# Multi-Connectivity for Multicast Video Streaming in Cellular Networks
###### Abstract  
The escalating demand for high-quality video streaming poses a major challenge for communication networks today. Catering to these bandwidth-hungry video streaming services places a huge burden on the limited spectral resources of communication networks, limiting the resources available for other services as well. Large volumes of video traffic can lead to severe network congestion, particularly during live streaming events, which require sending the same content to a large number of users simultaneously. For such applications, multicast transmission can effectively combat network congestion while meeting the demands of all the users by serving groups of users requesting the same content over shared spectral resources. Streaming services can further benefit from multi-connectivity, which allows users to receive content from multiple base stations simultaneously. Integrating multi-connectivity within multicast streaming can improve the system resource utilization while also providing seamless connectivity to multicast users. Toward this end, this work studied the impact of using multi-connectivity (MC) alongside wireless multicast for meeting the resource requirements of video streaming. Our findings show that MC substantially enhances the performance of multicast streaming, particularly benefiting cell-edge users who often experience poor channel conditions. We especially considered the number of users that can be simultaneously served by multi-connected multicast systems. It was observed that about 60% of the users that are left unserved under single-connectivity multicast are successfully served using the same resources by employing multi-connectivity in multicast transmissions. We prove that the optimal resource allocation problem for MC multicast is NP-hard. As a solution, we present a greedy approximation algorithm with an approximation factor of \((1-1/e)\). Furthermore, we establish that no other polynomial-time algorithm can offer a superior approximation. To generate realistic video traffic patterns in our simulations, we made use of traces from actual videos. Our results clearly demonstrate that multi-connectivity leads to significant enhancements in the performance of multicast streaming. m 2024  
A large portion of video traffic is made up of live streaming from social media and streaming platforms with millions of users watching the same content simultaneously. These live streams pose additional challenges for the network due to their high data rate, low latency, and overall quality of service requirements [2]. Using traditional one-to-one or unicast communications, such applications involves transmitting the same content separately to each user, thus consuming a large portion of the available bandwidth. Multicast transmissions are an efficient means of catering to such services by serving users that need the same content simultaneously [3,4]. Multi-connectivity allows users to receive content from multiple base stations simultaneously. Therefore, when a video is being streamed by several base stations, allowing multi-connectivity within multicast transmissions can further improve the performance of multicast streaming services. We use the term _Multi-Connectivity (MC) multicasting_ to refer to such a system where multi-connectivity is used alongside multicast transmissions. In this MC multicast system, users are capable of multi-connectivity and can, therefore, receive multicast content from multiple base stations simultaneously. This paper proposes the use of MC multicasting for catering to the simultaneous demands of bandwidth-hungry video streams. Integrating MC with multicast transmission not only boosts cell capacity, but also diminishes the reliance of good multicasting performances from the weakest users in the system. While MC has received considerable attention for its impact on throughput and handover improvements [5, 6, 7, 8], its unexplored integration with multicast transmissions presents a promising avenue for further research.