RFID Reader
A RFID reader is the main component of an RFID system. The reader uses an antenna to send and receive radio signals.
RFID readers can be fixed or incorporated into vehicles. Fixed readers create a defined interrogation zone.
COTS readers use a technique called frequency hopping to mitigate co-channel interference. This means the phase values of RSSI readings are changing every 0.2 s.
Detection
The RFID reader sends out a radio signal. When a compatible tag enters its range, it receives electromagnetic energy from the reader antenna and responds by sending a return signal that includes its own protocol, managing organization, asset description, and serial number (usually stored as 96-bit EPC data). The reader then relays this information to an associated system user, server, or database.
Since the tags don’t have power sources of their own, they rely on electromagnetism for their operation. A tagged product’s RFID Reader antenna is conductive and, when struck with an electromagnetic wave from the RFID reader, induces an electric current that powers its internal integrated circuit (IC). The IC then transmits a signal back to the antenna, which translates it into usable information.
One of the key advantages of RFID technology is that it can function without direct line of sight. In warehouses, for example, products can be covered by dust or dirt, and they’ll still be read at a distance.
However, because RFID readers emit radio signals, they can also be detected by unauthorized parties. This can pose a security or privacy concern, especially in military or medical settings where the ability to identify a patient quickly and accurately can be a life-or-death matter. To prevent this, manufacturers can create RFID detectors that detect and alert people of the presence of a bogus reader. The devices can be made with a few basic parts like cardboard, LEDs and copper tape.
Identification
An RFID reader, or interrogator, transmits and receives radio waves in order to communicate with and read tags. There are a variety of RFID readers available to choose from, ranging from handheld or mobile readers, which work much like barcode scanners, to fixed readers that can be installed at doorways and in portal configurations to automatically detect and read tags as they enter the reading range.
When an RFID tag is within the radiation range of the RFID reader, it awakens and starts to transmit a wireless signal that contains its own data back toward the antenna/reader. The data is detected and demodulated by the reader/antenna, then analyzed and stored in memory.
The data retrieved from an RFID tag can be used for a variety of purposes. For example, in retail environments, RFID can help reduce manual labor in processes that do not add value to the product and can improve productivity and scheduling.
Physicians should stay informed about the use of RFID in their clinical settings and ask patients questions if they suspect that RFID may have played a role in a medical device episode. They should also be aware that FDA recommends reporting suspected medical device malfunctions to MedWatch, the agency’s voluntary adverse event reporting program. If they have any concerns, physicians should consider obtaining a device interrogation in addition to their normal reporting procedures.
Localization
Accurate localization of RFID tags is an important requirement for many tracking and monitoring applications. However, there are several technical challenges to overcome. One of the most difficult is the fact that RFID readers can only detect a limited number of tags simultaneously, and the signal strengths of the detected tags vary significantly over time.
This paper proposes a new RFID tag localization method based on a reconfigurable reader antenna array. The system consists of four broadside directional antennas in the UHF RFID band, and it can efficiently interrogate multiple tags simultaneously. It also features a high gain of 8.9 dBi and can locate tags with on-body RFID sensors, which are difficult to position using conventional single unit reader antennas.
Various methods for RFID tag localization have been proposed in the literature, mainly based on estimated distances between a reader and the tags. These distances are computed based on the RSSI of the tag and the receiver’s signal strength measurement. However, this approach has poor accuracy, incurring meters of localization error.
MRLIHT solves this problem by first generating the response regions of RFID readers to individual tags. The potential location region of the individual is then determined based on these response regions. Finally, two algorithms are devised to estimate the location of the individual with high accuracy and efficiency.
Security
RFID security is an issue that needs to be taken seriously. Luckily, the short ranges of RFID make many types of hacking impractical but this does not mean that there are no risks at all.
One common attack is cloning. This is where a hacker clones a genuine card or tag and uses it to gain access to a facility or other area. Using the right tags and reader protection, desfire ev1 as well as an adequate security plan and monitoring, will help to prevent this type of attack.
Another common type of attack is man-in-the-middle (MITM). This occurs when a hacker listens to the communication between an RFID tag and reader and intercepts and manipulates the signals. This type of attack can be prevented by choosing tags that offer a challenge response authentication system which makes the information transmitted between the reader and tag cryptographic and encrypted.
Other possible attacks include counterfeiting, sniffing and tracking. The latter can occur when the unique serial number associated with a tag is used to link it with an identified individual. This can be a privacy concern for individuals or in military or medical settings a life-or-death matter. To avoid this you should use readers that only gather tag data one at a time and choose tags that provide the highest levels of security, such as Impinj Protected Mode.
