13 Network-assisted GNSS positioning method

25.3053GPPRelease 17Stage 2 functional specification of User Equipment (UE) positioning in UTRANTS

In this concept, different GNSS (e.g. GPS, Galileo, GLONASS and BDS) can be used separately or in combination to perform the location of a UE. The aim of such combination is to improve:

– the availability of the location service,

– the accuracy of the position,

– the sensitivity to e.g. fadings,

– the integrity of the signal,

– the reliability of the signal,

– the in-building penetration.

This can be done thanks to the combination of different global navigation satellite systems and the increased number of satellites.

13.1 Network-assisted GPS positioning method

Refer to clause 10.

"Modernized-GPS" refers to a family of modernized GPS satellites which bring support for new navigation signals, such as a Civilian L2 (L2C) signal, a Safety-of-Life L5 signal, and a new Civilian L1 (L1C) signal, together with improved navigation message data.

13.2 Network-assisted Galileo positioning method

The procedure is the same as for network-assisted GPS positioning method except that the Galileo satellites and parameters are used instead of those of the GPS.

13.3 Network-assisted GLONASS positioning method

The procedure is the same as for network-assisted GPS positioning method except that the GLONASS satellites and parameters are used instead of those of the GPS.

13.4 Network-assisted Satellite Based Augmentation Systems (SBAS)

Several independent but compatible satellite based augmentation systems exist: The American Wide Area Augmentation System (WAAS), the European Geostationary Navigation Overlay Service (EGNOS), the Indian GPS Aided GEO Augmented Navigation System (GAGAN), and the Japanese Multi-functional Satellite Augmentation System (MSAS). The (GPS-like) ranging signals from all these SBASs are here considered as a single GNSS, although this GNSS is not a standalone positioning system because of the small number of satellites and their distribution in space. Usually, this GNSS is used in combination with e.g., GPS, Galileo, or GLONASS ranging signals.

The procedure is the same as for network-assisted GPS positioning method except that the SBAS satellites and parameters are used instead of those of the GPS.

13.5 Network-assisted Quasi-Zenith Satellite System (QZSS)

Quasi-Zenith Satellite System (QZSS) is a regional navigation satellite system. The eccentricity and elevation of the satellite orbits are selected so that the minimum elevation angle through 24 hours in Japan is larger than about 60 degrees. The satellite signals are fully compatible and interoperable with current and modernized future GPS. Similar to SBAS ranging signals, this GNSS is not a standalone positioning system and is usually used in combination with other GNSS ranging signals, such as GPS, Galileo, GLONASS, etc.

The procedure is the same as for network-assisted GPS positioning method except that the QZSS satellites and parameters are used instead of those of the GPS.

13.6 Network-assisted BeiDou Navigation Satellite System (BDS) positioning method

The procedure is the same as for network-assisted GPS positioning method except that the BDS satellites and parameters [31] are used instead of those of the GPS.