A Neighbor Coverage based Probabilistic Rebroadcast for Reducing Routing Overhead in Mobile Ad hoc Networks

Abstract:Mobile ad hoc networks consist of a collection of mobile nodes which can move freely. These nodes can be dynamically self-organized into arbitrary topology networks without a fixed infrastructure.Due to high mobility of nodes in mobile ad hoc networks, there exist frequent link breakages which lead to frequent path failures and route discoveries. The overhead of a route discovery cannot be neglected. We propose neighbor coverage based probabilistic rebroadcast protocol for reducing routing overhead in MANETs. In order to effectively exploit the neighbor coverage knowledge, we propose a novel rebroadcast delay to determine the rebroadcast order, and then we can obtain the more accurate additional coverage ratio by sensing neighbor coverage knowledge.

Literature survey1) Ad-hoc On-Demand Distance Vector Routing----> Charles E. Perkins, Elizabeth M. Royer.

In this paper, author presents Ad-hoc On Demand Distance Vector Routing (AODV), a novel algorithm for the operation of such ad-hoc networks. Each Mobile Host operates as a specialized router, and routes are obtained as needed (i.e., on-demand) with little or no reliance on periodic advertisements.

Pros and cons: AODV is an on demand routing protocol in which routes are established on demand and destination sequence numbers are used to find the latest route to the destination. The connection setup delay is less. The HELLO messages supporting the routes maintenance are range-limited, so they do not cause unnecessary overhead in the network but the intermediate nodes can lead to inconsistent routes if the source sequence number is very old and the intermediate nodes have a higher but not the latest destination sequence number, thereby having stale entries.

2) Routing Overhead as A Function of Node Mobility: Modeling Framework and Implications on Proactive Routing--->Xianren Wu, Hamid R. Sadjadpour and J.J.Garcia-Luna-Aceves.

In this paper, author presents a mathematical framework for quantifying the overhead of proactive routing protocols in mobile ad hoc networks (MANETs). He focus on situations where the nodes are randomly moving around but the wireless transmissions can be decoded reliably, when nodes are within communication range of each other.

Pros and cons:In this paper author explains to reduce overhead problem in the proactive type routing protocols but not discussed about the overhead problem in the reactive type routing protocols.

3) Survey of Routing Protocols in Vehicular Ad Hoc Networks----> Kevin C. Lee, Uichin Lee and Mario Gerla.

In this paper, author discusses the advantages and disadvantages of topology-based and position-based routing protocols and explores the motivation behind their design and trace the evolution of these routing protocols.

Pros and cons:In this paper author summarizes the characteristics of representative routing protocols that have either been used or designed specifically for VANETs and also indicated the type and subtypes whether they are topology-based or position-based and whether they are proactive/reactive, DTN or Non-DTN, overlay or not.

4) A Routing Strategy for Vehicular Ad Hoc Networks in City Environments---> Christian Lochert, Hannes Hartenstein, Jing Tian, Holger Fler Dagmar and Hermann Martin Mauve.

In this paper, author analyze a position-based routing approach that makes use of the navigational systems of vehicles and compare this approach with non-position-based ad-hoc routing strategies (Dynamic Source Routing and Ad-Hoc On-Demand Distance Vector Routing).

Pros and cons:The first detailed micro-level analysis of pathologies for geographic face-based routing protocols, in the presence of location errors in static sensor networks was done but the Location errors can severely degrade performance inlocation-based forwarding schemes, making accurate location information a necessity for most geographic routing protocols.

5) Routing Protocols in Vehicular Ad Hoc Networks: A Survey and Future Perspectives---> Yun-wei Lin, Yuh-Shyan Chen and Sing-Ling Lee.

In this paper, author mainly survey new routing results in VANET. He introduce unicast protocol, multicast protocol, geocast protocol, mobicast protocol, and broadcast protocol. It is observed that carry-and-forward is the new and key consideration for designing all routing protocols in VANETs.

Pros and cons:This work surveys existing unicast, multicast, and broadcast protocols for VANETs and the work also surveys important multicast and geocast protocols for VANETs. A mobicast routing protocol in VANETs is also described and the broadcast protocols in VANETs are also introduced and predicted the tendency of the design of routing protocols for VANETs which must be the low communication overhead, the low time cost, and high adjustability for the city, highway, and rural environments.

6) VANET Connectivity Analysis----> Mohamed Kafsi , Panos Papadimitratos , Olivier Dousse, Tansu Alpcan, Jean-Pierre Hubaux

In this paper, author provided a thorough analysis of the connectivity of such networks by the results of percolation theory. RSU, Road side units are implemented to facilitate the vehicle connectivity.Extensive set of simulations that reveal the impact of main vehicle and transportation parameters and factors, such as vehicle density, traffic light, background vehicle traffic are also considered.

