Zebra Releases Dart Sensor to Meet New UWB Standard

By Claire Swedberg

The recently approved IEEE 802.15.4f specification provides an open standard that will enable ultra-wideband RFID technology users to mix products for the most competitive solution.

The IEEE approved the 802.15.4f active radio frequency identification standard in February of this year, and its publication is expected to occur this month. In anticipation of that development, Zebra Technologies has announced a new version of its Dart ultra-wideband (UWB) real-time location system (RTLS) sensor that will be compatible with that standard, while existing Dart sensors can be upgraded to meet the new standard via Zebra firmware.

IEEE 802.15.4f is an amendment to the IEEE 802.15.4-2011 standard for low-rate wireless personal area networks (LR-WPANs). The standard has a clause for UWB that stands by itself, as well as an additional clause specifying a separate protocol for 433 MHz and 2.4 GHz.

With the passage of the IEEE 802.15.4f standard, users of the technology can now build a system based on the open standard that would provide the framework for them to mix and match products from different vendors, or to enable the use of hybrid solutions with multiple types of technology, such as sensors with UWB tags, which typically operate at frequencies ranging from 500 MHz to 10.6 GHz, or other RFID solutions employing differing frequencies. The first UWB product to be released compatible with the new standard is an updated version of Zebra's Dart UWB RTLS sensor, which acts as a receiver for UWB tags that transmit data via short pulses, thereby enabling a user to locate the tags within a few feet.

With the new standard's adoption, compliant products from diverse vendors will now become interoperable.

During the past several years, Zebra Technologies has worked closely to develop the standard with other UWB companies, including Ubisense, Time Domain, Decawave and Guard RFID, says Tim Harrington, Zebra Technologies' VP of product strategy and vice-chair of the IEEE 802.15 Task Group. During that time, he reports, participants were creating a common physical layer (PHY) and media access control (MAC) sub-layer to the existing 802.15.4 protocol stack. The resulting 802.15.4f standard, based on that work, is designed to enable ultra-low-energy consumption, highly reliable communication and an air-interface protocol for active RFID and sensor applications, and to be flexible and configurable for a variety of active RFID transmission operations, such as from a reader to a tag, a tag to a reader, a reader to a select group of tags (multicast) and one tag to another (unicast).

Ultra-wideband RFID is typically used for asset tracking, Geiger counter systems with handheld readers, and RTLS solutions. Until now, the technology has been provided by companies as proprietary systems. That, however, is not always desirable for end users, according to Michael Liard, an analyst at VDC Research. "Customers want standards-backed technology," he says.

The objective with standardization was simplicity, Harrington says, and the IEEE 802.15.4f Task Group thus spent two years working to develop a standard that would make the technology low-cost to manufacture, with no custom chips required, and that could provide a long read range with low power consumption. The PHY was designed to provide accuracy greater than 1 meter (3.3 feet), the ability to accomplish 1 Hertz (Hz) transmission rates, and a seven-year battery life for ultra-wideband systems.

The new standard, Harrington notes, will promote competition by allowing users to mix and match the technologies they employ in order to build an appropriate UWB or active RFID solution. Technology providers and users worked together closely on the standard development, he reports, adding, "It was a very cooperative effort" that benefits all technology providers. "If the (active RFID) industry grows, we all get a piece of that (growth)."

"This is an example where vendors find some common ground in a collaborative way," Liard states, that is likely to benefit the UWB and active RFID industries, as well as end users. Customers, he adds—particularly large "tier-one" organizations—prefer a standard and are likely to be less comfortable with proprietary technology.

The Dart sensor is presently being used by companies within the aerospace industry, such as The Boeing Co., to track high-value and specialized tools used for building aircraft. West Cheshire College, located in the United Kingdom, is utilizing the technology to track attendance and monitor students' time in class. While Zebra has released the new open-standard version of the Dart sensor, it intends to offer new 802.15.4f-compatible tags in the near future.

The new Dart sensor does not vary in performance or features from its predecessor, Harrington says. "The focus for our latest DART product was to ensure it was hardware-compliant with the new standard, ensuring full compliance via a simple software upgrade," he explains. "UWB products that are not hardware-compliant will need to be physically replaced to be compliant with the new standard. Zebra's focus is on ensuring the lowest total cost of ownership for our customers, while ensuring they do not suffer any major downtime as they adopt the new standard."

Zebra also offers the Dart Vision Reader (DVR), a standalone unit housed in an all-weather enclosure and designed for use in outdoor environments. The DVR, which is compliant with IEEE 802.15.4f, can be used in conjunction with Dart sensors when a deployment requires both indoor and outdoor tracking.