U.S. patent application number 12/787408 was filed with the patent office on 2010-12-02 for method and apparatus for handling carriers.
Invention is credited to Meng-Hui Ou.
Application Number | 20100304786 12/787408 |
Document ID | / |
Family ID | 42641289 |
Filed Date | 2010-12-02 |
United States Patent
Application |
20100304786 |
Kind Code |
A1 |
Ou; Meng-Hui |
December 2, 2010 |
Method and Apparatus for Handling Carriers
Abstract
A method for handling carriers in a user equipment (UE) of a
wireless communication system is disclosed. The wireless
communication system supports Carrier Aggregation (CA) such that
the UE is able to perform transmission and/or reception through
multiple carriers. The method includes steps of configuring a
plurality of carriers, and deactivating a carrier of the plurality
of carriers according to a verification result.
Inventors: |
Ou; Meng-Hui; (Taipei City,
TW) |
Correspondence
Address: |
NORTH AMERICA INTELLECTUAL PROPERTY CORPORATION
P.O. BOX 506
MERRIFIELD
VA
22116
US
|
Family ID: |
42641289 |
Appl. No.: |
12/787408 |
Filed: |
May 26, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61180929 |
May 26, 2009 |
|
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|
Current U.S.
Class: |
455/552.1 |
Current CPC
Class: |
H04L 5/0007 20130101;
H04W 72/085 20130101; H04W 72/02 20130101; H04L 5/0033 20130101;
H04W 76/34 20180201; H04W 72/0453 20130101; H04L 5/001 20130101;
H04L 5/0098 20130101 |
Class at
Publication: |
455/552.1 |
International
Class: |
H04M 1/00 20060101
H04M001/00 |
Claims
1. A method for handling carriers in a user equipment (UE) of a
wireless communication system, the wireless communication system
supporting Carrier Aggregation (CA) such that the UE is able to
perform transmission and/or reception through multiple carriers,
the method comprising: configuring a plurality of carriers; and
deactivating a carrier of the plurality of carriers according to a
verification result.
2. The method of claim 1, wherein the verification result is a
time-count result of a timer corresponding to the carrier.
3. The method of claim 2, wherein deactivating the carrier of the
plurality of carriers according to the verification result is
deactivating the carrier when the time-count result of the timer is
greater than a predefined duration.
4. The method of claim 1, wherein the carrier is a carrier other
than a primary carrier.
5. The method of claim 1, wherein the carrier is a secondary
carrier.
6. The method of claim 1, wherein the wireless communication system
is a Long Term Evolution Advanced (LTE-A) system.
7. A communication device for handling carriers in a user equipment
(UE) of a wireless communication system, the wireless communication
system supporting Carrier Aggregation (CA) such that the UE is able
to perform transmission and/or reception through multiple carriers,
the communication device comprising: a processor for executing a
program; and a memory coupled to the processor for storing the
program; wherein the program comprises: configuring a plurality of
carriers; and deactivating a carrier of the plurality of carriers
according to a verification result.
8. The communication device of claim 7, wherein the verification
result is a time-count result of a timer corresponding to the
carrier.
9. The communication device of claim 8, wherein deactivating the
carrier of the plurality of carriers according to the verification
result in the program is deactivating the carrier when the
time-count result of the timer is greater than a predefined
duration.
10. The communication device of claim 7, wherein the carrier is a
carrier other than a primary carrier.
11. The communication device of claim 7, wherein the carrier is a
secondary carrier.
12. The communication device of claim 7, wherein the wireless
communication system is a Long Term Evolution Advanced (LTE-A)
system.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/180,929, filed on May 26, 2009 and entitled
"Method and apparatus for improving timing synchronization and
Carrier Aggregation in a wireless communication system", the
contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method and apparatus for
handling carriers, and more particularly, to a method and apparatus
for handling carriers in a user equipment of a wireless
communication system, so as to reduce waste of power, and enhance
the system performance.
[0004] 2. Description of the Prior Art
[0005] Long Term Evolution wireless communication system (LTE
system), an advanced high-speed wireless communication system
established upon the 3G mobile telecommunication system, supports
only packet-switched transmission, and tends to implement both
Medium Access Control (MAC) layer and Radio Link Control (RLC)
layer in one single communication site, such as in base stations
(Node Bs) alone rather than in Node Bs and RNC (Radio Network
Controller) respectively, so that the system structure becomes
simple.
