Abdallah Y. Alma'aitah

3D Passive Tag Localization Schemes for Indoor RFID Applications

Accurate and efficient localization of tags are of utmost importance for numerous existing and forthcoming RFID applications. In this paper, we introduce two novel methods for three dimensional localization of the passive RFID tags. In the first approach, namely Adaptive Power Multilateration (APM), using four RFID readers, distance estimations parameters are processed based on the minimal interrogation power and multilateration. Whereas in the second approach, namely Adaptive Power with Antenna Array (APAA), a single RFID reader equipped with horizontal and vertical smart antennas alongside with the readers adaptive power levels are used for the tags distance estimations. The APM scheme localizes the tags with comparatively finer granularity whereas the APAA scheme supports readers mobility and facilitates highly dense tag environments. Simulation results show that our proposed schemes provide more accurate localization than other indoor localization schemes.

RFID Localization Using Angle of Arrival Cluster Forming

Radio Frequency IDentification (RFID) has been increasingly used to identify and track objects automatically. RFID has also been used to localize tagged objects. Several RFID localization schemes have been proposed in the literature; some of these schemes estimate the distance between the tag and the reader using the Received Signal Strength Index (RSSI). From a theoretical point of view, RSSI is an excellent approach to estimate the distance between a sender and a receiver. However, our experiments show that there are many factors that influence the RSSI value substantially and that, in turn, has a negative effect on the accuracy of the estimated distance. Another approach that has been recently proposed is utilizing transmission power control from the reader side. Our experiments show that power control results are more stable and accurate than RSSI results. In this paper, we present a test-bed comparison between the power control and the RSSI distance estimation approaches for active RFID tags. We also present the Angle of arrival Cluster Forming (ACF) localization scheme that uses both the angle of arrival of the tags signal and the readers transmission power control to localize active tags. Our experiments show that ACF is very accurate in estimating the location of active RFID tags.

Tag Modulation Silencing: Design and Application in RFID Anti-Collision Protocols

Reliable and energy-efficient reading of Radio Frequency IDentification (RFID) tags is of utmost importance, especially in mobile and dense tag settings. We identify tag collisions as a main source of inefficiency in terms of wasting both medium access control (MAC) frame slots and readers energy. We propose modulation silencing (MS), a reader-tag interaction framework to limit the effect of tag collisions. Utilizing relatively simple circuitry at the tag, MS enhances the performance of existing anti-collision protocols by allowing readers to terminate collision slots once a decoding violation is detected. With shorter collision slots, we revisit the performance metrics and introduce a new generalized time efficiency metric and an optimal frame selection formula that takes into consideration the MS effects. Through analytical solutions and extensive simulations, we show that the use of MS results in significant performance gains under various scenarios.

Modulation silencing: Novel RFID anti-collision resolution for passive tags

RFID technology has been gaining popularity in several automated inventory management applications. In such applications, thousands of RFID tags are attached to different products and the reader(s) will be collecting tags IDs using an arbitration protocols. In the existing tag arbitration protocols, significant time and power are consumed on inevitable tag collisions. In this paper, collision time reduction mechanism, called Modulation Silencing Mechanism (MSM) is proposed. MSM accelerates ending of collision slots by allowing the collided tags to interpret the silencing feedback from the reader and stop their backscattering. The proposed mechanism achieves a considerable reduction in collision time; hence, we proposed a new generalized performance metric to consider the shorter duration of collision slots by MSM. In addition, we evaluate the main RFID arbitration protocols after applying MSM and the time efficiency of these protocols was significantly increased.

Area efficient-high throughput sub-pipelined design of the AES in CMOS 180nm

In this paper, efficient hardware of one of the most popular encryption algorithms, the Advanced Encryption Standard (AES), is presented. A modified sub-pipelined structure is proposed targeting high speed and low power-delay product of the compact AES design with on-the-fly key expansion unit. By adding 25.8% in hardware complexity to the existing ASIC designs, the throughput is increased more than 158% with better overall power-delay product. Compared to other compact AES implementation the proposed structure can go up to 6Gbit/sec with about 13k gate count.

