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GARUDA

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    • 1. GARUDA: Achieving Effective Reliability for Downstream Communication in Wireless Sensor Networks Seung-Jong Park, Member, IEEE, Ramanuja Vedantham, Member, IEEE, Raghupathy Sivakumar, Senior Member, IEEE, and Ian F. Akyildiz, Fellow, IEEE Report : Hsiung Chun Kuei IEEE TRANSACTIONS ON MOBILE COMPUTING, VOL. 7, NO. 2, FEBRUARY 2008
    • 2.
      • Data delivery can be critical
      • Guaranteed sink-to-sensors
      • Reliable downstream data
      Abstract http://wshlab2.ee.kuas.edu.tw
    • 3. Outline http://wshlab2.ee.kuas.edu.tw
    • 4. Introduction
      • Energy-aware protocols isn’t enough
        • Wireless Channel Errors
        • Congestion and Contention
        • Broadcast Storm
      http://wshlab2.ee.kuas.edu.tw
    • 5.
      • Delivered reliably
        • Control code
        • Query-data
        • Response result about sensor match data
      • Cornerstones of design
        • Reliable short-message.
        • V irtual infrastructure – core
        • Two-stage negative acknowledgment (NACK)
      Introduction http://wshlab2.ee.kuas.edu.tw
    • 6.
      • Assumptions
        • Downstream reliability
        • Communication and node failures
        • 100 % reliable message delivery
        • Message size less then one packet
        • Network model is static
      Framework http://wshlab2.ee.kuas.edu.tw
    • 7.
      • Single-/First-Packet Delivery
        • Benefits
          • Robust fading effects and collision.
          • Implicit NACK fit in short package.
          • Result in low energy.
      Framework http://wshlab2.ee.kuas.edu.tw
    • 8. Framework
        • Wait for first package(WFP) Pulse Transmission
      http://wshlab2.ee.kuas.edu.tw CS: carrier sensin
    • 9.
      • Loss Recovery Servers: Core
        • Goal
          • Minimize the retransmission overheads.
          • Constructed in a manage dynamic topology
        • Rationale of Core
          • MDS(Minimum Domination Set)
          • MSC(Minimum Set Cover)
      Design Element http://wshlab2.ee.kuas.edu.tw
    • 10. Framework
        • Instantaneous Core Construction
          • Sink
            • band-ID(bId) = 0
          • In 3i bands
            • Radom wait, and no invite message from the same band. It will be candidate.
            • Maintain upstream core’s information
          • In 3i+1
            • S 0 is S 1 ’s core ,when the new S 0 ’ core invite again, S 1 will trade off each other by delay time.
          • In 3i+2
            • When time out, the node will sends an anycast “core solicitation message” to 3(i+1) nodes. And then respond after a random waiting delay.
            • Boundary condition : not invite form core. Such condition can be detected.
      http://wshlab2.ee.kuas.edu.tw
    • 11. Framework
        • Loss Recovery for Core Nodes
          • Upstream core nodes
          • Downstream core nodes
            • A-map:myBM (successfully received packet),totBM(received and requested packets)
            • If A-map is from a valid source. Updating to totBM.
            • Send request , and set expire time. If receive the feedback to update to myBM
            • If no response from upstream core, requiring to default upstream core.
          • Intermediate noncore nodes
            • Set the vFlag to NULL when identifier is equal 3
      http://wshlab2.ee.kuas.edu.tw
    • 12. Framework
        • Loss Recovery for Noncore Nodes
          • Snoops all (re)transmissions from its core node.
          • After Period core presence timer, sends an explicit request to core node that response with A-map
      http://wshlab2.ee.kuas.edu.tw
    • 13. Performance evaluation
      • Evaluation of Single-Packet Delivery
      http://wshlab2.ee.kuas.edu.tw  
    • 14. Performance evaluation
      • Evaluation of Multiple-Packet Delivery
      http://wshlab2.ee.kuas.edu.tw (100 * 3.14 * 67 * 67) / (650 * 650) = 3.33620355 (800 * 3.14 * 67 * 67) / (650 * 650) = 26.6896284
    • 15. Performance evaluation
      • Microscopic Analysis
        • Optimality of the core
        • A-map overhead
        • Number of recovery events
        • Effect of random wireless errors
      http://wshlab2.ee.kuas.edu.tw
    • 16. Performance evaluation
      • Evaluation of Variants
        • Reliable Delivery within a Subregion
      http://wshlab2.ee.kuas.edu.tw
    • 17. Performance evaluation
        • Minimal Set of Sensors
      http://wshlab2.ee.kuas.edu.tw
    • 18. Conclusions
      • Future work
        • With mobility and in the presence of multiple sinks.
      • We can do ..
        • Take care of core ’s energy.
          • By reelection
        • Expand into multimedia
          • Addition to multi processes.
          • How many duplicate does the environment have?
      http://wshlab2.ee.kuas.edu.tw
    • 19. Q & A Thank for your attention
    • 20. Framework –D?
      • Two-Phase Loss Recovery
        • A-Map(Availability Map)
        • Function
          • Loss detection
          • Loss recovery
      http://wshlab2.ee.kuas.edu.tw
    • 21. Performance evaluation
      • Simulation Environment
        • 網路地形
          • 100 node,650mx650m,randomly deployed
          • Sink in center
          • Range 67m
          • 1Mbps
          • Message = 100 packets and 25 packets/per second (except for the single-packet-delivery part)
          • 1 packet = 1Kbyte
        • 協定參數
          • MAC protocol : CSMA/CA
          • Routing : flooding
          • Simple : 20 randomly topologies
          • So 95% confidence intervals
          • Error model : 5% fixed packet loss rate
      http://wshlab2.ee.kuas.edu.tw
    • 22. Other reliability semantics
      • Reliable Delivery within a Subregion
          • Without loss (100%)
          • First package decide the core.
