New Handheld RFID Reader Locates Tags Within Centimeters

AsReader's ASR-R250G reader, paired with a smartphone, employs software from RFLocus and can display the locations of tagged items in 3D from a range of about 10 meters.
Published: January 17, 2017

This month, RFID reader technology company AsReader, Inc. released a new handheld reader with a 10-meter (33-foot) read range. Using software from RFLocus enables the new reader’s users to not only interrogate an ultrahigh-frequency (UHF) RFID tag, but identify in 3D where that tag is located in relation to the reader, within a matter of centimeters.

The ASR-R250G is designed to be small and low in cost, the company reports. The handheld employs Apple iPhone- or Android-based devices, connected to the reader, to enable operation with an app. The new product also comes with built-in AsTagFinder software co-developed by RFLocus and AsReader. The AsReader open-source and royalty-free software-development kit (SDK) enables users to build an app to operate on the reader’s mobile device. Users can transmit data back to a server via the mobile device’s Wi-Fi connectivity, or via a cellular connection, or collect the data locally, off the network, and synch upon rejoining the network.

The ASR-R250G reader

RFLocus and AsReader collaborated on the “locating” software for use in the ASR-R250G model. The technology enables users to identify, in 3D, where tags are located in relation to the reader, accurate up to within centimeters.

AsReader, Inc. is based in Tustin, Calif., and is a subsidiary of parent company Asterisk, Inc., headquartered in Osaka, Japan. The ASR-R250G-23 reader operates in the United States bandwidths, while its European counterpart is the ASR-R250G-22 model. In the U.S. and European models, the 1-watt (30-dBm) power setting can also be lowered manually, or with automated logic to as low as 3-mW (5-dBm) when shorter read ranges are desired.

Paul Whitney

The company also offers UHF-, HF- and bar-code-based sled pocket devices linked to smartphones for short reads—about 1 to 2 meters (3.3 to 6.6 feet). The ASR-R250G reader is designed to be very compact, AsReader reports, and is aimed at providing a longer read range. “This is our first public foray into long-range RFID reading,” says Paul Archuleta Whitney, AsReader’s VP. By employing the software developed with RFLocus, he explains, AsReader can retain the small form factor and smartphone device compatibility of its other products, while providing the kind of long-range UHF reads typically offered by bulkier handheld readers.

“AsReader has released a device that is nothing like conventional readers,” says Gary Chen, RFLocus’s co-founder and managing VP. Because it accommodates a smartphone, he explains, the new reader is designed to enable use with an app, making it less expensive and smaller than most traditional PDA readers, with greater functionality. Additionally, the devices are built to provide both bar-code and RFID reading capabilities.

Most standard handhelds use received signal strength indicator (RSSI) technology to identify where a tag may be located, Chen explains. RFLocus software, in concert with AsReader hardware, also utilizes this measurement, as well as time domain phase difference of arrival (TD-PDOA), which consists of collecting and analyzing the sequence of data points in successive order as a reader is moving, according to Hajime Kamiya, RFLocus’s co-founder and CEO. This enables the reader to interrogate each tag nearly 1,000 times per second.

This data enables the reader to identify a more granular location in order to provide 3D location data. In that way, users can differentiate not only whether a tag is in front, behind or to the side of a reader, but also the specific shelf on which it is located. Chen notes that the system works with the high granularity as long as a reader is moving. Therefore, a user can carry a handheld around a room, or wave it past shelves or stacks of inventory, in order to collect location data. The software can determine if a reader is approaching a tag, as well as from what direction—above, below, left or right—and whether the device is moving toward or away from the tag. The handheld can emit sound alerts as the tag gets closer or further from it, and display location data on the phone or tablet screen.

The smartphone snaps onto each reader model via a strong magnetic connector that provides the data link between reader and phone, and also charges its battery. This hard magnetic connection allows a read range of approximately 10 meters (33 feet), Whitney says, though with a clear line of sight, he has used the readers at a distance of 17 meters (56 feet).

Hajime Kamiya

According to Whitney, AsReader’s customers have been requesting a product like the ones it already makes, that can fit in a worker’s pocket but be used in a lost-and-found mode. With a longer read range and highly granular location data, AsReader’s customers could use the Geiger counter mode to very quickly locate a specific item within a store, factory, hospital, warehouse or office.

AsReader is now developing software integration that, in the future, will enable users to create grids representing a warehouse or room, and to then use a handheld’s collected RFID read data to determine in which zone within a grid a particular tag is located, along with when it moves from one small zone to another. In this case, the technology could be used with RFID tags installed in the corners of a room, to serve as reference points. A smartphone with an AsReader device, running the AsReader-based app, could then read the tag ID numbers, identifying the reader’s own position within a room, along with each tag’s position.

AsReader and RFLocus expect to test the technology on drones this year. According to the company, the drones would use fixed RFID tags as reference points, and would interrogate each asset or inventory tag within a warehouse to specifically identify where each item is being stored or used.

Currently, says Mark Tailford, AsReader’s global division sales director, multiple retailers in the United States and Europe are testing the new reader. AsReader is also in discussions with health-care companies to track assets and pharmaceuticals, while some manufacturers are interested in using the technology for assembly work-in-progress, as well as lost-and-found functions for finding misplaced parts. If a custom vehicle were being built, the manufacturer could use the reader to quickly identify which items—such as premium parts—had been installed in it.

The new reader model is priced at $1,299 without a built-in bar-code scanner (or $1,449 with a 2D and 1D bar-code scanner). Users can order the device without the bar-code scanner at a lower price, Whitney notes, and use the smartphone’s camera for occasional bar-code scanning.