INTRODUCING EFFICIENT & IMPROVED.AODV ROUTING PROTOCOL FOR MANET
Anumeha
1, Prof. (Dr.) Bhawna Mallick
21
M .Tech. ( CSE ),
2Dean Academic & HOD, Galgotia College of Engineering & Technology, Greater Noida (India)
ABSTRACT
Mobile ad hoc networks (MANETs) are becoming more essential to wireless communications due to growing popularity of mobile devices. An ad-hoc network is a multi-hop wireless network where all nodes cooperatively maintain network connectivity without a centralized infrastructure. If these nodes change their positions dynamically, it is called a mobile ad- hoc network (MANET). Efficient protocols are used to forward data packet without much packet loss.In this paper, .an adaptive routing algorithm is presented in Mobile Ad hoc Networks using modified AODV by calculating the load on different routes using various parameters. The objective of this paper is to enhance the network performance of AODV, when frequent link failure in network due to mobility of the nodes in the network. The performance analysis and simulation are carried out to evaluate network performance using Network Simulator (NS-2), based on the quantitative metrics packet delivery ratio and average end to end delay. The simulated result helps to understand the behaviour of the protocol AODV in the distributed network environment. This paper proposed a new protocol Enhanced AODV (E-AODV) which is a modified version of AODV.
General Terms: Enhancing The Performance Of AODV Routing Protocol And Compare It With Other Routing Protocols.
Keywords: Ad hoc Network , AODV , Enhanced AODV, Packet delivery Ratio , End to End Delay , Throughput
I. INTRODUCTION
Ad hoc Network (MANET) [1, 2] is a wireless network of collection of independent mobile nodes that can communicate to each other via radio waves. The mobile nodes that are in radio range of each other can directly communicate, whereas others needs the aid of intermediate nodes to route their packets. These networks are fully distributed, and can work at any place without the help of any infrastructure. This property makes these networks highly flexible and robust. The dynamic change in MANET topology [3, 4] makes routing as a challenging task, a path is rendered inefficient and infeasible. The major issues for
Communication using wireless Network.
No centralized controller and no infrastructure.
Dynamic Network topology.
Frequently routing information updated.
Nodes can perform dual role hosts and routers.
mutual trust..
Network Simulator (NS-2) is an event driven, object oriented network simulating tool, very much used by the researchers, professors and students. Simulation is the process of creating a model with its behaviour. There are numerous network simulating tools available such as NS-2 , GloMoSim, OPNET, QualNet, etc. NS-2 is the out performs among all the other tools. The Routing protocols of MANET such as DSDV, DSR, AODV is implemented using NS-2 and it’s available as free open source programs. In this paper, AODV protocol is considered and its network performance is enhanced by E-AODV.
Security of goal of MANET:
Authentication
Integrity
Confidentiality
Availability
II. ROUTING PROTOCOL FOR MANET
Routing is the process to send information from one host to another host. Routing means route packet to its destination using efficient path. Protocols are set of rules. Routing protocols are required where source needs to communicate to the destination.
mobile ad hoc networks are medium access control (MAC), routing, security and quality of service provisioning. The paper addresses the routing problem in i.e., access control and security. Routing in MANET means the directed flow of data from source to destination maximizing the network performance. The characteristics of these networks are summarized as follows:
2.1 Reactive Routing Protocol
Routes are found when there is a need (on demand). Hence, it reduces the routing overhead. It does not need to search for and maintain the routes on which there is no route request. Reactive routing protocols are very pleasing in the resource- limited environment. However the source node should wait until a route to the destination is discovered. This approach is best suitable when the network is static and traffic is very light. Ex: DSR, AODV. [ 15, 16 ].
2.2 Proactive Routing Protocol
Routes to all destinations are maintained by sending periodical control messages. There is unnecessary bandwidth wastage for sending control packets. Proactive routing protocols are not suitable for larger networks, as it needs to maintain route information every node’s routing table. This causes more overhead leads to consumption of more bandwidth. Ex: DSDV [10,11]
2.3 Hybrid Routing Protocol
The Ad Hoc network can use the hybrid routing protocols that have the advantage of both proactive and reactive routing protocols to balance the delay and control overhead (in terms of control packages). The difficulty of all hybrid routing protocols is the complexity of organizing the network according to network parameters. The common disadvantage of hybrid routing protocols is that the nodes that have high level topological information maintains more routing information, which leads to more memory and power consumption.
