A base station side and user equipment side device and method in a wireless communication system, and a wireless communication system. The base station side device includes a processor configured to: respond to a random access request of the user equipment and determine that an access process initiated by the user equipment is a contention-based or a non-contention-based access process; and with respect to the contention-based access process, to prepare auxiliary access information for potential user equipment that has failed to access so that the user equipment that has failed to access and the base station can complete the access process based on interaction of auxiliary access information.