1 / 43

An RFID based Ubiquitous Architectural Framework for Mobile Object Tracking

University of Texas at Arlington. @. CSE. UTA. An RFID based Ubiquitous Architectural Framework for Mobile Object Tracking. Pradip De Center for Research in Wireless Mobility and Networking CReWMaN Department of Computer Science and Engineering The University of Texas at Arlington

siyavash
Download Presentation

An RFID based Ubiquitous Architectural Framework for Mobile Object Tracking

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. University of Texas at Arlington @ CSE UTA An RFID based Ubiquitous Architectural Framework for Mobile Object Tracking Pradip De Center for Research in Wireless Mobility and Networking CReWMaN Department of Computer Science and Engineering The University of Texas at Arlington Arlington, TX 76019

  2. PRESENTATION OUTLINE WHAT IS RFID ? APPLICATION AREAS MULTI-TAG READING COLLISION ARCHITECTURE AND TRACKING PROTOCOL DELAY ANALYSIS STORAGE STRUCTURE PRODUCT RECALL DISTRIBUTION ANALYSIS SIMULATION AND RESULTS FUTURE WORK REFERENCES

  3. What is RFID? • RFID as a technology.. • RFID TAGS (Transponders) • Tags consist of an Integrated Circuit (IC) and an Antenna • Tags can be as small as a grain of rice ! • Read Only or Read/Write or a combination of both • Active or Passive • Various Frequency ranges of operation • RFID Readers(Transceivers) • A Microcontroller based Interrogating Devices • Equipped with standard interfaces to interact with backend computing host systems

  4. RFID Applications.. • RFID provides a quick, flexible and reliable electronic means to detect, track and control a variety of items • A Plethora of Application areas – • Pharmaceutical - embedded RFID tags in prescription bottles • Amusement Parks - Location Stations • Libraries and Video Stores – Theft Detection and Misplacement • Security – Hands Free Access to secured areas • Toll Payment at Roads and Bridges • Logistics and Supply Chain Management is one of the major areas where this technology is deployed

  5. Checked Baggage passes under scanner RF tags incorporated into retail tickets

  6. Multiple Tag Reading - Collision • What happens when multiple tags are in the reader’s range? • All tags will become excited at the same time • Reader cannot detect individual tags from each other • A Collision Avoidance Algorithm necessary • A Query Tree Protocol has been proposed by the MIT-AutoID Center • Basic Idea is to sequentialize the reading of multiple tags • Achieves an O(n) bound for reading ‘n’ tags • 2.881n – 1 <= E[Ts] <= 2.887n - 1 Ching Law, Kai Lee and Kai-Yeing Siu, Efficient Memoryless Protocol for Tag Identification. MIT AutoId Center, October 2000

  7. Architecture • Objective of the Architecture • Basically a Distributed Tracking Architecture for Objects that are transacted between organizations • To harness RFID technology to provide automatic visibility and control over transaction items • Minimize delay and error incurred due to the involvement of human attendance

  8. Architecture.. • A Few Terminologies defined… • Electronic Product Code • 96 bits • Hierarchical • Savant – A Data Routing Server • Data Capture, Data Monitor and Data Transmission • Physical Markup Language (PML) • Common Language for describing physical Objects • Based on the syntax of XML • Every property of the object captured

  9. Architecture.. • A Few Terminologies defined… • PML Server • Repository for all types of information regarding the objects • Homes both static and dynamic information • SLA Server • Used to translate queries into decisions • The execution is done at the PML Server • Object Naming Service (ONS) • Similar in structure to the Internet DNS • Maps the EPC to the IP Address of its Home PML Server

  10. Site2 Home Server Intranet Interior Area 2 Site-2 Gateway Server Org-B RFID Readers Gateway Server Data Routing Server-2 Org-A Internet Intranet Main Site Data Routing Server Inter Organization Network RFID Readers Interior Area Intranet Site-1 Site1 Home Server Data Routing Server-1 Interior Area 1 Tracking ArchitectureA High Level View

