Amazon Sidewalk Location Resolution
This application note describes how each Amazon Sidewalk location resolution mechanism works: what the device contributes, how Amazon Sidewalk resolves it into a position, and what drives accuracy and failure. For the device-side API and how a device selects and sequences mechanisms, see the Amazon Sidewalk API User Guide.
Amazon Sidewalk resolves location through six mechanisms, numbered L1 through L6:
| Level | Mechanism | Resolved by |
|---|---|---|
| L1 | BLE gateway location | Amazon Sidewalk, from the gateway’s known position |
| L2 | FSK gateway location | Amazon Sidewalk, from the gateway’s known position |
| L3 | WiFi scan | AWS IoT Wireless, from an access-point database |
| L4 | GNSS scan | AWS IoT Wireless, from satellite data |
| L5 | LoRa MLAT | Amazon Sidewalk, by multilateration across gateways |
| L6 | GPS-assist | Amazon Sidewalk, with the device producing pseudoranges |
The L-number identifies the mechanism; it is not a ranking of power cost (LoRa MLAT at L5, for instance, is lower power than the GNSS scan at L4).
Where Resolution Happens
For every mechanism the device contributes a signal or a measurement and the position is resolved off-device. Mechanisms fall into two families, by where that resolution happens.
Resolved by AWS IoT Wireless (L3, L4). For a WiFi or GNSS scan, Amazon Sidewalk forwards the scan to the AWS IoT Wireless position-estimate service, which returns the coordinates.
Resolved within Amazon Sidewalk (L1, L2, L5, L6). For all other mechanisms Amazon Sidewalk computes the position itself:
- A BLE or FSK uplink is resolved from the receiving gateway’s known position.
- A LoRa uplink is multilaterated across the gateways that heard it.
- A GPS-assist exchange aids the device, then solves the pseudoranges the device returns.
When resolution fails, no location is produced for that attempt.
Each of the following pages covers one mechanism.