Implementation of Ad-Hoc Mesh Network

1. Implementation of Ad-Hoc Mesh Network Presentation by: Sudipto Das Rajesh Roy

2. Presentation Outline • Ad-hoc MeshNetwork – an overview • Advantages • Motivation and Practical Applications • Implementation at JadavpurUniversity Campus • Looking ahead : Possible enhancements

3. Ad-hoc MeshNetwork – an overview • Mesh network corresponds to a mix of ad-hoc and “Infrastructure” or “AP Based” approach. • The ad-hoc component of the mesh deals with • mesh devices communicating with each other • co-operation in forwarding traffic of each other to the nearest node supporting external connectivity. • A distributed system consisting of many wireless mobile stations/ nodes with no predetermined topology or central control. • Each device has to manage and maintain known optimal paths which can change very often due to mobility.

4. Ad-hoc MeshNetwork – an overview • All the nodes in the network may be sub-divided into two categories: • Client Node: • These may be the Mobile Nodes or the Forwarding Nodes that are within the ad-hoc network. • Gateway Node: • Nodes within the ad-hoc network but with external connectivity. • Help in forwarding packets to some external network or the internet. • Must have at least two interfaces – one for the ad-hoc network and the other connected to the internet

5. Ad-hoc MeshNetwork – an overviewHow it Works Forwarding Node Gateway Node Mobile Node Correspondent Node Internet Mobile Ad-hoc Mesh Network

6. Presentation Outline • Ad-hoc MeshNetwork – an overview • Advantages • Motivation and Practical Applications • Implementation at JadavpurUniversity Campus • Looking ahead : Possible enhancements

7. Advantages • Dynamic Route Discovery and Route Maintenance • no initial information about the routes from one node to another has to be provided. • The nodes can dynamically determine the appropriate route to forward packet to the destination nodes. • Character of mesh topology and ad-hoc routing promises greater stability in the face of changing conditions or failure at single nodes. • Adaptive Backbone provisioning • lack of the requirement to provide a wired backhaul connection to every node. • user traffic is relayed using wireless radios between nodes, until it reaches its destination.

8. Advantages • Fault-tolerance • Adaptive to failure in nodes or drop-outs in radio coverage – traffic is simply re-routed dynamically • Organization: • The decentralized nature of mesh networks lends itself well to a decentralized ownership model. • Each participant in the network owns and maintains their own hardware, which can greatly simplify the financial and community aspects of the system.

9. Presentation Outline • Ad-hoc MeshNetwork – an overview • Advantages • Motivation and Practical Applications • Implementation at JadavpurUniversity Campus • Looking ahead : Possible enhancements

10. Motivation and Practical Applications • Interconnection amongst the Universities • Connecting the various universities and colleges to create a wireless corridor that can be used for knowledge transfer and future research activities • Low cost connectivity to the rural areas • The vast uninhabited tracts of land in rural areas may be explored to extend connectivity to rural areas or to far-off cities by providing intermediate hops. • Future test bed for network research • Although a great deal of research has been done on Ad Hoc routing protocols, relatively little real-world evaluation has been carried out. • Most research published on the topic has been evaluated only in simulation. • While simulation can provide a great deal of information about many properties of a routing algorithm, unfortunately many real-world effects on a protocol's performance cannot be predicted in simulation.

11. Internet

12. Presentation Outline • Ad-hoc MeshNetwork – an overview • Advantages • Motivation and Practical Applications • Implementation at JadavpurUniversity Campus • Looking ahead : Possible enhancements

13. Implementation Details • Platform Used: • An easily deployable workstation that can support wireless interface(s) – our implementation, we have used workstations with Intel Pentium 4 processors (x86 architecture) and Linux Fedora Core – I installed • Wireless interface and its driver: • D-Link g520+ PCI Adapter with open source driver • Implementation of AODV routing protocol: • Our implementation uses an AODV implementation from NIST that requires NetFilter architecture. • Gateway feature included thereby providing external connectivity to the nodes in the Ad-hoc network.

14. Implementation Details • Application Program for Monitoring: A Client – Server application for monitoring the performance of the nodes in the network. It is a GUI based application developed in Java that provides a user friendly environment for the purpose of monitoring. • The Server Application • Acts much like a Daemon process that continually listens to a port (2048) assigned to it. • On receiving a connection, the Server services it and delivers the client the proper information according to the request received. • The Client Application • Provides a rough graphical representation of the present network scenario. • Information can be gathered from any node in the network, provided the server is running on the destination Node. • On requesting information about a particular node, the Client application opens a connection with the Server running on the destination node, gathers information and displays it.

15. Presentation Outline • Ad-hoc MeshNetwork – an overview • Advantages • Motivation and Practical Applications • Implementation at JadavpurUniversity Campus • Looking ahead : Possible enhancements

16. Looking ahead : Possible enhancements • Dynamic Host Configuration • Our implementation uses static configuration of IP addresses. • In a truly dynamic real scenario, it would be ideal to dynamically obtain an IP address that is valid & unique in the AODV subnet. • Use of Distributed and Dynamic Address Configuration in the network would impart a truly dynamic nature to the network. • QoS over Ad-hoc Networks • 802.11b was not designed with providing QoS in mind, and it is not trivial to provide QoS guarantees over such networks. • To bridge the gap, we envision to investigate the problem of providing QoS guarantees in a small sized 802.11b ad hoc wireless network.

17. Thank you