Presented by Zhu Jinshun
description
Transcript of Presented by Zhu Jinshun
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. IntroductionII. PreliminariesIII. SeasonIV. Performance EvaluationV. Related WorksVI. 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 collision Reader collision Reader-Tag collision
contentious region contentious tag
Anti-collision methods
Tag collision
Reader collision
Reader-Tag collision
FSA
Colorwave
Protocol stack: Season
I. IntroductionII. PreliminariesIII. SeasonIV. Performance EvaluationV. Related WorksVI. Conclusion
Outlines
Preliminaries
A. Tag CollisionB. Reader CollisionC. Reader-Tag CollisionD. System Model
Tag Collision
Mainly employ Time Dividing Multiple Accesses (TDMA)
A popular anti-tag-collision algorithmis Framed Slotted ALOHA (FSA)
Tag collision
Slot
Slot
Slot
………………
frame frame ……procedure:
Tag Collision - FSA
Tag Collision-FSA
Command :request, select, read/write, quit, reset
Types of slots :Idle, single, collided
Reader Collision
Reader Conflict Graph (RCG)Colorwave
Reader collisionRCG
Reader - Tag Collision
schedule (r1,r2 ) in sequence, we can only consider the other two types of collisions
Reader-Tag collision
System Model
I. IntroductionII. PreliminariesIII. SeasonIV. Performance EvaluationV. Related WorksVI. Conclusion
Outlines
Season
A. ObservationsB. Overview C. Season-ID. Season-IIE. Season-IIIF. Discussion
Season - Observations
Majority of tags are non-contentiousContentious tags cause the major delayThe signals from contentious tags can be received
Season - Overview
Season is a protocol stack two phases : Shelving Interference ( Season-I ) Joint Identification ( Season-II , Season-III )
Season - Overview
Season-I : non-contentious tagsSeason-II : active reader , passive readerSeason-III : data from contentious tags
Season - Season-I
concurrently identify tags the majority of tags can be identifiedSimilar to FSA , frames , equivalent
slotsdifferent from FSA , tune the length of
frames
Season - Season-I
One slot = 1/f the optimal choice of f isUSE , estimate Dynamically adjust the frame to -k
after the k-th tag is collected
SeasonSeason - Season-II
Joint Identification has two advantages: 1 、 can avoid reader collisions among
neighboring readers 2 、 Reduce the identification delay significantly
Season - Season-II
Active reader and passive readerActive 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-II
Season - Season-III
Cross-range tag collision
Cross-range tag collision, a new tag collisionSeason-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-IIIOn 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-IIIOn 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 numberSource Sensitive and Insensitive
I. IntroductionII. PreliminariesIII. SeasonIV. Performance EvaluationV. Related WorksVI. Conclusion
Outlines
Performance Evaluation
A. Evaluation MethodologyB. Implementation ResultsC. Simulation Results
Evaluation Methodology
Testbed and deploymentSimulating Real RFID ApplicationsPerformance Metrics
Evaluation Methodology
Testbed and deploymentuse a NI PXI-1044 RFID testing tool with PXI 5600 receiver as our passive readerinterrogation range 2mdeploy five readersfind that the percentage of contentious tags is less than 10%
Testbed and deploymentSimulating Real RFID ApplicationsPerformance Metrics
Evaluation Methodology
Simulating Real RFID Applicationstwo typical application scenarios and three random reader topologies Warehouse: 72 readers, 78,606 records Object tracking: 1653 records, includes the tag
locations, source, and identification time Random Topologies: “Sparse”,“Moderate”,“Dense”
Evaluation Methodology
Performance Metrics Throughput: the ratio of total number of tags to the overall
identification time Average Delay Read Rate: environment noise,multi-path, signal attenuation Scheduling Round: the efficiency of anti-reader-collision
Evaluation Methodology
Implementation Resultsemploy 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
Identifying tags with reader collisions
Identifying tags with reader collisions
the average delay of Season is no more than 300 time slots
I. IntroductionII. PreliminariesIII. SeasonIV. Performance EvaluationV. Related WorksVI. Conclusion
Outlines
Related Works
FSA, Colorwave, USE……
I. IntroductionII. PreliminariesIII. SeasonIV. Performance EvaluationV. Related WorksVI. Conclusion
Outlines
Related Works
Anti-collision is a crucial task
we propose an anti-collision protocol stack, Season
Our results show that Season significantly increases throughput, dramatically reduces the delay for tags
Thanks !