User's Guide

Gen2 BLE Sensor Family User Guide T0007796_UG_Portable Version 0.2
TEKTELIC Communications Inc. Page 14 of 30
cycle is 100%. This represents a continuous scan over each scan duration. A larger duty cycle
will increase the likelihood of receiving more beacon packets at the expense of consuming
more power. The scan period, duration, interval, and window are all configurable. For all user
configurable device settings, refer to the specific TRM document for that sensor).
Figure 1-5: The BLE Scan Schematic Procedure.
In the case of the variants that fall into the SafeAlert functional category, all BLE peripheral
devices are discoverable during BLE scans. At the end of each scan duration, up to n discovered
BLE devices with the strongest RSSIs are reported over LoRaWAN. The value n is user
configurable. If no devices are found, an empty list is uplinked. Over each scan duration, a BLE
device beacon may be observed (discovered) more than once. The Asset Trackers do not
support BLE Tx advertising.
In the case of the variants that fall into the Contact Tracing functional category, only other
Contact Tracing Devices are discoverable during the BLE scans. Signal strengths of discovered
devices are analyzed over multiple scans to determine the proximity of these other devices. If a
user-configurable threshold is breached, the Contact Tracing Device then begins recording the
contact duration with that device, which is later sent over LoRaWAN once the contact has
ended. Contact Devices are discoverable because they support BLE Tx advertising.
The Gen2 variants support BLE of Bluetooth 5.0. The BLE scan is performed in the passive mode
only, meaning that the sensor listens to surrounding beacons, but does not transmit to them to
request additional information.
NOTE: The BLE scan is exclusive to LoRa radio transmission; i.e. they do not overlap. If any
reporting becomes due at the same time of a BLE scan, the reporting will be done after the BLE
scan is complete.
1.4.2 Magnetic Reed Switch
The C-cell Gen2 sensor variants are equipped with a magnetic reed switch and shipped with a
magnet. Since the C-cell variants all have water-tight IP67 enclosures, there is no ability to have