III. AODV PROTOCOL
AODV is an on-demand routing algorithm in that it determines a route to adestination only when a node wants to send a packet to that destination. It is a relative of the Bellman-Ford distant vector algorithm, but is adapted to work in a mobile environment. Routes are maintained as long as they are needed by the source. AODV is capable of both unicast and
multicast routing.In AODV, every node maintains a table, containing information about which neighbor to send the packets to in order to reach the destination.
Sequence numbers, which is one of the key features of AODV, ensures the freshness of routes. AODV is a source initiated on-demand routing protocol. Every mobile node maintains a routing table that maintains the next hop node information for a route to the destination node. When a source node wishes to route a packet to a destination node, it uses the specified route if a fresh enough route to the destination node is available in its routing table. If not, it starts a route discovery process by broadcasting the Route Request (RREQ) message to its neighbours, which is further propagated until it reaches an intermediate node with a fresh enough route to the destination node specified in the RREQ, or the destination node itself.
Each intermediate node receiving the RREQ, makes an entry in its routing table for the node that forwarded the RREQ message, and the source node .The destination node or the intermediate node with a fresh enough route to the destination node, unicast the Route Response (RREP) message to the neighbouring node from which it received the RREQ. An intermediate node makes an entry for the neighbouring node from which it received the RREP, then forwards the RREP in the reverse direction. On receiving the RREP, the source node updates its routing table with an entry for the destination node, and the node from which it received the RREP. The source node starts routing the data packet to the destination node through the
neighbouring node that first responded with an RREP.. AODV are:
Route Request Message (RREQ)
Route Reply Message (RREP)
Route Error Message (RERR)
Route reply Acknowledgment (RREP-ACK) Message
HELLO Messages
3.1 Sequence Number
AODV differs from other on-demand routing protocols in that is uses sequence numbers to determine an up-to-date path to a destination. Every entry in the routing table is associated with a sequence number. The sequence number act as a route timestamp, ensuring freshness of the route. Upon receiving a RREQ packet, an intermediate node compares its sequence number with the sequence number in the RREQ packet. If the sequence number already registered is greater than that in the packet, the existing route is more up-to-date.
3.1.1 Route Discovery
When a source node desires to send a message to some destination node, and doesn’t have a valid route to the destination, it initiates a path discovery process to locate the other node. It broadcasts a route request (RREQ) control packet to its neighbours, which then forward the request to their neighbours, and so on, either the destination or an intermediate node with a new route to the destination is located. The AODV protocol utilizes destination sequence numbers to ensure that all routes contain the most recent route information. Each node maintains its own sequence number. During the forwarding process the RREQ intermediate nodes record the address of the neighbour from which the first copy of the broadcast packet is received in their route tables, thereby establishing a reverse path.Once the RREQ reaches the destination or an intermediate node with a fresh enough route, the destination or the intermediate node responds by unicasting a route reply (RREP) control packet back to the neighbour from which first received the RREQ [6,7].
3.1.2 Route Maintenance
A route discovered between a source node and destination node is maintained as long as needed by the source node. The destination node or some intermediate node moves, the node upstream of the break initiates Route Error (RERR) message to the affected active upstream neighbours/nodes. Consequently, these nodes propagate the RERR to their predecessor nodes.
This process continues until the source node is reached. When RERR is received by the source node, it can either stop
required[9,10].
IV. PROPOSED WORK
The algorithm performs its working in two modes one is the normal mode and the other is retransmission mode.
4.1 Normal Mode
The source node (S) Broadcast the Hello packet.
The neighbour nodes of the S receive the Hello packet and forward it until destination achieved.
The destination selects the shortest path from the possible path and unicast t he reply to the S the reply time is stored as reft time.
The S transfers the DATA through the selected Path.
When the data takes more than reft+th time then the protocol swiches to other mode.
4.2 Retransmission Mode
The Hello packet is retransmitted from the Source node (S).
If intermediate nodes that receive the RREQ message have energy > thE
Then forward the packet to its entire one hop adjacent nodes.
Else
Discard the node and go to step 6.
