Radio access network node, radio terminal, and method therefor

Patent metadata

Field	Value
Publication number	US-2022086704-A1
Application number	US-201917419643-A
Country	US
Kind code	A1
Filing date	Oct 31, 2019
Priority date	Jan 11, 2019
Publication date	Mar 17, 2022
Grant date	—

Abstract

A secondary node ( 2 ) transmits to a radio terminal ( 3 ), via a master node ( 1 ), a first RRC message indicating an execution condition of a conditional primary cell change of a primary cell of a secondary cell group from a first cell to a second cell. In addition, the secondary node ( 2 ) receives, via the master node ( 1 ), a second RRC message that is transmitted from the radio terminal ( 3 ) in response to a satisfaction of the execution condition. This contributes to, for example, allowing the secondary node to be aware of a satisfaction of an execution condition of a conditional PSCell change where RRC signaling between the secondary node and the radio terminal is performed via the master node.

First claim

1 - 8 . (canceled)

9 . A method for a radio access network node, the method comprising:
acting as a secondary node of dual connectivity for a radio terminal; transmitting to the radio terminal, via a master node of the dual connectivity, a first Radio Resource Control (RRC) message indicating an execution condition of a conditional primary cell change of a primary cell of a secondary cell group from a first cell to a second cell; and receiving, via the master node, a second RRC message that is transmitted from the radio terminal in response to a satisfaction of the execution condition.

10 . A method for a radio terminal, the method comprising:
performing dual connectivity of a master cell group associated with a master node and a secondary cell group associated with a secondary node; receiving from the secondary node, via the master node, a first radio Resource Control (RRC) message indicating an execution condition of a conditional primary cell change of a primary cell of the secondary cell group from a first cell to a second cell; and transmitting a second RRC message form the radio terminal to the secondary node via the master node, in response to a satisfaction of the execution condition.

11 - 23 . (canceled)

24 . A method for a radio access network node, the method comprising:
acting as a master node of dual connectivity for a radio terminal; receiving from a secondary node of the dual connectivity a first Radio Resource Control (RRC) message indicating an execution condition of a conditional primary cell change of a primary cell of a secondary cell group from a first cell to a second cell; forwarding the first RRC message to the radio terminal; receiving a second RRC message that is transmitted from the radio terminal in response to a satisfaction of the execution condition; and sending the second RRC message to the secondary node.

25 . The method according to claim 9 , further comprising detecting an initiation of the conditional primary cell change by receiving the second RRC message.

26 . The method according to claim 9 , further comprising, in response to receiving the second RRC message, stopping downlink data transfer to the radio terminal in a serving cell of the secondary cell group.

27 . The method according to claim 9 , wherein
the radio access network node is a central node of a base station, and the method further comprises, in response to receiving the second RRC message, stopping downlink data transfer to the radio terminal via a first distributed unit that serves the first cell.

28 . The method according to claim 27 , further comprising, in response to receiving, prior to the second RRC message, from the first distributed unit a control message indicating downlink data not yet transferred to the radio terminal, stopping downlink data transfer via the first distributed unit to the radio terminal.

29 . The method according to claim 28 , wherein the control message is a DOWNLINK DATA DELIVERY STATUS frame.

30 . The method according to claim 10 , wherein the second RRC message triggers the secondary node to stop downlink data transfer to the radio terminal in a serving cell of the secondary cell group.

Assignees

• Nec Corp

Inventors

• Futaki Hisashi
• Hayashi Sadafuku

Classifications

• H04W88/085

  Access point devices with remote components · CPC title

• H04W76/15

  Setup of multiple wireless link connections · CPC title

• H04W36/362 Primary

  Conditional handover · CPC title

• H04W36/36

  by user or terminal equipment · CPC title

• H04W36/00698

  using different RATs · CPC title