Tommaso Melodia, Cross-layer Quality of Service Provisioning ...


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Tommaso Melodia, Cross-layer Quality of Service Provisioning ...

  1. 1. Tommaso Melodia [email_address] Wireless Networks and Embedded Systems Laboratory Department of Electrical Engineering University at Buffalo, The State University of New York IEEE Upstate NY Workshop on Communications, Sensors and Networking 2007 Goldstein Student Center, Syracuse University, Syracuse, NY November 9, 2007 Cross-Layer Quality of Service Provisioning in Wireless Multimedia Sensor Networks
  2. 2. Outline <ul><li>Wireless Multimedia Sensor Networks (WMSN) </li></ul><ul><li>Cross-layer QoS in Support WMSN: Motivation </li></ul><ul><li>Cross-layer Controller Design Principles </li></ul><ul><li>Simulator Design </li></ul><ul><li>Preliminary Results </li></ul><ul><li>Conclusions and Questions </li></ul>
  3. 3. Wireless Multimedia Sensor Networks [7] I.F. Akyildiz, T. Melodia, K. Chowdhury, “A Survey on Wireless Multimedia Sensor Networks”, Computer Networks (Elsevier), March 2007.
  4. 4. Problems with Existing Sensor Networks <ul><li>Typically based on CSMA/CA MAC protocols </li></ul><ul><ul><li>Mutual Exclusion </li></ul></ul><ul><ul><li>Contention, carrier sense </li></ul></ul><ul><ul><li>Uncontrollable delays </li></ul></ul><ul><ul><li>Frequent collisions </li></ul></ul><ul><li>Power Consumption still high </li></ul><ul><ul><li>Chipcon 2420 transmit power 1mW </li></ul></ul><ul><ul><li>Exact Tx:Rx:Idle power ratios depend on hardware but Idle power is NOT NEGLIGIBLE </li></ul></ul><ul><ul><li>Need for sleep periods </li></ul></ul><ul><li>Proposals to modify existing protocols to provide QoS </li></ul><ul><ul><li>SPEED [9] </li></ul></ul><ul><ul><li>[9] HE, T., STANKOVIC, J. A., LU, C., and ABDELZAHER, T. F., “A Spatiotemporal Communication Protocol for Wireless Sensor Networks,” IEEE Trans. on Parallel and Distributed Systems , vol. 16, pp. 995–1006, October 2005 </li></ul></ul>
  5. 5. Networking with Ultra Wide Band (UWB) <ul><li>Need to depart from CSMA/CA based sensor networks </li></ul><ul><li>However, TDMA-based networks </li></ul><ul><ul><li>Require network-wide coordination </li></ul></ul><ul><ul><li>Scheduling is complex </li></ul></ul><ul><ul><li>Not scalable </li></ul></ul><ul><li>Leverage cross-layer interactions to optimize the communication process </li></ul><ul><li>Cross-layer Networking with </li></ul><ul><li>Time Hopping Impulse Radio Ultra Wide Band (TH-IR UWB) Communications </li></ul>
  6. 6. 3 12 8 1 T f =N h T c Time Hopping Code: 3, 12, 8, 1 Time Hopping Code: 11, 3, 12, 7 TH-IR UWB Physical Layer Model Gaussian Monocycle Impulse Response 11 3 12 7
  7. 7. CROSS LAYER CONTROL UNIT (XLCU) LOCALIZATION SUBSYSTEM NETWORK COORDINATION UNIT (NCU) GeoRouting Rate Control SYNCHRONIZATION SUBSYSTEM Admission Control TO NETWORK PEERS FLOW REQUIREMENTS Capacity Assignment Coding Rate Next Hop Selection Data Rate QoS Contracts A Cross Layer Module based on UWB QoS Scheduler UWB Modulator Channel Coder Source Coder
  8. 8. Design Principles <ul><li>Network Layer QoS Support enforced by a cross-layer controller </li></ul><ul><li>Geographical Forwarding </li></ul><ul><li>Hop-by-Hop QoS contracts </li></ul><ul><li>Integrated UWB Physical/MAC layer </li></ul><ul><li>Receiver-centric scheduling for QoS Traffic with Dynamic Channel Coding </li></ul>Routing MAC Physical Propagation Application
  9. 9. Hop-by-Hop QoS Contracts <ul><li>QoS is described in terms of </li></ul><ul><ul><li>Required Bandwidth </li></ul></ul><ul><ul><li>End-to-end delay </li></ul></ul><ul><ul><li>Admissible PER </li></ul></ul><ul><ul><li>E.g., different PER for I, P, and B frames in MPEG </li></ul></ul>Application A QoS Adapter XLCU Admission Control