A cooperative localization scheme using RFID crowdsourcing and time-shifted multilateration

RFID technology as an enabler of the Internet of Things (IoT) is extensively utilized for object localization. Existing RFID-based object localization techniques follow a centralized and coordinated approach. Indeed, none is designed to leverage RFID crowdsourcing for the purpose of object localization. In this paper, we propose a cooperative scheme to localize mobile RFID tags using heterogeneous, distributed and dynamic mobile RFID readers in indoor/outdoor environments. In addition, we introduce the concept of Time-Shifted Multilateration (TSM) to enhance location estimation accuracy of mobile tags when sufficient synchronous detection information is not available. We validate the proposed scheme and the TSM technique through extensive simulations using ns-3. Results show that our approach can achieve accurate location estimation in typical IoT settings.

Monitoring operational mining equipment using Sprouts Wireless Sensor Network platform

This paper discusses the application use of our WSN platform called Sprouts to monitor the current erosion conditions and retrieval of lost shovel-teeth in the Oil Sands mining operations of Ft. McMurray, Alberta, Canada. The modular architecture design of Sprouts allows us to customize the platform to monitor the thickness of shovel teeth and localize their position upon detachment. Utilizing our Sprouts plug-and-play protocol, we implement three sensor modules to monitor the thickness of the shovel tooth in operation using ultrasound waves, detect the event of a fallen shovel-tooth, and aid the retrieval of fallen shovel teeth using trilateration localization before they cause damage to crushers.

RFID tags authentication by unique hash sequence detection

With the rise of internet of things an immense number of RFID tags will be associated with different systems that require not only strong authentication protocols, but also time- and power- efficient protocols to authenticate more tags in a given time window. In current tag authentication protocols, a tag is considered authentic if the interrogators find a match to the tags encrypted (e.g., using some hashing function) reply in the systems database. Tree-based authentication protocols provide rapid authentication by limiting the searched keys at the interrogator from O(N) to O(log(N)), where N is the number of leaves in the balanced tree. However, if one tag is compromised in such protocols, other tags will be at risk of being compromised. In this paper we propose Unique Hash Sequence Authentication (UHSA) protocol. The protocol utilizes tag-interrogator interaction, with a continuous wave (CW) sensor at the tag to cut off tags encrypted reply when the received bits are enough to determine next node in the tree without receiving the whole reply. Cutting off the encrypted reply limits the information that can be obtained by the adversary to compromise the tag. In addition, the reduction in tag reply length greatly enhances the time and power efficiency of the RFID system during the authentication process by more than 90% when compared to existing authentication protocols.

Utilizing Sprouts WSN platform for equipment detection and localization in harsh environments

This paper discusses the application of our Wireless Sensor Network platform called Sprouts, to monitor the steel shovel-teeth on shovelling equipment used in oil sands mining operations in Ft. McMurray, Alberta, Canada. If a fallen shovel-tooth reaches the rock crushers, serious damage to the crusher gears is expected. The Sprouts platform is utilized to monitor the viability of the shovel-teeth on the shovel buckets teeth adapter. In addition, if a shovel-tooth becomes detached, Sprouts is used to estimate its location. By utilizing our Sprouts plug-and-play protocol, we implement a magnetic field and ultrasound distance sensor modules to detect the event of a fallen shovel-tooth. In addition, a wireless power transfer unit and two supplementary antennas are embedded in each shovel-tooth to aid in localizing (using trilateration) the part before it reaches the crusher.

Efficient and anonymous RFID tag counting and estimation using Modulation Silencing

In RFID based inventory systems, counting and estimating the number of the surrounding tags without reading each tag individually is a challenge. In this paper we propose an estimation function that considers the variance of collision and empty slots during the estimation frame. In addition, two schemes, Variance and Modulation Silencing based Estimation (VMSE) and Modulation silencing count (MSC), are proposed to utilize the accuracy of the estimation function and modulation silencing mechanism [1] in counting and estimating the number of RFID tags. In the proposed schemes, tags participating in collision and success slots are silenced to accelerate the counting process. Requiring only minimal modification to the reader-to-tag communication procedure, the proposed schemes achieve a significant performance gain when compared to existing counting protocols in the literature.