A service processing method, related device and communication system. The service processing method comprises: a radio access equipment in a mobile network receives a notification message; if the notification message indicates a failure of a link between a wireless local area network access point and a wireless local area network communication module of a user equipment (UE), the radio access equipment prepares to change packet transmission to the UE from via the wireless local area network access point to via the mobile network. The technical solution in an embodiment of the present invention increases timeliness and accuracy of acquiring WLAN-related information of a UE by a radio access equipment in a mobile network, thus enhancing integration between a mobile network and a WLAN.
