White Paper: Real-Time Location Tags for Enterprise Customers
By Charles Paumelle
Executive Summary
Apple AirTags, Tile trackers (the original tag, now enhanced by Amazon), or the Samsung Galaxy SmartTag+ are the current crop of contenders promising consumers the dream of “finding anything anywhere”. Enterprises looking at using these solutions for tracking their own things or people need to evaluate how they work and their suitability for their own use cases. This whitepaper describes how these consumer technologies work, their advantages, and some of the Enterprise-focused alternatives for indoor asset zoning or wide-area positioning.
Two dimensions of location
All location services require a way to assess the location of the object as well as a method to communicate that location over the Internet to the Cloud which will use and distribute that information:
How the location of the item is determined: absolute, declared or derived
How the information is brought back to the cloud: directly or indirectly
Absolute location of an object can be obtained from a system such as Global Navigation Satellite System (GNSS). This uses a network of geostationary satellites (e.g., GPS or Galileo) to communicate directly with a GNSS microchip on the object to calculate its current position expressed in Latitude/Longitude/Elevation (Altitude). Absolute location is well suited for moving objects with regular access to outdoors but is ill-suited for indoor objects.
Declared location is defined and simply entered by the owner or user of an object into a record, typically in an asset database or digital twin. Declared location is well suited for static objects, either outside or inside of buildings. Declared location can use Latitude/Longitude/Elevation or a more human-centric ontology such as “London / 123 High Street / 2nd Floor / Entrance hallway / Above door frame”.
Derived location is when an object is being located by one or more external devices whose location is pre-determined using the absolute or derived methods. It is well suited for moving objects with no geolocation capabilities of their own, for example Bluetooth beacons or RFID Tags. The more external devices report sight of this object, the more precise the derived location can be.
Direct connectivity requires the object to have its own Internet access, for example via Wi-Fi or cellular, allowing it to send its location information directly to the cloud. This is typical of smartphones, laptops or tablets for example.
Indirect connectivity allows the location data of objects with no direct Internet connectivity of their own to be sent to the cloud using another object with direct connectivity acting as a “bridge” to the Internet.
Location data ownership and access are a final major consideration. For example, Apple currently only allows the single owner of an AirTag to know its location, claiming its end-to-end encryption prevents even Apple employees to find one of them.
Consumer Tag location services: dumb tags & smart devices
All consumer tag solutions follow the same approach of using three components: “dumb tags” (also called beacons) constantly broadcasting a unique identifier (ID) which is picked up by nearby Internet-connected “smart devices”. These in turn forward that ID and signal strength alongside their own location details to a cloud server that uses Real-time Location Services (RTLS) to compute the location of the tags and make that available to applications and users authorised to see that location.
Fig1 – architecture of consumer real-time location tags
- Relatively inexpensive tags or “beacons” constantly broadcast a signal with their own ID, typically Bluetooth Low Energy (BLE), Near Field Communications (NFC) and/or Ultra-Wide Band (UWB). These tags have no synchronised clock, location capabilities or Internet connectivity of their own, hence the use of the term “dumb”.
- a range of Smart Devices (e.g., smartphones, tablets, computers, smart speakers, cameras, etc.) use their Internet access to forward this signal to the cloud and augment it with their own geolocation data. All smart devices participating in the scheme send all ID’s of eligible tags in their proximity as well as the relative signal strength (RSSI), a proxy for how close the tag was to the device at the time of reception of the signal. Smart Devices do not filter based on tag ownership, hence forming a large network of receivers.
- A “Real-Time Location Services” (RTLS) cloud server accumulates the time-stamped data sent by the Smart devices and uses it to compute the location of the tags and provide that information to applications and users.
Here are some of the specific features for each of the main providers:
| Provider | Tags technology | Smart Devices | Advantages | Drawbacks |
| Apple | BLE + NFC + UWB | – All iPhones running iOS 14.5+
– iPads – Mac |
– Large number of devices
– Solid established “Find My” service – Simplicity of use |
– UWB only works with latest phones (iPhone 11/12)
– Limited to geographies with high Apple Market share – Proprietary – Very strict data ownership rules |
| Samsung | BLE+UWB | – All Samsung Galaxy | – Native in Samsung Android, no app to install | – UWB only on latest Samsung phones
– Samsung-only, not supported on other Android devices |
| Tile | BLE | – Any phone running the Tile app
– Amazon-sidewalk enabled Echo speakers and Ring cameras |
– Original tag provider with established service
– Expansion beyond phones using fixed infrastructure in Amazon Sidewalk |
– Sidewalk is US-only
– No native OS integration: requires phones to install Tile app and let it run in the background |
Enterprise indoor positioning
Indoor positioning to track assets and inventory has been in use for many years. Popular technologies include RFID, Bluetooth and UWB. Each of these technologies offers its own set of advantages and drawbacks and fit different use case and physical environments.
RFID offers inexpensive passive (no battery) tags which can be stuck on anything, even smaller objects such as a paper file folder. That low cost allows deployments of thousands of tags at very low cost. However, the infrastructure to detect the tags is cumbersome and expensive. The range of detection is also very limited, making it more suitable for inventory management achieved by installing RFID readers at every entry/exit point rather than real-time tracking.