If Destination (D) receives RREQ message through a node N then it sends a RREP to (S) by forwarding it to (N) since (N) may contain at least one routing table entry for (S).
On receiving RREQ Message through different nodes, the destination (D) will send the RREP message through different nodes and they may reach the source node through different possible paths.
V. RESULTS
The AODV protocol is implemented using the NS2. Various parameters used for analysis are described below:
5.1 Throughput
The amount of data transfer from source mode to destination in a specified amount of time i.e. average number of bits delivered per second(Kbps) Calculated as: Throughput =(Packet Size/(stopTimestartTime) )*(8/1000).
5.2 Packet Delivery Ratio/Reception Ratio: Packet delivery Fraction (PDF):
The packet delivery fraction is defined as the ratio of number of data packets received at the destinations over the number of data packets sent by the sources. In other words, fraction of successfully received packets, which survive while finding their destination, is called as packet delivery ratio.Calculated as: PDF= (Received Packets / Packets Sent)*100
5.3 Average End to End Delay/Latency:
This is the average time involved in delivery of data packets from the source node to the destination node. In other words, it is the average amount of time taken by a packet to go from source to destination. The end-to-end delay includes allpossible delays in the network caused by route
discovery latency, retransmission by the intermediate nodes, processing delay, queuing delay andpropagation delay. To compute the average end to-end delay, add every delay for each successful data packet delivery and divide that sum by the number of successfully received data packets.
Calculated as EED= (Time packet received – Time packet sent) Total number of packets received
5.4 Normalized Routing Overhead:
The total number of routing packets transmitted during the simulation i.e. the sum of all transmissions of routing packets sent during the simulation. Calculated as Routing Overhead= Σ Transmission of routing packets.5.5 Packet Loss:
Packet loss occurs when one or more packets being transmitted across the network fail to arrive at the destination. It may be due to path breaks caused by the mobility of nodes and node failure dueto a drained battery. It is defined as the number of packets dropped by the routers during transmission.The Table 1 to table 4 shows the result of various parameters (described in 6.3) on various protocols i.e. AODV, DSDV, NAODV.
Table 1 : Shows the Comparison of DSDV, AODV and Modified AODV for 50 Nodes.
Table 2 : Shows the Comparison of DSDV, AODV and Modified AODV for 100 Nodes.
Table 2 : Shows the Comparison of DSDV, AODV and Modified AODV for 150 Nodes.
Table 4 : Shows the Comparison of DSDV, AODV and Modified AODV for 200 Nodes.
Figure 1: X Graph Comparison of PDR of Various Protocols
Figure 2: X Graph Comparison of END TO END DELAY of Various Protocols
Figure 3: X Graph Comparison of DROP RATIO of Various Protocols
Figure 4: X Graph Comparison of Normalized Load of Various Protocols
The graphical comparison shows that the EDYMO protocol enhances the throughput and decrease the routing load while maintaining the packet delivery ratio.The end 2 end delay is also reduced in the proposed protocol. The EDYMO performs slightly better than the DYMO protocol and quite better than the other protocols.
IV. CONCLUSION
In this paper, the description is given about the importanc of QoS( in terms of packet delivery ratio and average end to end delay) routing in Mobile Ad-Hoc networks, challenges came across, and the approach taken The performance evaluation of various routing protocols will help to make proper selection of routing protocol in ad-hoc networks according to the traffic, size of the network, and QoS requirement. This will positively decrease the computational cost by a large amount and
observing the simulation and analyzing the data, it is found that packets could get less end to end delay with a QoS based routing protocol when the traffic on the network
is high. This low end to end delay is meaningful for real time transmissions. When the traffic is relatively high on the network, not all the routes that are found by the AODV routing protocol have enough free data rate for sending packets ensuring the low end to end delay of each packet. As a result, the E-AODV protocol works well and shows its effects when the traffic on the network is relatively high. People who work on the area of ad hoc networks with the aim of improving QOS in terms of reduced the average end to end delay and enhanced packet delivery ratio for ad hoc networks can get benefit from this EAODV protocol. The modified AODV will outperform the conventional AODV in terms of routing overhead and packet delivery ratio. The simulation result shows that the modified AODV outperforms the other protocol in terms of throughput, delay and routing load. The throughput gets increased and the normalized routing load gets decreased.