  10. 10. QoS Contracts CONT_ESTABLISHED Calculates Link Requirement at node 4 ( ζ 4 , β 4 ( ζ 4 , SINR), α 4 δ ) 1 4 3 End-to-end Requirement ( ζ , β , δ ) a x 1 x a x 4 ADM_REQUEST Advance coefficient ADM_GRANTED ADM_GRANTED CONT_REQUEST <ul><li>Admission Control: </li></ul><ul><li>Check PER Constraint </li></ul><ul><li>Check Bandwidth Constraint </li></ul><ul><li>Check Delay Constraint </li></ul>5
  11. 11. Distributed Admission, Routing and Channel Coding Find next hop that minimizes energy consumption Coding Rate must provide the necessary PER, given interference Minimize: With constraints: 1)
  12. 12. Distributed Admission Control Functionality Given Coding Rates, bandwidth must be enough to accommodate all the flows Scheduler-dependent upper bound on delay 2) 3)
  13. 13. Integrated UWB Phy/MAC <ul><li>No need for mutual exclusion </li></ul><ul><li>Simultaneous transmissions can occur as long as two different time hopping sequences are used </li></ul><ul><li>THS = f(ID) </li></ul><ul><li>Need for MAC coordination </li></ul><ul><ul><li>Avoid collisions at the receiver </li></ul></ul><ul><ul><li>Avoid idle listening </li></ul></ul><ul><ul><li>Receiver must be listening when a transmitter sends data </li></ul></ul><ul><li>Must be simple </li></ul>b a d c THS(B) THS(D)
  14. 14. Receiver-Centric Scheduling SC (i) SC (N) SC (i) SC (N) 1, j 2,k j m i k N 3, j Upstream transmissions to N Upstream sink flow 1 flow 2 flow 1, 3 flow 1,2,3 flow 1,2,3 Scheduling Period N i SC (N) SC (N) SC( j) SC (i) i, 1 i, 3 i, 2 i, 1 i, 3 i, 2 Scheduling packet THS(N) Scheduling packet THS(i) 1, j 3, j j 1,m Start time + Coding Rate Scheduling packet THS(j)
  15. 15. Scheduling and Coding Rate Assignment For each flow, determine the coding rate that provides required PER Calculate Bandwidth Coefficient Calculate Delay Coefficient Start-tag each packet Finish-tag each packet
  16. 16. Physical Layer Simulation Signal Generation Multi-user Interference PPM Modulation Pulse Rep Coding Multi-path Channel (Molitsch) Convolution (FFT) Gaussian Noise Correlation Receiver THS Generation
  17. 17. Physical Layer Simulation Signal Generation Multi-user Interference PPM Modulation Pulse Rep Coding Multi-path Channel (Molitsch) Convolution (FFT) Gaussian Noise Correlation Receiver THS Generation
  18. 18. Network Simulation CROSS LAYER CONTROL UNIT (XLCU) UWB Propagation GeoRouting Rate Control Admission Control Capacity Assignment Coding Rate Next Hop Selection Data Rate QoS Contracts Developed an Object Oriented Discrete-event Java Simulator for UWB networking based that relies on results from the PHY simulator Results Visualization QoS Scheduler Channel Coder Source Coder Topology Generator
  19. 19. Performance Results <ul><li>49 nodes on a 100mx100m grid </li></ul><ul><li>Peak transmit power 0.28mW, Average Radiated power 1 µW </li></ul><ul><li>Impulse Rate 20Mpulse/s </li></ul><ul><li>Data Packet size = 125bytes </li></ul><ul><li>Group 1, 12 sources </li></ul><ul><ul><li>100kbit/s </li></ul></ul><ul><ul><li>0.1 s end-to-end delay </li></ul></ul><ul><ul><li>0% PER </li></ul></ul><ul><li>Group 2, 12 sources </li></ul><ul><ul><li>500kbit/s </li></ul></ul><ul><ul><li>0.1 s end-to-end delay </li></ul></ul><ul><ul><li>10% PER </li></ul></ul>
  20. 20. Throughput
  21. 21. Packets Received, Dropped
  22. 22. Delay per Flow
  23. 23. Average Group Delay
  24. 24. Summary <ul><li>Developed a cross-layer communication module for QoS delivery in Wireless Sensor Networks </li></ul><ul><ul><li>Based on time hopping impulse radio ultra wide band </li></ul></ul><ul><ul><li>Geographical forwarding </li></ul></ul><ul><ul><li>Concept of hop-by-hop QoS contract </li></ul></ul><ul><ul><li>Concurrent transmissions </li></ul></ul><ul><ul><li>Dynamic channel coding and receiver-centric scheduling </li></ul></ul>
  25. 25. Future Research Directions <ul><li>Optimal Distributed Source Coding, Routing and MAC for Video Sensor Networks </li></ul><ul><li>Developing in hardware a UWB sensor for multimedia streaming in sensor and actor networks </li></ul><ul><li>Multimedia Streaming in Underwater Sensor Networks </li></ul>
  26. 26. Thanks