Bluetooth offers the benefit of being an active technology where the tags are broadcasting constantly using a small battery. A low-cost infrastructure can then be installed around facilities to create location anchor points which report detected tags to a cloud server. Bluetooth is a very standard technology and whilst tags are not as inexpensive as RFID, they are good value and work for a long time on battery. Bluetooth’s main disadvantage is the lack of precision in the range between tags and the receiver, so this technology is not suited for very precise indoor location.
Ultra-Wide Band is the upcoming challenger to Bluetooth, offering sub-30cm/1ft precision thanks to the combination of 2 signals: Time of Flight (ToF) and Time Difference of Arrival (TDoA). That level of precision makes it ideal for granular asset tracking. The main challenge for UWB today remains the cost for both the tags and the infrastructure which is significantly higher than other technologies.
At Microshare, we’ve extensively deployed Bluetooth with LoRaWAN backhaul for Indoor asset zoning and contact tracing deployments globally. The primary drivers for this combination are cost/accuracy balance for thousands of tags combined with the ease of deployment of the smart infrastructure with no dependency on the local network or risk to the Chief Security Officer. Our approach to enabling data ownership across an organisation and its trusted third parties has also been particularly critical to our success in that field.
Fig 2. Asset Zoning illustration: Dumb tags (for example Bluetooth) broadcast an ID. Smart Scanners (e.g., Kerlink Wave) pick up that ID and send it alongside additional positioning information to the Microshare Smart Network using LoRaWAN low-power connectivity.
Wide area tracking
Tracking assets or people over large areas such as a city, a region, a whole country or even internationally needs a network. Most solutions today have relied on cellular and satellite networks with low-power wide area networks (LPWANs) rapidly becoming a more cost-effective alternative.
The two main approaches for wide-area tracking are Network geolocation and Global Navigation Satellite System (GNSS). Some solutions combine both.
Network geolocation uses a Derived/Direct approach and is common on both cellular and low-power networks such as LoRaWAN. Active tags or devices with an identifier known to the network but with no intrinsic knowledge of their own position (similar to the dumb tags mentioned previously) emit a signal as part of their normal operation. This signal is received by one or more fixed antennas whose position is pre-determined. The location of the object is estimated using triangulation and Time Difference of Arrival (TDoA), a method comparing the time in milliseconds it takes for the signal to arrive from the device to each antenna. The precision is achieved by having a dense network of receiving antennas and a well-trained algorithm.
GNSS location is used widely with an Absolute/Direct combination. Objects which have a GNSS chip on-board as well as a direct backhaul compute their location using the satellite-based positioning systems and send that data directly to their connectivity. Smartphones are a very common example of this: combining GNSS with cellular backhaul. There are many trackers on the market for anything from containers to luggage, pets or children backpacks that also use this approach, often using different backhaul depending on the scale of coverage needed and acceptable cost: container trackers can use satellite backhaul, luggage cellular and pets can use low-power wide-area networks such as LoRaWAN. The primary challenge with the GNSS-based approach remains the power budget required: these devices need to power both a location chip as well as a backhaul, leading to most requiring a rechargeable battery.
Hybrid indoor/outdoor positioning
If an object must be located with a good precision when out and about as well as within specific buildings, a hybrid approach is the only option. This consists of combining the precision and range of Absolute/Direct and the low-power and low-cost approach of a Derived/Indirect method.
A Hybrid locator will have the following on-board capabilities:
– GNSS for absolute positioning when outdoors
– BLE or UWB for derived positioning when indoors
– Internet connectivity to report location and receive notifications
Based on the power required for all these to function and the assumption the tracker will be used for several years, a hybrid locator needs a rechargeable battery. As of mid-2021, that means the user needs to charge the device on a regular basis, typically every few days, by plugging it into a power source or laying it on a wireless charging pad. We have a line of sight of affordable small solar cells which will offer more sustainable and easier constant recharging in the daytime removing the need to rely on the user remembering to charge the locators.
In the diagram, a tracker uses a simple logic of whether a GNSS absolute location is available (in which case that location is sent to the cloud) or not. If no GNSS location is available, we have 2 options for detecting and reporting a Derived location:
a) Direct: the tracker is scanning for fixed location markers (for example Bluetooth beacons) which have been declared and reports that information using its own internet connectivity
b) Indirect: the tracker is set to broadcast like a dumb tag (for example an iBeacon format). A Smart Scanner (for example a Kerlink Wave) is installed in the fixed location and scans for the tracker, reporting the location using its own internet connectivity
There are several GNSS+BLE+LoRaWAN trackers on the market with a variety of form factors that offer a great starting point for Hybrid tracking options. The key is to establish the real-world requirements and specialise the firmware and accompanying infrastructure (particularly indoors) to suit these requirements.
For more details on this technology, and to find out more about how Microshare EverSmart solutions can help you track your most valuable assets, please get in touch.
Charles Paumelle is a Co-Founder and the Chief Product Officer at Microshare.