714

Proc. of Int. Conf. on Advances in Computer Science 2010

Optimize Flooding in Wireless Mesh Cloud Soumen kanrar soumenconference@gmail.com | Department of Computer Engineering (DIATM –Durgapur, West Bengal INDIA) Abstract:- The Wireless mesh Network (WMN) is an emerging multi hop, heterogeneous, scalable, low cost, with easy maintenance robust network providing reliable service coverage.

The architecture of WMNs is a connectionless –oriented, and consists of mesh routers and mesh clients. In this architecture, static mesh routers form the wireless backbone, mesh clients access the network through mesh routers as well as directly meshing with each other. The WMN is dynamically selforganized and self-configured and self heal. To maintain the efficient performance and the connectivity in the wireless mesh cloud , The design architecture is important reduce the redundant packet in the wireless mesh cloud .

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Figure -1 Infrastructure WMN

Keywords: Optimize, control packet, WMN, flooding.

I. INTRODUCTION

to the mostly used IEEE 802.11 technologies. The mesh router forms a mesh of self configuring, self healing links among themselves. Conventional clients with an Ethernet interface can be connected to mesh routers Via Ethernet links. For the conventional clients with the same radio technologies as mesh routers, they can directly communicate with mesh routers. If different radio technologies are used, clients must communicate with their base station s that has Ethernet connection s to mesh routers. In Client WMNs, the network provides peer to peer networks among client devices. In this type of architecture client nodes constitute the actual network to perform routing and configuration functionalities as well as providing end user application to the user. Mesh router is not required for client WMN. Client WMN is same like the general Ad hoc network but end user have extra functionalities of routing and self configuration. The Hybrid WMN architecture is the combination of infrastructure and client meshing as shown figure -2. Mesh client can access the network through mesh routers as well as directly meshing with other mesh clients. The infrastructure provide connectivity to other networks likes Wi-Fi, WiMAX, cellular, the hybrid architecture have more advantage over WMN architecture. To improve the performance of WMN’s architecture, the routing capabilities of client provide improved connectivity and coverage inside WMN’s

The WMN is similar in operation to the Mobile ad hoc network (MANET) and it employs a multihop routing mechanism from source node to destination node.

However, unlike the MANET, WMN uses multiple interfaces and multiple radio frequencies. Furthermore, it uses high speed back- haul network and gateways to optimize the network performance and integration with other wireless networks. The mesh routers can also be gateway nodes to the exterior cloud or other networking technologies. These mesh routers operate as bridging points in inter network and integration with other wireless devices. The access point is a node interface for hosting and retransmission, it’s work as the integration between the mesh client and the mesh backbone infrastructure in WMN. The WMN is an excellent wireless access technology for multimedia and community broadband (IEEE 802.16). As various wireless networks evolve into the next generation to provide better services, a key technology, wireless mesh networks (WMNs), has emerged recently.

II. NETWORK ARCHITECTURE The architecture of WMNs can be classified into three types, Infrastructure/Backbone WMNs, Client WMNs and hybrid WMNs. Infrastructure/Backbone WMN. In this architecture, mesh routers from an infrastructure for clients, as shown in figure-1 the dashed and solid lines indicate wireless and wired link, respectively. The WMN infrastructure / backbone can be built using various types of radio technologies, in addition

255 © 2010 ACEEE DOI: 02.ACS.2010.01.714

Proc. of Int. Conf. on Advances in Computer Science 2010

packets or redundant packets received by the router that holds by that node for 30seconds. The buffer of the router can holds maximum 250 kilobits data.

IV. RESULT AND DISCUSSIONS Figure 3 represents the performance of the packet forwarding procedure. The traffic sent from the source node according to the heuristic procedure to the router.

Initially the source node sends maximum control packet to cover the remote nodes with 2000 bits/ second .During the time 0 to 60 seconds the source node send the packets within the range of (450 to 1000 bits per second). During the time interval 60+ seconds up to 300 seconds the simulation shows the source node send control packet within the range of (400 to 600 bits per second). The simulation shows clearly how the rate of transmission gradually decreases with respect to the increase of time.

The simulation results (Fig. 3) clearly indicates how the traffic load reduces inside the wireless mesh cloud.

Figure -2 Hybrids WMN

The system model design to improve the connectivity and coverage inside wireless mesh cloud by using efficient flooding of control packets. Let V be the set of all nodes in the mesh cloud and R be the set of router & gateway nodes such that the size of the set V is less than the size of set R. The source node initiate a message such that message be reached every client node passing through the minimum number of hops. The intermediate node only forwarded the control message. During the message broadcasting the source node selects some subset of nodes from the total set of “router & gateway” to relay the message. The router nodes or the gateway nodes forwarded the control message subject to condition that the newly received packet yet not received earlier and the router or the gateway node is last emitter node.