  11. Object Tracking Protocol Overview • Reader reports a triplet to the attached Savant • <EPC, timeStamp, Reader_Id> • Based on ATTACH/DETACH messages accordingly destined for the upstream Home PML Server for updating location • On recognition, Savant recieves an ACCEPT message back • Three readings confirming that an EPC has left the field makes the Savant generate a DETACH message for that EPC • Unrecognized ACCEPT message can also come back from the Home PML Server

  12. ProtocolFlow… Savant State Transition Reader State Transition

  13. Protocol Flow… PML Server State Transition

  14. Protocol Flow… Home PML Server State Transition

  15. Delay Analysis… • Delay incurred in sending ‘n’ EPC tags from a reader to the Home PML Server • Assumptions made – • The connection from the Reader onwards to the Network is assumed to follow standard Internet Protocols • The Reader uses the Query Tree Protocol to read the tags • The inter-arrival time of the packets from various Readers to the connected Savant follow a negative exponential distribution • The size of the packets arriving at the Savant and PML Server also follow a negative exponential distribution. • An arriving packet containing all stale tags is dropped at the Savant Ching Law, Kai Lee and Kai-Yeing Siu, Efficient Memoryless Protocol for Tag Identification. MIT AutoId Center, October 2000

  16. Delay Analysis… • The total delay equation is given by – Ttotal = E[Treader] + E[TRd-Savant] + E[TSavant-PML] + E[TremotePML] • E[Treader] = O(n) ≈ 2.88 * n • E[TRd-Savant] = Txdelay + E[Tsavant] / (1 - ρ) • ρ is the average occupancy of the Savant • E[Tsavant] = p * Ts1 + (1 - p) * Ts2 • p is the probability that the packet would not be dropped • Ts1 and Ts2 are the average service times for both types of packets

  17. Delay Analysis… • E[TSavant-PML] = p * (Txdelay + E[TPML] / (1 - ρ) ) • E[TPML] = q * Tp1 + (1 - q) * Tp2 • q is the probability that this PML server is the Home for all the tags in the packet • Tp1 and Tp2 are the service times for the two types of packets at the PML Server • E[TremotePML] = p * (1 - q) * (avginternetDelay + E[TrPML] / (1 - ρ) ) • E[TrPML] = TRP • TRP is the service time at the remote Home PML server

  18. Delay Analysis Results • The average Internet delay for a packet varies between 10 and 100 msec • T/TCP protocol assumed to transmit data • 3 packets sent to complete one transaction • 96 bits for each of the EPC and Reader ID and a 32 bit timestamp value • Assuming a 1 Mbps data rate we get delays ranging from 24 to 113 msec for transferring 100 to 500 tags. • average time to read a single tag has been found to be around 0.47 sec Andrew Corlett, D. I. Pullin and Stephen Sargood, Statistics of one-way Internet Packet Delays. 53rd IETF, Minneapolis, March 18, 2002 http://www.spec.com/PipelineJuly99.pdf Sep 1, 2003

  19. Delay Analysis Results

  20. Delay Analysis Results

  21. Storage Structure… • The need for an efficient storage structure for location information about the EPCs cannot be overlooked • Various forms of balanced search trees have been used to store information of ordered elements - provides access in logarithmic time • level linked 2-3 trees (for example) • We use a degree balanced k-ary search tree for the EPCs and use Finger Search for retrieval and updation G. S. Brodal. Finger Search Trees with constant insertion time. In Proc. 9th Annual ACM-SIAM Symposium on Discrete Algorithms, pages 540-549, 1998. Guy E. Blelloch et al. Space Efficient Finger Search on Degree-Balanced Search Trees. Symposium on Discrete Algorithms, 2003.

