U.S. patent application number 12/050177 was filed with the patent office on 2008-09-25 for method for enhancing data transmission efficiency for a radio resource control procedure for a wireless communications system and related apparatus.
Invention is credited to Richard Lee-Chee Kuo.
Application Number | 20080232313 12/050177 |
Document ID | / |
Family ID | 39591252 |
Filed Date | 2008-09-25 |
United States Patent
Application |
20080232313 |
Kind Code |
A1 |
Kuo; Richard Lee-Chee |
September 25, 2008 |
Method for Enhancing Data Transmission Efficiency for a Radio
Resource Control Procedure for a Wireless Communications System and
Related Apparatus
Abstract
A method for enhancing data transmission efficiency for a radio
resource control, hereinafter called RRC, procedure for a user
equipment, also called UE, in a CELL_FACH state in a wireless
communications system is provided. The method includes using a
dedicated HS-DSCH radio network transaction identifier, hereinafter
called H-RNTI, for a high speed downlink operation corresponding to
the CELL_FACH state; initiating an RRC update procedure; changing
to use a common H-RNTI for the high speed downlink operation if the
dedicated H-RNTI becomes invalid; and continuing using the
dedicated H-RNTI for the high speed downlink operation if the
dedicated H-RNTI remains effective.
Inventors: |
Kuo; Richard Lee-Chee;
(Taipei City, TW) |
Correspondence
Address: |
NORTH AMERICA INTELLECTUAL PROPERTY CORPORATION
P.O. BOX 506
MERRIFIELD
VA
22116
US
|
Family ID: |
39591252 |
Appl. No.: |
12/050177 |
Filed: |
March 18, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60896500 |
Mar 23, 2007 |
|
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Current U.S.
Class: |
370/329 |
Current CPC
Class: |
H04W 36/0055 20130101;
H04W 76/27 20180201; H04W 36/08 20130101 |
Class at
Publication: |
370/329 |
International
Class: |
H04Q 7/00 20060101
H04Q007/00 |
Claims
1. A method for enhancing data transmission efficiency for a radio
resource control, hereinafter called RRC, procedure for a user
equipment, also called UE, in a CELL_FACH state in a wireless
communications system, the method comprising: using a dedicated
HS-DSCH radio network transaction identifier, hereinafter called
H-RNTI, for a high speed downlink operation corresponding to the
CELL_FACH state; initiating an RRC update procedure; changing to
use a common H-RNTI for the high speed downlink operation if the
dedicated H-RNTI becomes invalid; and continuing using the
dedicated H-RNTI for the high speed downlink operation if the
dedicated H-RNTI remains effective.
2. The method of claim 1, wherein the RRC update procedure is a
cell update procedure or a UTRAN registration area, hereinafter
URA, update procedure.
3. The method of claim 1, wherein changing to use the common H-RNTI
for the high speed downlink operation if the dedicated H-RNTI
becomes invalid is changing to use the common H-RNTI for the high
speed downlink operation if the UE initiates the RRC update
procedure due to cell or URA reselection.
4. The method of claim 1, wherein continuing using the dedicated
H-RNTI for the high speed downlink operation if the dedicated
H-RNTI remains effective is continuing using the dedicated H-RNTI
for the high speed downlink operation if the UE initiates the RRC
update procedure due to periodical cell or URA update.
5. The method of claim 1, wherein the high speed downlink operation
comprises reception of a high speed downlink shared channel,
abbreviated to HS-DSCH.
6. The method of claim 5, wherein changing to use the common H-RNTI
for the high speed downlink operation comprises: setting an
HS_DSCH_RECEPTION_OF_CCCH variable to "TRUE" for putting the common
H-RNTI into effect; and starting reception of physical channels and
transport channels corresponding to the high speed downlink
operation according to configuration data of an information
element.
7. The method of claim 6, wherein the information element is a
"Downlink HS-PDSCH system information for connected mode"
information element or a "Downlink HS-PDSCH system information"
information element.
8. A communications device used in a CELL_FACH state in a wireless
communications system for enhancing data transmission efficiency
for a radio resource control, hereinafter called RRC, procedure,
the communications device comprising: a control circuit for
realizing functions of the communications device; a central
processing unit coupled to the control circuit for executing a
program code to operate the control circuit; and a memory coupled
to the central processing unit for storing the program code;
wherein the program code comprises: using a dedicated HS-DSCH radio
network transaction identifier, hereinafter called H-RNTI, for a
high speed downlink operation corresponding to the CELL_FACH state;
initiating an RRC update procedure; changing to use a common H-RNTI
for the high speed downlink operation if the dedicated H-RNTI
becomes invalid; and continuing using the dedicated H-RNTI for the
high speed downlink operation if the dedicated H-RNTI remains
effective.
