Mobile Ad hoc Network By Dr Anzar Ahmad

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

MOBILE ADHOC NETWORK(MANET)

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.

TYPES OF WIRELESS NETWORKS The IEEE 802. 11 standard defines two operational modes for WLANs Infrastructure-Based 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)

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.

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. ”

WHY AD HOC NETWORKS ? ♦ ♦ ♦ Ease of deployment Speed of deployment Decreased dependency on infrastructure Dynamic topology User flexibility

APPLICATION OF MANET

SUITABLE TO BE USED IN AREAS WHERE EARTHQUAKES OR OTHER NATURAL DISASTERS HAVE DESTROYED COMMUNICATION INFRASTRUCTURES.

PERFECTLY SATISFY MILITARY NEEDS LIKE BATTLEFIELD SURVIVABILITY, OPERATION WITHOUT PRE-PLACED INFRASTRUCTURE

COMMUNICATION BETWEEN SMART HOUSE HOLD

INTELLIGENT VEHICLES

CELLULAR VS AD HOC WIRELESS NETWORK Cellular Ad Hoc Wireless Networks Infrastructure based networks Infrastructure less networks Fixed, pre-located cell sites and base station and hence no rapid deployment No base station, and hence rapid deployment Static backbone network topology Highly dynamic network topologies with multihop Relatively caring environment and stable connectivity Hostile environment (noise, losses) and irregular connectivity Detailed planning before deploying base station No planning, automatically forms and adapts to changes High setup costs Less set up cost Large setup time Less setup time

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.

CHALLENGES IN MANET Ø Highly Dynamic Topology Ø Bandwidth-constrained, variable capacity links Ø Energy-constrained operation Ø Routing Ø Security

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.

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.

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.

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.

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

RESEARCH CHALLENGES AT DIFFERENT OSI LAYER Application layer: Security Qo. S Transport layer problems: (TCP over Ad hoc) End-to-end reliability Congestion control Qo. S 22

RESEARCH CHALLENGES(CONT…) MAC layer problems: Link layer reliability Qo. S Power conservation Network layer problems Routing; Qo. S Power conserving Multicast 23