top of page


PIDF-LO stands for Presence Information Data Format - Location Object.

It is a technical specification used in telecommunications and emergency services, particularly in the context of Enhanced 911 (E911) services. 

This format is crucial for conveying location information during emergency calls made over VoIP (Voice over Internet Protocol) and other IP-based communication systems.

  • Purpose: PIDF-LO is used to encode and transmit the location information of a caller or a device in IP-based communication systems. This is particularly important for emergency services, as it helps in accurately determining the caller's location, which is essential for a quick and effective emergency response.

  • Format: The format is based on the XML (eXtensible Markup Language) schema, allowing for the structured and standardized representation of location information. This includes geographic coordinates (like latitude and longitude), civic address information (such as street address, city, state, country), and other relevant location details.

  • Integration with E911: In the context of E911 services, PIDF-LO is used to automatically provide the caller's location to the emergency service operators. When a VoIP call is made to 911, the caller's location information, formatted in PIDF-LO, is transmitted along with the call so that emergency responders can be dispatched to the correct location even if the caller cannot communicate it.

  • Importance in VoIP Communications: Traditional landline phones are tied to a physical location, making it easier to determine the location of an emergency call. However, VoIP calls can be made from anywhere with an internet connection, making it challenging to pinpoint the caller's location. PIDF-LO addresses this challenge by ensuring that accurate location information is transmitted during the call.

  • Use in Other Applications: Beyond emergency services, the PIDF-LO format can also be used in various applications that require precise location information, such as location-based services, navigation systems, and mobile applications.

PIDF-LO plays a critical role in modern communication systems by enhancing the safety and effectiveness of emergency response services in an increasingly mobile and interconnected world.

bottom of page