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Mobility-Based Routing Overheads Management in RW Ad h oc Networks

Mobility-Based Routing Overheads Management in RW Ad h oc Networks

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Mobility-Based Routing Overheads Management in RW Ad h oc Networks

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  1. Mobility-Based Routing Overheads Management in RW Ad hoc Networks Gikaru, Wilfred Githuka Dissertation Talk – Muenster 2004 Technische Universität Dresden Fakultät Informatik Institut für Systemarchitektur

  2. Agenda • Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations and Simulations • Evaluation and Analysis • Summary and conclusions • Next step and Future work RO Management in RW Ad hoc Networks

  3. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and analysis • Evaluation • Summary and conclusions • Next step and Future work Introduction and Overview • Ad Hoc Networks • RWAdhoc Networks • Routing in Ad Hoc Networks • Protocol Classes • Mobility and reconfiguration • Performance of Routing Protocols • Throughput • Packet Delivery Ratio • Delay RO Management in RW Ad hoc Networks

  4. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Table 1 Motivation • Justification • Why do this piece of research and who needs it ? • Contribution to research? • What is expected or has been accomplished? • Research gap • Effects of Routing Overheads on Network/protocol Performance (both Node and network level) • Importance of Node location and motion parameters • Evidence • Network traffic analysis (from literature) RO Management in RW Ad hoc Networks

  5. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Approach • Making use of Node parameters • 1st approach: Reduction of neighbourhood discovery broadcasts (e.g. hello messages) • Node level – Link Availability forecast • 2nd approach: Reduction of route establishment broadcasts (e.g. route request broadcasts) • Network Level • Cone flooding • Destination Search method RO Management in RW Ad hoc Networks

  6. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level Ro management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Related work • Performance analysis is a hot reaserach topic • pinpoints deterioration of overheads but no concrete solution offered instead, new protocols are suggested for better results at a cost • Previous work favour specific protocol classes • on-demand reduce RO by maintaining only needed routes (aodv, tora etc) or maintaining multiple route (dsr) • proactive reduce RO using forwarding groups (olsr, gpsr etc) - no balance is offered in either cases • Location based (lar, geocast etc)protocols do not address Node level overhead reduction, moreover they do not consider destination‘s mobility and likely to miss target with higher margin • My approach offers suggestions to manage the Routing Overheads (RO) with a general approach common to most protocols – pulling together research issues with one focus • Handles RO management both at Node and Network levels RO Management in RW Ad hoc Networks

  7. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work n m n ’ R n R n,m C 2 n C 1 m q R m m’ Node level RO Management • Link availability forecast • Relative motion of nodes (the basic Idea) Fig 1. Relative movement of two nodes n and m RO Management in RW Ad hoc Networks

  8. Hello timer Link Status Timer Expires expires Check if Node is dormant No Node Active Get current Host status Yes Update neighbours list with current parameters No Unsafe Link ? Reset Hello Yes Timer to last Update plus Intv Load information in “Hello Message” packet Broadcast Hello Reset Hello timer Reset Link status timer • Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Link availability forecast. contd Figure 2: Algorithm for LinkAvailability forecast RO Management in RW Ad hoc Networks

  9. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Network level RO Management • Two approaches suggested. • Cone flooding method. • Limiting broadcast to a cone towards last known motion parameters of destination • Destination search reverse zone coverage method. • Maintaining routes longer and using them to identify possible location of destination again based on its motion history. RO Management in RW Ad hoc Networks

  10. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work y R d(xd,yd,zd) rI H r S(xs,ys,zs) x Figure 3.Search direction field of node d from node S z Cone flooding method I(xI,yI,zI) RO Management in RW Ad hoc Networks

  11. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Load packet with Sid, Did, Sloc, Dloc, Sav.speed, Dav.speed etc Receive packet Is Node Dst ? Broadcast packet N Y Compute r and rI Generate a Reply RI > r ? Y Newer inf of dest ? N N Drop pckt Y Forward packet towards dest Cone flooding - algorithm Figure 4 The Schematic diagram of the scheme RO Management in RW Ad hoc Networks

  12. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Z1 l R-r c rI r a D(xD,yD) b = H S(xs,ys) Z2 Destination search reverse zone coverage method I(xI,yI) Figure 5. Checking existence of I in search Region RO Management in RW Ad hoc Networks

  13. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Intermediate Node receives Request packet Load packet with Sid, Did, Sloc, Dloc, Sav.speed, Dav.speed etc Is Node Dest? N Y Old Rt Availbl Initiate Route Reply followed by Inf Packets N Y TTL expired? N Node performs Test 1 Send DestSearch Packet Use Nornal Flooding Y Node in Z1 ? Packet Received by Destination N Perform Test 2 Destination changes Source and Dest fields and inserts its motion parameters Y Node in Z2? N Destination replaces packet header with Route Request header and sends the packet towards the Source Y Drop pckt Record Packets inf and forward it. Destination search - algorithm Figure 6 RO Management in RW Ad hoc Networks

