Riccardo Colella

A Cost-Effective UHF RFID Tag for Transmission of Generic Sensor Data in Wireless Sensor Networks

The use of RF identification (RFID) technology for the automatic transmission of physical parameters in wireless sensor networks paves the way to a large class of attractive applications ranging from healthcare to automotive, diagnostic systems, robotics, and many others. Nevertheless, although some RFID tags capable to transmit sensor-like information are already on the market, only a limited number of sensors, such as those for temperature or pressure measurement, can be easily miniaturized and embedded in the RFID chip. The integration of more complex sensors, in fact, appears to be complicated and extremely expensive. In this paper, a cost-effective general-purpose multi-ID tag is proposed. It can be connected to generic sensors, regardless of the actual measured value, and it is capable to transmit, when interrogated by a standard RFID reader, a proper combination of ID codes that univocally codifies the sensor measured value. The functionalities of this device have been extensively validated under stressing conditions and the capability to transmit whatever kind of sensor data has been demonstrated.

A Cost-Effective SDR Platform for Performance Characterization of RFID Tags

The rigorous characterization of ultrahigh-frequency passive radio-frequency identification (RFID) tags is a challenging but mandatory task. Indeed, tags are the most critical devices in RFID systems: their performance should be adequately good, although stringent requirements in terms of compactness, used materials, and costs must be satisfied. Factors such as the goodness of the conjugate impedance matching between the chip and the antenna, the chip sensitivity, and the quality of the backscattered signal affect tag performance. Tag sensitivity and differential radar cross section (RCS) are the most significant metrics for tag characterization: they define the forward (from the reader to the tag) and the backward (from the tag to the reader) link reliability, respectively. Nevertheless, measurement of such metrics cannot be approached with conventional methods based on vector network analyzers or conventional RFID readers. Vice versa, commercially available instrumentation and solutions are very expensive and not totally flexible. In this paper, a novel approach for performance characterization of RFID tags is explored. To this end, we developed a very cheap (below

A framework for context-aware home-health monitoring

1000) and flexible tool based on software-defined radio, which enables measurement of tag sensitivity and differential RCS. An exhaustive experimental campaign has been carried out on ten commercial and four built-in laboratory RFID tags. Achieved results demonstrate the flexibility, accuracy, and appropriateness of the proposed approach.

Smart RFID Antenna System for Indoor Tracking and Behavior Analysis of Small Animals in Colony Cages

This paper presents a proposal for a context-aware framework. The framework is organised according to a general purpose architecture, centred around an ontological context representation. The ontology provides the vocabulary upon which software agents interoperate and perform rule-based reasoning, in order to determine the system response to context changes. Context data are provided by both static and dynamic sources, the core of which is a novel low-cost device enabling the integration of sensor networks with RFID systems. This paper describes system components and their coordinated operations by providing a simple example of concrete application in a home-care scenario.

Enhanced UHF RFID Sensor-Tag

Radio frequency identification (RFID) technology is more and more adopted in a wide range of applicative scenarios. Nevertheless, in many applications, commercial and general-purpose solutions can be unsuitable as in the case of the tracking of small-size living animals for the behavior analysis. In such a case, the whole RFID hardware, as well as the control software, should be opportunely tailored for the particular application. In this paper, a novel RFID-based approach enabling an effective localization and tracking of small-sized laboratory animals is proposed. It is mainly based on a near-field (NF) RFID multiantenna system working in the UHF bandwidth, to be placed below the animals cage, and able to rigorously identify the NF RFID tags implanted in laboratory animals. Once the requirements of the reader antenna have been individuated, an antenna system composed of a matrix of specifically designed segmented loops has been prototyped. Moreover, to improve the effectiveness of the whole tracking system, a properly algorithm based on the measured received signal strength indication has been developed and integrated. It aims at removing potential minor ambiguities of the data captured by the multiantenna system. The whole animal tracking system has been then largely tested on phantom mice to verify its ability to precisely localize each subject and to reconstruct its path. Additionally, a first test performed on living mice has been presented. The achieved and discussed results demonstrate the effectiveness of the proposed approach.

Smart Prototyping Techniques for UHF RFID Tags: Electromagnetic Characterization and Comparison with Traditional Approaches

A cost-effective integration of passive UHF RFID tags and sensors is still a challenge. In such a field, authors have already proposed a label-type multi-antenna Sensor-Tag, an RFID device accepting as input a generic sensor and allowing the transmission of the measured data towards a standard RFID reader. In this work a new enhanced version of Sensor-Tag is presented. It is based on optimized tag antennas designed by taking into account both size constraints and coupling effects. Compared with the old version, an appreciable size reduction is obtained and the working distance doubled, being now as good as a long range passive UHF tag.

