Towards Extended Bit Tracking for Scalable and Robust RFID Tag Identification Systems

The surge in demand for Internet of Things (IoT) systems and applications has motivated a paradigm shift in the development of viable radio frequency identification technology (RFID)-based solutions for ubiquitous real-Time monitoring and tracking. Bit tracking-based anti-collision algorithms have attracted considerable attention, recently, due to its positive impact on decreasing the identification time. We aim to extend bit tracking to work effectively over erroneous channels and scalable multi RFID readers systems. Towards this objective, we extend the bit tracking technique along two dimensions. First, we introduce and evaluate a type of bit errors that appears only in bit tracking-based anti-collision algorithms called false collided bit error in single reader RFID systems. A false collided bit error occurs when a reader perceives a bit sent by tag as an erroneous bit due to channel imperfection and not because of a physical collision. This phenomenon results in a significant increase in the identification delay. We introduce a novel, zero overhead algorithm called false collided bit error selective recovery tackling the error. There is a repetition gain in bit tracking-based anti-collision algorithms due to their nature, which can be utilized to detect and correct false collided bit errors without adding extra coding bits. Second, we extend bit tracking to 'error-free' scalable mutli-reader systems, while leaving the study of multi-readers tag identification over imperfect channels for future 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. MRTI-BT identifies tags exclusive to different RFIDs, concurrently. 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. 2013 IEEE.This work was supported by the Qatar National Research Fund (a member of Qatar Foundation) through NPRP under Grant 7-684-1-127. The work of A. Fahim and T. ElBatt was supported by the Vodafone Egypt Foundation.Scopu

A new Version of High Stability Output 12-Bit Tracking Analog to Digital Converter

    In this paper a 12-bit tracking analog-to-digital converter (ADC) is designed and its performance is verified. It continuously tests the analog input signal and makes correction when necessary. The resulting digital equivalent of the analog input signal is continuously updated. The least significant bit (LSB) of this converter jumps up and down to track the analog input and this causes the final output to be unstable. To overcome the problem of instability in the digital output the 12-bit tracking ADC is modified by introducing the test bit B0. The test bit is designed to have a voltage equals to that of the LSB. It always sets or resets in tracking the analog value. Using this technique the digital output B1 to B12 of the converter is maintained stable. Test and measurements are performed in the converter circuit to demonstrate the practicality of this version.              &nbsp

From M-ary Query to Bit Query: a new strategy for efficient large-scale RFID identification

The tag collision avoidance has been viewed as one of the most important research problems in RFID communications and bit tracking technology has been widely embedded in query tree (QT) based algorithms to tackle such challenge. Existing solutions show further opportunity to greatly improve the reading performance because collision queries and empty queries are not fully explored. In this paper, a bit query (BQ) strategy based Mary query tree protocol (BQMT) is presented, which can not only eliminate idle queries but also separate collided tags into many small subsets and make full use of the collided bits. To further optimize the reading performance, a modified dual prefixes matching (MDPM) mechanism is presented to allow multiple tags to respond in the same slot and thus significantly reduce the number of queries. Theoretical analysis and simulations are supplemented to validate the effectiveness of the proposed BQMT and MDPM, which outperform the existing QT-based algorithms. Also, the BQMT and MDPM can be combined to BQMDPM to improve the reading performance in system efficiency, total identification time, communication complexity and average energy cost

From M-ary Query to Bit Query: a new strategy for efficient large-scale RFID identification

The tag collision avoidance has been viewed as one of the most important research problems in RFID communications and bit tracking technology has been widely embedded in query tree (QT) based algorithms to tackle such challenge. Existing solutions show further opportunity to greatly improve the reading performance because collision queries and empty queries are not fully explored. In this paper, a bit query (BQ) strategy based Mary query tree protocol (BQMT) is presented, which can not only eliminate idle queries but also separate collided tags into many small subsets and make full use of the collided bits. To further optimize the reading performance, a modified dual prefixes matching (MDPM) mechanism is presented to allow multiple tags to respond in the same slot and thus significantly reduce the number of queries. Theoretical analysis and simulations are supplemented to validate the effectiveness of the proposed BQMT and MDPM, which outperform the existing QT-based algorithms. Also, the BQMT and MDPM can be combined to BQMDPM to improve the reading performance in system efficiency, total identification time, communication complexity and average energy cost

