5G Multicast Broadcast Services Over Non Terrestrial Networks: An In-Depth Performance Analysis

The integration of 5G Multicast Broadcast Services (5MBS) within 3rd Generation Partnership Project (3GPP)-based Non-Terrestrial Networks (NTN) represents a major advancement in bridging the digital divide and improving network efficiency for multicast and broadcast communication. This paper presents a comprehensive study on the integration of 5MBS over NTN, focusing on a simulation-based performance evaluation. NTN, including Geosynchronous Earth Orbit (GEO), Medium Earth Orbit (MEO), and Low Earth Orbit (LEO) satellite systems, offer extensive coverage capabilities, particularly benefiting rural and underserved areas. A key highlight is the incorporation of Hybrid automatic repeat request (HARQ)-based Time Interleaving (TIL) mechanisms, which enhance broadcast resilience in NTN environments. NTN channels are characterized by high user mobility and dynamic channel conditions. By leveraging time diversity and spreading coded bits across non-consecutive slots, the proposed approach mitigates the effects of fast-fading and Doppler shift scenarios, achieving performance gains from 1 dB at lower speeds to 2.8 dB at 500 km/h, ensuring robust communication under Line of Sight (LoS) and Non Line of Sight (NLoS) conditions. This study proposes a 5MBS solution tailored for NTN deployment using a Link Level Simulator (LLS), considering channel modeling, environmental factors, and high mobility scenarios. The results show that while existing NTN setups struggle to maintain performance in high-speed environments (e.g., airplanes), the proposed HARQ-based TIL significantly improves performance under these challenging conditions. These findings validate the feasibility of integrating 5MBS with NTN and highlight its potential to deliver scalable and reliable broadcast and multicast services. The study provides valuable insights for future enhancements in 5G-Advanced systems and lays the foundation for novel Terrestrial Networks (TN)-NTN convergent deployments, contributing to the evolution of satellite-based communication networks and the International Mobile Telecommunications (IMT)-2030 evaluation process.