Korea University Ubiquitous LAB. Chapter 8. Design selection Ph.D Chang-Duk Jung

Korea University Ubiquitous LAB. Link between hardware and virtual components Events Context Location Composition Event generation Time State and behavior History

Korea University Ubiquitous LAB. RFID middleware

Korea University Ubiquitous LAB. RFID middleware (con’t) RFID middleware should meet these requirements : –RFID data dissemination –Data filtering and aggregation –Reading from and writing to a tag –Privacy

Korea University Ubiquitous LAB. Frequency of operation Maximum reading distance –The maximum accurate reading distance between the reader and the tag Application type –Well-defined classes of applications are associated with a specific frequency range Operating conditions –Frequency determined with the help of the operating environment

Korea University Ubiquitous LAB. Frequency of operation If frequency is illegal in the region of deployment –Change the frequency to the closest permissible limit in the deployment location –Select vendors who can provide RFID systems that operate in the selected frequency –Apply for a special license from the government or appropriate governing body

Korea University Ubiquitous LAB. Hardware components

Korea University Ubiquitous LAB. Selecting tags Tag type –Read-only –Passive, active, or semi-active –Custom tags Frequency range –General performance characteristics –Regulatory requirements Read range performance –Read robustness –Reading distance of a tag from a reader –Tag antenna design –Tag density –Tag motion –Tag orientation

Korea University Ubiquitous LAB. Selecting tags (con’t) Data capacity –Quantity of data to be stored on the tag –Data protection requirements Tag form and size –The dimensions of the tag –The ruggedness of the tag Environmental conditions –The presence of environmental conditions, such as temperature and humidity, might affect tag performance Standards compliance –Should meet existing and emerging standards, including the expected EPC Global Class 1 Gen 2 and Class 2 requirements

Korea University Ubiquitous LAB. Selecting readers Reader type Legal restrictions Ability to upgrade Manageability Ruggedness Installation Quantity

Korea University Ubiquitous LAB. Selecting antennas Polarization Footprint Power and duty cycle Installation

Korea University Ubiquitous LAB. Selecting transmission lines A transmission line is used to connect the reader and the antenna Input impedance (Ω) of the antenna should match the characteristic impedance of the transmission line Increase in VSWR indicates increase in impedance mismatch

Korea University Ubiquitous LAB. Selecting transmission lines Percentage of reflected power and transmission loss as a function of VSWR VSWR Percentage of reflected power Transmission loss (dB) 1.0: : : : : : :

Korea University Ubiquitous LAB. Transmission line types Shielded pairCoaxial

Korea University Ubiquitous LAB. Physical length When the physical length of a transmission line— compared to the quarter wavelength (λ/4) of the energy that it is supposed to carry—is long, the transmission line is electrically long

Korea University Ubiquitous LAB. Selecting reader network hardware

Korea University Ubiquitous LAB. Reader network hardware RFID readers use protocols and interfaces to communicate with the host computer, such as –Serial –TCP/IP –Industrial networks

Korea University Ubiquitous LAB. Selecting mounting equipment for RFID systems You need to consider these portals for mounting your RFID systems: –Conveyors –Dock doors –Stretch wrap station –Forklifts –Smart shelves –Point of sale

Korea University Ubiquitous LAB. Conveyor mounting

Korea University Ubiquitous LAB. Dock doors

Korea University Ubiquitous LAB. Selecting mounting equipment for RFID systems (con’t) Stretch wrap stationForklift mounting

Korea University Ubiquitous LAB. Selecting mounting equipment for RFID systems (con’t) Smart shelves Point of sale

Korea University Ubiquitous LAB. Protection for RFID systems NEMA IP rating RFID shielding –RFID frequency-specific absorber shields –RFID frequency-specific ferrite absorbers for cables –RFID frequency-specific printed circuit board (PCB) shields

Korea University Ubiquitous LAB. Unit summary Determined the relation between virtual components and hardware components of RFID systems Discussed the hardware components of an RFID system and protection in an RFID system

Korea University Ubiquitous LAB. Review questions What are the tools and techniques recommended for RFID signal interference control? List the essential factors you need to consider for selecting the right RFID tag for your application.