RFID Tag Collision And What You Can Do To Prevent It
Radio-frequency identification has become an integral technology for a wide variety of tracking purposes, and many industries now rely on them for RFID inventory management and all kinds of other processes. While RFID continues to improve and is better than ever before, there remain certain challenges that organisations must be aware of when planning to implement it for their own applications. Chief among these is collision, which typically occurs in dense and dynamic environments that use lots of RFID tags and readers.
Read on to learn what this potential issue entails and the approaches to overcome it.
What is RFID Tag Collision?
RFID collision happens when an area that is saturated with RFID devices causes the signals to interfere with each other, resulting in delays or errors in communication and identification. This ultimately reduces the efficiency, accuracy, reliability, and overall performance of the RFID system in use.
RFID tag collision specifically refers to the phenomena of multiple tags causing interference by simultaneously responding to a fixed or handheld reader’s query. This issue becomes incredibly problematic when deploying readers in high-volume environments such as retail stores and warehouses where it is common to use tags that share the same frequency, antenna design, and receiver sensitivity.
To better understand why this happens, we must first learn about the mechanics behind the scenes. An RFID reader essentially creates an electromagnetic field whenever it sends out a query signal, and the nearby tags within it then respond with their unique identification data. Having numerous tags in such close proximity increases the likelihood of data collision from their concurrent response, resulting in the reader receiving incomplete or corrupted data that makes it difficult to accurately track down items.
How To Prevent Tag Collision
RFID tag collision can be attributed to several factors, the primary being the tags’ inability to coordinate their responses. Apart from inherent technology limitations of the chosen tags themselves, environmental variables like signal interference from other RF devices, liquids, and metals can also exacerbate the issue. Thankfully, there are several ways to resolve and completely avoid this issue, and these include:
1. Using anti-collision software
One foolproof way of preventing tag collision problems is to use advanced algorithms designed for anti-collision mitigation. These protocols give readers the capability to communicate with many tags in sequential order to significantly mitigate the odds of receiving simultaneous responses. Examples of these include the ‘Binary Tree’ and ‘Query Tree’ algorithms which have long been proven to be efficient at managing tag responses and are immune to the starvation problem wherein some tags don’t get picked up or identified.
2. Optimising item placement and the environment
Something as simple as streamlining the physical placement of tags can greatly reduce interference issues. It is also worth considering implementing some form of signal-dampening or shielding materials in hot spots where collision tends to occur to enhance the RFID system’s performance. Last but not least, it is recommended to perform extensive testing and optimisation on the system itself during the deployment stage to identify and address potential collision problems before rolling out full-scale implementation.
3. Adjusting tag power level
Making power adjustment to RFID readers and tags may help create a controlled reading environment that reduces the chance of tag collision from happening. This is because it delays that tag response for several milliseconds and allows the reader to identify them one by one.
Conclusion
Preventing RFID tag collision is crucial to ensuring smooth and efficient operations in environments where multiple RFID tags are present. By implementing strategies such as adjusting the reader’s power, utilising anti-collision protocols, and properly spacing tags, organisations can significantly reduce the risk of collision and maintain data accuracy. Adopting these practices will help ensure that RFID technology continues to deliver its full benefits without unnecessary disruptions.
