Search

US-12628004-B2 - Method for addition and change of conditional primary cells in a secondary cell group

US12628004B2US 12628004 B2US12628004 B2US 12628004B2US-12628004-B2

Abstract

A master node (MN) may send a secondary node (SN) addition request message to a target SN with an indication of a maximum number of candidate PSCells that can be configured by the target SN. The MN may receive an SN addition request acknowledge message with at least one candidate PSCell configuration from the target SN in response to the SN addition request message. The MN may send, if data forwarding is needed, a data forwarding message with an indication that the data forwarding is for a CPAC based procedure to a source SN. The MN may send a RRC message to a wireless communication device including the at least one candidate PSCell configuration and one or more associated CPAC execution conditions.

Inventors

  • Mengjie ZHANG
  • He Huang
  • Jing Liu
  • Li Yang

Assignees

  • ZTE CORPORATION

Dates

Publication Date
20260512
Application Date
20221020

Claims (20)

  1. 1 . A method, comprising: sending, by a master node (MN) to a target secondary node (SN), an indication of a maximum number of candidate primary cells in a secondary cell group (PSCells) that can be configured by the target SN, in an SN addition request message; receiving, by the MN from the target SN, an SN addition request acknowledge message with at least one candidate PSCell configuration, in response to the SN addition request message; sending, by the MN to a wireless communication device, a radio resource control (RRC) message including the at least one candidate PSCell configuration and one or more associated conditional PSCell addition or change (CPAC) execution conditions, to cause the wireless communication device to perform a CPAC procedure to the target SN when a candidate PSCell satisfies the one or more associated CPAC execution conditions; and sending, by the MN to a source SN if data forwarding is to take place, a data forwarding message with an indication that the data forwarding is for a CPAC based procedure.
  2. 2 . The method of claim 1 , wherein the indication of the maximum number of candidate PSCells is included in an information element of the SN addition request message, wherein the indication that the data forwarding is for the CPAC procedure is included in an information element of the data forwarding message.
  3. 3 . The method of claim 1 , wherein the wireless communication device selects a candidate PSCell, to perform a CPAC procedure to the selected candidate PSCell.
  4. 4 . The method of claim 3 , comprising: receiving, by the MN from the wireless communication device, a RRC message indicating execution of the CPAC procedure to the selected candidate PSCell; and sending, by the MN responsive to the RRC message, a Xn interface or X2 interface message to one or more candidate SNs other than the target SN, to release resources reserved for the CPAC procedure.
  5. 5 . The method of claim 4 , comprising: sending, by the MN to the source SN, an SN release message, to indicate release of resources of the source SN and cause the source SN to stop providing user data to the wireless communication device.
  6. 6 . The method of claim 1 , comprising: sending, by the MN ( 302 A) to the source SN ( 302 B) via a Xn interface or X2 interface message, an indication of a maximum number of cells allowed to be configured as candidate cells for the CPAC procedure, wherein the CPAC procedure is initiated by the source SN.
  7. 7 . The method of claim 6 , wherein the indication of a maximum number of cells is included in a RRC message included in the Xn interface or X2 interface message, wherein the RRC message is a CG-ConfigInfo message.
  8. 8 . A method, comprising: receiving, by a target secondary node (SN) from a master node (MN), an indication of a maximum number of candidate primary cells in a secondary cell group (PSCells) that can be configured by the target SN, in an SN addition request message; and sending, by the target SN to the MN, an SN addition request acknowledge message with at least one candidate PSCell configuration, in response to the SN addition request message, wherein the MN sends a radio resource control (RRC) message to a wireless communication device, the RRC message including the at least one candidate PSCell configuration and one or more associated conditional PSCell addition or change (CPAC) execution conditions, to cause the wireless communication device to perform a CPAC procedure to the target SN when a candidate PSCell satisfies the one or more associated CPAC execution conditions, wherein the MN sends, if data forwarding is to take place, a data forwarding message to a source SN with an indication that the data forwarding is for a CPAC based procedure.
  9. 9 . The method of claim 8 , wherein the indication of the maximum number of candidate PSCells is included in an information element of the SN addition request message, and wherein the indication that the data forwarding is for the CPAC procedure is included in an information element of the data forwarding message.