  22. Storage Structure… • EPCs are generally looked up in bulk! • Assumed to be clustered together if not contiguous! • Finger Search takes O(log d) worst case time • Finger Search is accomplished using a right-parent stack as an extra data structure consuming O(log n) extra space

  23. Storage Structure…

  24. Storage Structure…

  25. Storage Structure… • The information structure associated with each EPC • 96 bit EPC tag • Pointer to PML file at Home PML Server (H-PML) • List of location history and Timestamp • Time Stamp • PML Server Address • Savant Address • Reader ID

  26. Product Recall An important domain in need for automation badly ! Object Distribution to the destination is not the end of the road! Retained location information history needs to be leveraged! A simple strategy is to traverse the footsteps of the Distribution

  27. Product Recall… • With networked information available we devise a distributed scheme for handling the recall of objects • Every PML Server would be equipped with Recall Handling procedures! • The Recall Algorithm at each node comprises of • Recall Initiation Algorithm (RI) • Recall Handling Algorithm (RH) • The H-PML invokes RI and the subsequent PML servers to which the recall percolates invoke RH

  28. Product Recall…

  29. Product Recall…

  30. Product Recall…

  31. Product Recall… Recall Multicast Recall Trie Built

  32. Distribution Analysis… • A theoretical analysis of the EPC distribution in the PML server network – The motivation is to get a handle on the number of messages generated in both a distribution and a Recall • The Distribution network among the PML servers is Scale Free ~ • We model the distribution dynamics based on the way an infection spreads in a population • The basic model for the number of susceptibles and infected gives • N(t) = X(t) + Y(t)

  33. Distribution Analysis… • The differential equations for the spreading dynamics are • where • where

  34. Distribution Analysis… • The average rate of secondary infections given by • The final fraction of PML servers to which EPCs spread is given by where

  35. Distribution Analysis… The distribution of the node degree comes to from the total probability equation Similarly we have Using the above results we get By some mathematical manipulations we can express F in terms of the exponential integral as where

  36. Distribution Analysis…

  37. Distribution Analysis…

  38. Distribution Analysis…

  39. Simulation Results • Two phases • EPC Distribution Phase • EPC Recall Phase • In the first phase we populate fields of the k-ary search tree with simulated values • In the second phase the Recall Trie is built for the EPC set to be recalled

  40. Simulation Results…

  41. Simulation Results… The first plot shows the average number of messages/tag to perform a recall against the number of tags in each recall. The different curves are for different values of tags distributed. The second plot shows the average number of messages/tag needed to perform a recall against the number of tags distributed. The different curves are for different values of tags recalled. The results stabilize to a very low value for the average number of messages required for performing the recall !

  42. Future Work… • Extend the protocol to incorporate much needed security issues • Enhancement of the architecture to suit scenarios where surveillance and tracking is critical and intelligently predict intrusion or unwanted activities in such environments

  43. References • The Association for Automatic Identification and Data Capture Technologies. http://www.aimglobal.org/technologies/rfid/ • RFID Journal. http://www.rfidjournal.com/ • Kai-Yeing Siu, Ching Law and Kayi Lee, Efficient Memoryless Protocol for Tag Identification. MIT Auto-Id Center, October, 2000 • MIT Auto-ID Center Publications at http://www.autoidcenter.org/ • R. Bridgelall. Enabling mobile commerce through pervasive communications with ubiquitous RF tags; WCNC, 2003 • V. Stanford. Pervasive computing goes the last hundred feet with RFID systems; Pervasive Computing, IEEE, Volume: 2, Issue: 2, April-June 2003 Pages: 9-14 • G. S. Brodal. Finger search trees with constant insertion time. In Proc. 9th Annual ACM-SIAM Symposium on Discrete Algorithms, pages 540-549, 1998. • Guy Blelloch et al. Space Efficient Finger Search on Degree- Balanced Search Trees. Symposium on Discrete Algorithms, 2003. • R. Albert, H. Jeong and A. L. Barabasi, Nature (London) 401, 130 (1999) • R. M. Anderson and R. M. May, Infectious Diseases of Humans: Dynamics and Control(Oxford Univ. Press, Oxford, 1991). • R. M. May and R. M. Anderson, Philos. Trans R. Soc. London, Ser. B 321, 565 (1988). • The Savant - Version 0.1 (Alpha), Technical Manual. Oat Systems and MIT Auto-Id Center, February, 2002 • David L. Brock, The Physical Markup Language - A Universal Language for Physical Objects. MIT Auto-Id Center, February, 2001 • Mark Harrison et al, PML Server Developments, White Paper. MIT Auto-Id Center, June, 2003

More Related