RFID Tag Identification Using Bit Tracking / Abdel Rahman Youssef Mohamed Fahim

Supervisor: Tamer ElBatt

Thesis (M.A.)—Nile University, Egypt, 2016 .

"Includes bibliographical references"

Contents:
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 RFID overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Thesis organization . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Literature Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1 Tag collision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 Reader-reader collision . . . . . . . . . . . . . . . . . . . . . . . . . 8
3. Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.1 Bit tracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.2 Optimal binary tracking tree protocol (OBTT) [2] . . . . . . . . . . 12
4. Multi-Reader RFID Tag Identification using Bit Tracking (MRTI-BT) . . 15
4.1 System model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.2 Multi-reader RFID tag identification using bit tracking (MRTI-BT) 17
4.2.1 Random number generation . . . . . . . . . . . . . . . . . . 19
4.2.2 Collision handling . . . . . . . . . . . . . . . . . . . . . . . 21
ix
4.2.3 Parallel identification . . . . . . . . . . . . . . . . . . . . . 25
4.3 Performance evaluation . . . . . . . . . . . . . . . . . . . . . . . . 27
4.3.1 Simulation setup . . . . . . . . . . . . . . . . . . . . . . . . 28
4.3.2 Simulation results . . . . . . . . . . . . . . . . . . . . . . . 28
5. Repetition Gain in Bit-tracking Anti-Collision Algorithms to Recover Mistransition
Bit Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
5.1 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
5.2 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
5.3 Mis-transition selective recovering (MSR) . . . . . . . . . . . . . . 38
5.3.1 Choosing most reliable collided bit . . . . . . . . . . . . . . 39
5.3.2 Recovering bit errors . . . . . . . . . . . . . . . . . . . . . . 40
5.3.3 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
5.4 Performance Evaluation . . . . . . . . . . . . . . . . . . . . . . . . 43
5.4.1 Simulation Results . . . . . . . . . . . . . . . . . . . . . . . 43
6. Conclusion and Future Work . . . . . . . . . . . . . . . . . . . . . . . . . 47
6.1 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
6.2 Future work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Bibliography . . . . . . .

Abstract:
In this work, we study the problem of tag identification in single and multi-reader
RFID systems. First, we propose a novel solution to the reader-to-reader collisions
and tag collisions in multi-reader systems, using the concept of bit tracking. Second,
we explore the bit error types that could occur while using bit tracking. Although bit
tracking has a significant contribution on decreasing the identification time, we define
a bit error type coined mis-transition that occurs in bit-tracking based protocols only.
In addition, we propose a novel technique that tackles mis-transition bit error.
RFID systems consist of one or more readers and tags. Our main focus in this
work is on battery free RFID tag which is known as passive tags. Passive tags harvest
energy from RFID reader and follow the reader’s commands for collision resolving and
slot assigning.
In the first part of this work, we propose the multi-reader RFID tag identification
using bit tracking (MRTI-BT) algorithm which allows concurrent tag identification,
by neighboring RFID readers, as opposed to time-consuming scheduling. First,
MRTI-BT identifies tags exclusive to different RFIDs, concurrently. Second, the concept
of bit tracking and the proposed parallel identification property are leveraged
to reduce the identification time compared to the state-of-the-art. Our simulation
results exhibit considerable performance improvement with 113% reduction in the
identification time, on the average, compared to Season algorithm [1].
iv
In the second part of this work, we investigate the bit errors that could occur while
using bit tracking. Bit tracking based anti-collision algorithms have gained researchers
interest due to their significant contribution in decreasing the identification time.
They allow readers to detect the location of collided bits in a collision slot. However,
through our deep investigation in bit tracking, we found a new significant bit error
called mis-transition which increases the identification time. Mis-transition bit error
is different from flipped bit error and it occurs when a reader mistakenly declares
collision. In this work, we study and evaluate the effect of mis-transition bit error. In
addition, we propose a zero cost algorithm that tackles this problem without using any
coding scheme i.e, without adding extra coding bits. Tags may send their ID many
times to resolve collision. We make use of the successfully received bits in collision
slots to recover mis-transition bit error. Our simulations show the great potential of
using repetition gain on recovering bit errors.

Text in English, abstracts in English.