when geofence checks the telecom carrier database ...

Question

I am trying to undestand the link between the Azure geofence and the carrier

How often does the geofence quiz the carrier?

What is the database in which the carrier stores all the data?

What parameters does the pass to the carrier (I assume the device ID/phone number/ and request for location)

what data does the carrier pass back?

Dave

Answer 1

If you haven't already, I recommend going through this tutorial first: https://learn.microsoft.com/en-us/azure/azure-maps/tutorial-geofence and https://learn.microsoft.com/en-us/azure/azure-maps/azure-maps-event-grid-integration and https://learn.microsoft.com/en-us/azure/azure-maps/geofence-geojson

At a high level, here is how this service works:

• You create/upload a geofence in GeoJSON. In the properties of the geofence you can define a geometry id (required - unique), and optionally details on when the geofence is valid (daily/weekly, between certain hours, business days) as well as how frequently you want the geofence to stay alive before being ignored (e.g. 1 valid period. If you don't specify this option, it will be available until you delete it).
• Create an Event Grid instance to monitor the geofence. It will trigger whenever a point enters/leaves a geofence (little to no delay, just processing time).
• Create/Define a service or logic app that the event grid will call when triggered. The service will receive the unique geometry id of the geofence and id of the device that triggered the event. A distance value will be specified, a positive number indicates the device is outside of the geofence, while a negative number indicates it is inside the geofence.
• As your devices moves/ you have coordinates you want to test on the geofence, you call the geofence API and specify the device ID, coordinates, and optionally a search buffer (is within X meters of the geofence). This service will respond with a list of all currently valid geofences that are within the search radius of your point.
  • You can separately maintain additional desired details about your devices/geofences in a database and use the unique IDs used with the above services a s a way to link everything.

To answer your main question, the frequency at which this is triggered is 100% based on the frequency you call the geofence API with the device ID and a new coordinate.

All that said, there are a few things to take into consideration when using geofences, when the devices you are tracking are mobile phones. If you have a native app for mobile devices and have a small number of simple geofences you want to monitor at a high frequency (e.g. every GPS ping), it may be more efficient to use the local geofencing capabilities built into the operating system of the device. This is a good option when you want to trigger things like localized ads to the user when they enter a store or something. The Azure Maps geofencing API is more generic and can work with any coordinate, regardless of if it came from a device or not. In generally, in most common real time tracking scenarios, a frequency of checking the geofence is once every 15 seconds is typically the highest used. For example, a vehicle travelling at 80 km/h would travel 340 meters in 15 seconds (in most cases this would be the extreme distance change in that time period). Someone walking at a speed of 5 km/h would travel about 21 meters in 15 seconds.