A method of system information (SI) acquisition with reduced signaling overhead is proposed. To reduce SI broadcast overhead, the quantity of periodic SI broadcast and the frequency of on-demand SI acquisition need to be reduced. In order to reduce the quantity of periodic SI broadcasting, on-demand SI delivery is enabled. With on-demand SI delivery, signaling overhead is proportional to the frequency of SI acquisition. From the network side, the base stations proactively provide SI delivery options and delivers SI over unicast or scheduled broadcast. From the UE side, UE determines how to acquire SI, i.e., by listening to broadcast or by sending an on-demand request via existing procedures such as a random-access procedure over a random-access channel (RACH).