[0006] In LTE system, to keep an effective connection between a
user equipment (UE) and a Node B after the connection is
established, the UE triggers a timer T310 if the UE detects a radio
problem, e.g. the UE detects consecutive "out-of-sync" indications
from a physical layer (PHY). If the radio problem is not recovered
before the timer T310 is expired, the UE determines a radio link
failure (RLF) occurs, and triggers a connection re-establishment
procedure, to re-establish a normal connection.
[0007] However, to meet future requirements of all kinds of
communication services, the 3rd Generation Partnership Project
(3GPP) has started to work out a next generation of the LTE system:
the LTE Advanced (LTE-A) system. Carrier aggregation (CA), where
two or more component carriers are aggregated, is introduced into
the LTE-A system in order to support wider transmission bandwidths,
e.g. up to 100 MHz and for spectrum aggregation. Using CA, the
network of the LTE-A system provides multiple component carriers
instead of a single carrier for a UE, to establish multiple links
for simultaneously receiving and/or transmitting on these component
carriers.
[0008] At present, the characteristics of CA are quoted as
below:
[0009] (1) Supporting CA for both contiguous and non-contiguous
component carriers.
[0010] (2) It is possible to configure a UE to aggregate a
different number of component carriers in the uplink (UL) and the
downlink (DL), to obtain different bandwidths.
[0011] (3) From a UE perspective, there is one transport block and
one hybrid-ARQ (HARQ) entity per scheduled component carrier.
[0012] As can be seen, a UE with CA configured can utilize multiple
component carriers, and each of the component carriers may have a
different coverage range or radio quality. Thus, a radio problem on
a component carrier does not mean other component carriers are
useless, i.e. other component carriers may work. In such a
situation, if the UE can perform transmission/reception via normal
component carriers, then the UE does not have to perform the
connection re-establishment procedure regarding a radio problem on
a certain component carrier. If the UE does not perform the
connection re-establishment procedure, the UE must use other
methods for handling radio problem of a component carrier. In
general, the network can output a signaling to the UE, for
indicating the UE to deactivate specific component carriers.
However, when a certain component carrier has radio problems, the
UE may not be able to receive the signaling for deactivating
carriers promptly. In such a situation, the UE keeps monitoring a
physical downlink control channel (PDCCH) on the carrier where the
radio problem occurs, causing power waste.
[0013] Therefore, after CA is configured, if a component carrier
has a radio problem, the UE may waste power, which must be
improved.
SUMMARY OF THE INVENTION
[0014] It is therefore an objective of the present invention to
provide a method and apparatus for handling carriers in a wireless
communication system.
[0015] According to the present invention, a method for handling
carriers in a user equipment (UE) of a wireless communication
system is disclosed. The wireless communication system supports
Carrier Aggregation (CA) such that the UE is able to perform
transmission and/or reception through multiple carriers. The method
includes steps of configuring a plurality of carriers, and
deactivating a carrier of the plurality of carriers according to a
verification result.
[0016] According to the present invention, a communication device
for handling carriers in a user equipment (UE) of a wireless
communication system is disclosed. The wireless communication
system supports Carrier Aggregation (CA) such that the UE is able
to perform transmission and/or reception through multiple carriers.
The communication device comprises a processor for executing a
program, and a memory coupled to the processor for storing the
program. The program includes steps of configuring a plurality of
carriers, and deactivating a carrier of the plurality of carriers
according to a verification result.
[0017] These and other objectives of the present invention will no
doubt become obvious to those of ordinary skill in the art after
reading the following detailed description of the preferred
embodiment that is illustrated in the various figures and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a schematic diagram of a wireless communications
system.
[0019] FIG. 2 is a function block diagram of a wireless
communications device.
[0020] FIG. 3 is a diagram of a program of FIG. 2.
[0021] FIG. 4 is a flowchart of a process according to an
embodiment of the present invention.
DETAILED DESCRIPTION
[0022] Please refer to FIG. 1, which illustrates a schematic
diagram of a wireless communication system 10. The wireless
communication system 10 is preferably an LTE advanced (LTE-A)
system, and is briefly composed of a network and a plurality of
user equipments (UEs). In FIG. 1, the network and the UEs are
simply utilized for illustrating the structure of the wireless
communication system 10. Practically, the network may comprise a
plurality of base stations (Node Bs), radio network controllers and
so on according to actual demands, and the UEs can be devices such
as mobile phones, computer systems, etc.
