In a wireless communication system, a Session Management Function (SMF) transfers signaling to a User Plane Function (UPF) to deliver a wireless data service to a wireless User Equipment (UE). The UPF exchanges user data with the wireless UE over a source Radio Unit (RU) to deliver the wireless data service. A Radio Resource Control (RRC) detects the RU handover of the wireless UE from the source RU to a target RU and transfers an RU handover notice for the wireless UE the SMF. The SMF transfers new signaling to the UPF to modify the wireless data service for the wireless UE. The UPF exchanges additional user data with the wireless UE over the target RU to deliver the modified wireless data service to the wireless UE.