OPR: DSDV Based New Proactive Routing Protocol for Ad-hoc Networks

Suresh Kumar, R K Rathy Department of CSE,CITM

Faridabad, India e-mail: enthusk@yahoo.com, rathy.citm@yahoo.co.in

Diwakar Pandey Department of Computer Science and Mathematics

CCS University, Meerut, India e-mail: pandey_diwakar2k1@rediffmail.com

Abstract— An Ad-hoc network is a cooperative arrangement of the collection of mobile nodes without any centralized control. A central challenge in Ad-hoc networks is the design of routing protocols that can adapt its behavior with the frequent and rapid change in the network. The performance of the protocols varies with network characteristics and one protocol outperforms the other in some different network conditions. The optimal routing strategy is one that can adapt itself with the changing network topology and traffic pattern. This paper introduces DSDV based new proactive routing protocol. In this protocol the nodes only maintains information about their neighbors and neighbors-of-their-neighbor proactively. Each node stores only up to 2-hop nodes, thus reducing the total number of control traffic flowing in the network. When a node sends a packet to another node in the network, the neighbor node, which is closest to the destination, is selected to forward the packet. Keywords- Ad-hoc Network, Routing, Hop, OPR

I. INTRODUCTION Ad-hoc network is a collection of wireless mobile nodes forming a temporary network without any existing wire-line infrastructure. Communication between nodes is based on radio to radio multi-hoping. Ad-hoc networks are characterized by frequent topology change due to mobility of nodes. Nodes may join and leave the network at any time. The Ad-hoc routing protocols are classified into three broader categories Proactive, Reactive and Hybrid. DSDV [8] is a proactive routing protocol in which nodes maintain a table. The complete network view and route discovery process forces the proactive protocols to broadcast extremely large number of control packets, thus leading to wastage of bandwidth. Nodes exchange their tables periodically using hello messages. In DSDV protocol, a node has to store information about all the nodes in their routing table. DSR [7] and AODV[9] are reactive routing protocols. These do not store any information apriori. They find a route only when there is a packet to send. In the hybrid approach, the protocol uses the fundamental trade-off between proactive and reactive to find an optimal route. In this paper we present OPR (Optimal Path Routing) proactive routing protocol, which maintains information about its neighbors and neighbors-of-the-neighbor only.

Each OPR node periodically determines its 1-hop neighbors and 2-hop neighbors using hello messages. Thus reducing the amount of processing and storage required at each node. This also reduces the amount of traffic in the network by reducing the number of control packets required to exchange routing information. The Neighbor discovery is based on periodic Hello packets.

II. RELATED WORK SHARP [12], a hybrid routing protocol that tries to utilize the balance between proactive and reactive routing. BNNSA [13] is a routing algorithm that tries to find the best neighbor using NAT (Network Awareness Table) and BNNSA protocol stores neighbors in a sequence of the nearest to the farthest. MFR[15],DIR[16], and GEDIR[17] are GPS based routing methods which choose the neighbor which has best progress towards destination, and whose direction is closest to the direction of destination, and whose distance from the destination is minimum, respectively. SARP [14] selects the farthest node for forwarding a packet, but this farthest node may not always be the right choice and may not give shortest route. In all these protocols a node has to store information about all the participating nodes. In this paper a new routing protocol is introduced that not only stores information about its neighbors but also the information about neighbors-of-the-neighbor. The selection of the farthest node is based on the best move towards the destination.

III. OVERVIEW OF OPTIMAL PATH ROUTING DSDV issues broadcasts to announce every change in the overall connectivity of the Ad-hoc Network. Every time there is a change in the network topology due to mobility of nodes, DSDV triggers a broadcast of new connectivity information to the rest of the nodes in the network. This requirement imposes heavy load on the network. Also every node in DSDV maintains information about every other node in the network. Thus local movement has global effects in DSDV. In the proposed Optimal Path Routing, a local change does not affect the whole network. Any change in the topology only needs to be propagated to the neighbors.

