6G NR-U Based Wireless Infrastructure UAV: Standardization, Opportunities, Challenges and Future Scopes

Abstract

Providing ubiquitous connectivity for people and equipment with a wide range of service conditions is regarded as the major design goal of 6G networks. Moreover, the future 6G networks need to be extremely flexible to enable reliable and low-latency access for the dynamic number of mobile user equipment. The current base stations (BSs) and remote relay antennas are mostly, on the other hand, installed at fixed geographic locations based on long-term traffic patterns with little re-deployment flexibility. For most 6G applications, where dynamic data traffic occurs in both spatial and temporal domains, such rigid radio access networks (RANs) are unable to maintain ubiquitous connectivity. On the other hand, the rapid advancement of unmanned aerial vehicle (UAV) technology is creating a unique opportunity for the cellular operator to realize flying wireless infrastructure called wireless infrastructure UAV (WI UAV). WI UAV supports wireless connectivity and can stir itself to improve spectral efficiency, coverage, and quality of service of the end-users. This paper introduces 6G new radio in the unlicensed band (NR-U)-based WI UAV that can be used as a base station, relay, or data collector/disseminator. UAV are categorized based on their characteristics, applications, and operations. Further, this paper discusses various regulatory and standardization initiatives for integrating UAVs into the cellular network. Non-standalone NR-U network architecture is designed and explained for WI UAV. Several opportunities and design challenges of NR-U for the WI UAV are discussed and future scopes of WI UAVs are presented.

Swarm of UAVs for Network Management in 6G: A Technical Review

“…Bajracharya et al [58] presented a WI UAV with a 6G new radio running in the unlicensed band, which could be used as a relay, base station, or data collection/dissemination point. In this article, the authors have classed UAVs based on their characteristics, functions, and operations.…”

Designing a 6G Testbed for Location: Use Cases, Challenges, Enablers and Requirements

“…DUs are much simpler (and therefore, cheaper) and flexible than base stations, and can be added and removed with much less effort, allowing for a scalable network. Additionally, DUs may even be mounted on mobile platforms, to provide temporary connectivity for IoT [171] or disaster scenarios [172] using, for instance, Unmanned Aerial Vehicles (UAV).…”

Graph-Based Resource Allocation for Integrated Space and Terrestrial Communications

“…Following these limitations, several open challenges and research directions for the design and implementation of graph-based RA procedures are expanded in a greater detail: Modeling coexistence and communications between sub-networks on different layers of GRIST. As it has been explored in various studies [ 90 , 91 , 93 , 96 , 97 ], the realization of the coexistence and reliable information exchange between contemporary and future networks is non-trivial. In order to provide ubiquitous and saleable networks that ensure seamless communications on all four layers [ 93 , 96 ], the integration of TN and NTNs can be facilitated by graph-based algorithms for RA, energy conservation, data offloading, localization, and dynamic spectrum access in the unlicensed bands (that are suitable for upcoming aerial communication nodes [ 97 ]).…”

“…As it has been explored in various studies [ 90 , 91 , 93 , 96 , 97 ], the realization of the coexistence and reliable information exchange between contemporary and future networks is non-trivial. In order to provide ubiquitous and saleable networks that ensure seamless communications on all four layers [ 93 , 96 ], the integration of TN and NTNs can be facilitated by graph-based algorithms for RA, energy conservation, data offloading, localization, and dynamic spectrum access in the unlicensed bands (that are suitable for upcoming aerial communication nodes [ 97 ]). Such solutions will need to consider the physical parameters (speed, direction, weight, altitude of operation, size, available power supply/battery, etc.)…”

“…These aspects will then define the graphs’ structures and attributes within GRIST. The following two examples are given: (1) RA for a sub-network that includes terrestrial and aerial nodes ( Figure 8 a), is dependent on the physical parameters of the UAVs mentioned above, as well as on the movement speed and the spectrum access scheme (fixed/dynamic) of the ground users [ 96 , 97 ]. Together with the traditional RA problems in a terrestrial network, the graph-based solutions within GRIST will need to solve the problems of user and UAV mobility, determined by the aerial nodes’ battery limitation, transmission power, and available channels (incumbent or shared), which can also be described as vertex attributes.…”