Pros and cons: By this concept a valuable framework to assess the feasibility and performance of future applications relying on vehicular connectivity in urban scenarios.

--Clustering has the drawback of increasing the distance between equipped vehicles and its fluctuations. Thus, the largest cluster size remains low.RSUs do not significantly improve connectivity in all scenarios.This shows that connectivity cannot be taken for granted.

7) Measuring the Performance of IEEE 802.11p Using ns-2 Simulator for Vehicular Networks---->Todd Murray, Tammy Murray, Michael Cojocari, and Huirong Fu, Member of IEEE.

The objective of this research project is to measure the performance of the WAVE, Wireless Access for the Vehicular Environment protocol at the MAC layer, using the ns-2 simulator. Specifically, the simulations measure aggregate throughput, average delay, and packet loss metrics.

Pros and cons:

These enhancements are required to support the Intelligent Transportation Systems initiatives of the US Department of Transportation regarding vehicle-to- vehicle, vehicle-to-infrastructure, and infrastructure-to-vehiclecommunication. --Some factors could not include in this research i.e multi-channel operation and other road configurations.

8)Toward an Effective Risk-Conscious and Collaborative Vehicular Collision Avoidance System---->Todd Murray, Tammy Murray, Michael Cojocari, and Huirong Fu, Member of IEEE.

In this paper author introduced cooperative collision avoidance scheme for intelligent transport systems. presenting a cluster based organization of the target vehicles which define the movement of the vehicles, namely the directional bearing and relative velocity of each vehicle, as well as the inter vehicular distance.

Pros and cons:

According to the order of each vehicle in its corresponding cluster, an emergency level is associated with the vehicle that signifies the risk of encountering a potential emergency scenario. -- The relationship between the transmission ranges of the vehicles in a given cluster and the size of that cluster needs further investigation as if it is not clearly presented in this paper.

System analysisEXISTING SYSTEM:

One of the fundamental challenges of MANETs is the design of dynamic routing protocols with good performance and less overhead.The conventional on-demand routing protocols use flooding to discover a routeThey broadcast a Route RREQ packet to the networks, and the broadcasting induces excessive redundant retransmissions of RREQ packet and causes the broadcast storm problem.

DISADVANTAGE:

They broadcast a Route REQuest packet, which leads to a considerable number of packet collisions, especially in dense networks.Due to node mobility in MANETs, frequent link breakages may lead to frequent path failures and route discoveries, which could increase the overhead of routing protocols and reduce the packet delivery ratio and increasing the end-to-end delay.

PROPOSED SYSTEM:

We propose a novel rebroadcast delay to determine the rebroadcast order, and then we can obtain the more accurate additional coverage ratio by sensing neighbor coverage knowledge.Our approach combines the advantages of the neighbor coverage knowledge and the probabilistic mechanism, which can significantly decrease the number of retransmissions so as to reduce the routing overhead, and can also improve the routing performance.

ADVANTAGE:

We now obtain the initial motivation of our protocol: Since limiting the number of rebroadcasts can effectively optimize the broadcasting, and the neighbor knowledge methods perform better than the area based ones and the probability based ones

FLOW CHART

UML DIAGRAMS

USE CASE

SEQUENCE

ACTIVITYModules Route discovery by RREQ Failure detection by Err Calculating resending delay Route recovery by RREQ and RREP

Module block:

Route discovery: Initially all node collecting the data about neighbor nodes The network monitors having the detailed information of neighbor nodes such as routing table. It provides the connection information to Route manager. Failure Detection: The network monitor only provides the information about node details. Channel analyzer collecting detail about channel capability. If there is any problem with link channel then node will generate error message for inform about failure Calculating Resending Delay: When a neighbor receives an RREQ packet, it could calculate the rebroadcast delay according to the neighbor list in the RREQ packet and its own neighbor list. The rebroadcast probability would be low when the number of neighbor nodes are high which means host is in dense area The probability would be high when the numbers of neighbor nodes are low which means host is in sparse area. We are considering the duplicate packet while transferring the RREQ. So we can avoid the overhead in rebroadcasting.Route Recovery: In this section the signal handoff is done with the knowledge of route plan.(RREP) The route manager inform the channel fading

Requirements:Hardware: Single PC 20 Gb Hard disc space 1Gb RAMSoftware: Linux OS (Ubuntu 10.04) NS2.34Expected Outcomes:There are two results we will show in final time that is Nam window and xgraph.In Nam window, we will show the event which are going to happen in our network environment as animation part

Using xgraph we will show our theoretical result for provide the proof record.