2009 IACSIT Spring Conference

978-0-7695-3653-8/09 $25.00 © 2009 IEEE

DOI 10.1109/IACSIT-SC.2009.82

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2009 International Association of Computer Science and Information Technology - Spring Conference

978-0-7695-3653-8/09 $25.00 © 2009 IEEE

DOI 10.1109/IACSIT-SC.2009.82

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This will reduce the amount of traffic flowing over the network and also the amount of storage space required at each node. The format of Hello Message and the Data Packet is shown in Table1 and the format of two main data structures (1-Hop Neighbor Table and 2-Hop Neighbor Table) used in the protocol is shown in Table2.

A. Hello Message(Request/Reply)

All the nodes use beacon request packet to get information about their neighbors. The node, which receives a beacon request packet in turn, acknowledges by sending a beacon reply packet.

B. Data Packet

The data packet consists of Sequence Number, Address of Source node, Address of Destination node, List of already visited nodes by the data packet, and the location of the destination node.

C. 1-Hop Neighbor Table

It contains information of all the nodes in its neighborhood, namely location-id of neighbor, node-id, sequence-number, time of entry and the list of the neighbors-of-the-neighbor nodes.

D. 2-Hop Neighbor Table

It contains the information of all the nodes which are 2-hop away, namely location-id, node-id, sequence-number, time of entry and node-id of the 1-hop neighbor.

Table 1: Format of Hello Message and Data Packet Hello Message Data Packet

Field Size(Bytes) Field Size(Bytes) Pkt_Type 2 Seq_Num 2 Node_Id 4 Source_Id 4 Loc_Id 2 Dest_Id 4 Time(Age) 1 List_Visited_Nodes 4-64 Dest_Loc 2

Table 2: Format of 1HNT and 2HNT

1_Hop_Nbr_Table(1HNT) 2_Hop_Nbr_Table(2HNT)Field Size(Bytes) Field Size(Bytes)

Loc_Id 2 Loc_Id 2 Node_Id 4 1_Hop_Node_Id 4 Seq_Num 2 2_Hop_Node_Id 4 Time(Age) 1 Seq_Num 2 List_Nbr 4-64 Time(Age) 1

IV. ROUTING MECHANISM When a new node joins the network, it broadcasts hello message (beacon request packet). Then the neighbor nodes add the new node in their 1-hop node table and in turn send back beacon reply packet to the new node, so that the new node can initialize its 1-hop neighbor table. Further the neighbors send their 1-hop neighbor table to the new node and updated information to their neighbors. This process is repeated for every node joining the network and is periodically repeated based-on the mobility of the nodes. The nodes use this information to forward data packets. Due to mobility of nodes, whenever there is change in the topology, the nodes retransmits beacon request packets, so that the entries in the tables can be updated. This process facilitates in maintaining the consistent network view. When a node does not hear beacon packets from a neighbor within the specified time period, the node is assumed to be no longer present in the network. Thus the node removes information about that node and also passes this information to other neighbors, so that they can update their tables.

When there is a packet to be sent with a node, it checks the destination address of the packet and search it in its 1-hop and 2-hop tables. And if, it is found there, then the packet is forwarded to that node. If the destination is not found in any of the table, then the node will select a node from the 2-hop table that seems to be closer to the destination and forwards the packet through its 1-hop neighbor. Next hop will be considered based on the location id of a node.

V. OPTIMAL PATH ROUTING ALGORITHM Best_Next_Node_Selection(Packet P, 2HNT_SIZE)

{ //input Data Packet, 2 Hop neighbor Table // output Best next node If (2HNT_SIZE==1) // there is only one node in 2 hop neighbor table return Best_Node=2HNT[1].2_Hope_Node_Id Else { Min_Dist =

Calc_Dist(2HNT[1].Loc_Id , P.Dest_Loc) Best_Node=2HNT[i]. 2_Hope_Node_Id for (i=2 to 2HNT_SIZE) { Dist= Calc_Dist(2HNT[i].Loc_Id, P.Loc_Id) If(Dist <Min_Dist) { Min_Dist=Dist Best_Node=2HNT[i]. 2_Hope_Node_Id } }}

