Definition
RTG (Real-Time Geofencing) refers to a technology that, based on positioning and real-time location data, determines in real-time whether a device enters or leaves a preset geofence. RTG differs from static geofences by emphasizing "real-time" detection and triggering, supporting applications such as boundary alerts, boundary notifications, and event triggers. The RTG architecture typically includes: geofence configuration, positioning data streams, real-time judgment engine, and trigger actions (alerts, notifications, remote signaling, etc.). When combined with second-level positioning, RTG can support high-frequency geofence evaluations.
In cross-border scenarios, RTG needs to support multi-country positioning, multiple time zones, and multiple maps; one card for multiple countries ensures real-time location feedback of cross-border devices to support RTG judgments.
Technical Features and Architecture
The RTG technical architecture includes: Fence Layer——Geofence configuration (polygon, circle, route, etc.), supporting dynamic updates; Positioning Layer——Positioning, real-time positioning data streams, at second-level or higher frequency; Judgment Layer——Determining the relationship between points and polygons/circles, enter/leave state machine; Trigger Layer——Trigger boundary crossing alarm, boundary crossing push, event-triggered reporting. Combined with boundary crossing alarms, RTG is the technical implementation of alarms; combined with boundary crossing pushes, RTG supports scenario-based pushes. In cross-border scenarios, fence coordinates need to be unified (e.g., WGS84), and multi-country map services need to be adapted.
The RTG judgment frequency affects latency and computational load; high frequency requires optimization of algorithms and data compression.
Application in IoT and cross-border scenarios
RTG is widely applied in: Logistics and Distribution——Logistics Tracker Triggered when entering/leaving warehouses or sites Boundary Alert or Boundary Push;Charging Services——Triggered when vehicles enter Charging Station geofence Boundary Push, promotional information;Asset Monitoring——Boundary Alert when assets leave preset areas;Retail and Marketing——Push notifications when users enter mall or scenic area geofences. Cross-border logistics, cross-border charging, and cross-border fleets all rely on RTG to achieve location-based smart services, One Card Multi Country ensuring cross-border real-time location feedback.
SimtoLink provides stable connections for IoT devices in RTG scenarios, covering 200+ countries and regions, supporting cross-border logistics tracking, charging station and other scenarios.
Entry, Exit, and Hysteresis on a Real-Time Fence
Real-time geofencing continuously judges, on a stream of positions, whether an object has entered or left, and fires an alert or a business action when the state changes. The fence may be a circle, a polygon, or a band along a road. What is judged is the relation between a timed point and the fence, not a circle drawn on a static map. Each object should have a state machine: outside, inside, and an optional pending confirmation. A move from outside to inside counts as entry only after several qualified points in a row fall inside, or after the object has stayed inside longer than a set time. Exit works the same way. A single point in or out treats positioning jitter as a crossing. A hysteresis band is a buffer near the boundary. A point that falls in the buffer keeps the previous state, so a vehicle driving along the boundary does not enter and leave dozens of times in a minute.
A point must qualify before it takes part in the judgment. Qualified means young enough, an error smaller than the scale the fence allows, a coordinate reference frame that matches the fence, and time that is not reversed. A cell point with an error of hundreds of meters cannot judge a site a few tens of meters wide. If one cross-border map stores a fence in satellite coordinates and another in a locally offset frame, the same vehicle will be judged inside and outside at once on the two sides of a border. The triggered action should bind to the state change, not to every interior point, or a vehicle parked inside the fence will keep pushing. A leave followed by another entry is a new event and needs a new event number. It must not overwrite an alert from the previous time that has not ended.
When Real-Time Judgment May Be Turned On
Real-time judgment may be turned on when fence vertices are stored in one coordinate system and do not self-intersect, the position stream updates faster than the time the object needs to cross the fence, the hysteresis distance is larger than the typical positioning jitter of that scene, the state machine's confirmation count or dwell time has been set for the business, and downstream actions can deduplicate by event. If the object moves quickly and a position arrives only once a minute, it may pass through the fence with no point inside. That fence cannot be called valid in real time. Raise the report rate or thicken the fence. If an indoor site relies mainly on satellites, switch to beacon points or explicitly lower the judgment grade. Fences on a cross-border route should have their coordinates checked country by country. Do not reuse vertices from the headquarters base map on another map unchanged.
A False Crossing Caused by a Position Jump
A common mistake is a lost-lock point that jumps several kilometers away and triggers an exit, then jumps back a second later and triggers an entry, so the business shows repeated arrival and departure. Another is a self-intersecting polygon or a wrong vertex order, so a vehicle clearly inside the site is counted as outside. A third is to use the received time instead of the solution time, so a catch-up burst at a tunnel exit is treated as instantly crossing several fences. Without hysteresis, a fleet parked on the boundary fills the alerts. When the error field is ignored, a representative point of a cell falls in the center of the fence, and a device far outside the city is counted as back in the yard. The state machine should also ignore points that fail quality. A jump does not change state. Replay a catch-up upload by solution time. If the replay conflicts with an action already triggered at the time, open a review event instead of automatically opening a door or billing again.
A review event only prompts a person. It does not open a door, bill, or push again. A point inside the hysteresis band keeps the previous state until consecutive qualified points fall clearly outside the band.