  10. 10 . The method of claim 8 , wherein the wireless communication device selects a candidate PSCell, to perform a CPAC procedure to the selected candidate PSCell.
  11. 11 . The method of claim 10 , wherein the MN receives a RRC message from the wireless communication device, the RRC message indicating execution of the CPAC procedure to the selected candidate PSCell, and sends, responsive to the RRC message, a Xn interface or X2 interface message to one or more candidate SNs other than the target SN, to release resources reserved for the CPAC procedure.
  12. 12 . The method of claim 11 , wherein the MN sends an SN release message to the source SN, to indicate release of resources of the source SN and cause the source SN to stop providing user data to the wireless communication device.
  13. 13 . The method of claim 8 , wherein the MN sends to the source SN via a Xn interface or X2 interface message, an indication of a maximum number of cells allowed to be configured as candidate cells for the CPAC procedure, wherein the CPAC procedure is initiated by the source SN.
  14. 14 . The method of claim 13 , wherein the indication of a maximum number of cells is included in a RRC message included in the Xn interface or X2 interface message, wherein the RRC message is a CG-ConfigInfo message.
  15. 15 . A master node (MN), comprising: at least one processor configured to: send, via a transceiver to a target secondary node (SN), an indication of a maximum number of candidate primary cells in a secondary cell group (PSCells) that can be configured by the target SN, in an SN addition request message; receive, via the transceiver from the target SN, an SN addition request acknowledge message with at least one candidate PSCell configuration, in response to the SN addition request message; send, via the transceiver to a wireless communication device, a radio resource control (RRC) message including the at least one candidate PSCell configuration and one or more associated conditional PSCell addition or change (CPAC) execution conditions, to cause the wireless communication device to perform a CPAC procedure to the target SN when a candidate PSCell satisfies the one or more associated CPAC execution conditions; send, to a source SN if data forwarding is to take place, a data forwarding message with an indication that the data forwarding is for a CPAC based procedure.
  16. 16 . A target secondary node (SN), comprising: at least one processor configured to: receive, via a transceiver from a master node (MN), an indication of a maximum number of candidate primary cells in a secondary cell group (PSCells) that can be configured by the target SN, in an SN addition request message; and send, via the transceiver to the MN, an SN addition request acknowledge message with at least one candidate PSCell configuration, in response to the SN addition request message, wherein the MN sends a radio resource control (RRC) message to a wireless communication device, the RRC message including the at least one candidate PSCell configuration and one or more associated conditional PSCell addition or change (CPAC) execution conditions, to cause the wireless communication device to perform the CPAC procedure to the target SN when a candidate PSCell satisfies the one or more associated CPAC execution conditions, wherein the MN sends, if data forwarding is to take place, a data forwarding message to a source SN with an indication that the data forwarding is for a CPAC based procedure.
  17. 17 . The MN of claim 15 , wherein the indication of the maximum number of candidate PSCells is included in an information element of the SN addition request message, and wherein the indication that the data forwarding is for the CPAC procedure is included in an information element of the data forwarding message.
  18. 18 . The MN of claim 15 , wherein the wireless communication device selects a candidate PSCell, to perform the CPAC procedure to the selected candidate PSCell, wherein the at least one processor is further configured to: receive, via the transceiver from the wireless communication device, a RRC message indicating execution of the CPAC procedure to the selected candidate PSCell; and send, via the transceiver responsive to the RRC message, a Xn interface or X2 interface message to one or more candidate SNs other than the target SN, to release resources reserved for the CPAC procedure.
  19. 19 . The MN of claim 18 , wherein the at least one processor is further configured to: send, via the transceiver to the source SN, an SN release message, to indicate release of resources of the source SN and cause the source SN to stop providing user data to the wireless communication device.
