THE introduction of mobile RFID (Radio Frequency Identification), either as PDA scanners or vehicle-mounted devices is leading to significant productivity improvements in the supply chain.
In contrast to ordinary RFID implementations consisting primarily of fixed readers, mobile RFID typically requires the deployment of fewer readers, often less than a dozen.
Mobile RFID readers have become an integral part of the supply chain in most manufacturing enterprises, resulting in considerable cost savings.
The benefit of mobile RFID lies in its ability to provide a clear and accurate view on the inventory in the warehouse.
Beyond inventory insights, the latest RFID technology adds an important element to the data now available to enterprise applications: the location of an object.
This technology is known as Real Time Locating Systems (RTLS). Based on a variety of locationing technologies, RTLS literally determines the location of an object.
An additional technical challenge for real time locating is not just to know where an object currently is, but in which direction and how fast it is moving.
The result is not merely a momentary indication of location, but the basis for tracking and tracing in the production sequence and warehouse.
How does RTLS work?
RTLS tags are typically battery-powered and regularly send out a RF signal. Several mobile scanners read the tag data, which transfer the position of the tag using amplitude, time-of-flight, or differential time-of-flight information to the RTLS system.
Via a RTLS connector, the RFID middleware system forwards the device position data to the custom business module or Location Information System (LIS), the same system that also receives the inventory data from the mobile device connector.
Other RTLS approaches are available and include GPS, WiFi and optical sensing systems. Each of these technologies has different use scenarios, location accuracy, and implementation strategies.
GPS systems are best suited to applications out in the open, such as in a trucking yard or the highway.
WiFi and optical systems are best suited to environments under cover such as warehouses and hospitals.
Each of these technologies will also offer different location accuracy: GPS systems are accurate to 1 to 10m; optical locationing systems can be accurate to ± 5cm.
Middleware software, such as Sybase RFID Anywhere, supports many RTLS technologies, including RFID, WiFi, GPS and optical solutions, in a web-based, SOA (Service Oriented Architecture) environment.
The middleware correlates data from the mobile device connector with the RTLS connector to identify the current position of the tag read by mobile devices in the warehouse.
RTLS – The Logical Evolution Of RFID
The ingenuity of tracking goods, tools and people in the supply chain is obvious: has a container been moved since arrival? Has a box been delivered to the wrong aisle or production hall? Where are my staff at the moment? RTLS helps you answer these questions.
ABI Research, a leading international analyst firm in enterprise mobility, sees strong demand for RTLS applications in the supply chain in 2008 and beyond. According to ABI, asset tracking and RTLS are the two major factors driving global RFID revenues up from US$3.8bn in 2007 to US$8.4bn in 2012.
RTLS provides real-time insights into production sequences and not only helps keep track of everything of value on site, but enables you to correct truck and container movements, use your workforce more efficiently and synchronise replenishment of the production line.
RFID vs WiFi RTLS
Maturity and standardisation of WiFi networks have sparked a discussion about the benefits of RFID-powered RTLS compared to RTLS over an existing 802.11 wireless network. Fact is, we find both RFID and WiFi-enabled RTLS tags being successfully used in the field.
Although WiFi is gaining in popularity as a preferred standard in some industries such as mining and healthcare, RFID-based RTLS tags are the dominant standard in the manufacturing, retail and logistics industries.
For a good reason: once an RFID system is in place, the costs of upgrading to RFID-based RTLS can be low. A tag typically costs less than a quarter of its WiFi-enabled cousin.
Another rationale is location accuracy: RFID-based RTLS solutions can have a long communication range of 50 to 100m. With the ability to locate tags within 3m they can be more accurate than WiFi-based RTLS.
Together, mobile RFID and RTLS make a winning team to ensure productivity improvements in the supply chain and secure future growth for Australian manufacturers.
* Steve Dolan is director channel & alliances, Sybase Australia/NZ.