Indoor asset tracking is coming to mainstream now. Whether in hospital, or in warehouse, people are realizing that there are certain benefits that they cannot ignore any more in their business context.
But before you adopt it, would you not like to understand what it takes to implement? Of course there is this software called Real Time Location System (RTLS) but what about the tags? This is an attempt to make it simpler for you to decide.
Many Tag technologies
Every asset tracking system requires tags to be fixed on your assets. Now there are different tag technologies, like RFID, LoRA, BLE, UWB etc.
RFID can be both passive and active. Passive RFID tags do not have battery and therefore do not transmit by itself. RFID readers in vicinity sends search packets and the passive tags respond to them (they are passive after all!). Active Tags regularly send data which nearby Reader/Gateway captures. Sometimes people use Active RFID interchangeably with BLE or Bluetooth Low Energy.
So which tag should you choose?
The plain answer is it depends. For example, not all RTLS vendors support all tag types. In most cases vendors sell tags and other hardware as part of the full package solution. Other important factors depend on what you actually need.
Passive RFID tags cost the least among all of them but RFID readers some times miss reading passive RFID tags. In fact reading consistency is about 90%-95% for RFID readers with UHF antenna (UHF is the fastest among all the RFID system).
On the other hand UHF RFID readers are very expensive. Compared to that BLE devices cost magnitude cheaper. BLE is more accurate as well. UWB is the newest of the technologies and the technology is capable of precisely location an asset within a few centimeters. Hospitals traditionally went with RFID tags, many with vendor-proprietary active RFID solution. Proprietary solution makes you locked-in with vendor.
Incidentally INDTRAC RTLS works with almost all different hardware and tags and lets you change your tag system in future. For example, let’s say you decided to adopt BLE now. Later if you decide to upgrade to UWB, you can do that with INDTRAC.
Now coming back to relative benefits and costs. Typically UWB is the costliest solution at this point but offers most precise location articulation.
Here is a simple comparison chart for all the tags for quick reckoning.
| Feature | RFID | BLE | LoRa | UWB |
|---|---|---|---|---|
| Technology | Radio Frequency Identification | Bluetooth Low Energy | Long Range | Ultra Wide Band |
| Range | Short (~ 20 feet) | Short (~ 40 feet) | Very Long (~ 1 mile) | Long (~ 100 meters) |
| Accuracy | Low (~ 10 feet) | Medium (~ 2 feet) | Low (~ 100 feet) | High (~ 1 inch) |
| Power Consumption | Low | Low | Low | Medium |
| Tag Cost | $0.10 – $1.00 | $0.50 – $5.00 | $1.00 – $10.00 | $5.00 – $50.00 |
Summary
In summary, if you follow traditional solutions, you would use RFID. If accuracy is paramount for you, you would have to choose UWB. But in most cases, BLE serves both ends. It also offers relatively long battery life for tags. Gateways also do not cost as much as UHF RFID. They are also easier to install or replace. INDTRAC supports both Indian brands as well as international brands like Zebra , Impinj or INGICS .
