Communication control method, master base station, secondary base station, and user terminal

Patent metadata

Field	Value
Publication number	US-9699702-B2
Application number	US-201615222588-A
Country	US
Kind code	B2
Filing date	Jul 28, 2016
Priority date	Jan 31, 2014
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

A communication control method according to a first aspect is a method in a mobile communication system for supporting dual connectivity communication using a master base station for establishing RRC connection with a user terminal and a secondary base station for providing additional radio resources to the user terminal. The communication control method comprises: an inter-master base station handover procedure for performing handover of the user terminal from a source master base station to a target master base station without changing the secondary base station.

First claim

The invention claimed is:

1. A target master evolved Node-B (MeNB) for a mobile communication system supporting dual connectivity communication using: an MeNB that establishes a radio resource control (RRC) connection with a user equipment (UE); and a secondary evolved Node-B (SeNB) that provides additional radio resources to the UE, the target MeNB comprising:
a controller containing at least one processor and at least one memory, wherein the controller controls an inter-MeNB handover procedure that performs handover of the UE from a source MeNB to the target MeNB without changing the SeNB, wherein
the controller causes the target MeNB to:
receive a handover request message from the source MeNB, the handover request message including a global eNB ID of the SeNB;
transmit an SeNB addition request message to the SeNB in response to receiving the handover request message, the SeNB addition request message used to configure the SeNB as a new SeNB for the target MeNB;
receive, from the SeNB, an SeNB addition request acknowledgement message, which is a response to the SeNB addition request message, the SeNB addition request acknowledgement message including algorithm information indicating a security algorithm selected by the SeNB to perform communication with the UE; and
transmit, to the source MeNB, a handover request acknowledgement message, which is a response to the handover request message, in response to receiving the SeNB addition request acknowledgement message, the handover request acknowledgement message including the algorithm information received from the SeNB.

2. The target MeNB of claim 1 , wherein
the controller causes the target MeNB to transmit, to the SeNB, the SeNB addition request message including bearer type information indicating whether a bearer type to be used by the SeNB is a secondary cell group (SCG) bearer or a split bearer, wherein the SCG bearer does not pass through the MeNB, and the split bearer passes through the MeNB.

3. A secondary evolved Node-B (SeNB) for a mobile communication system supporting dual connectivity communication using: a master evolved Node-B (MeNB) that establishes a radio resource control (RRC) connection with a user equipment (UE); the SeNB providing additional radio resources to the UE, the SeNB comprising:
a controller containing at least one processor and at least one memory, wherein the controller controls an inter-MeNB handover procedure that performs handover of the UE from a source MeNB to a target MeNB without changing the SeNB, wherein
the controller causes the SeNB to:
receive an SeNB addition request message from the target MeNB, the target MeNB having received a handover request message from the source MeNB, the SeNB addition request message used to configure the SeNB as a new SeNB for the target MeNB, wherein the handover request message includes a global eNB ID of the SeNB;
transmit, to the target MeNB, an SeNB addition request acknowledgement message, which is a response to the SeNB addition request message, the SeNB addition request acknowledgement message including algorithm information indicating a security algorithm used by the UE to perform communication with the SeNB;
receive, from the source MeNB, an SeNB release request message that requests releasing configurations corresponding to the source MeNB, the source MeNB receiving a handover request acknowledgement message from the target MeNB; and
after receiving the SeNB release request message, receive a UE context release message from the source MeNB, the UE context release message requesting release of a UE context for the UE.

4. The SeNB of claim 3 , wherein the controller further causes the SeNB to:
release configurations corresponding to the source MeNB in response to receiving the SeNB release request message.

5. The SeNB of claim 3 , wherein
the controller causes the SeNB to receive, from the target MeNB, the SeNB addition request message including bearer type information indicating whether a bearer type to be used by the SeNB is a secondary cell group (SCG) bearer or a split bearer, wherein the SCG bearer does not pass through the MeNB, and the split bearer passes through the MeNB.

6. The SeNB of claim 3 , wherein
the controller, in response to receiving the SeNB release request message from the source MeNB, causes the SeNB to release configurations corresponding to the source MeNB while keeping configurations corresponding to the target MeNB.

7. A source master evolved Node-B (MeNB) for a mobile communication system supporting dual connectivity communication using an MeNB that establishes a radio resource control (RRC) connection with a user equipment (UE) and a secondary evolved Node-B (SeNB) that provides additional radio resources to the UE, the source MeNB comprising:
a controller containing at least one processor and at least one memory, wherein the controller controls an inter-MeNB handover procedure that performs handover of the UE from the source MeNB to a target MeNB without changing the SeNB, wherein
the controller causes the source MeNB to:
transmit a handover request message to the target MeNB, the handover request message including a global eNB ID of the SeNB;
receive, from the target MeNB, a handover request acknowledgement message, which is a response to the handover request message, the handover request acknowledgement message including algorithm information indicating a security algorithm selected by the SeNB to perform communication with the UE;
transmit an SeNB release request message to the SeNB in response to receiving the handover request acknowledge message, the SeNB release request message requesting release of configurations corresponding to the source MeNB;
receive a first UE context release message from the target MeNB, the first UE context release message requesting release of a UE context for the UE; and
transmit a second UE context release message to the SeNB, the second UE context release message requesting release of the UE context.

8. The source MeNB of claim 7 , wherein transmission of the SeNB release request message to the source MeNB enables the SeNB to release configurations corresponding to the source MeNB while keeping configurations corresponding to the target MeNB.

Assignees

• Kyocera Corp

Inventors

• Fujishiro Masato
• Mitsui Katsuhiro
• Nagasaka Yushi
• Morita Kugo
• Tong Fangwei
• Chang Henry

Classifications

• H04W36/06

  Reselecting a communication resource in the serving access point · CPC title

• H04L29/12575

  Electricity · mapped topic

• H04W36/28 Primary

  involving a plurality of connections, e.g. multi-call or multi-bearer connections · CPC title

• H04W36/165

  for reducing network power consumption (H04W36/18 - H04W36/22 take precedence) · CPC title

• H04W88/16

  Gateway arrangements · CPC title