Dual Mode

GPStream PGPS now integrates the functionality of a previous stand-alone product – GPStream SAGPS – and can now operate in two modes: Connected and Autonomous. In Connected Mode, PGPS receives small (2 kB) weekly data transfer, also known as a “seed” file, delivered from Rx Networks’ Internet based PGPS servers. This advantageously compares with other chipset-proprietary extended ephemeris solutions that require ~70 kB/week for each satellite constellation. The PGPS client uses these seeds to locally generate 7 days of satellite orbit and clock predictions. In Autonomous Mode, when there is no network access, PGPS uses broadcast ephemeris (BCE) collected by

the GNSS chipset to generate its own seeds and produce up to 3 days of satellite orbit and clock predictions. Autonomous Mode works with as little as one BCE observation but continues to develop and refine the prediction every time a new BCE is obtained.

PGPS can intelligently switch between modes, maintaining a consistent user experience as the device moves in and out of connectivity, without requiring a real-time AGNSS connection. This is particularly helpful in roaming scenarios or in markets where data plans are not affordable. Alternatively, PGPS can be configured to operate solely in either mode.

Designed for easy integration with existing A-GNSS standards and a wide variety of hardware and software platforms, GPStream PGPS is the only truly ubiquitous extended ephemeris solution that works with any network, device or chipset architecture.

Dual Constellation

PGPS supports both GPS and GLONASS constellations.  Additional constellations will be supported as they become commercially viable.

Benefits

• Improved user experience
• Lower battery consumption
• Flexible flash memory usage
• Patent protection
• Standards-friendly
• Platform independent

Specifications

Overview

GPStream™ PGPS is an Assisted-GNSS solution designed to substantially enhance the satellite acquisition performance of virtually any GNSS positioning engine, whether a chipset or next-generation software-GNSS. In practical terms, this means a reduction of Time-To-First-Fix from 45 seconds to 2 seconds or less. Moreover, fixes can be achieved in difficult environments where they were previously impossible.

PGPS works on any mainstream mobile operating system as well as proprietary embedded platforms, and can seamlessly adjust its performance if the device has full, occasional, or no network access at all. PGPS consists of a lightweight and patented software client that enables the device to generate its own GNSS assistance data, i.e. extended ephemeris. Extended ephemeris is a close approximation of the real broadcast ephemeris constantly transmitted by the satellites, which must normally be received by the device before it can start calculating its position.

PGPS preloads extended ephemeris data into the GNSS chipset, thereby avoiding the latency and higher bandwidth usage inherent in real-time Assisted-GNSS approaches. The net result is super fast satellite acquisition and improved GNSS sensitivity. In other words, a better user experience when consuming Location-Based Services.

14 Day Predictions

GPStream™ PGPS 7 builds on PGPS 6 by increasing the prediction period from seven to 14 days (from three to five days for Autonomous Mode).

Dual Mode

In Connected Mode, PGPS receives small files (4.5 kB per constellation) every two weeks to enable full constellation predictions of the satellite orbits. This advantageously compares with other chipset-proprietary extended ephemeris solutions that require ~150 kB transfers for each satellite constellation. The PGPS client uses these seeds to locally generate 14 days of satellite orbit and clock predictions.

If a network connection is not available, PGPS invokes the Autonomous Mode functionality of a previously stand-alone product – GPStream SAGPS™, predicting the orbits of observed satellites for the next five days. Autonomous Mode works with as little as one broadcast ephemeris (BCE) observation but continues to develop and refine the prediction every time a new BCE is obtained.

PGPS can intelligently switch between modes, maintaining a consistent user experience as the device moves in and out of connectivity, without requiring a real-time AGNSS connection. This is particularly helpful in roaming scenarios or in markets where data plans are not affordable. Alternatively, PGPS can be configured to operate solely in either mode.

Dual Constellation

PGPS supports both GPS and GLONASS constellations.  Additional constellations will be supported as they become commercially available.

Benefits

• Improved user experience
• Fast fix regardless of state of connectivity
• Lower battery consumption
• Highly bandwidth efficient
• Patent protection
• Platform independent

Specifications