Geofencing

The foundational feature is the creation of a virtual boundary, or geofence, around a specific geographic area. This perimeter is defined by coordinates (latitude/longitude) and a radius, or by drawing a polygon on a map. The system continuously monitors device location relative to this invisible fence.

Geofencing is an event-driven system. The primary automation triggers are:

• Entry: When a tracked device crosses into the defined geographic area.
• Exit: When a device crosses out of the defined area.
• Dwell Time: Triggered after a device remains inside (or outside) a zone for a specified duration.

Different technologies enable geofencing with varying precision and battery efficiency:

• GPS: High accuracy outdoors, but power-intensive.
• Wi-Fi & Cellular: Uses network triangulation; less precise but better for indoor/urban use and battery life.
• Bluetooth Beacons: For hyper-local, indoor fencing (e.g., within a store).

Upon a trigger event, the system executes a pre-defined action. Common examples include:

• Sending a push notification (e.g., "Welcome to our store! Here's a coupon").
• Logging data for attendance or time tracking.
• Automating smart home devices (e.g., turning on lights).
• Triggering location-based alerts in security or asset-tracking applications.

The geofence radius can be adjusted from meters to kilometers, balancing precision with battery drain and network requests. A smaller radius (50-100m) is used for precise retail or security alerts, while a larger radius (1km+) might be used for regional marketing or weather alerts. Precision is limited by the underlying location technology's accuracy.

Real-world applications demonstrate its versatility:

• Retail & Marketing: Send promotions when customers are near a store.
• Fleet & Asset Management: Monitor vehicle entry/exit from depots or job sites.
• Smart Home: Automate thermostats or lights based on user's proximity.
• Parental/Security: Receive alerts when a person or asset leaves a safe zone.

Retailers use geofencing to send push notifications or SMS messages to customers' smartphones when they enter a predefined area, such as near a store. This enables location-based marketing, offering coupons, promotions, or alerts about in-store events. For example, a coffee shop can send a discount offer to users within a one-block radius.

Companies with vehicle fleets implement geofencing for asset tracking and operational efficiency. The system can:

• Automate dispatch when a vehicle enters a service area.
• Send alerts for unauthorized vehicle use if a truck leaves its designated route.
• Trigger automated time tracking for drivers entering and leaving a job site, streamlining payroll and compliance.

Municipalities deploy geofencing to manage urban mobility and public services. Common applications include:

• Geo-restricted speed limits for electric scooters or bikes in pedestrian zones.
• Automated toll collection when vehicles enter congestion charge zones.
• Managing access to restricted traffic areas (e.g., city centers) for delivery vehicles.

Organizations use geofencing as a perimeter security tool. It can automatically:

• Lock or unlock doors when an authorized employee's smartphone enters the geofence.
• Send alerts if a high-value asset moves outside a safe zone.
• Restrict the functionality of company-owned devices (e.g., disabling cameras) inside sensitive facilities.

This application focuses on monitoring and safety alerts. Parental control apps use geofences to notify parents when a child arrives at or leaves school or home. Similarly, personal safety apps can alert designated contacts if a user enters or exits a specific, potentially unsafe area.

In location-based gaming (e.g., Pokémon GO), geofences define where in-game events, items, or characters spawn, tying gameplay directly to the physical world. AR applications use geofencing to trigger the display of contextual digital information or experiences when a user is at a specific landmark or point of interest.

The most precise method, using signals from a constellation of satellites to calculate latitude, longitude, and altitude. It provides meter-level accuracy outdoors but is power-intensive and ineffective indoors.

• Primary Use: High-accuracy outdoor positioning for navigation and asset tracking.
• Limitation: Requires a clear line of sight to satellites.

Determines location by scanning for nearby Wi-Fi access points (APs) and comparing their MAC addresses and signal strengths to a known database. Effective for indoor positioning where GPS fails.

• How it works: The device detects APs; a service (like Google or Apple) maps these to physical locations.
• Accuracy: Typically 10-20 meters, dependent on AP density.

Estimates location based on the signal strength and timing to multiple cell towers. The device's position is calculated where the coverage areas intersect.

• Primary Use: Provides a coarse location fix when other methods are unavailable.
• Accuracy: Ranges from 100 meters to several kilometers, making it suitable for regional geofencing.

Uses small, low-power hardware devices (beacons) that broadcast a unique identifier via Bluetooth Low Energy (BLE). A mobile device detects the beacon's signal strength (RSSI) to estimate proximity.

• Primary Use: Hyper-local, context-aware triggers (e.g., entering a specific store aisle).
• Key Feature: Enables precise micro-location and indoor navigation.

Maps a device's public IP address to a geographic location using databases maintained by internet service providers and geolocation services. This is a network-level method, not device-specific.

• Primary Use: Determining country, region, or city for content localization and fraud prevention.
• Limitation: Imprecise (city-level) and can be inaccurate with VPNs or proxies.

Modern devices combine multiple signals (GPS, Wi-Fi, cellular, Bluetooth, accelerometer, gyroscope) using algorithms to provide a more accurate, reliable, and power-efficient location fix. This is the standard approach in smartphones.

• Key Benefit: Maintains location accuracy in challenging environments (urban canyons, indoors).
• Example: Apple's Core Location and Google's Fused Location Provider use this technique.

A cryptographic protocol that verifies an entity's physical presence at a specific geographic coordinate at a specific time. Unlike simple GPS data, it provides tamper-proof attestations to prevent spoofing. This is a foundational primitive for trustless geofencing applications.

The if-then rules encoded within a smart contract that execute based on oracle data. In geofencing, this logic checks if a verified location meets predefined geographic criteria (e.g., if (location == Zone_A) { mintToken(); }). It transforms location data into actionable on-chain outcomes.

A security technique that regulates who or what can view or use resources. Geofencing is a form of physical access control for digital assets, restricting smart contract functions (like minting, voting, or claiming) to users provably located within a designated area.

A cryptographic method allowing one party to prove knowledge of data without revealing the data itself. In advanced geofencing, ZK-proofs can enable privacy-preserving location verification, where a user proves they are in a valid zone without disclosing their exact coordinates.

The application of regulatory or policy rules within decentralized finance protocols. Geofencing is a key tool for automated compliance, allowing protocols to restrict services (e.g., trading, lending) based on a user's jurisdiction to adhere to local regulations like sanctions lists.