In recent years, the maturing of RFID and Cloud computing have followed a similar trajectory from niche specialism to mainstream business tools. Their convergence forms a key part of the emerging concept of “The Internet of Things” where network enabled, geo-located objects and sensors provide the input for an array of imaginative software solutions touching all aspects of our lives.
Using web based software to track and trace RFID enabled objects around the world is an extremely powerful concept and it is one that we have sought to deliver to our customers. Waer Systems has a long history of solving complex business problems through our Cloud based software. Waer’s RFID architecture is a modular system that is designed to complement our core offering and it can also be deployed independently and interfaced directly to other systems. How this is achieved, is down to the cloud based architecture of Waer’s solution.
When we designed our RFID module, we wanted to make sure that it fitted into our existing cloud architecture. This would provide a number of key benefits for our customers:
- Global visibility – The primary user interface is the web browser and so the system is available to anybody anywhere with a web-enabled device.
- Software as a Service – Because the software engine is hosted by Waer, all updates and enhancements are managed centrally by Waer and these can be rapidly rolled out to a global user base.
- Reduced hardware overheads – Because the software can be purchased as a service, there are no expensive investments in Server hardware and its corresponding maintenance.
- Scalability – Cloud based services are inherently scalable. Additional server power can be added and taken away with ease. New devices can be brought into the network and physical locations brought on-line with minimal effort.
- Integration options – With the software being designed for operation in the cloud there are lots of options for integration using XML and other technologies.
Our approach to the architecture was therefore driven by ensuring that it was cloud based, open and extendable.
RFID Cloud Architecture
To implement our cloud based architecture we broke it down into discreet elements that would exist independently of one another:
- RFID Tags
- RFID Gates – Incorporating Antennas and Readers
- RFID Gate Server
- RFID Handheld Devices
- WAERlinx – Incorporating core WAERlinx, WAERconsole and WAERflow
Two key considerations for exposing these elements in the cloud are security and availability. We took steps to secure the hardware and software to make sure that information was only available to registered users within our software. To ensure availability we have implemented monitoring software and built in redundancy and failover to the hardware platforms.
A key objective in the design of our RFID solution is that it is interoperable with other systems on a global scale. For this reason it was critical that we adopted internationally recognised RFID tag encoding standards for our application. The obvious choice was the EPC Gen 2 standard which is the internationally recognised standard for UHF RFID item encoding.
This standard is controlled by GS1 and embodies a number of different encoding standards depending on the nature of the items being tracked. For part number/service identification, for example there is the Global Trade Identification Number (GTIN) and for asset life-cycle tracking there is the Global Individual Asset Identifier (GIAI).
We therefore adopted this standard and based our tag and RFID hardware selection decisions on it. A key feature of the standard is that it is specific to UHF technology. UHF is the default choice when choosing RFID technology because of its long read range and as a result the choice of tags and hardware that support it is extensive.
RFID Gates are made up of one or more antennas attached to an RFID reader. RFID readers generally have 2 or more antenna ports. As an RFID tag passes through the antenna field, it is picked up and read by the reader. The reader can be configured for the environment in which it is working, the tag frequency for example or the read-range can all be set with the reader. It also handles some low level issues such as read collision.
The reader will capture the scans but in order to be of use in a cloud environment, they need to be made available over the internet. To enable this we use the Low Level Reader Protocol (LLRP). This protocol is designed to provide a common network interface to RFID devices and as such it is ideally suited implementing cloud based solutions. As long as the reader can be reached over the network then its captured reads can be interrogated by application software which, in the case of the Waer solution, is the RFID Gate Server.
RFID Gate Server
The RFID Gate Server is a cloud based Web application which allows the operators to use and maintain the RFID gates. A single gate server controls all the gates in the network. Users can log into the Gate Server application at a given location and use it to interact with an RFID gate. If the gate is an operator driven gate, the operator can review the captured scans and then process them.
System administrators can use the gate server to create new gates and maintain existing ones. We provide several different options for how gates can be set up:
- Interactive – In interactive mode, an operator manages the gate, validating the scans and selecting processing options for the captured data.
- Autonomous – In autonomous mode the gate will process all the scans received without any interaction from an operator.
- Directional – a directional gate is like the autonomous gate except that it can detect whether the movement is inbound or outbound. This is achieved by using multiple antennas and using the timestamps of when the tag is read by each antenna to determine direction.
To make the architecture extendable we chose to separate the RFID Gate Server from core WAERlinx and deliver it as a separate autonomous module. This would give us the option to integrate it with other applications without needing to use our core engine. We therefore used XML over HTTP as a standard interface mechanism for the Gate Server and built a web service in core WaerLinx to interface to it.
RFID Handheld Reader
Handheld RFID readers are necessary where the container is too large or heavy to go through the RFID gate or the environment is not suitable for a fixed gate. This might be the case if the site in question belongs to a 3rd party that is unwilling to install a fixed gate. A further feature of these devices is that they can be GPRS enabled so that they can be used in areas with limited access to standard wired and wireless networks. We designed the software running on these devices to operate in store/forward mode so if there is no access to any network at a specific location, for example a difficult environment such as one might find in mining, they can still be used to perform operations and then the scans can be transmitted later once the device is back in range of a network. They are also the preferred option when it comes to taking an RFID based stock count.
For our handheld application, we use the same XML interface as the Gate Server meaning that the handheld application is equally extendable.
Once the scans are captured in WAERlinx, all the power of our core product can be brought to bear on the management of the supply chain. As this application is delivered over the internet using the web browser, it completes the cloud solution for the RFID platform.
All of the functionality to support the movement of items and the stock-count process is found in core WaerLinx. XML requests are received from the Gate Server and Handheld scanners; they are processed and the system returns a response back to the calling device. This is where the more complex features like service management and alert handling are brought into play. The bulk of system maintenance is handled within the core product. Users can import new items into the application and create new sites and locations to move them into.
Using WAERconsole, operators can run detailed reports and enquiries on the supply chain that they are supporting. They can run a wide range or reports including the inventory position and transaction history against the various items. These reports can be displayed graphically as KPIs and are available on a range of devices including tablet and smart-phones.
WAERflow is our integration platform which enables information sharing between systems. This component can be used to interface data between partner systems to further extend the reach of the system.
A successful implementation of RFID in the Cloud needs some key ingredients:
- Internationally recognised RFID encoding standards should be adopted
- Each individual element needs to be able to stand-alone as an independant networked device
- Each networked device needs to be effectively secured
- Each networked device needs to be monitored to guarantee uptime
- Sufficient redundancy and failover needs to be built into the solution
- RFID gate configuration needs to be flexible to allow a variety of operational options
- GPRS and Store/Forward techniques can extend the reach of RFID to inhospitable environments
- LLRP can be used to communicate between RFID readers and cloud based application software
- RFID needs to be underpinned by great application software to really deliver its benefits
- That software needs to have good integration capabilites to extend the RFID benefit to other systems