  14. Implementations • Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work • The ns-2 Simulation tool (free ware) used • Suitability: time based and suitable for Mobile Ad Hocs • Real world situations – (under improvement) • Other tools in the field • GloMoSim - free ware, OpNet - commercial, QualNet - commercial • All available tools are tools under development • Updates of the tool and existing protocols at times results to contradicting simulation results that require a lot of adjustments (time consuming) • Newer versions at times not compatible with simulation platform RO Management in RW Ad hoc Networks

  15. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Simulations and Analysis • Basic results and comparisons with existing algorithms • Performance of Routing Protocols (DSR and AODV-hello) • Comparing of AODV-hello with AODV-Link Avaialbility RO Management in RW Ad hoc Networks

  16. Figure 8(a) • Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work General performance of Routing Protocols (DSR and AODV) Average delay deteriorates with increase in number of nodes (more conjestion) RO Management in RW Ad hoc Networks

  17. Figure 8(b) • Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work General performance of Routing Protocols (DSR and AODV) contd. Packet Delivery ratio reduces with increase in number of nodes in the network (conjestion) RO Management in RW Ad hoc Networks

  18. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Figure 8(c) General performance of Routing Protocols (DSR and AODV) contd Throughput increase due to more routes to destination available as more nodes are in the network RO Management in RW Ad hoc Networks

  19. Figure 8(d) • Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work General performance of Routing Protocols (DSR and AODV) With increase in number of nodes, more traffic is generated dominated by Routing packets RO Management in RW Ad hoc Networks

  20. Figure 9(a) Protocol performance with increase in number of nodes at a rate of 8 pckts per second and mobility of 20 m/s • Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Comparing AODV-hello with AODV- Link Avaialbility Routing Overhead reduced at higher Number of Nodes . At nn=50/40 we have 20% reduction and about 33% at nn=80/64. RO Management in RW Ad hoc Networks

  21. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Figure 9(b) Comparing AODV-hello with AODV- Link Avaialbility Improvement in Average Delay at high numer of nodes. From 50 and above, delay reduction of about 20% achieved RO Management in RW Ad hoc Networks

  22. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Figure 9(c) Comparing AODV-hello with AODV- Link Avaialbility No Significant gain in Delivery Ratio. For fewer nodes, higher delay introduced by computations for transmission decision RO Management in RW Ad hoc Networks

  23. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Figure 9 (d) Comparing AODV-hello with AODV- Link Avaialbility contd. No significant gain in throughput for increase in Node number. However with increase in rate, throughput improved by about 25% (see fig 10a). RO Management in RW Ad hoc Networks

  24. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Figure 10 (a) Comparing AODV-hello with AODV- Link Avaialbility contd. Better throughput with reduced Routing Overhead at higher traffic rates for 100 nodes RO Management in RW Ad hoc Networks

  25. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Figure 10 (b) Comparing AODV-hello with AODV- Link Avaialbility contd. Significant drop in Routing Overhead for 100 nodes RO Management in RW Ad hoc Networks

  26. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Evaluation • Observations • Most of the bandwidth is occupied by routing packets (data occupies less than 20 % in tested protocols • Delivery ratio affected by dropping of packets due to • Unavailability of routes due to premature deletion of routes (aodv) • Luck of fresh routes (dsr) • Dropping from filled up if-queues (bandwidth shortage, congestion etc) as a result of increased RO • Gains in the suggested approaches. • Link Availability algorithm brings about reduction in neighbourhood broadcasts (hello messages) • Reduction of Routing Overheads leads to: • Improvement in protocol performance (throughput, Average delay and delivery ratio) • Requirements and restrictions of approach • Only has effect after nodes have knowledge of the initial neighbourhood – communication has to be established first • Available tools don’t allow for complete real world simulations RO Management in RW Ad hoc Networks

  27. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work Summary and Conclusions • Suggested schemes handle Routing Overhead management both at Node and Network level • Motion history plays an important role in aproximating possible target location • Network congestion (resultig from RO) is the main factor affecting network/protocol performance • Schemes results to less overheads and higher availablility of bandwidth • Performance improvement as a result of less congested network • Scheme suitable a cross section of protocols • Further improvements expected from the second scheme RO Management in RW Ad hoc Networks

  28. Introduction and Overview • Motivation • Approach • Related work • Node level RO management • Network level RO management • Implementations • Simulations and Analysis • Evaluation • Summary and conclusions • Next step and Future work • END Next Step and Future work • What happens next: • Completion of simulation and Evaluation of second scheme • Action plan for follow-up: • Simulation of Network level RO reduction • Evaluation of results • Revisit Node level RO reduction scheme • General evaluations • Final Conclusions • Optimisation of routes • Simulation Tests with nodes having independent properties and variables • transmission radii • varying speeds, • unpredicted change in direction • varying and unpredicted rates of transmission etc RO Management in RW Ad hoc Networks

  29. Thankyou ! Discussion time ....... RO Management in RW Ad hoc Networks