The end 2 end delay is also decreased. In future following work can be done:
The analysis of proposed protocol for various other parameters.
The proposed protocol can be extended for security.
The proposed protocol can be extended to deal with various attacks.
VII. ACKNOWLEDGMENTS
I would like to express my deepest gratitude to my Guide Prof. (Dr.) Bhawna Malik Dean Academic & HOD and asstt.
Proff. Mr. Raj Kumar Singh Rathor (M.Tech. Co-coordinator) for his guidance and support. I would also like to thank Mr.Sanjay Kumar for devoting his time in discussing ideas with me and giving his invaluable feedback
REFERENCES
[1]. N. Wang, Y. Huang and J. Chen, “A stable weight-based on- demand routing protocol for mobile ad hoc networks” Information Sciences 177(2007), pp. 5522-5537, 2007.
[2]. International Journal of Computer Applications (0975 – 8887) Volume *– No.*, ___________ 2015 [3]. Charles E. Perkins, “Ad Hoc Networking”, Addison
[4]. Wesley, USA, 2001.
[5]. David B. Johnson, Davis A. Maltz, “The Dynamic
[6]. Source Routing Protocol for Mobile Ad hoc Networks”, Internet Draft, draft-ietf-manet-dsr-03.txt, Oct.
1999.
[7]. H. Hassanein, and A. Zhou, “Load-aware Destination-controlled Routing for MANETs” , Elsevier Computer
[8]. Communications, pp. 1551-1559, 26(2003).
[9]. G. Chakrabarti, and S. Kulkarni, “Load Balancing and Resource Reservation in Mobile Ad hoc networks”, [10]. Elsevier Ad Hoc Networks, accepted 14 April, 2004.
[11]. S. Ahn, Y. Lim and J. Choe, “A Load-Balancing Approach in Ad-Hoc Networks”, ICOIN 2003, LNCS 2662, pp. 672-681, 2003.
[12]. J-H. Song, V. Wong, and V. C. M. Leung, “Load-Aware On-Demand Routing (LAOR) Protocol for Mobile Ad hoc Networks”, The 57th IEEE Semiannual Vehicular
[13]. Technology Conference, pp. 3:1753-1757, 2003.
[14]. Yu-Chee Tseng, Wen-Hua Liao, Shih-Lin Wu, “Mobile Ad Hoc Networks and Routing Protocols”, Handbook of
[15]. Wireless Networks and Mobile Computing, Edited by Ivan Stojmenovic´ Copyright ©2002 John Wiley &
Sons, Inc. ISBNs: 0-471- 41902-8 (Paper); 0-471-22456-1 (Electronic).
[16]. Srdjan Krco and Marina Dupcinov, “Improved Neighbor Detection Algorithm for AODV Routing Protocol”,
[17]. IEEE Communications Letters, vol. 7, No.12, December 2003.
[18]. Venugopalan Ramasubramanian and Daniel Mossee
[19]. “BRA: A Bidirectional Routing Abstraction for Asymmetric Mobile Ad Hoc Networks”, IEEE/ACM [20]. Transactions on Networking, Vol 16, No.1,February 2008.
[21]. Hua Qu, Peng Zhang, Ji-Hong Zhao, “A New Local Repair Scheme Based on Link Breaks for Mobile Ad Hoc Networks”, 2009 Seventh Annual Communications Networks and Services Research Conference [22]. “Network Simulator, ns-2,” available online at http://www.isi.edu/nsnam/ns/.
[23]. Perkins C and E. Royer, “Ad-hoc on-demand distance vector routing,” in Proceedings of Second IEEE Workshop on Mobile Computing Systems and Applications, February1999, pp.90–100.
[24]. [14] Boukerche A, “Performance Comparison and Analysis of Ad hoc Routing Algorithms,” In Proc.of IEEEICPCC,
[25]. 2001, pp.171- 178
[26]. Perkins C, E. Belding-Royer, and S. Das, “Ad hoc on-demand distance vector (AODV) routing,”IETFRFC3561,July2003.
[27]. Doyle S L. Doyle, A. Kokaram, T. Forde. “Ad-hoc n etworking, randommarkov fields and decision making”.
[28]. IEEE Signal Processing Magazine, 2006
