LEO Mega-Constellations for 6G Global Coverage: Challenges and Opportunities

Abstract

Mega-constellations have the potential for providing 6G Internet owing to the unique advantage of global coverage. However, current satellite technologies are not omnipotent. There are still many challenging problems that need to be solved for mega-constellations to support 6G, e.g., efficient resource allocation, gratifying mobility management, and large-scale full-time TT&C (tracking, telemetry, and command). This paper starts with a novel definition of LEO mega-constellations and a brief review regarding the current typical mega-constellations, discussing the development direction of the mega-constellation air interface. Then, the key technologies development status of satellite networks is illustrated and analyzed from five aspects: network protocol, multiple access, satellite handover, TT&C, and interference mitigation, especially their adaptability in mega-constellations for 6G global coverage. Finally, considering the features and requirements of 6G, future challenges for mega-constellations and some potential solutions are proposed.

Functional Security and Trust in Ultra-Connected 6G Ecosystem

“…In the case of satellites, the constellations are pre-validated. In contrast, with the involvement of autonomous vehicles (be it in the air, ground or sea), the topology gets severely affected, and trust becomes an essential factor on top of the security of communication when handovers are involved [9] [10]. These trust issues go beyond the topology and involve several data spaces where the trust needs to be maintained between the satellites and the autonomous vehicles to ensure accurate delivery of services.…”

“…These values further help to get the operational latency for a security function with a specific observation that the number of passes in the protocol and the time of evaluation at a hop has far more considerable impact than the number of hops used in the handover process as channel latency will be extremely low in 6G setup. Another observation is if the network needs to attain an operational complexity of ≤100ms, the security protocol requires to complete all handover operations with the number of passes in the range [8,9], [7,8], and [6,7] for 1, 2 and 3 number of hops, respectively at a constant decision time of 10ms for each pass. Though these results do not give conclusive evidence as each pass may involve an operation with a different decision time, these results can provide an expected range for the number of passes in a protocol, which can be used by the researchers when designing secure handover techniques for 6G ecosystem.…”

Deep learning‐based space debris detection for space situational awareness: A feasibility study applied to the radar processing

“…This makes them ideal for applications such as Internet access, remote sensing, and navigation. Moreover, the shorter signal path in LEO reduces the amount of power required to transmit signals to and from satellites, making them more cost‐effective [5].…”

“…This makes them ideal for applications such as Internet access, remote sensing, and navigation. Moreover, the shorter signal path in LEO reduces the amount of power required to transmit signals to and from satellites, making them more costeffective [5].However, the increase in the number of satellites also heightens the possibility of satellite collisions, hence generating debris in orbit and, in turn, enhancing the possibility of further collisions. This phenomenon is like the growth of the asteroid belt.…”

Deriving Upper Bound on Channel Capacity of LEO Satellite Communication Link at sub-THz Frequencies

“…will require that the next generation of wireless communication system namely 6G be designed at THz frequencies (0.1 to 10 THz) [2]. The mega constellations of LEO satellites would play significant part in the next generation communication infrastructure with its seamless integration in the upcoming 6G network [3]. These satellite networks will be deployed at sub-THz bands due to larger available bandwidth that will lead to higher data rates of multi-giga bits per sec (MGbps) [4] with lower latency [5].…”