By Mary Catherine O'Connor
June 18, 2007—Two providers of
RFID-based real-time location systems for
asset tracking have announced the addition of
GPS technology to their offerings. Santa Clara, Calif.-based
WhereNet has introduced GPS capabilities to version 4.0 of its Marine Terminal Solution, a hardware/software package for tracking cargo containers in a marine terminal environment.
Identec Solutions, based in Lustenau, Austria, has added GPS to its I-Q
RFID tag. Both companies say the addition of GPS technology will enable end users to track high-value assets even when the installed RFID technology is unable to provide visibility at the granularity they require.
WhereNet Marine Terminal Solution version 4.0 employs active 2.4 GHz tags that comply with the
ISO 24730 standard for real-time location systems. The solution determines the asset locations not by placing RFID tags on cargo containers, but by deploying tags on the large mechanical arms the container-handling equipment uses to move containers from place to place in a marine terminal. WhereNet location sensors, installed throughout the terminal, determine the location of the WhereNet tag (WhereTag) on the container-handling equipment. The Marine Terminal Solution then associates this data with a timestamp of when the equipment sets down a particular container. The WhereNet system identifies each container by pulling its ID number from the
optical character recognition camera attached to the crane.
Under this system, WhereNet can ensure location accuracy within 4 feet—which is plenty for finding cargo containers 8 feet wide. By adding the option of using GPS receivers to locate the containers, WhereNet can provide its real-time location system to customers unable to install all of the WhereNet location sensors needed to locate an asset to within 4 feet. To collect the GPS data, WhereNet combined a GPS receiver with a WhereTag
active tag. The tag is housed together in a WhereTrack controller, which also contains a
Wi-Fi modem. The modem is used to upload applications to the
microprocessor, and to send the GPS data over the WhereLAN network of Wi-Fi locating access points, along with the tag ID and the crane's operational data, needed to determine when a container was set down. For sites without Wi-Fi coverage, the controller uses WhereLAN's ISO 24730 2.45 GHz channel for communication back to the location sensors.
In the past, says John Rosen, WhereNet's director of product marketing, companies might have picked GPS-only tracking systems over WhereNet's
RTLS in marine environments. One reason, he explains, is that they lacked the light poles or other tall structures needed to install enough location sensors to accurately determine the crane arm's location (and, thus, the container location). Rosen hopes that offering the use of GPS receivers to collect location data will make WhereNet's Marine Terminal Solution attractive to a larger pool of terminal operators.
In addition, WhereNet has modified its Visibility Software Server (VSS)
middleware to be able to process GPS coordinate data and link that data to the WhereNet container-tracking application software. Rosen notes that the WhereTrack system provides a means for companies currently using GPS-only systems to increase the visibility of containers as cranes place them in areas where obstructions created by buildings or ship births prohibit the clear line of sight to satellites required by GPS receivers. "We are seeing some sites where a hybrid installation of GPS and RTLS might be the best solution," he says.
Peter Linke, president and CEO of Identec Solutions, says that Identec decided to create a new
tag with an integrated GPS receiver—which it calls the GPS tag—partly because recent advances in GPS receiver technology have reduced the amount of battery power the receivers require. This means the company could add the capability to capture GPS data without appreciably reducing a tag's battery life.