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return Best_Node } Forward_Packet(Packet P, Node Node_Id) // Input data packet and the node id //Output Forwarding the data packet to the node id Send the data packet to the node-id Calc_Dist(Node , Node)

// Input Co-ordinates of two nodes // Output Distance between the nodes

Handle_Packet(Packet P) { If (P.Dest_Id==me) then Process the packet If(found(P.Dest_Id, 1HNT)) //Destination is in the I hop neighbor table Send the packet to the dest. In the 1 hop neighbor table If(found(P.Dest_Id, 2HNT)) then //Destination is in the 2 hop neighbor table Forward_Packet(P,Dest_Id) //forward the packet to the destination with the help of the //neighbor of the destination in the 1 hop neighbor table. Else { Best_Node= Best_Next_ Node_ Selection(P, 2HNT) Forward (P, Best_Node) } }

VI. SCENARIO CONSIDERED We have considered the Ad-hoc Network scenario by taking terrain size of 800m*500m with 9 nodes (arbitrarily taken), in which 8 nodes are there initially with locations 1: (250,250), 2: (250,150), 3: (350,250), 4: (150,250), 5: (250,50), 6: (450,300), 7: (400,450), 8: (50,300) and the ninth node enters at location 9: (50,200) as shown in Figure 1. Figure 1: Initial Topology with 8 nodes and new node9 wishing to join the network

The following explains the node joining and leaving mechanism of the protocol in the network.

A. New Node Joining the Network When node 9 joins the network, it broadcasts hello message. The node 8 and node 4 receives that hello message and add node 9 in their 1-hop node table. After this both, node 4 and node 8 sends their neighbor tables to node 9, so that it can initialize its 2-hop node table. Entries of 1-hop neighbor table and 2-hop neighbor table of node4 and node9 are shown below (For brevity fields Seq_Num and Time (Age) have not been listed).

1-Hop Neighbor Table of node4

2-Hop Neighbor Table of node4

1-Hop Neighbor Table of node9

2-Hop Neighbor Table of node4

B. Packet Processing In the scenario considered, Node9 is taken as the source node and Node7 is the destination node.

1. The source Node9 checks its 1HNT for Dest_Node 7, and is not found there. 2. The source Node9 then checks its 2HNT table for Dest_Node 7, and is not found there also. 3. Now source Node9 select Node1 from the 2HNT and forwards the packet through its 1-hop neighbor

Node_id Loc_id Neighbour_Nodes 2 250,150 1,5,3 1 250,250 2,3 8 50,300 -

1_Hop_Node_Id 2_Hop_Node_Id Loc_Id 2 1 250,250 2 5 250,50 2 3 350,250 1 2 250,150 1 3 350,250 8 - -

Node_Id Loc_Id Neighbour_Node 4 150,250 1,2,8 8 50,300 4

1_Hop_Node_Id 2_Hop_Node_Id Loc_Id 4 1 250,250 4 2 250,50 4 8 350,250 8 4 150,250

1

2

34

5

6

7

8

9

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i.e. Node4. Here Node1 is selected because its position is closer to the destination Node7 . 4. After receiving the packet, Node1 again checks (i) If it is the intended Dest_Node , process the Packet. (ii) If it has Dest_Node in its 1HNT (iii)If it has Dest_Node in its 2HNT 5. Node7 is in the 2HNT of Node1, so the Node1 then forwards the packet through Node3, which is the 1-hop neighbor of Node1, for reaching at Node7. 6. Node7 upon receiving the packet sends acknowledgement through the reverse path. From the considered scenario it is observed that the proposed protocol will reduce the total amount of storage and the processing requirements at each node

VII. CONCLUSIONS The proposed Optimal Path Routing (OPR) protocol works proactively using optimal path routing mechanism. The protocol assumes that each node is equipped with GPS receivers to locate node positions. By maintaining the routing tables of neighbors and neighbors-of-the-neighbor nodes, the routing overheads have been kept to the minimum. The protocol also reduces the storage and the processing requirement at each node. In our future work we are working for the implementation of this protocol in NS2 and to compare its performance with DSDV and other routing protocols.

