Research Paper on 'Evolution of Non-Terrestrial Networks From 5G to 6G'

Our fascination with satellite communications knows no bounds. While we have yet to succeed with 5G Non-terrestrial networks (NTNs), technically and commercially, research literature is heavily focused on evolution of NTNs for 6G. 

A recently updated research paper titled 'Evolution of Non-Terrestrial Networks From 5G to 6G: A Survey' looks at the following topics: 

  • NTNs Integration In 5G Ecosystem
  • NTNs Operation in mmWave
  • NTNs Integration In IoT
  • NTNs Integration In MEC Networks
  • ML-Empowered NTNs
  • Higher Layer Advancements
  • NTNs Field Trials & Industrial Efforts
  • NTNs Integration In 6G and Beyond
    • Use Cases
      • Satellite
      • UAV
    • Architectures
      • Open-RAN
      • Multi-Segments
      • 3D Cell-free
      • Mega LEO Constellation
    • Technological Enablers
      • X-Communication Co-Design
      • Intelligent Reconfigurable Surfaces
      • Multi-Mode Communication
      • Dynamic Spectrum Access
      • THz Communication
      • AI-Empowered Networks
      • Task-Oriented Communications
      • Quantum Satellite Networks
    • Higher Layer Aspects
      • Software-Defined Satellite
      • Quick UDP Internet Connections
      • Network Slicing and Virtualization
      • Highly distributed RAN

The following is the conclusion from the paper:

NTNs are perceived to play a significant role in the forthcoming generations of wireless networks, thanks to their lower cost and widespread reach. The unique characteristic of NTNs in providing global and on-demand coverage can facilitate a diverse range of new applications and services that are accessible to anything, anywhere, at anytime. With the steady progression towards the advanced wireless ecosystem, additional tasks are being delegated to NTNs justifying their broader integration into the TNs.

Considering the increasingly essential roles of NTNs, we provided an extensive review study on partially and fully integrated GAS networks from 5G to 6G by discussing the remarkable techniques ranging from new services (e.g., IoT and MEC), to new spectrum bands (e.g., mmWave and THz), to new approaches (e.g., ML). It is noted that, although NTNs will be rapidly adopted to complement the existing terrestrial infrastructure, several challenges arising from the technical peculiarities such as distinguished characteristics of the NT channel, Doppler effect, handover, seamless vertical integration, etc., need to be addressed. UAVs mobility pose critical challenges due to blockage and beam misalignment, particularly at higher frequencies viz., mmWave and THz.

Satellite integration with cellular networks using mmWave links seemed to be an important research domain, however, large propagation delays, Doppler effects, and co-channel interference need to be mitigated. For IoT networks, NTN integration is quite promising, especially, where terrestrial infrastructure does not exist. Moreover, MEC integration in NTN can overcome the computation limitations by offloading the complex processes while opportunistically accessing the different network segments. For instance, UAV’s onboard computation limitation demands offloading of heavy tasks to ground or space. Notably, ML-based methods can provide effective solutions to address several challenges such as network deployment optimization, channel estimation, mobility management, etc. However, more attention is required for an E2E ML-based corrective actions particularly in multisegment GAS networking. Further, for a reconfigurable and dynamically adaptable NTNs, the adoption of SDN is found to be a potential paradigm. It is also concluded that NTN-TN integration will most likely happen first at an architecture level and later at the PHY level.

Our review, further presented industry’s position in 5G NTNs integration efforts. Finally, we detailed the NTNs integration in 6G ecosystem from various perspectives entailing new use cases, supporting architectures, key technological enablers, and higher layer aspects.

With new advancements in satellite technology and connectivity, we will surely see a lot more of these research papers in the near future.

Related Posts