A lot has been said about “supply chain visibility” over the past decade, however, the reality is that the technologies necessary to provide real time supply chain visibility are only just emerging.

Technologies such as conventional passive RFID, and the use of mobile computing devices like RF and Voice terminals, can provide a degree of visibility, but they are generally transactional-based.

That is, they only provide real time data at the precise moment the transaction occurs. By its very nature, logistics is a dynamic process.

People, stock, vehicles, equipment and, importantly, information are constantly on the move. Having access to real time information is obviously more important in some areas than others.

Take healthcare, for example. If certain medical equipment or supplies are required urgently, any delay in finding the equipment or supplies could be life-threatening. Because of this, the healthcare sector has been one of the pioneers in the use of new Real Time Locating Systems (RTLS), including Wi-Fi-enabled Active RFID tags and Unified Asset Visibility (UAV) software.

Other industries that have been quick to realise the benefits afforded by RTLS include manufacturing, defence and logistics/transport.

Wi-Fi-enabled RFID Developed by US-based wireless IT specialist AeroScout, Wi-Fi-enabled RFID tags use existing Wi-Fi networks as the core for a host of visibility data, providing a cost-effective method of implementing RTLS. 

Wi-Fi-enabled Active RFID tags can also include sensors to detect events such as motion and temperature changes, extending their functionality. Active RFID tags provide location accuracy to within a couple of metres.

For applications requiring more accurate location details, down to less than one metre, AeroScout Exciters provide highly configurable ‘choke point’ detection capabilities.

Exciters trigger very precise and immediate notification that a tag has passed a certain threshold (like a doorway or a gate). RTLS can track assets indoors, outdoors, or in a mix of indoor/outdoor environments.

Radio signals perform differently indoors versus outdoors, so different location determination algorithms must be used.

Unified Asset Visibility (UAV) Software One of the hurdles to achieving supply chain visibility has been that there is no single “right” technology for visibility – most businesses have complex needs that often require a combination of visibility methods for multiple uses.

For example, Wi-Fi RFID is best for asset tracking across large enterprise facilities, while Ultra-Wide Band (UWB) provides high accuracy in small areas, and Passive RFID provides auto-identification of high-volume items, and then there are technologies like GPS and GPRS, which also have an important role to play in enabling supply chain visibility.

Also developed by AeroScout, UAV consolidates data relating to the location, condition and status of mobile assets from multiple data sources into a single integrated solution, giving users the ability to view their supply chain in real time like never before.

UAV takes real time data from a variety of sources including Wi-Fi networks, LANs and WANs, GPS equipped devices, GPRS, and emerging technologies such as UWB and choke points, and displays it all in real time on a standard web browser.

AeroScout’s MobileView software provides real time locating data based on both Time Difference of Arrival (TDOA) and Received Signal Strength Indication (RSSI) methods, enabling accurate location monitoring in both indoor and outdoor environments.

Real Time Real Life Applications In manufacturing, RTLS can be a valuable tool in helping to identify batches of stock to facilitate efficient handling and distribution, with the car industry being an early adopter, using RTLS to locate specific vehicles in massive car parks containing thousands of cars which all look the same!

Dematic is currently working on its first RTLS project involving the use of Wi-Fi-enabled RFID tags and UAV software for a customer in China.

The customer operates a fleet of 230 forklifts and over 600 pallet trucks, and has more than 22,000 people on its 670,000 sqm site.