1. BodyT2 Throughput and Time Delay Performance Assurance for Heterogeneous BSNs Zhen Ren, Gang Zhou, Andrew Pyles, Mathew Keally, Weizhen Mao, Haining Wang College of William and Mary presented by 姚俊鹏

2. Outline Motivation Problem Definition and Analysis BodyT2 Design Performance Evaluation Conclusions

3. BSN body sensor (mote) aggregators Data Center

4. Outline Motivation Problem Definition and Analysis BodyT2 Design Performance Evaluation Conclusions

5. Motivation -requirements(1) Applications that are performance-critical Requiring stringent throughput and time delay performance assurance Smart healthcare Assisted livingEmergency response Interactive controlsAthletic performance evaluation

6. Motivation -research challenges Irregular BSN link quality. –Available resources must be adaptively rescheduled according to efficiency and cost. Heterogenous BSN radio platforms. –Need to achieve the performance assurance in a radio-agnostic manner.

7. Motivation -existing works Provide statistical throughput and/or time delay performance assurance. provide best effort solutions for enhancing throughput and/or reducing time delay. Provide either throughput or time delay performance assurance, but not both. Based on an individual-polling scheme.

8. Motivation -goal Propose a novel and efficient radio agnostic solution for heterogeneous BSNs. Allows different data streams to request different throughput and time delay performance assurances.

9. Outline Motivation Problem Definition and Analysis BodyT2 Design Performance Evaluation Conclusions

10. Problem Definition and Analysis -outline Group-Polling v.s. Individual-Polling Throughput Assurance Joint Assurance of Throughput and Time Delay

11. Group-Polling vs Individual-Polling Individual-polling –Each data packet is preceded by a polling packet –Not appropriate for practical radio-agnostic system deployment Group-polling –A packet train following a single polling packet Efficiency( fewer polling packets) Catering to radio-agnostic BSN designs VMAC ： abstracts common MAC behaviors with time-domain parameters: T(minPkt) and T(maxPkt)

12. Throughput Assurance data steam specifies its throughput requirement decide the time schedule for each data stream P problem

13. Joint Assurance of Throughput and Time Delay data steam i on sensor mote k specifies its throughput requirement as –The requested time delay bound –The througput requirement –The priority Specify how much time each stream on mote uses NP-hard problem

14. Outline Motivation Problem Definition and Analysis BodyT2 Design Performance Evaluation Conclusions

15. BodyT2 Design -outline  An empirical solution for practical system deployment. Admission Control Time Resource Scheduling Enforcing Time Schedule on VMAC

16. Admission Control Required time for satisfying all streams’ requests number of data packetsnumber of polling packets available time

17. Admission Control The minimum required time for sending data and polling packets for mote k The maximum gap allowed

18. Admission Control necessary condition of admission control sufficient admission condition

19. accept decision is made; all data streams are finally rejected and removed

20. algorithm for scheduling the next packet train The most recently scheduled packet train We give mote k1’s packet train j a schedule if and only if we can foresee that any other mote(k2) can also have its packet train j scheduled.

21. algorithm for scheduling the next packet train Time between A and D should be long enough to schedule B and C Make sure enough room to schedule packet train A Make sure A and previous packet train j-1 is bounded by Gk1

23. Time Resource Scheduling Sequentially computes the time allocated to each packet train. QoS data –requires throughput and time delay guarantee The best effort data –does not

25. Enforcing Time Schedule on VMAC Located on both the aggregator and motes. Extended VMAC –Checks the remaining allocated time –Checks the specified time delay constraint for each packet. –Notifies the aggregator to terminate packet train if no packet to send.

26. VMAC on aggregator Sends polling message with the allocate time length Indicate time period for motes’ best effort communication

27. VMAC on motes Compute the amount data of each stream Organize data into packet train with earlier deadlines Check before send packet –remaining allocated time < –deadline > current time + –only QoS data packet remaining >>termination of the packet train

28. Outline Motivation Problem Definition and Analysis BodyT2 Design Performance Evaluation Conclusions

29. Performance Evaluation -outline TelosB Mote Lab Tests Real Body Experiments

30. Performance Evaluation -settings(1) Is compared with –The state-of-the art BodyQoS. –The best effort solution in the TinyOS 2.x. Performance metrics –The percentage of delivered throughput –The data packet deadline miss ratio –The average energy consumed

31. Performance Evaluation -settings(2) Interference settings

32. Performance Results of TelosB Mote Lab Tests Delivered Throughput –A higher timely delivered throughput ratio –A more stable throughput delivery ratio –Gain more performance when interference increases.

33. Performance Results of TelosB Mote Lab Tests Deadline miss ratio –Achieves an extremely low deadline miss ratio –Remains almost constantly when interference increases.

34. Performance Results of TelosB Mote Lab Tests Energy consumption per delivered byte –Uses less energy than BodyQoS –Energy consumption remains stable when interference increases.

35. Performance Results of Real Body Experiments in Android

37. Outline Motivation Problem Definition and Analysis BodyT2 Design Performance Evaluation Conclusions

38. Proposes a novel approach to provide joint assurance in a radio-agnostic manner Based on group-polling scheme Prove the joint throughput and time delay assurance is NP-hard. Demonstrate that BodyT2 achieves superior performance over existing solutions

39. Thank you! Any Questions?