1 / 39

A Practical Multi-Channel Access Control Protocol for Wireless Sensor Networks

A Practical Multi-Channel Access Control Protocol for Wireless Sensor Networks. Hieu Khac Le al etc. Presented By Xin Che 10/26/09. Introduction. Related Works. Theoretical Analysis. Why do we need to minimize the inter-channel communication ? Extract cost in channel switching

curt
Download Presentation

A Practical Multi-Channel Access Control Protocol for Wireless Sensor Networks

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. A Practical Multi-Channel Access Control Protocol for Wireless Sensor Networks HieuKhac Le al etc. Presented By XinChe 10/26/09

  2. Introduction

  3. Related Works

  4. Theoretical Analysis • Why do we need to minimize the inter-channel communication ? • Extract cost in channel switching • Retranmissions due to the deafness problem

  5. Theoretical Analysis • Observations • New channel should only be allocated when needed. • Some nodes should be more likely to initiate channel switch than others • Global view • Nodes with limited view should act locally to minimize cross-channel communications • The best local action is to follow a node with a better view.

  6. Theoretical Analysis • Problem Formulation: • We partition the nodes in the network into different sets, each assigned a separate home channel, such that • The communication within each set is limited to local capacity • Communication across sets is minimized

  7. Theoretical Analysis • In a graph, • Each node is a communication device • Link cost is the amount of communication • The K-way Cut Problems • Minimize the K • Each cluster/set should satisfy the capacity constraint.

  8. Theoretical Analysis • Solutions to The K-way Cut Problems • [4] O. Goldschmidt and D. S. Hochbaum. Polynomial algorithm for the K-cut problem, 1988 • For K = 3 , O(n4); For K = 4, O(n9) • [10] Y. Kamidoi, S. Wakabayashi, and N. Yoshida. Faster algorithms for finding a minimum K-way cut in a weighted graph, 1997 • More efficient, For K = 3 , O(n4); For K = 4, O(n9) All require a-priori knowledge of K and heavy weight!

  9. Theoretical Analysis • Constraints • The K (channel number) is not fixed • Limited capacity for each sensor nodes

  10. 3.1.1 The Algorithm

  11. 3.1.1 The Algorithm • Channel Congestion Measure

  12. 3.1.1 The Algorithm • Channel Switch Method

  13. 3.1.1 The Algorithm • Summary The • The question reduces to • who should initiate the split ? • who should follow into the new cluster?

  14. 3.1.1 The Algorithm • sinks are better positioned to make decisions on channel allocation ! • observe that in a wireless sensor network, nodes are usually not equal in contributing to network load. • they should act differently in terms of channel switching probability. • two extreme examples : • Data Source node • Sink node • Channel congestion typically occurs at sinks. • Hence, sinks have a more global view of traffic than sources.

  15. 3.1.1 The Algorithm

  16. 3.1.1 The Algorithm • Summary

  17. 3.1.1 The Algorithm • Summary • Channel Expansion • sink-like nodes initiate such transitions with a higher probability and the senders of them followed. • Minimize cross cluster communicaiton • Channel Shrinking • When a channel is no longer congested, nodes on this channel invite those from the next (higher) channel in the ladder to switch to the underutilized frequency. • sink-like nodes initiate such transitions with a higher probability and the senders of them followed.

  18. 3.2 The Self-Configuration Problem • considers the dynamics of channel expansion and channel shrinking • it is important that such transitions are stable. • Use feedback Control theory • the control signal is the probability for a node to switch channel • The use of probabilities takes the distributed nature of the control system into account. • Should prevents all nodes from switching at the same time, which would not improve the situation.

  19. 3.2 The Self-Configuration Problem • 3.2.1 Channel Expansion if if

  20. 3.2 The Self-Configuration Problem • 3.2.3 Choosing the Controller Gains

  21. 3.2 The Self-Configuration Problem • 3.2.4 Channel Overflow

  22. 4. Protocol Design • Component Structure

  23. 4. Protocol Design • Time-trigger Activity • Channel States Update • Neighbors’ Home Channel Maintenance • Message Types

  24. 4. Protocol Design

  25. 4. Protocol Design • Functional Description

  26. 4. Protocol Design • Functional Description

  27. 6. Evaluation • 6.1 Experimental Test bed Evaluation

  28. 6. Evaluation • 6.1 Experimental Test bed Evaluation

  29. 6. Evaluation • 6.1 Experimental Test bed Evaluation

  30. 6. Evaluation • 6.1 Experimental Test bed Evaluation

  31. 6. Evaluation • 6.1.2 Effect of Utilizing Mutiple Channels

  32. 6. Evaluation • 6.1.2 Effect of Utilizing Mutiple Channels

  33. 6. Evaluation • 6.1.3 Network of Independent Sub-networks

  34. 6. Evaluation • 6.1.3 Network of Independent Sub-networks

  35. 6. Evaluation • 6.1.3 Network of Independent Sub-networks

  36. 6. Evaluation • 6.1.4 Network of Lightly Connected Sub-networks

  37. 6. Evaluation • 6.2 Simulation and Scaling

  38. 6. Evaluation • 6.2 Simulation and Scaling

  39. 7. Conclusion • Pro • A pratical design, implementation, and evaluaiton of a multi-channel MAC protocol for WSNs. • A distributed heuristic algorithm for channel partition to minimize cross-channel communication. • A feed-back control strategy to stable to channel partition and avoid congestion. • Light-weight MAC protocol on MicaZ motes. • Cons • Only throughput metrics, no delay, message loss • Only Used for converged cast.

More Related