REFERENCES [1] Fall Kevin, Varadhan Kannan, editors, NS-Documentation [2] The CMU Monarch Project. http://www.

monarch.cs.cmu.edu/. Computer Science Department, Carnegie Mellon University

[3] Broch J., Maltz D.A., Johnson D.B., Hu Y.C.,Jetcheva J., A Performance Comparison of Multi-Hop Wieless Ad Hoc Network Routing Protocols, Proc. of the ACM/IEEE International Conference on Mobile Computing and Networking (MobiCom), October 1998.

[4] Broustis Ioannis, Jakllari Gentian, Repantis Thomas, Molle Mart, A Comprehensive Comparison of Routing Protocols for Large-Scale Wireless MANETs”, http://www.cs.ucr.edu/~mart /preprints/iwwan06.pdf

[5] Dyer Thomas D. , Boppana Rajendra V. A Comparison of TCP Performance over three Routing Protocols for Mobile AdHoc Networks, ACM Symposium on Mobile Ad Hoc Networking & Computing (Mobihoc), October 2001

[6] Feeney L. M., An Energy Consumption Model for Performance Analysis of Routing Protocols for Mobile Ad Hoc Networks, Mobile Networks and Applications, Vol. 6, pp. 239-249, June 2001.

[7] Johnson D. B., Maltz D. A., Hu YihChun , The Dynamic Source Routing Protocol for Mobile Ad Hoc Networks (DSR), <draft- ietf-manet-dsr-10.txt> draft, July 2004.

[8] Perkins Charles E , Bhagwat Pravin, Highly dynamic Destination-Sequenced Distance-Vector routing (DSDV) for mobile computers, Proc. of the SIGCOMM ’94.

[9] Perkins C., Belding-Royer E., Das S. , Adhoc On-Demand Distance Vector (AODV) Routing, RFC 3561, July 2003.

[10] Rauscher K. F., Wireless Emergency Response Team – Final Report for the Sep. 11, 2001 NYC WTC Terrorist Attack, Oct. 2001

[11] Xu Y., Heidemann J., Estrin D., Geography-informed Energy Conservation for Ad-hoc Routing, Proc. ACM MOBICOM’01, July 2001.

[12] Venugopalan R, Zygmunt J. Haas, SHARP: a hybrid adaptive routing protocol for mobile ad hoc networks , International Symposium on Mobile Ad Hoc Networking & Computing archive Proceedings of the 4th ACM international symposium on Mobile ad hoc networking & computing ,PP: 303 - 314 , 2003 ,ISBN:1-58113-684-6

[13] Goel, A.; Sharma, A.K. , A power managed based multicast routing protocol for mobile ad hoc network , Wireless and Optical Communications Networks, 2006 IFIP

[14] Goel, A.; Sharma, A.K. , SARP: A Self Adjustable Routing Protocol Journal of CSI Vol. , pp

[15] Chunjiang Wang; Yuanapos;an Liu, The performance analysis of routing strategy MFR in ad hoc DS-CDMA network,Communication Technology Proceedings,ICCT 2003.Volume 2,9-11 April 2003 Page(s): 1274 - 1277

[16] Latiff, L.A.; Ali, A. Fisal, N. ,Power reduction quadrant-based directional routing protocol (Q-DIR) in Mobile Ad Hoc Network Telecommunications and Malaysia International Conference on Communications, ICT-MICC 2007. IEEE International Conference,14-17 May 2007

[17] Watanabe, Mika Higaki, Hiroaki , No-Beacon GEDIR: Location-Based Ad-Hoc Routing with Less Communication Overhead, Information Technology, 2007.2-4 April 2007.

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