A Talk on Mobile Ad hoc Networks (Manets) Dr. O.B.V. RAMANAIAH obvramanaiah@gmail.com PROFESSOR, CSE Dept, JNTUH College of Engineering, HYDERABAD – 500 085

OUTLINE Brief Intro to Manets Routing Options CONCLUSION Unicast, Broadcast, Multicast & Geocast CONCLUSION 17-18JUNE2019 ASN LECTURE PPTS

Types of Mobile Networks Two Types - Conventional (with Infrastructure) - MANETs (without any Infrastructure) 17-18JUNE2019 ASN LECTURE PPTS

Mobile Ad Hoc Networks (MANETs) (1) MH2 MH4 Asymmetric link MH3 MH5 Symmetric link MH7 MH1 MH6 17-18JUNE2019 ASN LECTURE PPTS

Mobile Ad Hoc Networks (MANETs) (1) MH2 Physical Mobility of MH2 MH2 MH4 Asymmetric link MH3 MH5 Symmetric link MH7 MH1 MH6 Mobility Causes Topology and Hence Route Changes 17-18JUNE2019 ASN LECTURE PPTS

Decreased Dependence on Infrastructure Why Ad Hoc Networks ? Ease of Deployment Speed of Deployment Decreased Dependence on Infrastructure 17-18JUNE2019 ASN LECTURE PPTS

Many Applications … Military Environments Civilian Environments Emergency Operation Search-and-Rescue PAN 17-18JUNE2019 ASN LECTURE PPTS

Unicast, Broadcast, Multicast, Geocast, Anycast Besides… Webcast Telecast 17-18JUNE2019 ASN LECTURE PPTS

Unicast Routing Approaches Topology-Based Depends on the information about existing links to forward packets Position-Based Sender uses location service to determine the position of Destination Node (Physical location of each or some nodes determine their own position through GPS or some other positioning technique) 17-18JUNE2019 ASN LECTURE PPTS

Topology Based Protocols Proactive Protocols Traditional distributed shortest-path protocols Maintain routes between every host pair at all times Based on periodic updates; High routing overhead Example: DSDV (Destination Sequenced Distance Vector) Reactive Protocols Determine route as and when needed Source initiates Route Discovery Example: DSR (Dynamic Source Routing) Hybrid Protocols Adaptive; Combination of proactive and reactive Example : ZRP (Zone Routing Protocol) 17-18JUNE2019 ASN LECTURE PPTS

Proactive Routing Approaches Destination-Sequenced Distance-Vector (DSDV) Protocol Distance Vector Routing = DVR = Bellman-Ford Algorithm Proactive version for Manets DSDV Each MH Broadcasts routing updates periodically Maintains a routing table for all possible destinations Sequence Numbers enable the MHs to distinguish stale routes from new ones How to decide whether the Update is Current or Stale? 17-18JUNE2019 ASN LECTURE PPTS

DSDV … MH X takes the following steps: If S(X) > S(Y), then X ignores the routing information received from Y If S(Y) = S(X), and cost of going through Y is smaller than the route known to X, then X sets Y as the next hop to Z If S(X) < S(Y), then X sets Y as the next hop to Z, and S(X) is updated to equal S(Y) X Y Z : … 17-18JUNE2019 ASN LECTURE PPTS

Dynamic Source Routing (DSR) When node S wants to send a packet to node D, but does not know a route to D, node S initiates a Route Discovery Source node S floods Route Request (RREQ) Each node Appends Own Identifier when forwarding RREQ 17-18JUNE2019 ASN LECTURE PPTS

Route Discovery in DSR (1) Represents a node that has received RREQ for D from S B A S E F H J D C G I K Z M N L 17-18JUNE2019 ASN LECTURE PPTS

Route Discovery in DSR (2) B A S E F H J D C G I K Represents transmission of RREQ Z Y Broadcast transmission M N L [S] [X,Y] Represents list of identifiers appended to RREQ 17-18JUNE2019 ASN LECTURE PPTS

Route Discovery in DSR (3) B A S E F H J D C G I K Node H receives packet RREQ from two neighbors: potential for collision Z Y M N L [S,E] [S,C] 17-18JUNE2019 ASN LECTURE PPTS

Route Discovery in DSR (4) B A S E F H J D C G I K Node C receives RREQ from G and H, but does not forward it again, because node C has already forwarded RREQ once Z Y M N L [S,C,G] [S,E,F] 17-18JUNE2019 ASN LECTURE PPTS

Route Discovery in DSR (5) B A S E F H J D C G I K Z Y M Nodes J and K both broadcast RREQ to node D Since nodes J and K are hidden from each other, their transmissions may collide N L [S,C,G,K] [S,E,F,J] 17-18JUNE2019 ASN LECTURE PPTS

Route Discovery in DSR (6) B A S E F H J D C G I K Z Y Node D does not forward RREQ, because node D is the intended target of the route discovery M N L [S,E,F,J,M] 17-18JUNE2019 ASN LECTURE PPTS

Route Reply in DSR (2) S D Route Reply (RREP) is Unicast to S by D B A F H J D C G I K Z Y M N L RREP [S,E,F,J,D] Represents RREP control message Route Reply (RREP) is Unicast to S by D 17-18JUNE2019 ASN LECTURE PPTS

Hybrid Routing Approaches … Zone Routing Protocol (ZRP) All nodes within hop distance at most d from a node X are said to be in the Routing Zone of X. IARP: Proactively maintain routes to all nodes within the source node’s own zone Neighbour Discovery Protocol (NDP) IERP: Use an on-demand protocol (similar to DSR or AODV) to determine routes to outside zone Bordercast Routing Protocol (BRP) 17-18JUNE2019 ASN LECTURE PPTS

Zone Routing Protocol (ZRP) (2) S L K G H I J A B C D E All nodes except L are in the Routing Zone of S with Radius = 2 17-18JUNE2019 ASN LECTURE PPTS

Zone Routing Protocol (ZRP) (3) Zone Radius, K = 2 F B D S performs Route Discovery for D Denotes route request 17-18JUNE2019 ASN LECTURE PPTS

Zone Routing Protocol (ZRP) (5) Zone Radius, K = 2 F B D S performs route discovery for D Denotes route reply E knows route from E to D, so route request need not be forwarded to D from E 17-18JUNE2019 ASN LECTURE PPTS

Zone Routing Protocol (ZRP) (4) Zone Radius, K = 2 F B D S routes DATA to D Denotes route taken by Data 17-18JUNE2019 ASN LECTURE PPTS

Some More Protocols … PROACTIVE AODV Fisheye State Routing REACTIVE Link Reversal Routing TORA PROACTIVE WRP (Wireless RP) OLSR (Optimized LSR) MPR (Multipoint Relays) Hybrid Fisheye State Routing Landmark (LANMAR) CBRP 17-18JUNE2019 ASN LECTURE PPTS

Textbook (Cordeiro & Agrawal) 1/e, Cambridge Pubs, Rs 450/- 17-18JUNE2019 ASN LECTURE PPTS

Questions ?