US 2020/0267608 A1 · BASE STATION APPARATUS AND METHOD THEREOF

Abstract

A secondary base station (2) receives an SeNB addition request message (302) from a second master base station (3) while providing a radio terminal (4) with a secondary cell group (SCG) for DC in cooperation with a first master base station (1). If the SeNB addition request message (302) explicitly or implicitly indicates that a master base station in DC for the radio terminal (4) is to be changed from the first master base station (1) to the second master base station (3), the secondary base station (2) considers that the SeNB addition request message (302) requests modification of the SCG that has already been configured. It is thus, for example, possible to contribute to performing a procedure for changing a master base station in Dual Connectivity (DC) by using existing inter-base station interface procedures and inter-base station signaling messages.

Claims13

Dependent claims

1-17. (canceled)

A Secondary Radio Access Network (RAN) node comprising:

at least one memory storing instructions;
and
at least one processor configured to process the instructions to:
operate a Secondary Cell Group (SCG);
communicate with a radio terminal configured to perform dual connectivity using the SCG and a Master Cell Group (MCG) operated by a first Master RAN node;
receive from a second Master RAN node, during a handover procedure from the first Master RAN node to the second Master RAN node, a Secondary RAN Node Addition Request message including a Secondary RAN node UE X2AP ID;
and
reject a Secondary RAN Node Addition Request procedure corresponding to the Secondary RAN Node Addition Request message by using a Secondary RAN Node Addition Reject message, in a case where the Secondary RAN node UE X2AP ID included in the Secondary RAN Node Addition Request message does not match any identity that is used to identify the radio terminal in the Secondary RAN node.

5 more elements

A radio terminal comprising:

at least one radio transceiver to communicate with a first Master Radio Access Network (RAN) node, a second Master RAN node, and a Secondary RAN Node;
and
at least one processor configured to communicate with the first Master RAN node and the second Master RAN node and to change a master RAN node in the dual connectivity from the first Master RAN node to the second Master RAN node while keeping a connection to a Secondary Cell Group (SCG) in the secondary RAN node, wherein
the Secondary RAN Node is configured to:
receive from the second Master RAN node, during a handover procedure from the first Master RAN node to the second Master RAN node, a Secondary RAN node Addition Request message including a Secondary RAN node UE X2AP ID;
and
reject the Secondary RAN node Addition Request message by using a Secondary RAN Node Addition Reject message, in a case where the Secondary RAN node UE X2AP ID included in the Secondary RAN node Addition Request message does not match any identity that is used to identify the radio terminal in the Secondary RAN node.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application

16/800,008Filed 25 Feb 2020

Priority

JP 2015-15273531 Jul 2015

Published

20 Aug 2020

Term ends

Not estimatedThe source records don’t support an estimate.

Classification10 codes

H04W 36/0033
For data sessions of end-to-end connection: with transfer of context information
H04W 16/32
Cell structures: hierarchical cell structures
H04W 36/0069
Transmission or use of information for re-establishing the radio link: in case of dual connectivity, e.g. decoupled uplink/downlink
H04W 36/04
Hand-off or reselection arrangements: reselecting a cell layer in multi-layered cells

Base station apparatus and method thereof

Life of this patent

Base station apparatus and method thereof

Life of this patent

Abstract

Claims13