[0023] Please refer to FIG. 2, which is a functional block diagram
of a communication device 100 in a wireless communication system.
The communication device 100 can be utilized for realizing the UEs
in FIG. 1. For the sake of brevity, FIG. 2 only shows an input
device 102, an output device 104, a control circuit 106, a central
processing unit (CPU) 108, a memory 110, a program 112, and a
transceiver 114 of the communication device 100. In the
communication device 100, the control circuit 106 executes the
program 112 in the memory 110 through the CPU 108, thereby
controlling an operation of the communication device 100. The
communication device 100 can receive signals input by a user
through the input device 102, such as a keyboard, and can output
images and sounds through the output device 104, such as a monitor
or speakers. The transceiver 114 is used to receive and transmit
wireless signals, deliver received signals to the control circuit
106, and output signals generated by the control circuit 106
wirelessly. From a perspective of a communication protocol
framework, the transceiver 114 can be seen as a portion of Layer 1,
and the control circuit 106 can be utilized to realize functions of
Layer 2 and Layer 3.
[0024] Please continue to refer to FIG. 3. FIG. 3 is a diagram of
the program 112 shown in FIG. 2. The program 112 includes an
application layer 200, a Layer 3 202, and a Layer 2 206, and is
coupled to a Layer 1 218. The Layer 3 202 performs radio resource
control. The Layer 2 206 comprises a Radio Link Control (RLC) layer
and a Medium Access Control (MAC) layer, and performs link control.
The Layer 1 218 performs physical connections.
[0025] In LTE-A system, the Layer 1 218 and the Layer 2 206 may
support a Carrier Aggregation (CA) technology, which enables the UE
to perform transmission and/or reception through multiple carriers.
In such a situation, the embodiment of the present invention
provides a carrier processing program 220 for appropriately
handling carriers, so as to avoid power waste, and thus, enhance
the system performance.
[0026] Please refer to FIG. 4, which illustrates a schematic
diagram of a process 40. The process 40 is utilized for handling
carriers in a UE of the wireless communication system 10, and can
be compiled into the carrier processing program 220. The process 40
includes the following steps:
[0027] Step 400: Start.
[0028] Step 402: Configure a plurality of carriers.
[0029] Step 404: Deactivate a carrier of the plurality of carriers
according to a verification result.
[0030] Step 406: End.
[0031] According to the process 40, after CA is applied, the UE can
deactivate specific carrier according to the inner verification
result. In other words, in the embodiment of the present invention,
the UE does not need to receive signaling from the network, but can
autonomously deactivate carriers. As a result, if a carrier has a
radio problem, according to the embodiment of the present
invention, the UE can deactivate the carrier autonomously.
[0032] Preferably, the carrier that the UE can deactivate
autonomously in step 404 belongs to carriers other than a primary
carrier, i.e. secondary carriers. In addition, the verification
result can be a time-count result of a timer. For example, when a
secondary carrier has a radio problem, the UE can start a
corresponding timer, and autonomously deactivate the secondary
carrier upon expiry of the timer, i.e. the time-count result of the
timer reaches or is greater than a predefined duration. As a
result, even if the UE does not receive a signaling for
deactivating the secondary carrier, since the UE has autonomously
deactivated the secondary carrier, the UE does not monitor PDCCH on
the carrier, such that power waste can be avoided. As to the
network, the network can disable the signaling for deactivating
carriers, and determine the UE has autonomously deactivated the
secondary carrier after a predefined duration from the occurrence
of the radio problem. Noticeable, the idea of the present invention
is that the UE can autonomously deactivate carriers without
signaling of the network. Thus, the aforementioned description
about the network is to give an example.
[0033] In the embodiment of the present invention, after CA is
applied, if a carrier has a radio problem, the UE can autonomously
deactivate the carrier, so as to prevent unnecessary power
consumption, and enhance the system performance.
[0034] In summary, when CA is applied, the UE can autonomously
deactivate carriers, so as to prevent the issue caused by a radio
problem on a certain carrier, and enhance the system
performance
[0035] Those skilled in the art will readily observe that numerous
modifications and alterations of the device and method may be made
while retaining the teachings of the invention. Accordingly, the
above disclosure should be construed as limited only by the metes
and bounds of the appended claims.
* * * * *