Random Access Process Analysis of 5G New Radio Based Satellite Links

Integration of the satellite component into the fifth generation (5G) new radio (NR) system is an ongoing activity within the 3GPP standardization body. However, as the 5G NR system is primarily designed for terrestrial applications, its direct usage with satellite communications may raise problems whose solutions affect its underlying design principles and operation. This paper addresses this adaptation and then analyses the suitability of the 5G NR random access procedure for satellite usage. Although many of the already standardized configuration parameters and procedures are flexible enough and can be used without modifications, the timing advance (TA) calculations, its value transmission, as well as associated timers' configuration require reworking. Furthermore, we also observed the guard interval needed by the physical random access signal may be reduced using the so called minimum common delay that has to be transmitted to the terminals.