1. Presented by Zhu Jinshun Season: Shelving Interference and Joint Identification in Large- scale RFID Systems

2. How RFID works Typical RFID system

3. Basic Tag Assembly

4. I. Introduction II. Preliminaries III. Season IV. Performance Evaluation V. Related Works VI. Conclusion Outlines

5. Introduction Collisions in RFID systems Anti-collision methods

6. tag reader Collisions in RFID systems Tag collision Reader collision Reader-Tag collision

7. Collisions in RFID systems Tag collisionReader collisionReader-Tag collision contentious regioncontentious tag

8. Anti-collision methods Tag collision Reader collision Reader-Tag collision FSA Colorwave Protocol stack: Season

9. I. Introduction II. Preliminaries III. Season IV. Performance Evaluation V. Related Works VI. Conclusion Outlines

10. Preliminaries A. Tag Collision B. Reader Collision C. Reader-Tag Collision D. System Model

11. Tag Collision Mainly employ Time Dividing Multiple Accesses (TDMA) A popular anti-tag-collision algorithm is Framed Slotted ALOHA (FSA) Tag collision

12. SlotSlot SlotSlot SlotSlot……… frame …… procedure Tag Collision - FSA

13. Command request, select, read/write, quit, reset Types of slots Idle, single, collided

14. Reader Collision Reader Conict Graph (RCG) Colorwave Reader collision RCG

15. Reader - Tag Collision schedule (r1,r2 ) in sequence, we can only consider the other two types of collisions Reader-Tag collision

16. System Model

17. I. Introduction II. Preliminaries III. Season IV. Performance Evaluation V. Related Works VI. Conclusion Outlines

18. Season A. Observations B. Overview C. Season-I D. Season-II E. Season-III F. Discussion

19. Season - Observations Majority of tags are non-contentious Contentious tags cause the major delay The signals from contentious tags can be received

20. Season - Overview Season is a protocol stack two phases Shelving Interference Season-I Joint Identication Season-II Season-III

21. Season - Overview Season-I non-contentious tags Season-II active reader passive reader Season-III data from contentious tags

22. Season - Season-I concurrently identify tags the majority of tags can be identied Similar to FSA frames equivalent slots different from FSA tune the length of frames

23. Season - Season-I One slot = 1/f the optimal choice of f is USE estimate Dynamically adjust the frame to -k after the k-th tag is collected

24. SeasonSeason - Season-II Joint Identication has two advantages: 1 can avoid reader collisions among neighboring readers 2 Reduce the identication delay signicantly

25. Season - Season-II Active reader and passive reader Active readers,two conditions: 1 cover edges as most as possible 2 will not incur signal interference among themselves when concurrently activated

26. Season - Season-II the Maximal Weighted Independent Set (MWIS) Notation v CH(v) JOIN(v,u) EXIT v either a clusterhead or an ordinary node

27. Season - Season-II

29. Season - Season-III Cross-range tag collision Cross-range tag collision, a new tag collision Season-III to allow active and passive readers to identify contentious tags collaboratively

30. Season - Season-III Given that the set of active readers is A and the set of passive readers is the P On one hand, for active readers… On the other hand, for passive readers…

31. Season - Season-III On one hand, for active readers: estimate the number of contentious tags TDMA keep the tags in active state util all FINISH broadcast silence

32. Season - Season-III On one hand, for passive readers: listen, estimate send a FINISH message if no neighboring passive readers, otherwise, next scheduling round

33. Season - Season-III For example

34. Season - Discussion Unbalanced Loads of Readers session number Source Sensitive and Insensitive

35. I. Introduction II. Preliminaries III. Season IV. Performance Evaluation V. Related Works VI. Conclusion Outlines

36. Performance Evaluation A. Evaluation Methodology B. Implementation Results C. Simulation Results

37. Evaluation Methodology Testbed and deployment Simulating Real RFID Applications Performance Metrics

38. Evaluation Methodology Testbed and deployment use a NI PXI-1044 RFID testing tool with PXI 5600 receiver as our passive reader interrogation range 2m deploy ve readers nd that the percentage of contentious tags is less than 10%

39. Testbed and deployment Simulating Real RFID Applications Performance Metrics Evaluation Methodology

40. Simulating Real RFID Applications two typical application scenarios and three random reader topologies Warehouse: 72 readers, 78,606 records Object tracking: 1653 records, includes the tag locations, source, and identication time Random Topologies: Sparse,Moderate,Dense Evaluation Methodology

41. Performance Metrics Throughput: the ratio of total number of tags to the overall identication time Average Delay Read Rate: environment noise,multi-path, signal attenuation Scheduling Round: the efciency of anti-reader-collision Evaluation Methodology

42. Implementation Results employ a NI PXI-1044 testing tool with a PXI 5600 receiver as the passive reader, Alien reader as the active reader We can observe that the passive reader achieves a read rate of 0.73 in 60% of testing cases. The average value of its read rates is up to 0.71, which is nearly as good as that in the single-reader deploying scenario.

43. Identifying tags without reader collisions when number of tag is above 100, Season-I has 30.6% and 42.2% time saving on average than BT and FSA

44. Identifying tags without reader collisions Season-I, up to 0.4 and 60% of the cases has a throughput higher than 0.37

45. Identifying tags with reader collisions

47. the average delay of Season is no more than 300 time slots

48. I. Introduction II. Preliminaries III. Season IV. Performance Evaluation V. Related Works VI. Conclusion Outlines

49. Related Works FSA, Colorwave, USE……

50. I. Introduction II. Preliminaries III. Season IV. Performance Evaluation V. Related Works VI. Conclusion Outlines

51. Related Works Anti-collision is a crucial task we propose an anti-collision protocol stack, Season Our results show that Season signicantly increases throughput, dramatically reduces the delay for tags

52. Thanks !