NG-RAN Positioning Architecture
Introduction:
NG-RAN (Next Generation Radio Access Network) is the Radio Access Network (RAN) for the 5th Generation (5G) mobile communication system. One of the key features of NG-RAN is its advanced positioning architecture, which provides improved positioning accuracy and new positioning features compared to previous cellular systems. In this article, we will discuss the technical aspects of the NG-RAN positioning architecture, including the different positioning methods and the architecture of the positioning system.
Overview of NG-RAN Positioning Architecture:
The NG-RAN positioning architecture is based on a hybrid positioning approach that combines different positioning methods to provide accurate and reliable positioning information. The positioning methods used in NG-RAN include Global Navigation Satellite Systems (GNSS), cellular positioning, and Non-Terrestrial Networks (NTN) positioning. The architecture of the NG-RAN positioning system is designed to integrate these different positioning methods into a single system that can provide accurate and reliable positioning information to mobile devices.
Technical Details:
GNSS Positioning:
GNSS positioning is a satellite-based positioning method that is used to determine the location of mobile devices using signals from global navigation satellite systems such as GPS, Galileo, and GLONASS. The NG-RAN positioning architecture uses GNSS positioning to provide accurate positioning information in outdoor environments where the mobile device has a clear line of sight to the satellites.
Cellular Positioning:
Cellular positioning is a network-based positioning method that uses measurements from the cellular network to determine the location of mobile devices. The NG-RAN positioning architecture uses cellular positioning to provide positioning information in indoor and urban environments where GNSS signals may be weak or unavailable.
Cellular positioning is based on the measurement of signal characteristics such as time difference of arrival (TDoA), angle of arrival (AoA), and time of arrival (ToA). These measurements are used to calculate the position of the mobile device using triangulation or trilateration techniques. The NG-RAN positioning architecture uses advanced signal processing techniques to improve the accuracy and reliability of cellular positioning, including advanced algorithms for TDoA and AoA measurements.
NTN Positioning:
NTN positioning is a new type of positioning method that uses non-terrestrial networks such as Low Earth Orbit (LEO) satellites, High Altitude Platform Stations (HAPS), and Unmanned Aerial Vehicles (UAVs) to provide positioning information. The NG-RAN positioning architecture uses NTN positioning to provide positioning information in areas where GNSS and cellular positioning may be unavailable or unreliable, such as remote or sparsely populated areas.
The NG-RAN positioning architecture is designed to integrate these different positioning methods into a single system that can provide accurate and reliable positioning information to mobile devices. The architecture consists of three main components: the Positioning Measurement Unit (PMU), the Positioning Calculation Unit (PCU), and the Positioning Function (PF).
Positioning Measurement Unit (PMU):
The PMU is responsible for measuring the signals from the different positioning sources and providing the measurement data to the PCU for processing. The PMU consists of different sensors and receivers that are used to measure GNSS, cellular, and NTN signals. The PMU also includes advanced signal processing algorithms that are used to improve the accuracy and reliability of the measurement data.
Positioning Calculation Unit (PCU):
The PCU is responsible for processing the measurement data from the PMU and calculating the position of the mobile device. The PCU consists of different algorithms and models that are used to calculate the position of the mobile device based on the measurement data from the different positioning sources. The PCU also includes a database of reference signals and measurements that are used to improve the accuracy and reliability of the positioning calculations.
Positioning Function (PF):
The PF is responsible for providing the positioning information to the mobile device and the network. The PF consists of different software modules that are responsible for generating and transmitting the positioning information to the mobile device and the network. The PF also includes different positioning protocols and interfaces that are used to exchange the positioning information between the mobile device and the network.
In addition to the three main components of the NG-RAN positioning architecture, there are also different positioning modes and positioning services that are supported by the architecture.
Positioning Modes:
The NG-RAN positioning architecture supports different positioning modes that are optimized for different use cases and applications. The positioning modes include standalone positioning, network-based positioning, and hybrid positioning.
Standalone Positioning:
Standalone positioning is a mode where the mobile device calculates its position using only the signals from one or more positioning sources. This mode is used when the mobile device is not able to access the network or when it requires a fast positioning fix.
Network-based Positioning:
Network-based positioning is a mode where the mobile device uses the signals from the network to calculate its position. This mode is used when the mobile device has access to the network and requires accurate and reliable positioning information.
Hybrid Positioning:
Hybrid positioning is a mode where the mobile device uses a combination of signals from the network and the positioning sources to calculate its position. This mode is used when the mobile device requires accurate and reliable positioning information in challenging environments.
Positioning Services:
The NG-RAN positioning architecture supports different positioning services that provide different levels of accuracy and reliability depending on the application requirements. The positioning services include Emergency Services (ES), Location Services (LS), and User Plane Services (UPS).
Emergency Services:
Emergency Services (ES) is a positioning service that is designed to provide accurate and reliable positioning information for emergency calls. The NG-RAN positioning architecture supports different methods for ES positioning, including GNSS positioning, cellular positioning, and hybrid positioning.
Location Services:
Location Services (LS) is a positioning service that is designed to provide accurate and reliable positioning information for location-based services such as navigation, advertising, and social networking. The NG-RAN positioning architecture supports different methods for LS positioning, including GNSS positioning, cellular positioning, and hybrid positioning.
User Plane Services:
User Plane Services (UPS) is a positioning service that is designed to provide positioning information in the user plane without requiring additional signaling between the mobile device and the network. The NG-RAN positioning architecture supports different methods for UPS positioning, including GNSS positioning, cellular positioning, and hybrid positioning.
Conclusion:
The NG-RAN positioning architecture is a key feature of the 5G mobile communication system that provides improved positioning accuracy and new positioning features compared to previous cellular systems. The architecture uses a hybrid positioning approach that combines different positioning methods, including GNSS, cellular, and NTN positioning, to provide accurate and reliable positioning information in different environments and use cases. The architecture is designed to integrate these different positioning methods into a single system that can provide accurate and reliable positioning information to mobile devices. The architecture supports different positioning modes and positioning services that provide different levels of accuracy and reliability depending on the application requirements. Overall, the NG-RAN positioning architecture is an important area of research and development for future wireless communication systems that require advanced positioning capabilities.