in MANET I will adopt the method to check the performance of AODV, OLSR and ZRP by using OPNET Modeler. I will make a mobile ad hoc network and check the delay and network load by putting different numbers of nodes or as guide by my supervisor.