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Why prefer RFID over BLE for sensor applications?

  • Abhishek Shukla
  • Aug 30, 2023
  • RFID
RFID over BLE for sensor applications

“A short answer to this question ‘Why prefer RFID over BLE for sensor applications?’ would be, ‘because RFID is cost-effective.’ While BLE beacons cannot work without batteries and require maintenance, passive UHF RFID tags can be used as sensors at extremely low costs.”

When it comes to item-level tagging, Radio Frequency Identification (RFID) technology has established itself as the prominent technology in AIDC. In the retail sector, RFID tags are used for item-level tagging, identification, and tracking. RAIN RFID tags are used on items, pallets, and supply packages which provide enhanced visibility inside warehouses and enable real-time tracking. 

BLE, on the other hand, is a wireless Bluetooth LE technology that uses Bluetooth low energy standard for transmitting low-energy, small packets of information at low data rates while using low power. Low Power consumption is an inherent feature of BLE specification. Nonetheless, BLE beacons operate on batteries. Unlike Passive UHF RFID tags, BLE beacons provide periodic advertisement with response (PAwR). This exact feature is used for BLE sensing applications.

With the wearable market size at 61.30 billion USD in 2022 and 71.91 billion USD in 2023, which is expected to grow at a CAGR (compound annual growth rate) of 14.6% between 2023-2030, the wearable market is expected to reach 181.14 billion USD by 2030 (Grand View Research).

RFID Tags as Sensors

Apart from identification and data capture, RFID tags can also be used for sensing applications. UHF passive RFID tags are designed by encasing a silicon microchip and antenna. When an RFID tag antenna detects an RF signal coming from an RFID reader, it uses this signal to power the IC. The tag then sends the encoded data to the reader which decodes it for the end-users. For sensing applications, the microchip is programmed to sense temperature, humidity, fill level (in bins), toxic gases, etc. The sensing data is coupled with the unique tag ID which allows for accurate sensor data from each RFID tag.

In chipless RFID sensors, however, sensing application is not carried out by a microchip. Instead, chipless RFID tags don’t use a silicon microchip but use linear encoding methods like TDR (Time Domain Reflector) encoding and Frequency Domain encoding techniques to store information. Chipless RFID sensors are designed by using extremely sensitive materials such as iconic plastic crystals, conductive polymers (PEDOTs), and nanostructured metal oxide. These materials are extremely susceptible to environmental changes such as temperature, humidity, etc. 

RFID sensor tags are extremely cost-effective as chipless RFID tags are designed to be cheaper than passive UHF RFID tags that cost around 4-5 US cents (INR 3 onwards).

BLE Technology and Sensors

Bluetooth Low Energy technology is the preferred choice in wearables. With the widespread use of smartphones, these wearable devices can easily send the sensing data on the user’s smartphone which also comes with built-in BLE technology.

Many wearable devices such as smartwatches, smart wristbands (Fitbits), headwear, eyewear, footwear, neckwear, bodywear (vests), and others are small devices and since BLE technology is the most suitable due to their small form factor, most of these devices use BLE for sensing applications. 

Wearable devices are able to sense heart rate, blood glucose levels, blood-oxygen saturation levels, and other health-specific parameters and display it on the device itself or send the data to users’ smartphones. BLE technology is the perfect technology for transmitting small sensing data, periodically for as long as need be. 

Since BLE technology consumes extremely low power, BLE offers a long life to such battery-operated devices, say 5-6 years. Some devices such as smartwatches and wristbands can be charged using a USB cable as well.

Why prefer RFID over BLE?

Now that we know how RFID and BLE technologies are used for sensing applications, it is fair to say that BLE is most suitable for wearable devices but RFID sensor tags are most suited overall. The sensing feature is embedded inside the RFID sensor tags and these tags are extremely low costs. 

Let’s see some more reasons why RFID is a preferable choice over BLE for sensing applications:

Power Efficiency

One of the significant advantages of RFID over BLE beacons is its power efficiency. RFID tags are passive devices that do not require a power source of their own. They are powered by the energy emitted by RFID readers during communication. This power-efficient mechanism enables RFID tags to have a longer lifespan and eliminates the need for frequent battery replacements. 

In contrast, BLE beacons rely on batteries, which need to be periodically replaced or recharged, making them less suitable for applications where battery life is critical. Batteries effectively reduce the overall lifetime of the wearable devices that are used for sensing applications even though these devices can last 3-4 years. 

Scalability and Cost

RFID technology offers superior scalability and cost-effectiveness when compared to BLE beacons. RFID systems can support a large number of tags simultaneously, making them suitable for applications that require sensing at various points at once. With large amounts of data coming in from multiple sensor tags frequently, RFID performs better than BLE.

Moreover, the cost of RFID tags has significantly reduced over the years, making them more affordable for large-scale deployments. BLE beacons are costly. Sensing devices that use BLE technology are more costly than an RFID sensor tag, limiting their scalability and affordability.

Security and Privacy

Lastly, RFID technology offers better security and privacy features compared to BLE beacons. RFID tags can be encrypted and secured using various authentication protocols, ensuring that only authorized readers can access the information. RFID tags can be easily concealed or embedded within objects, enhancing their security.

 BLE beacons, however, are more susceptible to unauthorized access or tampering due to their broadcasting nature. BLE beacons broadcast data using the 2.4GHz frequency band which can be captured by many smartphones at once. 

While both RFID and BLE beacons have their merits, RFID technology emerges as the preferred choice for sensor applications due to its extended range, power efficiency, scalability, cost-effectiveness, security, and resistance to environmental interference. RFID sensor tags are the preferred choice for sensing applications such as waste bins (sensing fill-level), outdoor temperature sensing, sensing the body temperature of livestock and pets, tagging food items, and monitoring humidity and temperature during transport and storage of such perishables, etc, BLE would be a way to costly for such applications. 

Disclaimer: The information presented here is for general information purposes only and true to best of our understanding. Users are requested to use any information as per their own understanding and knowledge. Before using any of the information, please refer to our Privacy Policy and Terms and Conditions.

  • Created on Aug 30, 2023
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