A cellular base station is configured to execute functions of: a plurality of packet data convergence protocol (PDCP) entities corresponding to a plurality of bearers used in performing a communication with a user terminal in which the user terminal is configured to utilize radio resources of the cellular base station and a wireless local area network (WLAN) access point; and a specific entity that provides a PDCP packet with a header including a bearer identifier to generate a specific packet, the PDCP packet generated by each of the plurality of PDCP entities. The bearer identifier is for identifying a bearer to which the specific packet belongs, from the plurality of bearers. The specific entity transmits the specific packet to the user terminal via the WLAN access point.