Random Access Procedure for 5G/6G Direct-to-Satellite LEO Connectivity with Limited-Capacity IoT Devices

The current connectivity landscape shows a growing proliferation of connected devices and the need for global coverage. The Internet of Things (IoT) is a key factor in this exponential growth, including limited-capacity IoT devices, which are widely used in challenging environments, such as remote monitoring. Along with this, the rapid evolution of satellite communications, with signals transmitted from space, broad coverage, and ubiquity, poses new challenges to the demand for massive connectivity in terms of efficiency, latency, and network management. In this context, fifth-generation (5G) networks and the their upcoming sixth-generation (6G) evolution are emerging as important enablers. This paper provides some challenges and research directions in the random access procedure for direct connection to LEO satellites from limited-capacity 5G IoT devices.