Semantic communication in 6G mega-satellite networks: system design and standardization

Satellite networks have been recognized as a pivotal component of 6G infrastructure by the 3rd Generation Partnership Project (3GPP) since Release 17, enabling global internet connectivity. However, the expanding user base and the increasing demand for content-rich applications will significantly raise data transmission needs, placing additional pressure on traditional satellite systems that are constrained by limited spectrum and bandwidth resources. Fortunately, semantic communication (SemCom) offers a transformative solution by transmitting only the essential meaning of information, reducing bandwidth consumption and alleviating these capacity limitations. This article explores the application of SemCom in 6G mega-satellite networks, focusing on system design, key components and their functionalities, and standardization, with the aim of guiding industrial implementation. We investigate various use cases for SemCom in satellite networks, and demonstrate the performance enhancements through simulations based on the Starlink constellation. Finally, we identify the challenges and provide future perspectives to foster the real-world deployment of SemCom-enhanced satellite networks toward global connectivity.