BLE or RFID? - Things to consider before you decide for your hospital
A hospital RTLS primarily is a software that uses wireless technologies e.g. RFID, BLE or UWB, to provide you real time indoor location intelligence (for example, which asset is currently in which zone?) for your hospitals. Most RTLS vendors tie their software to a specific technology, which means deciding vendor itself selects the technology. But is the optimal? Would you not like to understand the cost-benefits independently before you let your vendor choose for you?
When it comes to hospital RTLS, hospitals in US have predominantly adopted RTLS based on RFID though cost is very high. It's also true that RFID (especially active RFID) based RTLS is there for a very long time. BLE in fact is a recent addition. Interesting thing is both BLE and active RFID uses 2.4 GHz band but while BLE standard is open, active RFID is often proprietary and therefore costlier.
Understanding RFID
RFID is wireless radio frequency (RF) based standard and works on multiple RF bands, designated as LF (Low Frequency), HF (High Frequency) and UHF (Ultra High Frequency). Accuracy and speed increases from LF to UHF. Main components of this technology is RF Tag, RF Antenna and RF Readers. RF Tag can be active which means the tag has a battery and sends data on its own. Passive RF tag on the other hand is without battery and it can only send the data using the reflected RF energy (from the reader). The advantage of passive RF Tag is that it has almost unlimited life (no battery replacement) and also costs 10 times less than an active RF tag. To read passive RF Tags, the RFID reader must use high-gain antenna.
UHF RFID operates at 860-930 MHz (For India designated band is 865-867 MHz) but the high gain makes it a little unattractive to use in radio-sensitive places inside the Hospital.
RFID protocols were designed for reading inventory which makes it little difficult to employ it for indoor location tracking in real time. Given the high cost of UHF RFID readers (above USD 1,000), building RFID infrastructure for a hospital is often prohibitively expensive. While most leading vendors started supporting WiFi in the their RFID readers in latest products, old models typically do not support WiFi, which means it needs its separate network making the installation expensive. For a medium-sized hospital, RFID infrastructure costs have been reported between $200,000 and $600,000, depending on the facility's size and specific requirements.
Due to high cost, a hospital typically uses only a few fixed Reader placed at strategic location to cover entire floor area. But that also brings down effectiveness of tracking. Large inaccuracy of location with RFID based RTLS is a common refrain.
How BLE is different?
Most Hospital RTLS employs active RFID hardware which typically uses the regulation-free 2.4GHz. This is the same frequency band that is used in Microwave Ovens all over the world, as well as Bluetooth Devices and basic WiFi network. Given the low power gain used, it is considered safe.
BLE stands for Bluetooth Low Energy and is used in sensor network ubiquitously. Being lightweight, the devices come with very small form factor. BLE works in the same way as active RFID. But since BLE standard is open, BLE devices have proliferated a lot faster. That effectively has brought down the cost of BLE tags and BLE gateways. BLE gateways cost 10 times lesser than a RFID reader and it can use the hospital's WiFi network which in turn brings down the overall installation cost for BLE based RTLS.
For a 40 room hospital, it was reported to cost below USD 100K. However, we should remember, the cost of BLE tags are higher compared to passive RFID tags and battery of a BLE tag typically needs replacement every 1-2 years.
Active RFID vs BLE
Both of them need battery which means it requires periodic battery replacement. Additionally active RFID devices and tags are relatively more costly. More importantly vendor lock-in is one major aspect of using active RFID hardware. In comparison BLE devices are available off-the-shelf and can be upgraded / replaced with different vendor's products at ease without any service downtime.
A ready comparison chart
| Feature | UHF RFID | BLE |
|---|---|---|
| Frequency Band | 860–956 MHz | 2.4 GHz |
| Range | Up to 100 meters (depending on tag and reader / antenna) | less than UHF RFID |
| Data Rate | Up to 640 kbps | Up to 2 Mbps |
| Accuracy | Typically within a margin of a few meters. Passive tags sometimes are missed by the Readers during periodic scanning | Better than RFID. BLE Tags send the data themselves - eliminating the issue of missed scans. |
| Power Consumption | Passive tags require no power; active tags have batteries | Low power consumption; suitable for battery-powered devices |
| Cost | Passive tags are cost-effective; active tags are more expensive | Generally low-cost due to widespread adoption |
| Typical Applications | Asset tracking, inventory management, supply chain logistics | Asset tracking, personnel monitoring, proximity marketing, indoor navigation |
| Tag Cost | Passive UHF RFID tags: Approximately $0.10 to $0.50 per tag. Active RFID tags: Approximately $5 to $15 per tag. |
BLE tags: Approximately $2 to $10 per tag. |
| Reader/Gateway Cost | Fixed RFID readers: Approximately $1,400 to $8,000 per unit.
Handheld RFID readers: Approximately $1,000 to $4,500 per unit. |
BLE gateways: Approximately $100 to $500 per unit. |
INDTRAC Approach
INDTRAC promises to work with almost all leading BLE and passive UHF RFID readers. INDTRAC also qualifies vendor hardware before they are recommend to you so that you can choose the technology most suited for your use case and budget without any worries. For BLE tags, INDTRAC proactively monitors the battery and alerts you to replace the battery when a tag battery loses the power. BLE tags mostly use ubiquitously available low-cost coin lithium battery which makes the replacement cost very marginal.
There is another advantage with using BLE -- you can seamlessly use the RTLS to monitor zone-wise temperature, humidity or VOC almost at the same expense as that of asset tracking infrastructure.
