• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
Protocol Optimizations using anonymous EPC Gen2 Inventories
 

Protocol Optimizations using anonymous EPC Gen2 Inventories

on

  • 539 views

 

Statistics

Views

Total Views
539
Views on SlideShare
537
Embed Views
2

Actions

Likes
0
Downloads
2
Comments
0

1 Embed 2

http://www.teco.edu 2

Accessibility

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    Protocol Optimizations using anonymous EPC Gen2 Inventories Protocol Optimizations using anonymous EPC Gen2 Inventories Presentation Transcript

    • TECOProtocol Optimizationsusing anonymous EPC Gen2 Inventories
    • Local Inventory Problem How many products of a certain type are in a shelf ?4-Apr-12 Copyright TecO 2007, Restricted Use 2
    • Conventional Solution 10000  Use high level interfaces .95 .99  Get IDs of all/selected 8000 tags 6000 Problem:  Long readingstime (ms) m e s ) ( t i  Static environment 4000  Still uncertainty 2000 0 Solution: 0 10 20 30 40 50 60 70 80 number of tags  Statistical approach Source: Vogt, H. (2002). Efficient Object Identification with Passive RFID Tags. 4-Apr-12 Copyright TecO 2007, Restricted Use 3
    • Problem: Channel Arbitration S ing le Tag Repl y QueryRep or Interrogato r Select CW Query CW Ack CW QueryRep QueryAdjust if EPC is valid NAK if EPC NAK is invalid Ta g RN16 PC + EPC+ CRC16 T4 T1 T2 T1 T2 C ollided R eply No Repl y Invalid AC K Inte rrogato r Query CW QueryR CW QueryRep CW Ack CW QueryRep Collision No No Detected Reply Reply Ta g RN16 RN16 T1 T2 T1 T3 T1 T34-Apr-12 Copyright TecO 2007, Restricted Use 4
    • Idea 1: No IDs - just count S ing le Tag Repl y QueryRep or Interrogato r Select CW Query CW Ack CW QueryRep QueryAdjust if EPC is valid NAK NAK if EPC is invalid Ta g RN16 PC + EPC+ CRC16 T4 T1 T2 T1 T2 50% Speed up4-Apr-12 Copyright TecO 2007, Restricted Use 5
    • Idea 2: Count Collisions and empty slots C ollided R eply N o Re ply Inte rrogato r Query CW Query CW Collision No Detecte d Reply Tag RN16 T1 T2 T1 T3 Collision means 2 or more Tags calculate: min # of tags estimate: # tags4-Apr-12 Copyright TecO 2007, Restricted Use 6
    • Estimation of # Tags in Slotted Aloha Frame Lower bound Estimation Source: Vogt, H. (2002). Efficient Object Identification with Passive RFID Tags.4-Apr-12 Copyright TecO 2007, Restricted Use 7
    • Algorithm (1) Select Product (prefix in EPC memory) (2) Start a new Round of 2Q slots (3) Count Success, Empty and Collisions (4) Calculate estimated and minimal number of Tags4-Apr-12 Copyright TecO 2007, Restricted Use 8
    • Fully EPC Gen2 compatible Query Power-up & ~killed Slot NEW ROUND QueryRep slot CMD: Query [mismatched QueryAdjust Counter inventoried or SL flags] Reply: None CMD: Select Action: Return to ready Ready Reply: None. Note 1 CMD: Query NEW ROUND Action: New round CMD: Query [slot > 0 & matching Reply: Note 3 (inventoried & SL) flags] CMD: All other Reply: None Action: Remain in ready Reply: None CMD: QueryRep, QueryAdjust [slot <> 0] Arbitrate Reply: None NEW ROUND CMD: QueryAdjust, QueryRep [slot=0] CMD: Query [slot = 0 & matching Reply: New RN16 (inventoried & SL) flags] CMD: Select Reply: New RN16 Action: Return to ready Reply: None. Note 1 CMD: Query Action: New round CMD: QueryAdjust [slot = 0] Reply Reply: New RN16 Reply: Note 3 CMD: All other Action: Return to arbitrate Reply: None. CMD: ACK [valid RN16] CMD: ACK [valid RN16] CMD: None within time T2 Reply: PC, EPC, CRC-16 Reply: PC, EPC, CRC-16 Action: Return to arbitrate CMD: Req_RN [invalid RN16] Reply: None. Reply: None Acknowledged CMD: Req_RN [valid RN16] & {access password = 0} Reply: Handle CMD: Req_RN [valid RN16] & {access password <> 0} CMD: ACK [valid han dle] Reply: handle Reply: PC, EPC, CRC-1 6 CMD: Req_RN, Read, Write, Lock, BlockWrite, BlockErase Reply: See state-transition tables CMD: Select CMD: Kill [valid handle & kill password = 0] Action: Return to ready Open Reply: Error code Reply: None. Note 1 CMD: Kill, Access [invalid handle] CMD: Query Reply: None Action: New round Reply: Notes 2, 3 CMD: Access [valid handle & valid access password] CMD: QueryRep, QueryAdjust Reply: handle when done4-Apr-12 Action: Return to ready Copyright TecO 2007, Restricted Use 9
    • Tag Requirements  EPC Gen2  ...4-Apr-12 Copyright TecO 2007, Restricted Use 10
    • Reader Requirements  Stage 1: Get # of collisions Get # of slots / frames Select product group*  Stage 2: Set # of slots/frames  Stage 3: Raw Reader/No Firmware Change Algorithm (i.e. No ACKs) * product distribution could also be estimated4-Apr-12 Copyright TecO 2007, Restricted Use 11