HANDOVER METHOD, NETWORK DEVICE, USER EQUIPMENT AND COMMUNICATION SYSTEM

Disclosed are a handover method, a network device, a user equipment, and a communication system. The handover method includes: updating a next hop chaining counter value and a next hop key in response to receiving a first handover request sent by a source base station for handing over a user equipment to a target base station, and sending a second handover request to the target base station; restoring the next hop chaining counter value and the next hop key to values before the update in response to receiving a message indicating that a handover preparation fails sent by the target base station; and sending a handover command to the source base station in response to receiving the message indicating that the handover preparation is successful sent by the target base station, to make the source base station control the user equipment to perform handover reconfiguration with the target base station.