9. The communications device of claim 8, wherein the RRC update
procedure is a cell update procedure or a UTRAN registration area,
hereinafter URA, update procedure.
10. The communications device of claim 8, wherein changing to use
the common H-RNTI for the high speed downlink operation if the
dedicated H-RNTI becomes invalid is changing to use the common
H-RNTI for the high speed downlink operation if the communications
device initiates the RRC update procedure due to cell or URA
reselection.
11. The communications device of claim 8, wherein continuing using
the dedicated H-RNTI for the high speed downlink operation if the
dedicated H-RNTI remains effective is continuing using the
dedicated H-RNTI for the high speed downlink operation if the
communications device initiates the RRC update procedure due to
periodical cell or URA update.
12. The communications device of claim 8, wherein the high speed
downlink operation comprises reception of a high speed downlink
shared channel, abbreviated to HS-DSCH.
13. The communications device of claim 12, wherein changing to use
the common H-RNTI for the high speed downlink operation comprises:
setting an HS_DSCH_RECEPTION_OF_CCCH variable to "TRUE" for putting
the common H-RNTI into effect; and starting reception of physical
channels and transport channels corresponding to the high speed
downlink operation according to configuration data of an
information element.
14. The communications device of claim 13, wherein the information
element is a "Downlink HS-PDSCH system information for connected
mode" information element or a "Downlink HS-PDSCH system
information" information element.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/896,500, filed on Mar. 23, 2007 and entitled
"Method And Apparatus for Improving HS-DSCH Reception when CCCH is
mapped on HS-DSCH 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 for enhancing data
transmission efficiency for a wireless communications system and
related communications device, and more particularly to a method
for enhancing data transmission efficiency with a high speed
downlink operation for a radio resource control procedure in a
wireless communications system and related communications
device.
[0004] 2. Description of the Prior Art
[0005] The third generation (3G) mobile telecommunications system
has adopted a Wideband Code Division Multiple Access (WCDMA)
wireless air interface access method for a cellular network. WCDMA
provides high frequency spectrum utilization, universal coverage,
and high quality, high-speed multimedia data transmission. The
WCDMA method also meets all kinds of QoS requirements
simultaneously, providing diverse, flexible, two-way transmission
services and better communication quality to reduce transmission
interruption rates. Through the 3G mobile telecommunications
system, a user can utilize a wireless communications device, such
as a mobile phone, to realize real-time video communications,
conference calls, real-time games, online music broadcasts, and
email sending/receiving. However, these functions rely on fast,
instantaneous transmission. Thus, targeting at the third generation
mobile telecommunication technology, the 3rd Generation Partnership
Project (3GPP) provides High Speed Package Access (HSPA)
technology, which includes High Speed Downlink Package Access
(HSDPA) and High Speed Uplink Package Access (HSUPA), to increase
bandwidth utility rate and package data processing efficiency to
improve uplink/downlink transmission rate.
[0006] On the basis of HSDPA, the 3GPP further introduces HS-DSCH
reception in a CELL_FACH state allowing the UE in the CELL_FACH
state to monitor a High Speed Downlink Shared Channel (HS-DSCH)
accompanied with a Shared Control Channel for HS-DSCH (HS-SCCH) for
downlink data reception, so as to improve a peak data rate, a
signaling delay, a state transition delay, download times and
flexible cell capacity.
[0007] A UMTS radio access network (UTRAN) enables the HS-DSCH
reception in the CELL_FACH state by including parameters, related
to radio resource control (RRC) configuration of HS-SCCH, HS-DSCH
and a common HS-DSCH radio network transaction identifier (common
H-RNTI), in the system information broadcast. For the UE in an idle
mode, the parameters are configured in a "Downlink HS-PDSCH system
information" information element (IE) included in a system
information block (SIB) type 5/5bis. For the UE in an RRC
connection mode, the parameters are configured in a "Downlink
HS-PDSCH system information for connected mode" IE included in an
SIB type 6.
[0008] The UE may use a common or a dedicated H-RNTI to perform the
HS-DSCH reception in the CELL_FACH state. The common and dedicated
H-RNTIs are both used as an identity of the UE so that the UE can
receive its own packets. Furthermore, the common H-RNTI can be
shared by multiple UEs, whereas each dedicated H-RNTI is only
allocated to one UE. During reception of media access control (MAC)
packets, the UE using the common H-RNTI needs to determine whether
the received packets belong to it via UE identification information
(i.e. UE ID and UE ID Type) in the packet header. On the other
hand, the MAC packets for the UE using the dedicated H-RNTI include
no UE identification information to provide better data
transmission efficiency.
