What Is Assisted GPS?

If you own a smartphone and have used tools like Google or Apple Maps for navigation, chances are you’ve experienced the benefits of Assisted GPS or A-GPS/aGPS for short. Quick, accurate geolocation services in a portable and compact form factor, today’s GPS devices are incomparable to what was “state of the art” just five or ten years ago. 

What Is GPS? 

Global Positioning System, or GPS as it is more commonly known, is a satellite-based navigation system that enables geolocation services anywhere on Earth with an unobstructed line of sight to four or more GPS satellites. GPS specifically refers to the satellite system owned and operated by the United States and is one of several GNSS (Global Navigation Satellite System) currently used alongside GLONASS, Galileo, Beidou, and other regional systems.

What Is Assisted GPS?

Assisted GPS augments quality and precision of location data by supplementing it with external data sources. This is especially useful in geographic locations where a clear line of sight to satellites is inaccessible - whether due to natural geographic features like forests and mountains or human-made ones like skyscrapers overhead bridges. 

There are two modes of Assisted GPS:

Mobile Station Assisted (MSA)

GPS devices receive supplementary info (reference time, acquisition help, etc.) from a mobile service provider. An Assisted GPS server calculates and returns the position of the GPS device. 

Mobile Station Based (MSB)

GPS devices receive orbital data or almanac for the GPS satellites, allowing them to acquire satellites more quickly. Location calculation is performed locally on the GPS device. 

Assisted GPS in IoT Applications

While Assisted GPS is fairly ubiquitous in everyday use, it is a functionality that needs to be designed into IoT devices. Hardware manufacturers accomplish this by incorporating modules like the Semtech LR1110, which supports multiple GNSS (GPS/Beidou) and WiFi scanning and LoRa, into the end product. Although there are a fair number of devices that support Assisted GPS at the moment, it is a market that will continue to grow and evolve as the digital transformation progresses and technology advances.