Method for coordination of control plane traffic management during device reconfigurations and related apparatus
The present disclosure relates generally to communications, and more particularly to communication methods and related devices and nodes for control plane traffic management. Among other things, the disclosure presents a method performed by a central unit (CU) of a network node for coordination of control plane traffic management during a communication device reconfiguration in a telecommunications network. The method may, e.g., comprise receiving information from a distributed unit (DU) of the network node alerting the CU to reset a packet data convergence protocol (PDCP) sequence number of control plane traffic signaled from the communication device as a consequence of an event in the telecommunications network; and responsive to receiving the information, resetting the PDCP sequence number of the control plane traffic signaled from the communication device.
1 . A method performed by a central unit (“CU”) of a source network node for coordination of control plane traffic management during a communication device reconfiguration in a telecommunications network, the method comprising:
receiving information from a distributed unit (“DU”) of the source network node alerting the CU to reset a packet data convergence protocol (“PDCP”) sequence number of control plane traffic signaled from the communication device as a consequence of an event in the telecommunications network; and
responsive to receiving the information, resetting the PDCP sequence number of the control plane traffic signaled from the communication device,
wherein receiving the information comprises receiving from the DU an uplink message from a target cell and an indicator that the uplink message is a first message sent from the target cell.
2 . The method of claim 1 , wherein the uplink message comprises a radio resource control (“RRC”) message from the target cell.
3 . The method of claim 1 , wherein the indicator comprises a flag indicating that the uplink message is the first message sent from the target cell.
4 . The method of claim 3 , wherein the flag comprises a re-established signaling radio bearer (“SRB”) flag indicating that the RRC message is the first message on a re-established SRB flow.
5 . The method of claim 1 , wherein the uplink message is received from the DU over an F1 interface.
6 . The method of claim 1 , wherein the uplink message comprises an uplink RRC message transfer message.
7 . The method of claim 1 , further comprising:
receiving from the DU an other message comprising an indication that the DU supports sending one or more messages that include the indicator; and
responsive to receiving the other message, waiting to reset the PDCP sequence number of the control plane traffic signaled from the UE until the CU receives the uplink message including the indicator.
8 . A source network node in a telecommunications network, the source network node configured to provide a central unit (“CU”), the source network node comprising:
processing circuitry; and
memory coupled to the processing circuitry and having instructions stored therein that are executable by the processing circuitry to cause the CU to perform operations comprising:
receiving information from a distributed unit (“DU”) of the source network node alerting the CU to reset a packet data convergence protocol (“PDCP”) sequence number of control plane traffic signaled from the communication device as a consequence of an event in the telecommunications network; and
responsive to receiving the information, resetting the PDCP sequence number of the control plane traffic signaled from the communication device,
wherein receiving the information comprises receiving from the DU an uplink message from a target cell and an indicator that the uplink message is a first message sent from the target cell.
9 . The source network node of claim 8 , wherein the uplink message comprises a radio resource control (“RRC”) message from the target cell.
10 . The source network node of claim 8 , wherein the indicator comprises a flag indicating that the uplink message is the first message sent from the target cell.
11 . The source network node of claim 10 , wherein the flag comprises a re-established signaling radio bearer (“SRB”) flag indicating that the RRC message is the first message on a re-established SRB flow.
12 . A method performed by a distributed unit (“DU”) of a source network node for coordination of control plane traffic management during a communication device reconfiguration in a telecommunications network, the method comprising:
signaling a message to a central unit (“CU”) of the source network node comprising an indicator of timing of a packet data convergence protocol (“PDCP”) sequence number for control plane traffic signaled from the communication device for an event in the telecommunications network,
wherein signaling the message to the CU comprises signaling an uplink message from a target cell and the indicator that the uplink message is a first message sent from the target cell.
13 . The method of claim 12 , wherein the uplink message comprises a radio resource control (“RRC”) message from the target cell.
14 . The method of claim 12 , wherein the indicator comprises a flag indicating that the uplink message is the first message sent from the target cell.
15 . The method of claim 14 , wherein the flag comprises a re-established signaling radio bearer (“SRB”) flag indicating that the RRC message is the first message on a re-established SRB flow.
16 . The method of claim 12 , wherein the message is signaled by the DU to the CU over an F1 interface.
17 . The method of claim 12 , wherein the message comprises an uplink RRC message transfer message.
18 . A source network node of a telecommunications network, the source network node configured to provide a distributed unit (“DU”), the source network node comprising:
processing circuitry; and
memory coupled to the processing circuitry and having instructions stored therein that are executable by the processing circuitry to cause the DU to perform operations comprising:
signaling a message to a central unit (“CU”) of the source network node comprising an indicator of timing of a packet data convergence protocol (“PDCP”) sequence number for control plane traffic signaled from the communication device for an event in the telecommunications network,
wherein signaling the message to the CU comprises signaling an uplink message from a target cell and the indicator that the uplink message is a first message sent from the target cell.
19 . The source network node of claim 18 , wherein the indicator comprises a flag indicating that the uplink message is the first message sent from the target cell.
20 . The DU source network node of claim 19 , wherein the flag comprises a re-established signaling radio bearer (“SRB”) flag indicating that the RRC message is the first message on a re-established RB flow.