Asset Tracking: BLE-based RTLS Solution vs Passive RFID

Asset Tracking: BLE-based RTLS vs. RFID

April 20, 2022

Will Sanderson

Just about every industry has a need for asset tracking and IoT affords enterprises this capability. Whether it’s keeping track of high-value equipment in pharmaceutical settings or clothing inventory in retail, enterprises depend on the data of their assets’ locations in real-time for operational purposes.

Real-Time Location Systems (RTLS) can help many enterprises, but, while the task seems simple enough, the ability to keep track of assets in real-time is complicated.

That’s because there are so many variables at play like range, hardware costs, and location accuracy desired. There are two leading technologies that enterprises typically consider for wireless RTLS – passive RFID (radio frequency identification) and BLE-based (Bluetooth Low Energy). Each has its advantages and disadvantages, but BLE shines when the ability to accurately pinpoint a high-value asset’s most current location is at play and a requirement for enterprises.

A Tale of Two Technologies 

Deciding whether to standardize on a BLE-based RTLS or passive RFID involves some tradeoffs since both technologies have pros and cons.

Passive RFID  

RFID is a popular option because the technology uses low-frequency tags, which do not require batteries. As a result, tags are inexpensive. Plus, passive RFID offers inconspicuous form factors, is easily deployed, and can track assets of any size or value. Therefore, many enterprises equate the cost-effective tags to a lower-cost RTLS solution. But in many scenarios, that’s not the case.

Passive RFID is an ideal asset tracking solution when cost-per-asset is the priority—thanks to its low-cost tags—and when assets only need to be tracked at specific checkpoints. The tracking capabilities of a passive RFID solution are generally event-based and provide only a snapshot of an asset’s location—meaning it can tell you if an asset is in a room (or not), but it can’t provide the precise location at any one moment in time. For example, if an enterprise is looking for an IoT solution to prevent theft in a retail store, RFID is an attractive option from a cost, asset tracking and infrastructure perspective. That’s because you only need inexpensive RFID tags on each asset and a single gate at the entrance of a store which serves as a “chokepoint” to identify when an item passes through a location. An alternative option to using gates is to utilize wands, which employees use to scan a tag to locate an asset.

However, consider an enterprise looking to track the latest location of portable assets across a large multi-building campus. A passive RFID solution would struggle to provide the level of accuracy needed because it would only be able to track whether an asset is in a specific room or building, but not its exact and most current location (i.e., southwest corner of a room). Supporting room- or building-level accuracy, like in the retail theft example above seems cost-effective, but to obtain the level of specificity needed to effectively track assets across a large, multi-building campus requires more infrastructure costs—either additional chokepoints (i.e., gates) or employees’ time (i.e. if using wands)—and additional connectivity costs. While room-level accuracy is possible with passive RFID, the trade-off—low tag costs for high infrastructure and/or OPEX costs to manage an RFID solution—makes passive RFID a costly option for RTLS in the long run.

Bluetooth Low Energy (BLE-based) 

BLE (Bluetooth Low Energy) is a low-power wireless technology that’s especially suitable for short-range communication and ideal for use cases where longer battery life supersedes data transfer speed.

BLE-based RTLS systems include two primary components – the static “locator” which defines a location and the dynamic “tag” which is attached to the asset needing tracking. In the MachineQ architecture, the BLE asset tag “beacons” to the location bridge (or locator), which captures the data and backhauls it to our gateways wirelessly over LoRaWAN®. Because of the RF characteristics and low infrastructure costs associated with BLE-based solutions; it is able to surpass RFID in terms of location accuracy. Additionally, while BLE tags require batteries, they are inexpensive and last far longer than competing protocols such as ultrawide band (UWB), making BLE an attractive option for reducing long-term total cost of ownership (TCO).

comparing enabling technologies for asset tracking

This helps explain why the number of BLE tag form factors has exploded in recent years. These tags are used for a variety of applications within healthcare facilities, warehouses, construction sites and factories. BLE can be used to track items as well as people – workers in construction zones, patients in healthcare hospitals, and visitors in office buildings.

For example, a BLE-based RTLS solution is more suitable for a life sciences company looking to track portable lab equipment across a large campus because BLE offers exceptional location accuracy down to a sub-room level. Tags are placed on the assets, which transmit a signal that’s picked up by location bridges. The location bridges are mounted in fixed locations and assigned coordinates. Therefore, if an asset moves from one room to another, the wireless signals heard by the location bridges will change and the system can identify the new and most current location. This provides enterprises with better access to real-time location data. If the same life sciences company utilized a passive RFID solution, there would need to be chokepoints placed in each room to denote that the item has passed into a new room, but it would only be able to provide its last known position and not its most current and exact location.

There are many different use cases for asset tracking and different wireless technologies that are right for the job. If there is a need for more event-based tracking (like the retail example above), then passive RFID is a suitable solution. But if you need to know the most current location, in an automated fashion, with a high level of accuracy—like the life sciences example above—a BLE-based RTLS solution is the right choice for the job.

Not all RTLS solutions are equal or suitable for your enterprise needs. Contact us at info@machineq.com to ensure you’re fully understanding the options available.