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CN-122002417-A - Secondary cell group change based on dual connectivity

CN122002417ACN 122002417 ACN122002417 ACN 122002417ACN-122002417-A

Abstract

Example embodiments of the present disclosure relate to dual connection-based (DC-based) secondary cell group changes. A method includes receiving an inter-secondary-node handover configuration from a first network device for a dual connection-based secondary-cell group change, performing at least one measurement related to a second cell provided by the second network device, reporting the at least one measurement to the first network device, receiving an indication from the first network device to initiate the dual connection-based secondary-cell group change, initiating a cell handover from the first cell provided by the first network device to the second cell based on the inter-secondary-node handover configuration, adding the second cell to the secondary-cell group based on the indication, and deactivating a primary-cell group including the first cell.

Inventors

  • H.M. Gulsu
  • S Saierwajianapasi
  • J. Steinchuck
  • K. Koldi Bach
  • A. Arjuna

Assignees

  • 诺基亚技术有限公司

Dates

Publication Date
20260508
Application Date
20251107
Priority Date
20241107

Claims (10)

  1. 1. A user equipment, comprising: At least one processor, and At least one memory storing instructions that, when executed by the at least one processor, cause the user equipment operating in a single connection to at least: Receiving, from a first network device, an inter-secondary node handover configuration for a dual connection-based secondary cell group change; performing at least one measurement related to a second cell provided by a second network device; reporting the at least one measurement to the first network device; Receive, from the first network device, an indication to initiate the dual connection-based secondary cell group change; initiating a cell handover from a first cell provided by the first network device to the second cell based on the inter-secondary node handover configuration; adding the second cell to a secondary cell group based on the indication, and Deactivating a primary cell group comprising the first cell.
  2. 2. The user device of claim 1, wherein the instructions, when executed by the at least one processor, further cause the user device to: A packet data convergence protocol entity for the primary cell group is maintained.
  3. 3. The user equipment of claim 1 or 2, wherein the instructions, when executed by the at least one processor, further cause the user equipment to: Based on the indication, at least one of: Resetting at least one of a radio link control entity, a medium access control entity and a physical layer entity for the primary cell group; stopping at least one of radio link monitoring and radio link failure detection for the primary cell group; Stopping beam failure detection for the primary cell group; Stopping the measurement of the primary cell group; Triggering a re-establishment procedure based on detecting a radio link failure for the secondary cell group, and The method further includes converting signaling radio bearers for the primary cell group to separate bearers for both the primary cell group and the secondary cell group, wherein a portion of the separate bearers corresponding to the primary cell group is disabled.
  4. 4. The user equipment of claim 1 or 2, wherein the first cell serves as a primary cell for the user equipment, and wherein the instructions, when executed by the at least one processor, further cause the user equipment to: Maintaining the primary cell configuration of the first cell in a suspended state, and In response to switching back to the first cell, the primary cell configuration is activated if a secondary cell group configuration is suspended.
  5. 5. The user equipment of claim 1 or 2, wherein the instructions, when executed by the at least one processor, further cause the user equipment to: transmitting a measurement report identifying the second cell to the first network device, Wherein the secondary inter-node handover configuration is received from the first network device after sending the measurement report.
  6. 6. The user equipment according to claim 1 or 2, wherein the secondary inter-node handover configuration is received via radio resource control signaling.
  7. 7. The user equipment of claim 1 or 2, wherein the indication is received via medium access control signaling.
  8. 8. The user equipment of claim 1 or 2, wherein the instructions, when executed by the at least one processor, further cause the user equipment to: Performing a random access procedure with the second network device to convert the second cell into a primary and secondary cell, and And sending a radio resource control reconfiguration complete message to the second network device.
  9. 9. The user equipment of claim 1 or 2, wherein the instructions, when executed by the at least one processor, further cause the user equipment to: a radio resource control reconfiguration complete message is sent to the second network device without a random access procedure with the second cell to switch the second cell to a primary secondary cell.
  10. 10. The user equipment according to claim 1 or 2, wherein the inter-secondary node handover configuration comprises at least one secondary cell group configuration of at least one candidate cell, the at least one candidate cell comprising the second cell.

Description

Secondary cell group change based on dual connectivity Technical Field Various example embodiments relate generally to the field of telecommunications and, more particularly, relate to methods, apparatus, devices, and computer-readable storage media for dual connection-based (DC-based) secondary cell group change. Background When a User Equipment (UE) moves from the coverage area of one cell to another cell, a serving cell change needs to be performed at some point in time. low-Layer Triggered Mobility (LTM), also known as layer 1 (L1)/layer 2 (L2) based inter-cell mobility, has been introduced to enable serving cell change via L1/L2 signaling. LTM helps reduce delay, overhead, and interrupt time during handover. Disclosure of Invention In a first aspect, a user equipment is provided. The user equipment comprises at least one processor and at least one memory storing instructions that when executed by the at least one processor cause the user equipment operating in a single connectivity mode to at least receive an indication from a first network device to initiate a dual connectivity based secondary cell group change, add a first cell or a second cell to a secondary cell group based on the indication, the first cell provided by the first network device and serving the user equipment and the second cell provided by the second network device, and deactivate a primary cell group comprising the first cell. In a second aspect, a first network device is provided. The first network device includes at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the first network device to at least receive at least one measurement from a user device operating in a single connectivity mode related to a second cell provided by a second network device, determine to initiate a dual connectivity-based secondary cell group change for the user device based on the at least one measurement, send an indication to the user device to initiate the dual connectivity-based secondary cell group change, and enter the user device from the single connectivity mode to the dual connectivity mode based on the determination. In a third aspect, a second network device is provided. The second network device includes at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the second network device to at least receive a request for a secondary node addition from the first network device, the request indicating that the secondary node addition is to be used for a dual connection-based secondary cell group change for the user device, and determine that the primary cell group is to be deactivated by the user device for the dual connection-based secondary cell group change based on the request. In a fourth aspect, a method is provided. The method includes receiving an indication from a first network device to initiate a dual connection-based secondary cell group change, adding a first cell or a second cell to the secondary cell group based on the indication, the first cell being provided by the first network device and serving the user device and the second cell being provided by the second network device, and deactivating a primary cell group comprising the first cell. In a fifth aspect, a method is provided. The method includes receiving at least one measurement from a user equipment operating in a single connection mode related to a second cell provided by a second network device, determining to initiate a dual connection based secondary cell group change for the user equipment based on the at least one measurement, sending an indication to the user equipment to initiate the dual connection based secondary cell group change, and causing the user equipment to enter a dual connection mode from the single connection mode based on the determination. In a sixth aspect, a method is provided. The method includes receiving a request for a secondary node addition from a first network device, the request indicating that the secondary node addition is to be used for a dual connection-based secondary cell group change for a user device, and determining that a primary cell group is to be deactivated by the user device for the dual connection-based secondary cell group change based on the request. In a seventh aspect, a first apparatus is provided. The first apparatus includes means for receiving an indication from a first network device to initiate a dual connection-based secondary cell group change, means for adding a first cell or a second cell to the secondary cell group based on the indication, the first cell being provided by the first network device and serving the user device and the second cell being provided by the second network device, and means for deactivating a primary cell group comprising the first cell. In an eighth aspect, a second apparatus is provided. The second apparatus includes means for receiving at leas