Bulk reading
Encyclopedia
For RFID tags, bulk reading is the extension of single reading to a set of tags. A group of objects, all of them RFID tagged, shall be read completely from one single reader position in timely coincidence.
(ISO 18000-3), UHF (ISO 18000-6) and SHF
(ISO 18000-4) RFID tags. However, as RFID communications address RFID tags strictly sequentially, the time needed for bulk reading grows linearly with the number of labels to be read. (This means it takes twice as long to read twice as many labels.) Due to collision effects, the time required is in fact greater.
dipole antennas. In case any of the tags are shielded by other tags, they might not be sufficiently illuminated to return a sufficient response.
The response conditions for inductively coupled HF
RFID tags and coil antennas in magnetic fields (with UHF RFID tags and NFC
communications antennas also in magnetic fields) appear better than for UHF or SHF dipole fields, but then distance limits apply and may prevent success.
However, when a single RFID tag might be seen as not guaranteeing a proper read, a bunch of RFID tags, where at least one will respond, may be a safer approach for detecting a known grouping of objects. In this respect, bulk reading is a fuzzy
method for process support.
From the perspective of cost and effect, bulk reading is not reported as an economized approach to secure process control in logistics.
Limitations
Bulk reading is a possible use of HFHigh frequency
High frequency radio frequencies are between 3 and 30 MHz. Also known as the decameter band or decameter wave as the wavelengths range from one to ten decameters . Frequencies immediately below HF are denoted Medium-frequency , and the next higher frequencies are known as Very high frequency...
(ISO 18000-3), UHF (ISO 18000-6) and SHF
SHF
SHF may refer to:* Super high frequency, radio frequencies in the range of 3 GHz and 30 GHz* Société de l'histoire de France, a society formed in 1833 to study French history* Souther-Hillman-Furay Band, a mid-1970s country-rock band....
(ISO 18000-4) RFID tags. However, as RFID communications address RFID tags strictly sequentially, the time needed for bulk reading grows linearly with the number of labels to be read. (This means it takes twice as long to read twice as many labels.) Due to collision effects, the time required is in fact greater.
Principle
A bulk of RFID tags has to be illuminated by the interrogating signal just like a single tag. This is not a challenge concerning energy, but with respect to visibility, especially in electromagnetic fields and using UHF or SHFSHF
SHF may refer to:* Super high frequency, radio frequencies in the range of 3 GHz and 30 GHz* Société de l'histoire de France, a society formed in 1833 to study French history* Souther-Hillman-Furay Band, a mid-1970s country-rock band....
dipole antennas. In case any of the tags are shielded by other tags, they might not be sufficiently illuminated to return a sufficient response.
The response conditions for inductively coupled HF
High frequency
High frequency radio frequencies are between 3 and 30 MHz. Also known as the decameter band or decameter wave as the wavelengths range from one to ten decameters . Frequencies immediately below HF are denoted Medium-frequency , and the next higher frequencies are known as Very high frequency...
RFID tags and coil antennas in magnetic fields (with UHF RFID tags and NFC
NFC
NFC may refer to:* Nagacorp FC, a Cambodian sporting club* National Finance Center, a division of the United States Department of Agriculture* National Football Conference, a constituent conference of the National Football League...
communications antennas also in magnetic fields) appear better than for UHF or SHF dipole fields, but then distance limits apply and may prevent success.
Operational advantage
Under operational conditions, bulk reading is no technology of secure operation. Bulk reading can be a rough guide for logistics decisions. But due to a high proportion of reading failures, it is not (yet) suitable for inventory management.However, when a single RFID tag might be seen as not guaranteeing a proper read, a bunch of RFID tags, where at least one will respond, may be a safer approach for detecting a known grouping of objects. In this respect, bulk reading is a fuzzy
Fuzzy mathematics
Fuzzy mathematics forms a branch of mathematics related to fuzzy set theory and fuzzy logic. It started in 1965 after the publication of Lotfi Asker Zadeh's seminal work Fuzzy sets. A fuzzy subset A of a set X is a function A:X→L, where L is the interval [0,1]. This function is also called a...
method for process support.
From the perspective of cost and effect, bulk reading is not reported as an economized approach to secure process control in logistics.