Rendezvous-Based Directional Routing: A Performance Analysis

1. Rendezvous-Based Directional Routing:A Performance Analysis Bow-Nan Cheng (RPI) Murat Yuksel (UNR) Shivkumar Kalyanaraman (RPI)

2. Motivation • Infrastructure / Wireless Mesh Networks • Characteristics: Fixed, unlimited energy, virtually unlimited processing power • Dynamism – Link Quality • Optimize – High throughput, low latency, balanced load • Mobile Adhoc Networks (MANET) • Characteristics: Mobile, limited energy • Dynamism – Node mobility + Link Quality • Optimize – Reachability • Sensor Networks • Characteristics: Data-Centric, extreme limited energy • Dynamism – Node State/Status (on/off) • Optimize – Power consumption Main Issue: Scalability

3. Scaling Networks: Trends in Layer 3 Flood-based Hierarchy/Structured Unstructured/Flat Scalable OLSR, HSLS, LGF Hierarchical Routing, VRR, GPSR+GLS Mobile Ad hoc / Wireless Infrastructure Networks DSR, AODV, TORA, DSDV WSR Kazaa, DHT Approaches: CHORD, CAN Peer to Peer / Overlay Networks Gnutella SEIZE Ethernet Wired Networks Routers (between AS)

4. Trends: Directional Antennas • Directional Antennas – Capacity Benefits • Theoretical Capacity Improvements - factor of 4p2/sqrt(ab) where a and b are the spreads of the sending and receiving transceiver ~ 50x capacity with 8 Interfaces (Yi et al., 2005) • Sector Antennas in Cell Base Stations – Even only 3 sectors increases capacity by 1.714 (Rappaport, 2006) • Directional Antennas – Simulations show 2-3X more capacity (Choudhury et al., 2003)

5. Free-Space-Optical Ad Hoc Networks Trends: Hybrid FSO/RF MANETs • Current RF-based Ad Hoc Networks: • 802.1x with omni-directional RF antennas • High-power – typically the most power consuming parts of laptops • Low bandwidth – typically the bottleneck link in the chain • Error-prone, high losses Free-Space-Optical (FSO) Communications Mobile Ad Hoc Networking • High bandwidth • Low power • Dense spatial reuse • License-free band of • operation • Mobile communication • Auto-configuration • Spatial reuse and angular diversity in nodes • Low power and secure • Electronic auto-alignment • Optical auto-configuration (switching, routing) • Interdisciplinary, cross-layer design

6. ORRP Big Picture Orthogonal Rendezvous Routing Protocol • ORRP Primitive • Local sense of direction • leads to ability to forward • packets in opposite • directions A 180o 98% S T Up to 69% Multiplier Angle Method (MAM) Heuristic to handle voids, angle deviations, and perimeter cases B

7. Motivation Metrics: • Reach Probability • Path Stretch / Average Path Length • Total States Maintained • Goodput • End-to-End Latency Scenarios Evaluated: • Various Topologies • Various Densities • Various Number of Interfaces • Various Number of Connections • Transmission Rates • Comparison vs. AODV, DSR A Path Stretch: ~1.2 1x4 ~ 3.24 98% 57% By adding lines, can we decreasepath stretch and increasereach probability without paying too much penalty? B

8. 2 1 3 Reachability Numerical Analysis P{unreachable} = P{intersections not in rectangle} Probability of reachdoesnotincrease dramatically with addition of lines above “2” (No angle correction) 4 Possible Intersection Points

9. Path Stretch Analysis Path stretch decreases with addition of lines but not as dramatically as between 1 and 2 lines (No angle correction)

10. NS2 Sim Parameters/Specifications • All Simulations Run 30 Times, averaged, and standard deviationsrecorded Reach Probability Average Path Length Goodput End-to-End Latency Number of Lines Amount of State Maintained Number of Control Packets

11. Effect of Number of Lines on Various Topologies and Network Densities Average Path Length decreases with addition of lines under similar conditions. APL increases in rectangular case because of higher reach of longer paths Dense - 98% - 99% Reach Probability increases with addition of lines but not as dramatically as between 1 and 2 lines Medium – 95.5% - 99% Sparse - 90% - 99% Medium - 66% - 93% Sparse - 63% - 82%

12. Numerical Analysis vs. Simulations Angle Correctionwith MAM increases reach dramatically!

13. Effect of Network Density Average Path Length Eval Total Packet Latency Eval Average Path Length decreasesfor increased number of lines in ORRP but still longer than shortest path protocols Total end to end Latency decreasesfor increased number of lines in ORRP. This is significantly better than DSR and AODV

14. Effect of Number of Connections and CBR Rate Packet Delivery Success Aggregate Network Goodput Delivery Success increasesfor increased number of lines but remains constant with number of CBR connections Aggregate Network Goodput increasesfor increased number of lines. It is about 20-30X more network goodput than DSR and AODV

15. Additional Simulation Results • Network Voids • Average path length fairly constant (Reach and State not different) • Number of Interfaces • Increasing # of interfaces per node yields better results for reach, average path length, and average goodput to a certain point determined by network density. • Number of Continuous Flows • Average path length remains fairly constant with increased flows but increases with less lines. The average is still higher than AODV and DSR path lengths. • Control Packets • Control packets sent by ORRP with multiple lines are significantly more than with AODV and DSR because ORRP is hybrid proactive and reactive so CP increase with time. But because medium is used more efficiently, goodput remains high.

16. Summary • Addition of lines yields significantly diminishing returns from a connectivity-state maintenance/control packets perspective after 1 line • Addition of lines yields better paths from source to destination and increasesgoodput • Using Multiplier Angle Method (MAM) heuristic, even only 1 line provides a high degree of connectivity in symmetric topologies • Addition of lines yields better aggregate godoput overall and about 20x more goodput than DSR and AODV • Increasing the number of interfaces per node yieldsbetter resultsfor reachability, average path length, and average goodput up to a certain point that is determined by network density • As number of continuous flows increase, ORRP with increased lines delivers more packets successfully.

17. Future Work • Mobile ORRP (MORRP) • Hybrid Direction and Omni-directional nodes • Exploring additional heuristics to maintain straight-line paths • Expanding to overlay networks (virtual directions) Thanks! Questions or Comments: chengb@rpi.edu