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A MAC Protocol for Mobile Ad Hoc Networks Using Directional Antennas

A MAC Protocol for Mobile Ad Hoc Networks Using Directional Antennas. 컴퓨터 및 정보통신공학 강 창 호. 목차. ABSTRACT INTRODUCTION DIRECTIONAL ANTENNAS IN AD HOC NETWORKS SIMULATION MODEL SIMULATION RESULTS CONCLUSION. ABSTRACT. ABSTRACT.

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A MAC Protocol for Mobile Ad Hoc Networks Using Directional Antennas

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  1. A MAC Protocol for Mobile Ad Hoc Networks Using Directional Antennas 컴퓨터 및 정보통신공학 강 창 호

  2. 목차 • ABSTRACT • INTRODUCTION • DIRECTIONAL ANTENNAS IN AD HOC NETWORKS • SIMULATION MODEL • SIMULATION RESULTS • CONCLUSION

  3. ABSTRACT

  4. ABSTRACT • Ad hoc network of mobile wireless terminals(with multiple directional antennas) • Reduce the radio interference • Improving the packet throughput • Problem • Frequent node movements • Locating and Tracking

  5. INTRODUCTION

  6. INTRODUCTION • Mobile Ad Hoc Network • Medium Access Control(MAC) • CSMA , CSMA/CA • DBTMA, FAMA, CARMA • Bandwidth utilization and throughput • MAC protocol • Using directional antennas

  7. INTRODUCTION • Typical MAC protocols • Using omnidirectional antennas • Need to communicate • Neighbors located in any direction

  8. Directional antenna • Reduce the interference • Nodes lying outside its directional pattern • Can eliminate the interfering signals • From directions other than the signal source

  9. Directional antenna • Finding the desired direction • Reception using a directional antenna • Mobile terminal • May have limitations of size • And the complexity/cost of communication hardware

  10. Propose a MAC protocol • Use directional antennas • In an ad hoc network • Where the mobile nodes • Do not have nay location information • Use an RTS/CTS exchange

  11. DIRECTIONAL ANTENNAS IN AD HOC NETWORKS

  12. Model Description • N mobile terminals(nodes) • Radio tranceivers • Share the same wireless channel • Transmission range • Transmission power • Antenna gain • Receiver sensitivity • Channel characteristics • Noise

  13. Model Description • M directional antennas • Conical radiation pattern • Spanning an angle of 2π/M radians • Maintain this orientation at all times • Correctively span • non-overlapping beam directions

  14. Model Description • Active and Passive mode • Use only active antenna • Complete attenuation • Outside the conical pattern • At any given time • Only one radio transceiver per node • Transmit and receive only one packet

  15. MAC Protocol Using Directional Antennas

  16. MAC Protocol Using Directional Antennas • TRSS : total received signal strength • ST : sensing threshold • DSN : data source node • DDN : data destination node • OLN : other listening node • OTH : off-the-air

  17. Defer and transmit • Monitoring • TRSS > ST • Wait util TRSS < ST • Wait for LongIFS • Wait for random access backoff period

  18. Defer and transmit • TRSS < ST • For atleast LongIFS • Initiate transmission • TRSS > ST (for backoff period) • Backoff delay is canceled

  19. Proposed MAC protocol Active Passive CTS CTS Passive Passive Transmit CTS packet on all antennas DDN M.P Active Passive OLN CTS RTS RTS DATA CTS M.P Passive Active RTS Defer and transmit an RTS packet all antennas OLN Begin or extend an OTH2 period DSN Passive Passive RTS RTS OLN Begin an OTH period

  20. SIMULATION MODEL

  21. SIMULATION MODEL • Indoor radio propagation model • Multipath fading • Parameterized radio receiver charateristics

  22. SIMULATION MODEL • nxn square grid • N2 stationary wireless nodes • Specified by the user • Transmitter power • Receiver sensitivity for carrier sensing • Minimum signal-to-interference • Grid spacing

  23. SIMULATION RESULTS

  24. PARAMETER1 • 15x15 uniform grid • 225 node ad hoc network

  25. PARAMETER2

  26. Result 1 Move randomly with a speed of 3 m/s

  27. Result 2 Movement speed (m/s)

  28. CONCLUSION

  29. CONCLUSION • Use directional antennas • Use variation of the RTS/CTS exchange • Improve the throughput

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