BLE tag tracking with zone anchors

Understand how zone anchors are used in BLE tag tracking solutions.

BLE anchor localization uses BLE anchors such as the ZA3500 to localize trackers over BLE. A BLE anchor listens to BLE advertisements sent by a tracker that is attached to an asset. BLE anchors are always installed at fixed locations. They send detected BLE ID's to the Sensolus platform, where the location of the detected tracker is set to the location of the BLE anchor. Since BLE anchors are often not powered by batteries they can scan and send messages almost continuously, meaning that there is almost no delay when a tracker is located. This means it is the ideal localization technique if you need to know immediately when assets arrive or leave a certain location.

BLE zone anchors

BLE tag trackers can be localized at dedicated zones using fixed BLE zone anchors. Zone anchors scan for nearby BLE tag trackers and send this information to the Sensolus platform over NB-IoT or 4G.

BLE zone anchors:

Figure 1. Tag tracking with fixed zone anchor
Note: Using BLE tag trackers and fixed zone anchors is ideally if you want to track your assets at dedicated places. Some requirements must be taken into account:
  1. The zones you want to track are enumerable.
  2. The zones can be equipped with infrastructure (the zone anchors).
  3. There is no visibility required between the zones.
Note: It is also to combine externally powered tracker infrastructure and BLE zone anchor infrastructure which makes it possible to combine in transit tracking and tracking of your assets at dedicated places.

The functioning of BLE anchors

A tracker is attached to an asset. When it comes in the vicinity (up to 70 meters) of a BLE anchor, the anchor picks up the BLE advertisements sent out by the tracker on fixed time intervals (for example, every second). The BLE anchor is a sort of gateway that is connected to the internet via Ethernet, Wi-Fi or 4G/SIM and sends the location information periodically to the Sensolus platform where the locations are then mapped and visualized.


Figure 2. Functioning of BLE anchor localization

How scanning and sending works with zone anchors

Figure 3. Scanning and sending tag information with zone anchors

The BLE tag trackers advertise every 4 seconds (default setting) their unique ID (BLE advertisement interval)

The BLE zone anchor scans every 5 seconds (default setting) for BLE tag trackers in its proximity (BLE scan).

All unique detected tag ID's are stored in the BLE anchor memory until it is sent to the cloud.

Every 5 minutes (default setting) the BLE anchor sends the list of detected tag tracker ID's to the platform.

BLE anchors

The Sensolus platform supports several models of BLE anchors:

  • ZA 3510 anchor
  • ZA 3500 anchor
  • ZA 3505 anchor
  • Aruba Wi-Fi AP: Aruba is a brand of Wi-Fi access points with integrated BLE scanning functionality.