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

How RFID works Typical RFID system

Basic Tag Assembly

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

Introduction Collisions in RFID systems Anti-collision methods

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

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

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

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

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

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

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

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

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

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

System Model

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

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

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

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

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

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

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

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

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

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

Season - Season-II

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

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…

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

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

Season - Season-III For example

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

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

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

Evaluation Methodology Testbed and deployment Simulating Real RFID Applications Performance Metrics

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%

Testbed and deployment Simulating Real RFID Applications Performance Metrics Evaluation Methodology

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

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

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.

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

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

Identifying tags with reader collisions

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

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

Related Works FSA, Colorwave, USE……

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

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

Thanks !