Joint Communication, Sensing, and Computing in Space-Air-Ground Integrated Networks: System Architecture and Handover Procedure

With the ongoing expansion of user numbers and the diversity of business types, wireless networks are progressing toward broader spatial dimensions and increased functionality. With respect to coverage, the space-air-ground integrated network (SAGIN) is considered a promising solution for providing seamless global connectivity to emerging services. In terms of functionality, wireless networks are expected to offer not only communication services but also sensing and computing services, which are crucial for certain businesses. However, within SAGIN there is a significant variance in performance among different types of radio access networks (RANs). This necessitates a reconsideration of system architecture and handover selection schemes to meet the quality of service (QoS) requirements of various business applications. The main focus of this article is to explore the integration of sensing and mobile edge computing (MEC) with SAGIN and also to examine the system architecture, selection schemes, and handover procedures. We first provide an overview of SAGIN's capabilities and highlight its integrated architecture. Subsequently, we introduce several handover selection schemes, followed by an elaboration on the redesigned handover procedure for SAGIN. Finally, we present some simulation results and discuss challenges that need to be addressed in practical implementation.