1. Jadavpur University Centre for Mobile Computing & Communication Implementation of Ad-Hoc Mesh Network Presentation by: Sudipto Das Rajesh Roy

2. Jadavpur University Centre for Mobile Computing & Communication Presentation Outline Ad-hoc Mesh Network – an overview Advantages Motivation and Practical Applications Implementation at Jadavpur University Campus Looking ahead : Possible enhancements

3. Jadavpur University Centre for Mobile Computing & Communication Ad-hoc Mesh Network – 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. Jadavpur University Centre for Mobile Computing & Communication Ad-hoc Mesh Network – 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. Jadavpur University Centre for Mobile Computing & Communication Internet Ad-hoc Mesh Network – an overview How it Works Forwarding NodeGateway NodeMobile Node Mobile Ad-hoc Mesh Network Correspondent Node

6. Jadavpur University Centre for Mobile Computing & Communication Presentation Outline Ad-hoc Mesh Network – an overview Advantages Motivation and Practical Applications Implementation at Jadavpur University Campus Looking ahead : Possible enhancements

7. Jadavpur University Centre for Mobile Computing & Communication 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. Jadavpur University Centre for Mobile Computing & Communication 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. Jadavpur University Centre for Mobile Computing & Communication Presentation Outline Ad-hoc Mesh Network – an overview Advantages Motivation and Practical Applications Implementation at Jadavpur University Campus Looking ahead : Possible enhancements

10. Jadavpur University Centre for Mobile Computing & Communication 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. Jadavpur University Centre for Mobile Computing & Communication Internet

12. Jadavpur University Centre for Mobile Computing & Communication Presentation Outline Ad-hoc Mesh Network – an overview Advantages Motivation and Practical Applications Implementation at Jadavpur University Campus Looking ahead : Possible enhancements

13. Jadavpur University Centre for Mobile Computing & Communication 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. Jadavpur University Centre for Mobile Computing & Communication 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. Jadavpur University Centre for Mobile Computing & Communication Platform Used An easily deployable (preferably single board computer) workstation that can support wireless interface(s) - our implementation, we have used workstations with Intel Pentium 4 processors (x86 architecture). Linux with Fedora Core – I kernel (kernel version 2.4.22-1.2115nptl) Should have processing power enough to process the various packets which it has to transmit. For ease of deployment, mesh nodes need to have a low power consumption

16. Jadavpur University Centre for Mobile Computing & Communication Wireless Interface and its driver D-Link g520+ PCI Adapter with TIACX111 chip. Data transfer rates up to 22Mbps Fully compatible with standard 802.11b-compliant devices We have used an open source driver from a renowned Linux Open Source Project (Source Forge). The nodes may use an optional antenna for the purpose of extending the ranges to up to 1Km (D-Link ANT24-0800)

17. Jadavpur University Centre for Mobile Computing & Communication An Implementation of the Ad-hoc routing protocol Our implementation uses AODV as the routing protocol - AODV implementation ‘Kernel AODV’ from National Institute of Standards and Technology - uses Linux NetFilter architecture for the purpose of routing packets. Gateway feature included thereby providing external connectivity to the nodes in the Ad- hoc network.

18. Jadavpur University Centre for Mobile Computing & Communication Application program for monitoring Client Server application, developed by the JU team, that can be used to monitor the performance of the various other nodes in the network. It is a GUI based program developed in JAVA and for the node to execute this application. The Server application must run on every node from which statistics have to be gathered, while the client can be used in a node from where the monitoring is done

19. Jadavpur University Centre for Mobile Computing & Communication Application program for monitoring The Server Application Acts much like a Daemon process that continually listens to a port (2048) assigned to this application. On receiving a connection, the Server services it and delivers the client the proper information according to the request received. Provides introductory information and status information about the node on which the server is running.

20. Jadavpur University Centre for Mobile Computing & Communication Application program for monitoring The Client Application User friendly GUI based application that gives a rough graphical representation of the present network scenario. Can be used for the purpose of monitoring the other nodes in the network. Information can be gathered from any node in the network. 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.

21. Jadavpur University Centre for Mobile Computing & Communication Presentation Outline Ad-hoc Mesh Network – an overview Advantages Motivation and Practical Applications Implementation at Jadavpur University Campus Looking ahead : Possible enhancements

22. Jadavpur University Centre for Mobile Computing & Communication 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.

23. Jadavpur University Centre for Mobile Computing & Communication Thank you