Does the Sentrius RG1xx gateway support geolocation using LoRaWAN's TDOA (Time Difference of Arrival) technique for tracking purposes?

Answer

No, our Sentrius RG1xx gateway leverages the RG1xx-M2 Concentrator Card, built with Semtech's SX1301 and SX1257 radios (x2). To fully support TDOA, however, the hardware would need to incorporate the SX1303 chip − or a newer, more advanced solution. TDOA (Time Difference of Arrival) is a method in LoRaWAN used to estimate a device's location by measuring the slight time differences in its signal reaching multiple gateways, using ChirpStack and/or the Semtech LoRa Cloud, for example.

Simply put, each LoRaWAN gateway picks up the signal at slightly different times, and these time differences are used to calculate the device's position. For this to work, a LoRa end-device and multiple gateways with synchronized clocks are required. TDOA is especially useful in places where GPS does not work well, such as indoors, in urban environments with tall buildings, or areas with limited GPS signal.

By eliminating the need for GPS hardware on the device, this geolocation technique lowers overall power consumption while enabling efficient, long-range tracking. However, accuracy depends on the precise synchronization of the gateways' clocks and can be affected by multiple environmental factors like signal interference. It's a common choice for asset tracking, logistics, and smart city projects.