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. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks2 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

3. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks3 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 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

4. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks4 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) 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

5. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks5 Approach Making use of Node parameters 1 st approach: Reduction of neighbourhood discovery broadcasts (e.g. hello messages) –Node level – Link Availability forecast 2 nd approach: Reduction of route establishment broadcasts (e.g. route request broadcasts) –Network Level Cone flooding Destination Search method 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

6. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks6 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 destinations 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 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

7. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks7 Node level RO Management Link availability forecast –Relative motion of nodes (the basic Idea) n C 1 m n m R n,m Fig 1. Relative movement of two nodes n and m 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 R n R m C 2 n m

8. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks8 Link availability forecast. contd Check if Node is dormant No Yes Unsafe Link ? Get current Host status Yes No Node Active Hello timer expires Link Status Timer Expires Load information in Hello Message packet Update neighbours list with current parameters Reset Hello Timer to last Update plus Intv Broadcast Hello Reset Link status timer Reset Hello timer Figure 2: Algorithm for Link Availability forecast 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

9. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks9 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. 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

10. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks10 Cone flooding method I(x I,y I,z I ) rIrI r R 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 3. Search direction field of node d from node S x y z S(x s,y s,z s ) d(x d,y d,z d ) H

11. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks11 Cone flooding - algorithm Load packet with S id, D id, S loc, D loc, S av.speed, D av.speed etc Broadcast packet Figure 4 The Schematic diagram of the scheme 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 Y Y Y NN Receive packet Is Nod e Dst ? Compute r and r I Generate a Reply R I > r ? New er inf of dest ? Forward packet towards dest Drop pckt

12. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks12 Destination search reverse zone coverage method Figure 5. Checking existence of I in search Region I(x I, y I ) l r rIrI R-rc a b = H 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 Z2Z2 S(x s,y s ) Z1Z1 D(x D,y D )

13. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks13 Destination search - algorithm Packet Received by Destination Destination changes Source and Dest fields and inserts its motion parameters Destination replaces packet header with Route Request header and sends the packet towards the Source 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 Drop pckt Y Y Y N Y N N N Node in Z 1 ? Record Packets inf and forward it. Perform Test 2 Node in Z 2 ? Is Node Dest? Intermediate Node receives Request packet Node performs Test 1 TTL expire d? Initiate Route Reply followed by Inf Packets N Y Load packet with S id, D id, S loc, D loc, S av.speed, D av.speed etc Send DestSearch Packet Old Rt Availb l Use Nornal Flooding Figure 6

14. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks14 Implementations 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 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

15. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks15 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 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

16. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks16 General performance of Routing Protocols (DSR and AODV) Figure 8(a) Average delay deteriorates with increase in number of nodes (more conjestion) 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

17. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks17 General performance of Routing Protocols (DSR and AODV) contd. Figure 8(b) Packet Delivery ratio reduces with increase in number of nodes in the network (conjestion) 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

18. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks18 General performance of Routing Protocols (DSR and AODV) contd Figure 8(c) Throughput increase due to more routes to destination available as more nodes are in the network 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

19. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks19 General performance of Routing Protocols (DSR and AODV) Figure 8(d) With increase in number of nodes, more traffic is generated dominated by Routing packets 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

20. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks20 Comparing AODV-hello with AODV- Link Avaialbility 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 Routing Overhead reduced at higher Number of Nodes. At nn=50/40 we have 20% reduction and about 33% at nn=80/64. 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

21. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks21 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 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

22. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks22 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 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

23. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks23 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). 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

24. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks24 Figure 10 (a) Comparing AODV-hello with AODV- Link Avaialbility contd. Better throughput with reduced Routing Overhead at higher traffic rates for 100 nodes 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

25. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks25 Comparing AODV-hello with AODV- Link Avaialbility contd. Figure 10 (b) Significant drop in Routing Overhead for 100 nodes 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

26. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks26 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 dont allow for complete real world simulations 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

27. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks27 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 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

28. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks28 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 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

29. Technische Universität Dresden Fakultät Informatik Institute für Systemarchitektur RO Management in RW Ad hoc Networks29 Thankyou ! Discussion time.......