Method of configuring dual connectivity to UE in heterogeneous cell deployment

Patent metadata

Field	Value
Publication number	US-9526044-B2
Application number	US-201414273089-A
Country	US
Kind code	B2
Filing date	May 8, 2014
Priority date	May 8, 2013
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

A method and a macro cell eNB are disclosed. The method includes receiving a measurement report message of the small cell from the UE connected to the macro cell, determining to configure dual connectivity with the macro cell and the small cell to the UE based on a measured value contained in the measurement report message, transmitting a dual connectivity request message for requesting connection with the UE to the small cell, receiving a dual connectivity response message indicating that the small cell is connected to the UE to determine to allocate a resource to the UE, from the small cell, and transmitting an RRC configuration message for requesting addition of connection with the small cell, to the UE.

First claim

What is claimed is:

1. A method of configuring dual connectivity to a user equipment (UE) by a macro cell in a heterogeneous cell deployment in which a macro cell and a small cell coexist, the method comprising:
determining to configure a dual connectivity with the macro cell and the small cell for a UE connected to the macro cell, based on a measurement result for the small cell;
transmitting, to the small cell, a dual connectivity request message for requesting a connection with the UE, wherein the dual connectivity request message comprises information of an evolved universal terrestrial radio access network (E-UTRAN) radio access bearer (E-RAB) parameter;
receiving a dual connectivity response message indicating that the small cell has determined to connect to the UE and allocate a resource to the UE, from the small cell; and
transmitting, to the UE, an RRC configuration message for requesting an addition of a connection with the small cell while maintaining a connection with the macro cell,
wherein the dual connectivity request message includes information indicating a first resource that the small cell should avoid when scheduling the UE and information indicating a second resource that the small cell can allocate when scheduling the UE,
wherein the first resource and the second resource are defined in units of a physical resource block (PRB), and
wherein the first resource is determined by considering another UE having a dual connectivity to the macro cell and the small cell.

2. The method according to claim 1 , further comprising transmitting a dual connectivity complete message for requesting establishment of a data radio bearer (DRB) with the UE when the UE completes synchronization with the small cell, to the small cell.

3. The method according to claim 1 , further comprising transmitting a path switch request message for requesting modification of a bearer to the UE to a mobility Management entity (MME) for supporting the small cell according to switching of a user plane (U-plane) of the UE when the UE completes synchronization with the small cell.

4. The method according to claim 3 , wherein:
the path switching request message is transmitted to a serving gateway (S-GW) from the MME; and
the S-GW establishes an S1 downlink bearer with the small cell.

5. The method according to claim 1 , wherein a user plane (U-plane) of the UE is switched to the small cell from the macro cell or is newly generated according to a relation with the small cell when the dual connectivity is configured to the UE.

6. The method according to claim 1 , wherein the measurement result is obtained based on at least one of intensity of a signal received from the small cell, reference signal received power (RSRP), reference signal received quality (RSRQ), and a signal to interference plus noise ratio (SINR).

7. The method according to claim 1 , wherein the information about the first resource is information about a resource allocated to another UE having dual connectivity to the macro cell and the small cell by the small cell.

8. The method according to claim 1 , wherein the dual connectivity request message comprises a dedicated preamble that the UE is supposed to transmission to the small cell, and an indicator indicating switching of the U-plane.

9. A macro cell eNB for configuring dual connectivity to a user equipment (UE) in a heterogeneous cell deployment in which a macro cell and a small cell coexist, the macro cell eNB comprising;
a transmitter;
a receiver; and
a processor connected to the transmitter and the receiver to configure dual connectivity to the UE,
wherein the processor is configured to:
determine to configure a dual connectivity with the macro cell and the small cell for a UE connected to the macro cell, based on a measurement result for the small cell,
control the transmitter to transmit to the small cell a dual connectivity request message for requesting a connection with the UE, wherein the dual connectivity request message comprises information of an evolved universal terrestrial radio access network (E-UTRAN) radio access bearer (E-RAB) parameter,
control the receiver to receive a dual connectivity response message indicating that the small cell has determined to connect to the UE and allocate a resource to the UE, from the small cell, and
control the transmitter to transmit an RRC configuration message for requesting an addition of a connection with the small cell while maintaining a connection with the macro cell, to the UE,

wherein the dual connectivity request message includes information indicating a first resource that the small cell should avoid when scheduling the UE and information indicating a second resource that the small cell can allocate when scheduling the UE,
wherein the first resource and the second resource are defined in units of a physical resource block (PRB), and
wherein the first resource is determined by considering another UE having a dual connectivity to the macro cell and the small cell.

10. The macro cell eNB according to claim 9 , wherein the processor controls the transmitter to transmit a dual connectivity complete message for requesting establishment of a data radio bearer (DRB) with the UE when the UE completes synchronization with the small cell, to the small cell.

11. The macro cell eNB according to claim 9 , wherein the processor controls the transmitter to transmit a path switch request message for requesting modification of a bearer to the UE to a mobility management entity (MME) for supporting the small cell according to switching of a user plane (U-plane) of the UE when the UE completes synchronization with the small cell.

12. The macro cell eNB according to claim 11 , Wherein:
the path switching request message is transmitted to a serving gateway (S-GW) from the MME; and
the S-GW establishes an S1 downlink bearer with the small cell.

13. The macro cell, eNB according to claim 9 , wherein a user plane (U-plane) of the UE is switched to the small cell from the macro cell or is newly generated according to a relation with the small cell when the dual connectivity is configured to the UE.

14. The macro cell eNB according to claim 9 , wherein the measurement result is obtained based on at least one of intensity of a signal received from the small cell, reference signal received power (RSRP), reference signal received quality (RSRQ), and a signal to interference plus noise ratio (SINR).

15. The macro cell eNB according to claim 9 , wherein the information about the first resource is information about a resource allocated to another UE having dual connectivity to the macro cell and the small cell by the small cell.

16. The macro cell eNB according to claim 9 , wherein the dual connectivity request message comprises a dedicated preamble that the UE is supposed to transmission to the small cell, and an indicator indicating switching of the U-plane.

Assignees

• Lg Electronics Inc

Inventors

• Choi Hyeyoung
• Chung Jaehoon
• Byun Ilmu
• Lee Eunjong
• Cho Heejeong
• Hann Genebeck

Classifications

• H04W40/36

  due to handover · CPC title

• H04W36/0072 Primary

  of resource information of target access point · CPC title

• H04W76/025

  Electricity · mapped topic

• H04W36/00692

  using simultaneous multiple data streams, e.g. cooperative multipoint [CoMP], carrier aggregation [CA] or multiple input multiple output [MIMO] (allocation of physical resources in CoMP or in CA H04L5/0035) · CPC title

• H04W36/249

  according to timing information · CPC title