1. Routing in Heterogeneous Wireless Ad Hoc Networks Sivaram Cheekiralla, Daniel W. Engels ICCCN 2007

2. Outline Introduction Preliminaries Routing Protocol Simulations Conclusions

3. Introduction Advantage of Directional Antennas - increased spatial reusability - provision of higher communication range - achieve a better performance Drawback of Directional Antennas - economic concern

4. Motivation and Goal Most of existing work on wireless ad hoc networks assume homogeneous networks To discuss routing issues in a heterogeneous network

5. Preliminaries (System model) B 15dB

6. Preliminaries (System model) A Idle mode B C D Broadcasting mode EEA Unicasting modeReceive mode

7. Related work (DSR) Building of the route_record during route discovery

8. Related work (DSR) Propagation of the route reply with the route_record

9. Related Work (ETX metric) Find high-thruput paths Account for lossy links Account for asymmetric links Account for inter-link interference Independent of network load (don’t incorporate congestion)

10. ETX metric AB ForwardReverse 10012234

11. Related work (Route ETX) Route ETX 1 2 2 3 5 Link Quality 100% 50% 33% 20%

12. power-controlled ETX metric ABC ETX ETX1

13. SD … RREQ (ETX1) RREQ (ETX) RREP RREQ (ETX1) ？ RREP Compare with previous RREQ message Example

14. Simulations SimulatorQualnet FactorValue Communication range of Omni-Directional250m Communication range of Omni-Directional500m transmission power (ETX probes)15dB transmission power (ETX1 probes)20dB Discovery process (using ETX probes)100s Actual traffic simulation200s Data packet size500 bytes

15. Aggregate throughput for the grid topology

16. Aggregate throughput in the random topology

17. Asymmetry ratio with ETX metrics

18. Conclusions This paper presented a novel routing metric for routing in heterogeneous networks This paper provide a shorter and better links for higher throughput Future work: address the various MAC layer issues in heterogeneous networks in greater detail

19. Thank you