Heuristic procedure to find the set of ‘router & gateway’ Step -1 V is the set of all nodes and R is the set of ‘router and gateway’ nodes Step -2 Initially the set R is empty Step -3 Select nodes from the subset (V-R) say vi , v j such that

Figure 3 Traffic sent from the source node

The figure 4 represents the traffic passed through a router node. Initially the router passes packets with the rate of 2200 bits per second. The extra 200 bits that is attached with the packet, which is the header of that router. During the time interval 10 to 300 seconds the router passes the packet with the rate of 2000 bits per second to 600 bits per second toward the next router.

i ≠ j

Step -4 Add node vi to the set R subject to condition,

vi is one

covering of 2 hops neighbor of v j .

III. SIMULATION ENVIRONMENT OPNET was used to build the simulation model. All the operations are done by using OPNET MODELER 16.0 PL1. The simulation was run for 5 minutes. In the simulation, router holds the packet for 6.0 seconds, topological control interval was 5 seconds, packet transmit interval 2.0seconds. The transmit power at the sender and intermediate node is 5 mill watts and the data transmit rate was 11 Mbps. Where the area of the simulation was 500squear miters. The particular topology of the node holds for 15 seconds. The intermediate node or router or gateway buffer the packet for 6 seconds. Any duplicate

Figure 4 Traffic pattern passing through the router

Figure 5 represents the graphical view of the of the traffic received at the client node. This is more than 2 hops 256

© 2010 ACEEE DOI: 02.ACS.2010.01.714

Proc. of Int. Conf. on Advances in Computer Science 2010

distance from the source node. Initially the client node receives packets with rate of 35000 bits per seconds. The client node received higher bits rate compare to the packet sent by the source node because of the header file that is attached with each control packet. During the time interval 60 seconds to 300 seconds the client node receives the control packet within the range of 15000 bits per second to 20,000 bits per seconds. The simulation figure clearly represents how the traffic load decreases inside the wireless mesh cloud.

REFERENCES [1] Soumen Kanrar , Mohammad Siraj “Performance of modeling wireless networks in realistic environment” IJCN Vol -2, Issue -1, 2010.

[2] FEBA: A Bandwidth Allocation Algorithm for Service Differentiation in IEEE 802.16 Mesh Networks IEEE/ACM transactions on networking, vol. 17, no. 3, June 2009.

[3] Real-world Performance of Current Proactive Multi-hop Mesh Protocols The 8th IFIP Annual Mediterranean Ad Hoc Networking Workshop 2009.

[4] Mobility –aware clustering algorithms with interference constraints in wireless mesh networks – Rami Langer a,b,*,Nizar Bouabdallah c, Raouf Boutaba a Computer Networks 53(2009) pp 25-44.

[5] P. Kinney, IEEE 802.15 General Interest in Mesh Networking, IEEE 802.15 Request for Information of a Mesh Network Study Group, presentation slides, November 2003.

[6] Mesh Networking Forum, Building the business case for implementation of wireless mesh networks, Mesh Networking Forum 2004, San Francisco, CA, October2004.

[7] P. Piggin, B. Lewis, P. Whitehead mesh networks in fixed broadband wireless access: multipoint enhancements for the 802.16 standard, IEEE 802.16 presentation slides, July 2003.

Figure 5 Traffic received at the client node

V. CONCLUSION REMARKS

[8] ‘Simulation Results of the OLSR Routing Protocol for Wireless Network’ ALaouiti, P. Muhlethaler, A.Najid, E.Plakoo, 1st Mediterranean Ad-Hoc Networks Workshop (Med-Hoc-Net), Sardegna, Italy 2002.

In this work we have proposed packet forwarding approach to reduce the traffic load in the wireless mesh cloud. To minimize the traffic load we try to minimize the number of the routers and gateways in the wireless mesh cloud. For finding the router and gateway nodes we have proposed a heuristic procedure to find the minimal number of ‘router and gateway’ nodes. The observed set of ‘router and gateway’ nodes is eventually used to relay the control packet or rebroadcast the control packet.

[9] P. Whitehead, P.Piggin, B. Lewis, S.Lynch ‘Mesh extensions to IEEE 802.16 and 16a, IEEE 802.16 proposal, May 2003.

[10] “The Optimized Link State Routing Protocol, Evaluation through Experiments and Simulation” T.H Clausen, G. Hansen, L. Christen and G. Behrmann IEEE Symposium on “Wireless Personal Mobile Communications” September 2001.

257 © 2010 ACEEE DOI: 02.ACS.2010.01.714