RFID Sensor-Tags Feeding a Context-Aware Rule-Based Healthcare Monitoring System

Over the last few years, the active and growing interest in Radiofrequency Identiflcation (RFID) technology has stimulated a conspicuous research activity involving design and realization of passive label-type UHF RFID tags customized for speciflc applications. In most of the literature, presented and discussed tags are prototyped by using either rough-and-ready procedures or photolithography techniques on rigid Printed Circuit Boards. However, for several reasons, such approaches are not the most recommended, in particular they are rather time-consuming and, moreover, they give rise to low quality devices in one case, and to cumbersome and rigid tags in the other. In this work, two alternative prototyping techniques suitable for cost-efiective, time-saving and high-performance built-in-lab tags are introduced and discussed. The former is based on the joint use of ∞exible PCBs and solid ink printers. The latter makes use of a cutting plotter to precisely shape the tag antenna on thin copper sheets. Afterwards, a selection of tags, designed and manufactured by using both traditional and alternative techniques, is rigorously characterized from the electromagnetic point of view in terms of input impedance and whole tag sensitivity by means of appropriate measurement setups. Results are then compared, thus guiding the tag designer towards the most appropriate technique on the basis of speciflc needs.

Enhanced UHF RFID Tags for Drug Tracing

Along with the growing of the aging population and the necessity of efficient wellness systems, there is a mounting demand for new technological solutions able to support remote and proactive healthcare. An answer to this need could be provided by the joint use of the emerging Radio Frequency Identification (RFID) technologies and advanced software choices. This paper presents a proposal for a context-aware infrastructure for ubiquitous and pervasive monitoring of heterogeneous healthcare-related scenarios, fed by RFID-based wireless sensors nodes. The software framework is based on a general purpose architecture exploiting three key implementation choices: ontology representation, multi-agent paradigm and rule-based logic. From the hardware point of view, the sensing and gathering of context-data is demanded to a new Enhanced RFID Sensor-Tag. This new device, de facto, makes possible the easy integration between RFID and generic sensors, guaranteeing flexibility and preserving the benefits in terms of simplicity of use and low cost of UHF RFID technology. The system is very efficient and versatile and its customization to new scenarios requires a very reduced effort, substantially limited to the update/extension of the ontology codification. Its effectiveness is demonstrated by reporting both customization effort and performance results obtained from validation in two different healthcare monitoring contexts.

Sensor data transmission through passive RFID tags to feed wireless sensor networks

Radio Frequency Identification (RFID) technology is playing a crucial role for item-level tracing systems in healthcare scenarios. The pharmaceutical supply chain is a fascinating application context, where RFID can guarantee transparency in the drug flow, supporting both suppliers and consumers against the growing counterfeiting problem. In such a context, the choice of the most adequate RFID tag, in terms of shape, frequency, size and reading range, is crucial. The potential presence of items containing materials hostile to the electromagnetic propagation exasperates the problem. In addition, the peculiarities of the different RFID-based checkpoints make even more stringent the requirements for the tag. In this work, the performance of several commercial UHF RFID tags in each step of the pharmaceutical supply chain has been evaluated, confirming the expected criticality. On such basis, a guideline for the electromagnetic design of new high-performance tags capable to overcome such criticalities has been defined. Finally, driven by such guidelines, a new enhanced tag has been designed, realized and tested. Due to patent pending issues, the antenna shape is not shown. Nevertheless, the optimal obtained results do not lose their validity. Indeed, on the one hand they demonstrate that high performance item level tracing systems can actually be implemented also in critical operating conditions. On the other hand, they encourage the tag designer to follow the identified guidelines so to realize enhanced UHF tags.

SPARTACUS: Self-Powered Augmented RFID Tag for Autonomous Computing and Ubiquitous Sensing

The use of Radio Frequency Identification (RFID) technology for the automatic transmission of physical parameters in wireless sensor networks paves the way to a large class of attractive applications, ranging from healthcare to automotive, diagnostic systems, robotics and many others. Nevertheless, although some RFID tags capable to transmit sensor-like information are already on the market, only a limited number of sensors, such as those for temperature or pressure measurement, can be easily miniaturized and embedded in the RFID chip. The integration of more complex sensors, in fact, appears to be complicated and extremely expensive. In this paper, a cost-effective general-purpose multi-ID tag is proposed. It can be connected to generic sensors, regardless of the actual measured value, and it is capable to transmit, when interrogated by a standard RFID reader, a proper combination of ID codes that univocally codifies the sensor measured value. The functionalities of this device have been extensively validated under stressing conditions and the capability to transmit whatever kind of sensor data has been demonstrated.