New Empirical Indoor Path Loss Model using Active UHF-RFID Tags for Localization Purposes

A Comparative Survey on Silicon Based and Surface Acoustic Wave (SAW)-Based RFID Tags: Potentials, Challenges, and Future Directions

“…As described in the previous sections, since the form factor of the RFID tag is dependent on the frequency at which the tag is operating [7], a reduced wavelength will require a very small size tag which will be compact, compatible and highly suitable for many applications such as human tracking. Thus, with such modern RFID tag designs, it is possible to design more such tags with unique ID's that can also be read at an increasingly greater distances than were thought to be possible using magnetic induction coupling between the reader and the tag many years ago.…”

“…The read range of an active RFID tag can be anywhere between a meter to tens of meters and is an ideal tag for locating different types of pallets or items and for labeling the product with more such specifications or serving as landmark points for locating other objects that are in the close proximity to the reference active tag. The lifetime of active tags is usually up to a period of five years from the time the operation/usage is started [7]. Like passive IC based tags, active tags also possess certain advantages and limitations.…”

“…A more detailed description of SAW tags will be provided in the RFID tag technology section. Other auto-ID techniques [7] such as bar codes, EAS and magnetic stripes do exist but they are constrained by several factors such as Line-of-Sight (LOS) requirement between the scanner and the object to be read, close contact (very short read range), inability to survive in harsh weather and, very limited number of object reads per second. On the other hand, RFID technologies are free from all such constraints and hence more favorable than bar code and others.…”

“…Papers [10] and [11] explained the rules and regulations of deploying and using the RFID system and an application scenario in school buses where passive silicon based IC tags were deployed in the school children's bags, with the objective to enhance the safety. Paper [7] briefly explains the usage of passive and active silicon based IC tags for two different Indoor propagation models namely the Dual One Slope Model (DOSM) and Dual One Slope with Second Order Polynomial Model (DOSSOM) and showed that the accuracy had improved by around 5 cm when using the DOSSOM model. On the other hand, many review papers have also been published in the domain of RFID so far.…”

“…While paper [28] discusses chipless RFID tags, it neither covered all chipless RFID technologies nor provided detailed insights on important aspects such as privacy and security. Papers [7] and [26] focused only on silicon based IC active and passive tags and a general description on silicon based IC tags, without a detailed comparison addressing all performance metrics that affect tag performance metrics such as read range, cost, security and privacy and longevity. Although paper [27] does cover almost all kinds of chipless RFID tags and includes performance metrics such as read range, the paper still lacks a detailed explanation of different designs in SAW RFID tags and a quantitative comparison across crucial parameters such as cost and security across such tags which also strongly determines the ability of them to penetrate the RFID market.…”