Abstract: The method is applied to a communications system including a first network device, a second network device, and a terminal device. The terminal device is communicatively connected to the first network device and the second network device respectively. The method includes: sending, by a network device, a first message to the terminal device, where the first message is used to determine that the terminal device stops communication with the first network device, or the first message is used to determine that the terminal device releases a protocol stack and a data radio bearer that are corresponding to the first network device; and the network device is the first network device or the second network device. Therefore, power consumption of the terminal device or the first network device and waste of air interface resources can be reduced, and flexibility can effectively be improved in a communication process.

Abstract: A communication method includes: sending, by a first device, a handover request message to a second device, and receiving a handover acknowledgement message returned by the second device, where the handover acknowledgement message carries common system information of the second device; sending, by the first device, a handover command to a terminal, where the handover command includes the common system information of the second device; sending, by the first device, a second message to the terminal based on a first message, so that the terminal obtains changed communications system information of the second device based on the second message, where the first message is sent by the second device, and the first message is used to indicate a change occurring in the common system information of the second device.

Abstract: A route update method relating to a communications field includes: sending a medium access control protocol data unit (MAC PDU), wherein the MAC PDU comprises a first buffer status report (BSR); and canceling, in response to the sending of the MAC PDU, a scheduling request triggered prior to the MAC PDU assembly. The first BSR comprises a buffer status up to the last event that triggers a BSR prior to the MAC PDU assembly.