Page 53 - Kaleidoscope Academic Conference Proceedings 2022

Extended reality – How to boost quality of experience and interoperability

integrated network control architecture. The major obtained from the SOC. GST availability, weather
difference is that the scope of each function is not E2E conditions, feeder and service link quality, and GST
network service, but within the given network segment. interface measurements (e.g. frequencies, Doppler shift,
modulation methods and transmission speeds) can be
The network control internal interfaces are used for obtained from the GST. Similarly, service/user
receiving monitoring/control data from the physical or requirements, service types and their QoS requirements (e.g.
functional network elements in different granularity and traffic rate, tolerable call drop, maximum latency, and
time scale. Both the types and values of control data may security levels), and link performances for payload
differ in different kinds of network segments. Standard transmission (e.g. throughput, latency, jitter, and packet
frameworks and methods for control data collection in loss rates) can be available from the NOC. Therefore, the
terrestrial networks have been defined by various SDOs SOC, GST, and NOC should be able to provide telemetry
such as ITU, IETF, 3GPP, and ETSI. For example, control data to the NTN control system and receive telecommands
data collection and transmission functions of terrestrial 5G from there through standard network control internal
networks are well defined in 3GPP technical specifications interfaces.
on architecture enhancement to support network data
analytics, such as 3GPP TS 23.288 [19]. They can collect The control data service function contains data repository
control data based on subscription to events occurring in and related functions for maintaining and providing control
network functional elements, such as the User Plane data to both the internal network state analysis function and
Function (UPF), Session Management Function (SMF), and external integrated network control system through the
Access and Mobility management Function (AMF), and network control external interfaces. As in the integrated
from local data repositories collocated with individual control system, the network state analysis function of the
functional elements. Similarly, for NFV and SDN-based individual network control system can apply machine
virtualized data networks, the control data collection learning and other data mining techniques to process the
methods and interfaces have been specified in detail in control data, together with service requirements and user
ETSI NFV standards [20]. However, NTN network intent parameters, and assess the network status (e.g.
segments still lack standard frameworks of network control resource utilization, performances, anomaly detection, fault
internal interfaces for collecting control data and issuing and failure prediction). The control data is provided to the
control commands from remotely. The concept and integrated network control system based on subscriptions,
approaches used in TN data collection can be gradually whose formats are negotiated in advance.
introduced into NTN segments as the new generation of
NTN space and ground components also support NFV and As stated earlier, the integrated network control system
SDN. processes data obtained from TN and NTN network
segments to assess the E2E network service performance
NTN control data can be roughly divided into the following and make network control decisions. The network control
four groups: (1) preset system parameters, (2) service/user decisions are fed to the individual network control system’s
requirements, (3) system monitoring parameters, and (4) network resource control, management and optimization
NTN link control parameters. The preset system parameters function. The network resource allocation, management,
such as satellite orbit coordinates and number of satellites and optimization function also receives the network state
(in a constellation), coordinates and number of GSTs, analysis results from the local network state analysis
number of communication interfaces, their types (e.g. function. It uses both the E2E network control decision
physically/logically connected, FSO or RF links, made by the integrated network control system and local
transparent or regenerative, and antenna patterns), beam network state to make an appropriate decision to control its
coverage size and numbers, fixed or movable beam types, network segment. The decisions are given to the network
total bandwidth, and total power are static parameters. control and orchestration function.
Similarly, service/user requirements such as service type
(e.g. voice, video, browsing, and sensors data), and QoS The network control and orchestration functions generate
requirements (e.g. minimum traffic rate, tolerable call drop control commands and send them to the related controlled
or packet loss rate, maximum latency, and security levels) elements. For example, the control commands in NTN can
are also static parameters. System monitoring parameters be for increasing bandwidth allocation to a beam, changing
are dynamic parameters such as the number of active user beam projection angles, selection of a different GST,
terminals, resource (RF and FSO) utilization, weather switching RF links to FSO links, rerouting of traffic in
conditions, Doppler shift, and performance (e.g. throughput, satellite constellation or satellite-HAPS networks, and so on.
latency, jitter, packet loss and call drop rates). NTN link The difference between the global network control and
control parameters such as beam RF bands or FSO orchestration functions of the integrated network control
wavelengths and coding rate (with or without encryption) system and local individual network segment control
are dynamic parameters. system is that the global network control commands can be
generated in an abstract format while the local control
In current NTN systems, this control data is available in commands are generated in the form of a given network
different components. For example, satellite coordinates, segment technology-specific syntax. For example, the NTN
satellite conditions, and inter-satellite link quality can be control and orchestration function should be able to

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