[0009] The UE selects a suitable common H-RNTI to use from the
common H-RNTI parameter. On the other hand, if the UTRAN attempts
to allocate a dedicated H-RNTI to the UE, the UTRAN sends a related
configuration through RRC procedures, such as an RRC connection or
a cell update procedure, and the UE stores the configuration in a
H-RNTI variable. Each time the HS-DSCH reception in the CELL_FACH
state is enabled, the UE uses the dedicated H-RNTI if the H-RNTI
variable is set; otherwise the UE uses the common H-RNTI.
[0010] The UE has an HS_DSCH_RECEPTION_CELL_FACH_STATE and an
HS_DSCH_RECEPTION_OF_CCCH variable revealing a use state of the
dedicated and common H-RNTIs, respectively. When the
HS_DSCH_RECEPTION_CELL_FACH_STATE variable is set to "TRUE", the UE
receives packets mapped to a Dedicated Traffic Channel (DTCH) and a
Dedicated Control Channel (DCCH) according to the dedicated H-RNTI.
When the HS_DSCH_RECEPTION_OF_CCCH variable is set to "TRUE", the
UE receives packets mapped to a Common Control Channel (CCCH)
according to the common H-RNTI. If both of the variables are set to
"FALSE, this means that the HS-DSCH reception in the CELL_FACH
state is deactivated.
[0011] The UE may initiate the cell update procedure during the
HS-DSCH reception in the CELL_FACH state, and the cause to initiate
the cell update procedure may be cell reselection, periodical cell
update, a radio link failure, an RLC unrecoverable error or uplink
data transmission. The UE also initiates a URA update procedure
when performing UTRAN registration area reselection (URA
Reselection) or a periodical URA update.
[0012] As long as the cell/URA update procedure is initiated, the
UE sets the HS_DSCH_RECEPTION_OF_CCCH variable to "TRUE", and
starts reception of physical channels (i.e. HS-SCCH and HS-PDSCH)
and transport channels (HS-DSCH) according to configuration data of
the "Downlink HS-PDSCH system information for connected mode" IE or
the "Downlink HS-PDSCH system information" IE.
[0013] In other words, the UE of the prior art uses the common
H-RNTI for receiving downlink packets when the UE initiates the
cell/URA update procedure, irrespective of the procedure initiation
cause.
[0014] Consider the following scenarios in which the UE uses the
dedicated H-RNTI for the HS-DSCH reception in the CELL_FACH state
and meanwhile initiates the cell/URA update procedure due to
cell/URA reselection or periodical cell/URA update. When the
procedure initiation cause is cell/URA reselection, the dedicated
H-RNTI becomes invalid, and thereby the UE clears the dedicated
H-RNTI and then changes to use the common H-RNTI. Instead, the
dedicated H-RNTI is still valid when the procedure initiation cause
is periodical cell/URA update, so the UE does not clear the
dedicated H-RNTI but also changes to use the common H-RNTI.
[0015] From the standpoint of the RRC, receiving packets based on
the common H-RNTI engages more radio resources than based on the
dedicated H-RNTI, since the downlink packets include the UE
identification information for the UE using the common H-RNTI, but
no UE identification information is included for the UE using the
dedicated H-RNTI.
SUMMARY OF THE INVENTION
[0016] The present invention therefore provides a method for a UE
in a CELL_FACH state in a wireless communications system and
related communications device that utilizes the HS-DSCH reception
in the CELL_FACH state for enhancing data transmission efficiency
for an RRC update procedure.
[0017] The present invention discloses a method for enhancing data
transmission efficiency for an RRC procedure for a UE in a
CELL_FACH state in a wireless communications system. The method
includes using a dedicated H-RNTI for a high speed downlink
operation corresponding to the CELL_FACH state; initiating an RRC
update procedure; changing to use a common H-RNTI for the high
speed downlink operation if the dedicated H-RNTI becomes invalid;
and continuing using the dedicated H-RNTI for the high speed
downlink operation if the dedicated H-RNTI remains effective. The
RRC update procedure is preferably a cell or a URA update
procedure.
[0018] The present invention further discloses a communications
device in a CELL_FACH state of a wireless communications system for
enhancing data transmission efficiency for an RRC procedure. The
communications device includes a control circuit, a processor and a
memory. The control circuit is used for realizing functions of the
communications device. The processor is installed in the control
circuit and used for executing a program code to command the
control circuit. The memory is installed in the control circuit and
coupled to the processor, and used for storing the program code.
The program code includes using a dedicated H-RNTI for a high speed
downlink operation corresponding to the CELL_FACH state; initiating
an RRC update procedure; changing to use a common H-RNTI for the
high speed downlink operation if the dedicated H-RNTI becomes
invalid; and continuing using the dedicated H-RNTI for the high
speed downlink operation if the dedicated H-RNTI remains
effective.
