Methods and apparatus for activating and deactivating secondary cells in a carrier aggregation environment

Patent metadata

Field	Value
Publication number	US-10136328-B2
Application number	US-201113817707-A
Country	US
Kind code	B2
Filing date	Aug 19, 2011
Priority date	Aug 19, 2010
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

A method and an apparatus for activating and deactivating secondary cells in a carrier aggregation environment are provided. In one embodiment, a Medium Access Control (MAC) Control Element (CE) command is received from a base station for activating/deactivating a secondary cell associated with a User Equipment (UE). The secondary cell configured for the UE is activated/deactivated based on the MAC CE command. Further, a first uplink grant is received from the base station upon activation/deactivation of the secondary cell. Accordingly, quality information (e.g., channel quality information, sounding reference signal information, and the like) associated with the cell(s) is transmitted to the base station in the received first uplink grant over a physical uplink shared channel. Furthermore, a hybrid automatic repeat request entity associated with the secondary cell is reset.

First claim

The invention claimed is:

1. A method for activating/deactivating a secondary cell at a user equipment (UE) in a communication system based on carrier aggregation, the method comprising:
receiving, from a base station, control information for activating/deactivating at least one secondary cell;
activating the at least one secondary cell using the control information;
after activating of the at least one secondary cell, receiving a grant information from the base station;
transmitting, to the base station, quality information comprising channel quality information (CQI) based on the grant information;
detecting an expiry time of the at least one secondary cell; and
deactivating the at least one secondary cell in response to the expiry time,
wherein, if the quality information comprising the CQI based on the grant information is not received by the base station, the control information for activating/deactivating at least one secondary cell is retransmitted by the base station, to the UE.

2. The method of claim 1 , further comprising:
resetting a hybrid automatic repeat request (HARQ) entity associated with the at least one secondary cell upon deactivating the at least one secondary cell or upon activating the at least one secondary cell; and
setting a new data indicator (NDI) associated with one or more HARQ processes to a predefined value if the at least one secondary cell is deactivated,
wherein the resetting of the HARQ entity comprises:
flushing HARQ buffers associated with the one or more HARQ processes if the at least one secondary cell is deactivated.

3. The method of claim 1 , further comprising:
stopping any uplink transmission on the at least one secondary cell in response to the expiry time.

4. A method for activating/deactivating a secondary cell at a base station in a communication system based on carrier aggregation, the method comprising:
transmitting, to a user equipment (UE), control information for activating/deactivating at least one secondary cell;
transmitting, to the UE, first grant information;
if quality information comprising channel quality information (CQI) based on the first grant information is received from the UE,
transmitting, to the UE, information related to an expiry time of the at least one secondary cell; and
if the CQI based on the first grant information is not received from the UE, retransmitting to the UE the control information for activating/deactivating at least one secondary cell,
wherein the at least one secondary cell is deactivated in response to the expiry timer detected by the UE.

5. The method of claim 4 ,
wherein a hybrid automatic repeat request (HARQ) entity associated with the at least one secondary cell is reset upon deactivating the at least one secondary cell or upon activating the at least one secondary cell,
wherein a new data indicator (NDI) associated with one or more HARQ processes of the HARQ entity is set to a predefined value if the at least one secondary cell is deactivated, and
wherein HARQ buffers associated with the one or more HARQ processes are flushed upon resetting of the HARQ entity.

6. The method of claim 4 , wherein any uplink transmission on the at least one secondary cell is stopped in response to the expiry time.

7. A user equipment (UE) for activating/deactivating a secondary cell in a communication system based on carrier aggregation, the UE comprising:
a transceiver configured to:
receive, from a base station, control information for activating/deactivating at least one secondary cell,
receive, from the base station, a grant information, and
transmit, to the base station, quality information comprising channel quality information (CQI) based on the grant information; and

at least one processor configured to:
activate the at least one secondary cell using the control information,
detect an expiry time of the at least one secondary cell, and
deactivate the at least one secondary cell in response to the expiry of the timer,

wherein, if the quality information comprising the CQI based on the grant information is not received by the base station, the control information for activating/deactivating at least one secondary cell is retransmitted by the base station to the UE.

8. The UE of claim 7 , wherein the at least one processor is further configured to:
reset a hybrid automatic repeat request (HARQ) entity associated with the at least one secondary cell upon activating the at least one secondary cell,
reset the HARQ entity associated with the at least one secondary cell upon activating the at least one secondary cell or upon deactivating the at least one secondary cell by flushing HARQ buffers associated with one or more HARQ processes, and
set a new data indicator (NDI) associated with one or more HARQ processes to a predefined value if the at least one secondary cell is deactivated.

9. The UE of claim 7 , wherein the at least one processor is further configured to control the transceiver to stop any uplink transmission on the at least one secondary cell in response to the expiry time.

10. A base station for activating/deactivating a secondary cell in a communication system based on carrier aggregation, the base station comprising:
a transceiver configured to:
transmit, to a user equipment (UE), control information for activating/deactivating at least one secondary cell,
transmit, to the UE, first grant information,
if quality information comprising channel quality information (CQI) based on the first grant information is received from the UE, transmit, to the UE, information related to an expiry time of the at least one secondary cell, and
if the quality information comprising the CQI based on the first grant information is not received from the UE, retransmit, to the UE, the control information for activating/deactivating at least one secondary cell; and

at least one processor configured to control operation of the transceiver,
wherein the at least one secondary cell is deactivated in response to the expiry timer detected by the UE.

11. The base station of claim 10 ,
wherein a hybrid automatic repeat request (HARQ) entity associated with the at least one secondary cell is reset upon deactivating the at least one secondary cell or upon activating the at least one secondary cell,
wherein a new data indicator (NDI) associated with one or more HARQ processes of the HARQ entity is set to a predefined value if the at least one secondary cell is deactivated, and
wherein HARQ buffers associated with the one or more HARQ processes are flushed upon resetting the HARQ entity.

12. The base station of claim 10 , wherein any uplink transmission on the at least one secondary cell is stopped in response to the expiry time.

Assignees

• Baghel Sudhir Kumar
• Manepalli Venkateswara Rao
• Samsung Electronics Co Ltd

Inventors

• Baghel Sudhir Kumar
• Manepalli Venkateswara Rao

Classifications

• H04L1/0027

  Scheduling of signalling, e.g. occurrence thereof · CPC title

• H04W16/00 Primary

  Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures · CPC title

• H04W24/02

  Arrangements for optimising operational condition · CPC title

• H04W88/08

  Access point devices · CPC title

• H04L1/0026 Primary

  Transmission of channel quality indication · CPC title