An effective frame breaking policy for dynamic framed slotted aloha in RFID

The tag collision problem is considered as one of the critical issues in RFID system. To further improve the identification efficiency of an UHF RFID system, a frame breaking policy is proposed with dynamic framed slotted aloha algorithm. Specifically, the reader makes effective use of idle, successful, and collision statistics during the early observation phase to recursively determine the optimal frame size. Then the collided tags in each slot will be resolved by individual frames. Simulation results show that the proposed algorithm achieves a better identification performance compared with the existing Aloha-based algorithms

Bit error rate measurement above and below bit rate tracking threshold

Bit error rate is measured by sending a pseudo-random noise (PRN) code test signal simulating digital data through digital equipment to be tested. An incoming signal representing the response of the equipment being tested, together with any added noise, is received and tracked by being compared with a locally generated PRN code. Once the locally generated PRN code matches the incoming signal a tracking lock is obtained. The incoming signal is then integrated and compared bit-by-bit against the locally generated PRN code and differences between bits being compared are counted as bit errors

Quantitative Information-Flow Tracking for C and Related Languages

We present a new approach for tracking programs' use of data througharbitrary calculations, to determine how much information about secretinputs is revealed by public outputs. Using a fine-grained dynamicbit-tracking analysis, the technique measures the information revealedduring a particular execution. The technique accounts for indirectflows, e.g. via branches and pointer operations. Two kinds ofuntrusted annotation improve the precision of the analysis. Animplementation of the technique based on dynamic binary translation isdemonstrated on real C, C++, and Objective C programs of up to half amillion lines of code. In case studies, the tool checked multiplesecurity policies, including one that was violated by a previouslyunknown bug

Convolutional coding techniques for data protection

Results of research on the use of convolutional codes in data communications are presented. Convolutional coding fundamentals are discussed along with modulation and coding interaction. Concatenated coding systems and data compression with convolutional codes are described

Статичні похибки генераторів компенсувального сигналу для АЦП слідкувального типу із ваговою надлишковістю

В статті проведено аналіз статичних похибок генераторів компенсувального сигналу, побудованих на неточному ЦАП із ваговою надлишковістю, для багаторозрядних АЦП слідкувального типу. Складено математичні моделі статичних похибок генераторів компенсувального сигналу до та після коригування. Доведено, що застосування процедури самокалібрування ЦАП із ваговою надлишковістю, побудованих на неточних елементах, та запропонованих методів генерування компенсувального сигналу дає змогу істотно (на 2-3 порядки) зменшити абсолютну похибку і таким чином підвищити точність всього АЦП.В статье проведен анализ статических погрешностей генераторов компенсирующего сигнала, построенных на неточном ЦАП с весовой избыточностью, для многоразрядных АЦП следящего типа. Составлены математические модели статических погрешностей генераторов компенсирующего сигнала до и после корректировки. Доказано, что применение процедуры самокалибровки ЦАП с весовой избыточностью, построенных на неточных элементах, и предложенных методов генерирования компенсирующего сигнала позволяет существенно (на 2-3 порядка) уменьшить абсолютную погрешность и таким образом повысить точность всего АЦП.The static error of the compensating signal generators for a multi-bit tracking ADC built on inaccurate DAC with weight redundancy is analyzed in this article. The mathematical model of the compensating signal generators static error before and after correction is proposed. It is proved that the use of the self-calibration procedures of a DAC with weight redundancy built on inaccurate elements and proposed methods of a compensating signal generating can significantly (by 2-3 orders) reduce the absolute error and thereby improve the accuracy of the ADC