[0019] 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
[0020] FIG. 1 is a functional block diagram of a communications
device.
[0021] FIG. 2 is a diagram of the program code shown in FIG. 1.
[0022] FIG. 3 is a flowchart diagram of a process according to an
embodiment of the present invention.
DETAILED DESCRIPTION
[0023] Please refer to FIG. 1, which is a functional block diagram
of a communications device 100. For the sake of brevity, FIG. 1
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 code 112, and a transceiver 114 of the communications
device 100. In the communications device 100, the control circuit
106 executes the program code 112 in the memory 110 through the CPU
108, thereby controlling an operation of the communications device
100. The communications 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, delivering received signals to the
control circuit 106, and outputting signals generated by the
control circuit 106 wirelessly. From a perspective of a
communications 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. Preferably,
the communications device 100 is utilized in a HSPA system of a
third generation (3G) mobile communications system and supports
high speed downlink operation corresponding to a CELL_FACH state
including HS-DSCH reception in the CELL_FACH state.
[0024] Please continue to refer to FIG. 2. FIG. 2 is a diagram of
the program code 112 shown in FIG. 1. The program code 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 includes a radio resource
control (RRC) entity 222 for controlling the Layer 1 218 and the
Layer 2 206 and performing peer-to-peer communication with a
network terminal, such as a Node-B or a UTRAN. In addition, the RRC
entity 222 can switch the communications device 100 among the idle
mode, CELL_PCH, URA_PCH, CELL_FACH and CELL_DCH states.
[0025] When the communications device 100 is in the CELL_FACH state
and performs the HS-DSCH reception in the CELL_FACH state, the
embodiment of the present invention provides an H-RNTI managing
program code 220 in the program code 112 to enhance the data
transmission efficiency. Please refer to FIG. 3, which illustrates
a schematic diagram of a process 30 according to an embodiment of
the present invention. The process 30 is applied to a UE of a
wireless communications system, and can be compiled into the H-RNTI
managing program code 220. The process 30 includes the following
steps:
[0026] Step 300: Start.
[0027] Step 302: Use a dedicated H-RNTI for the high speed downlink
operation corresponding to a CELL_FACH state.
[0028] Step 304: Initiate a cell or a URA update procedure due to a
procedure initiation cause.
[0029] Step 306: Change to use a common H-RNTI for the high speed
downlink operation if the dedicated H-RNTI becomes invalid due to
the procedure initiation cause.
[0030] Step 308: Continue using the dedicated H-RNTI for the high
speed downlink operation if the dedicated H-RNTI remains effective
due to the procedure initiation cause.
[0031] Step 310: End.
[0032] In the process 30, the high speed downlink operation
includes the HS-DSCH reception in the CELL_FACH state. The UE
provides the initiation cause for the network terminal during the
cell/URA update procedure. The procedure initiation cause of the
cell update procedure could be cell reselection, periodical cell
update, a radio link failure, an RLC unrecoverable error or uplink
data transmission, whereas the procedure initiation cause of the
URA update procedure could be URA reselection or periodical URA
update.
[0033] The downlink packets include the UE identification
information for the UE using the common H-RNTI but no UE
identification information is included for the UE using the
dedicated H-RNTI. In this situation, if the procedure initiation
cause is cell/URA reselection, causing the dedicated H-RNTI to
become invalid, the UE clears the dedicated H-RNTI and then changes
to use the common H-RNTI. To put the common H-RNTI into effect, the
UE preferably sets an HS_DSCH_RECEPTION_OF_CCCH variable to "TRUE"
and starts reception of related physical (i.e. HS-SCCH and
HS-PDSCH) and transport channels (i.e. HS-DSCH) according to
configuration of an information element (IE) sent by the network
terminal. The IE can be a "Downlink HS-PDSCH system information for
connected mode" or a "Downlink HS-PDSCH system information" IE.
[0034] If the procedure initiation cause is periodical cell/URA
update keeping effectiveness of the dedicated H-RNTI, the UE
continues using the dedicated H-RNTI, which supports better data
transmission efficiency than the common H-RNTI.
[0035] In conclusion, the UE of the prior art changes to use the
common H-RNTI for the HS-DSCH reception in the CELL_FACH state
during the cell/URA update procedure irrespective of the procedure
initiation cause. In the embodiment of the present invention, the
UE changes to use the common H-RNTI only if the dedicated H-RNTI
becomes invalid. If the dedicated H-RNTI stays effective during the
cell/URA update procedure, the UE continues using the dedicated
H-RNTI for less radio resource consumption and better data
transmission efficiency.
[0036] 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.
* * * * *