          • Not choose itself?
            • 要怎麼決定成為 core? 透過什麼權值來證明它是好機器 ?
      • Cover the Sensing Field
          • 2R away from the nearest core node
            • Ownership (defined by its transmission range)
          • Core node can choose itself as a candidate
            • 結點少 , 自己判斷成為 core?
      • Probabilistic Subset
        • Scope sensing(ex:25%)
        • Triggers detected during the preliminary sensing
        • p% be candidate be core
      http://wshlab2.ee.kuas.edu.tw
          • <- 是否使用在對某些興趣點做訂閱時使用 ?
    • 23.
        • Environment considerations
          • Scarcity of bandwidth and energy.
        • Message considerations.
          • The protocol to consider large-sized messages only before. but WSN need small-sized queries.
          • So issues on what kind of loss recovery.
        • Reliability considerations
          • 100 percent reliable delivery to only a subregion.
      Introduction -D http://wshlab2.ee.kuas.edu.tw
    • 24. Related work -D
      • Before
        • Efficient flooding
          • Classify: probability-based, area-based and neighbor-knowledge-based
          • Can’t guarantee the reliability.
        • “ Minimizing Broadcast Latency and Redundancy in Ad Hoc Networks”
          • Broadcast tree and schedules transmissions.
          • Greedy strategy to minimize the latency and the number of retransmissions
          • Not suit large-scale networks
        • Pump Slowly, Fetch Quickly (PSFQ)
          • Relatively slow speed, using in-sequence forwarding.
          • Recover missing data packets from immediate neighbors.
          • Single-packet isn’t concider.
        • TinyDB : Query processor
          • Minimize power consumption
          • accuracy of query
          • No different services
      http://wshlab2.ee.kuas.edu.tw
    • 25.
      • Challenges
      • Environment Constraints
        • Not relying on statically constructed mechanism
          • dynamics of the network
        • Tremendous amount of spatial reuse.
      Problem definition -D http://wshlab2.ee.kuas.edu.tw
    • 26. Problem definition -D
      • Acknowledgment (ACK)/NACK Paradox
        • NACK
          • Effective loss advertisement mechanism.
          • Low loss probabilities are not inordinately high.(The package is small)
          • Can‘t handle the unique case. When lost message at a part of node.(The middle node die)
          • Not aware, it cannot advertise a NACK to request retransmissions.(The aware message disappear.)
        • ACK-based recovery
          • Focus on all-packet-lost problem.
          • 只能復原一個封包 ? 所以 WSN 會傳不到一個封包 ? 為了節省網路使用率 ? 還是能自救就自救 ? 這樣比較節省頻寬
          • Deficiencies of ACK implosion (big overhead). ( 過度確認問題 )
      http://wshlab2.ee.kuas.edu.tw
    • 27. Problem definition -D
      • Reliability Semantics
      http://wshlab2.ee.kuas.edu.tw
    • 28. GARUDA Design Element -D
          • 前言
            • 機制 Two-phase loss recovery strategy that uses out-of-sequence forwarding
            • 選舉系統 Simple candidacy-based approach for the core construction
            • Improve NACK-based.
      http://wshlab2.ee.kuas.edu.tw
    • 29. GARUDA Design Element -D
        • Instantaneous Core Construction
          • First packet delivery to determine the hop_count
          • 3i hop distance
          • Core lies
            • Constructed using a single-packet flood
            • Leveraged for more efficient and fair core construction.
      http://wshlab2.ee.kuas.edu.tw
    • 30. GARUDA Design Element -D
      • Multiple Reliability Semantics
        • SPT(short path tree) can shortly delay.
      http://wshlab2.ee.kuas.edu.tw 因為我沒探討其他信賴的題目
    • 31.
      • Loss Recovery Servers: Core
        • Goal
          • Minimize the retransmission overheads.
          • Constructed in a manner (the dynamic topology)
        • Rationale of Core
          • MDS(Minimum Domination Set)
          • MSC(Minimum Set Cover)
      Design Element http://wshlab2.ee.kuas.edu.tw
            • 定義 MDS 以及 MSC 的問題 , 指出他們在這個模型中的腳色及相關性
      MDS
    • 32. Design Element -D
        • A=PAPX(MDS)
        • B=OPT(MSC)
        • Cost = A/B
        • Classification
          • Case 1 = optimal
          • Case 2 = worst case
          • Case 3 = half good or worst
        • Sum up
          • Replacing by approximation ratio
          • Using Approximation MDS
          • is what?
      http://wshlab2.ee.kuas.edu.tw 重點 !! 詳細了解每個為什麼 建構的 cost G d :upper bound of the ratio
    • 33. Design Element
      • Loss Recovery Process
        • Out-of-Sequence Packet Forwarding with
        • A-Map(Availability Map)
        • Two-Stage Loss Recovery
          • Why does two-stage need?
            • Avoid collide
            • Single require
            • Second recovery short than two hops
          • Step
            • Loss recovery for core nodes
              • Uni-cast from upstream core
            • Loss recovery for noncore nodes
              • Use the overhead – A-MAP, it’s basic flooding.
      http://wshlab2.ee.kuas.edu.tw
    • 34. Design Element
      • Reliable Single-/First-Packet Delivery ? No relation
        • Predict , 重傳 when the first-packet missed. ?
        • Benefits
          • Robust fading effects ( 因為主動 )
          • Robust to collision ( 沒人在聽的時候還是會尋找 ?)
          • Implicit NACK (suit in short package )
          • Result in low energy
      http://wshlab2.ee.kuas.edu.tw
    • 35. Implicit ACK http://wshlab2.ee.kuas.edu.tw 802.11 Implicit ACK Gain