1. Overview

1.1 Introduction

The Amazon Sidewalk Location Library enables Sidewalk customers to use a range of cloud-based location solvers. Available in SDK >= 1.19, this library provides an API that automatically selects the most power- and time-efficient location mechanism based on available hardware and network conditions. Developers will also have finer-grained control to configure and override the mechanism used to determine location as required.

1.2 Supported Location Methods

The location library supports three types of location resolution methods:

1. Sidewalk Network Location over BLE — Leverages existing BLE connections to determine location through the Sidewalk network.
2. WiFi Scan — Scans for nearby WiFi access points and sends MAC addresses to the cloud for location resolution.
3. GNSS Scan — Uses Global Navigation Satellite System to collect satellite vehicle data for coordinate resolution.

These methods are supported on two available link types:

• BLE (Bluetooth Low Energy)
• LoRa (Long Range)

FSK with WiFi/GNSS scanning enabled is not currently supported.

WiFi and GNSS scanning leverage the Semtech LoRa Basics Modem middleware to manage and conduct scans on the device.

1.3 Location Levels

Location levels are ordered by lowest effort first (power consumption and time) and are defined by the available hardware on the device. The library automatically steps down through levels at configurable timeouts.

1.3.1 Level 1: Connected to Sidewalk via BLE

• Power Consumption: No additional power draw.
• Description: If the device can be located via BLE over the Sidewalk network, the device notifies the cloud to resolve the location with no further effort. If the device is not connected via BLE or location cannot be resolved, the next level is attempted.

1.3.2 Level 2: LoRa Location Trigger

• Power Consumption: Low power consumption.
• Description: Sends a location trigger over LoRa (Link Type 3) to the cloud for location resolution. Requires the LoRa link to be network synced. This level is used when the device is not connected via BLE but has an active LoRa connection.

1.3.3 Level 3: Send WiFi Scan

• Power Consumption: Low power consumption.
• Description: Conduct and send a WiFi scan. A minimum of 1 AP must be found in the scan or the next level will be attempted. If the cloud receives a low confidence score or no resolution is found, the device application must be notified to increment and try the next level.

1.3.4 Level 4: Send GNSS Scan

• Power Consumption: Higher power consumption than WiFi scanning.
• Description: Conduct and send a GNSS scan. A minimum of 4 Satellite Vehicles must be found for the scan to be valid.

1.4 Architecture

The library provides a single interface for application developers to consume APIs for uplinking location data. WiFi and GNSS have corresponding Platform Abstraction Layers (PALs) that are required when these features are enabled.

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