  20. 20 . The MN of claim 15 , wherein at the at least one processor is configured to: send, to the source SN ( 302 B) via a Xn interface or X2 interface message, an indication of a maximum number of cells allowed to be configured as candidate cells for the CPAC procedure, wherein the CPAC procedure is initiated by the source SN, wherein the indication of a maximum number of cells is included in a RRC message included in the Xn interface or X2 interface message, wherein the RRC message is a CG-ConfigInfo message.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of priority under 35 U.S.C. § 120 as a continuation of PCT Patent Application No. PCT/CN2020/106098, filed on Jul. 31, 2020, the disclosure of which is incorporated herein by reference in its entirety. TECHNICAL FIELD The disclosure relates generally to wireless communications, including but not limited to systems and methods for adding and changing conditional primary cells in a secondary cell group (PSCells). BACKGROUND The standardization organization Third Generation Partnership Project (3GPP) is currently in the process of specifying a new Radio Interface called 5G New Radio (5G NR) as well as a Next Generation Packet Core Network (NG-CN or NGC). The 5G NR will have three main components: a 5G Access Network (5G-AN), a 5G Core Network (5GC), and a User Equipment (UE). In order to facilitate the enablement of different data services and requirements, the elements of the 5GC, also called Network Functions, have been simplified with some of them being software based so that they could be adapted according to need. SUMMARY The example embodiments disclosed herein are directed to solving the issues relating to one or more of the problems presented in the prior art, as well as providing additional features that will become readily apparent by reference to the following detailed description when taken in conjunction with the accompany drawings. In accordance with various embodiments, example systems, methods, devices and computer program products are disclosed herein. It is understood, however, that these embodiments are presented by way of example and are not limiting, and it will be apparent to those of ordinary skill in the art who read the present disclosure that various modifications to the disclosed embodiments can be made while remaining within the scope of this disclosure. At least one aspect is directed to a system, method, apparatus, or a computer-readable medium. A master node (MN) may send a secondary node (SN) addition request message to a target SN with an indication of a maximum number of candidate primary cells in a secondary cell group (PSCells) that can be configured by the target SN. The MN may receive an SN addition request acknowledge message with at least one candidate PSCell configuration from the target SN in response to the SN addition request message. The MN may send, if data forwarding is needed, a data forwarding message with an indication that the data forwarding is for a conditional PSCell addition or change (CPAC) based procedure to a source SN. The MN may send a radio resource control (RRC) message to a wireless communication device including the at least one candidate PSCell configuration and one or more associated CPAC execution conditions, to cause the wireless communication device to perform a CPAC procedure to the target SN when a candidate PSCell satisfies at least one of the one or more CPAC execution conditions. In some embodiments, the indication of a maximum number of candidate PSCells may be included in an information element of the SN addition request message. In some embodiments, the indication that the data forwarding is for a CPAC procedure may be included in an information element of the data forwarding message. In some embodiments, the wireless communication device may select a candidate PSCell residing in a candidate SN other than the source SN, or a candidate PSCell residing in the source SN when a single radio bearer three (SRB3) is not configured, to perform a CPAC procedure to the selected candidate PSCell. In some embodiments, the MN may receive a RRC message from the wireless communication device indicating execution of the CPAC procedure to the selected candidate PSCell. In some embodiments, the MN may send, responsive to the RRC message, a Xn interface or X2 interface message to one or more candidate SNs other than the target SN, to release resources reserved for the CPAC procedure. In some embodiments, the MN may receive a Xn interface or X2 interface message from the target SN indicating successful completion of the CPAC procedure that includes identification information of the selected PSCell. In some embodiments, the MN may send another Xn interface or X2 interface message to one or more candidate SNs other than the target SN, to release resources reserved for the CPAC procedure. In some embodiments, the MN may send an SN release message to the source SN when the selected PSCell is not a candidate PSCell residing in the source SN, to indicate release of resources of the source SN and cause the source SN to stop providing user data to the wireless communication device. In some embodiments, the MN may determine whether to modify or cancel CPAC configuration for one or more candidate PSCells according to measurement results related to the target SN. In some embodiments, the MN may send a message to the target SN indicating to modify or cancel the CPAC configuration for the one