Mobile Ad hoc Network By Dr. Anzar Ahmad ( Associate Professor) Deptt. of ECE

1. Mobile Ad hoc Network By Dr. Anzar Ahmad (Associate Professor) Deptt. of ECE Contact No.: +919634321293 Email : anz_hmd@yahoo.com

2. Mobile adhoc network(MANET)

3. What is Wireless Network ? Wireless network is a network set up by using radio signal frequency to communicate among computers and other network devices wirelessly.

4. Types of Wireless Networks • The IEEE 802.11 standard defines two operational modes for WLANs • Infrastructure-Based Networks • Networks which include any infrastructure behind its operation • e.g traditional cellular systems which have MSC, BTS etc) • Infrastructure-Less Networks • Networks which does not include any infrastructure behind itself • e.g MANET (Useful when infrastructure not available, impractical, or expensive e .g Mobile Ad-hoc Network (MANET)

5. DRAWBACKS of existing Network • Setting up of fixed access points and backbone infrastructure is not always viable/possible. • Infrastructure may not be present everywhere like in a disaster area or battle-field or in a remote area. • We need such a network which must not have any infrastructure behind its operation.

6. MANET: Mobile Ad-hoc Network “A mobile ad hoc network is a collection of wireless nodes that can be dynamically set up ANYWHERE and ANYTIME, without using any pre-existing network infrastructure & which can form any arbitrary topology.”

8. Why Ad Hoc Networks ? Ease of deployment Speed of deployment Decreased dependency on infrastructure Dynamic topology User flexibility

9. Application of MANET

10. Suitable to be used in areas where earthquakes or other natural disasters have destroyed communication infrastructures.

11. perfectly satisfy military needs like battlefield survivability, operation without pre-placed infrastructure

12. Communication between smart house hold

13. Intelligent vehicles

14. Cellular Vs Ad Hoc Wireless network

15. Technical and Research Challenges • Ad hoc architecture has many benefits, such as • self-reconfiguration • adaptability to highly variable mobile characteristics, • These benefits pose new challenges to MANET • There are several technical and research challenges that need to be addressed.

16. Challenges in MANET • Highly Dynamic Topology • Bandwidth-constrained, variable capacity links • Energy-constrained operation • Routing • Security

17. Dynamic Topologies • Nodes are free to move randomly; thus, the network topology - which is typically multi-hops may change randomly and rapidly at unpredictable times.

18. Bandwidth-constrained, variable capacity links • Wireless links have significantly lower capacity than their hardwired counterparts. • Less throughput because of fading, noise, and interference as compare to wired network.

19. Energy-constrained operation • Nodes in a MANET may rely on batteries or other exhaustible means for their energy. • For these nodes, the most important system design criteria for optimization may be energy conservation.

20. Routing • Routing in MANET is clearly different from routing found in traditional infrastructure networks. • MANET generally have lower available resources compared with infrastructure networks and hence there is a need for optimal routing. • Routing in MANET needs to take into account many factors including topology, selection of routing path and routing overhead, and it must find a path quickly and efficiently.

21. Security • MANET has very low security level till date because of its multi-hop and no centralized control which is again a big issue

22. Research Challenges At Different OSI Layer • Application layer: • Security • QoS • Transport layer problems: (TCP over Ad hoc) • End-to-end reliability • Congestion control • QoS

23. Research Challenges(Cont…) • MAC layer problems: • Link layer reliability • QoS • Power conservation • Network layer problems • Routing; • QoS • Power conserving • Multicast