U.S. patent number RE47,212 [Application Number 14/884,156] was granted by the patent office on 2019-01-22 for method for reducing power consumption of a terminal in cellular system.
This patent grant is currently assigned to Electronics and Telecommunications Research Institute. The grantee listed for this patent is Electronics and Telecommunications Research Institute. Invention is credited to Seung-Chan Bang, Jae-Heung Kim, Jung-Im Kim, Kyoung-Seok Lee, Byung-Han Ryu.
United States Patent |
RE47,212 |
Kim , et al. |
January 22, 2019 |
Method for reducing power consumption of a terminal in cellular
system
Abstract
Provided is a method and apparatus for discontinuously
transmitting/receiving packets for low-power consumption of a
terminal in a cellular system for packet transmission. The present
invention provides a method and apparatus that can perform a
low-power consuming operation when a terminal is in active state in
a cellular system. The method for discontinuously
transmitting/receiving packet data to reduce power consumption of a
terminal in a cellular system, including the steps of: a)
establishing discontinuous transmission/reception (DTX/DRX)
parameters including discontinuous DTX/DRX cycle information for
terminals operating in a transmission suspension mode, which is a
sub-state of an active state; and b) performing DTX/DRX based on
the DTX/DRX parameters in the terminals operating in the
transmission suspension mode.
Inventors: |
Kim; Jae-Heung (Daejon,
KR), Kim; Jung-Im (Daejon, KR), Lee;
Kyoung-Seok (Daejon, KR), Ryu; Byung-Han (Daejon,
KR), Bang; Seung-Chan (Daejon, KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
Electronics and Telecommunications Research Institute |
Daejon |
N/A |
KR |
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Assignee: |
Electronics and Telecommunications
Research Institute (Daejeon-si, KR)
|
Family
ID: |
1000003486857 |
Appl.
No.: |
14/884,156 |
Filed: |
October 15, 2015 |
PCT
Filed: |
March 06, 2007 |
PCT No.: |
PCT/KR2007/001094 |
371(c)(1),(2),(4) Date: |
January 05, 2009 |
PCT
Pub. No.: |
WO2007/102689 |
PCT
Pub. Date: |
September 13, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
12281913 |
Mar 6, 2007 |
8560025 |
Oct 15, 2013 |
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Foreign Application Priority Data
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Mar 7, 2006 [KR] |
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10-2006-0021316 |
Mar 10, 2006 [KR] |
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10-2006-0022697 |
Feb 2, 2007 [KR] |
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10-2007-0010883 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W
52/04 (20130101); H04B 1/38 (20130101); H04W
52/287 (20130101); H04W 52/286 (20130101); H04W
52/44 (20130101) |
Current International
Class: |
H04B
1/38 (20150101) |
Field of
Search: |
;455/574 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1 414 201 |
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Apr 2004 |
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EP |
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10-1999-0066380 |
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Aug 1999 |
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KR |
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1999-0066380 |
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Aug 1999 |
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KR |
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99/38278 |
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Jul 1999 |
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WO |
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01/03381 |
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Jan 2001 |
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WO |
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Other References
International Search Report for PCT/KR2007/001094 dated Jun. 16,
2007. cited by applicant.
|
Primary Examiner: Tarae; Michelle
Claims
What is claimed is:
1. A method for discontinuous reception operation of a terminal in
wireless communication system, comprising of: transmitting
preferred information for low power-consuming operation to a base
station; receiving parameters for performing the discontinuous
reception operation from the base station; and performing, in an
active state, the discontinuous reception operation based on the
received parameters, wherein messages from the base station are
monitored discontinuously according to a discontinuous reception
cycle, wherein uplink synchronization is sustained until a
predetermined time is expired and the uplink synchronization is not
sustained after the predetermined time is expired in the active
state, wherein the parameters are configured by the base station
based on the preferred information.
2. The method as recited in claim 1, wherein the parameters include
information of the predetermined time.
3. The method as recited in claim 1, wherein the preferred
information is a low power-consuming operation indicator preferred
by the terminal.
4. The method as recited in claim 1, wherein the discontinuous
reception operation is initiated when a discontinuous reception
operation initiation message is received from the base station.
5. The method as recited in claim 1, wherein the parameters are
received through a broadcasting channel from the base station.
6. A .Iadd.communication .Iaddend.method .[.for supporting
discontinuous reception operation of a terminal in a base station
in wireless communication system.]. .Iadd.performed by.Iaddend.,
.Iadd.the method .Iaddend.comprising.[.of.].: receiving
.[.preferred.]..Iadd., at a base station, a first message
comprising first .Iaddend.information .[.for.]. .Iadd.on a
preference of a terminal about implementing .Iaddend.low
.[.power-consuming operation.]. .Iadd.power consumption
.Iaddend.from the terminal; .[.configuring parameters for
performing the discontinuous reception operation of the terminal
which is capable of transmitting/receiving data to/from the base
station.]. .Iadd.determining, at the base station, a first
parameter at least based on the first information.Iaddend.;
transmitting .[.the configured parameters.]..Iadd., at the base
station, a second message comprising the first parameter
.Iaddend.to the terminal; and .[.transmitting messages to the
terminal, wherein the parameters are configured to support
discontinuous reception operation by the terminal in an active
state, wherein the messages are discontinuously monitored according
to a discontinuous reception cycle by the terminal, wherein uplink
synchronization is sustained until a predetermined timer is expired
and the uplink synchronization is not sustained after the
predetermined timer is expired in the active state being capable of
transmitting/receiving data to/from the base station, wherein the
parameters are configured by the base station based on the
preferred information.]. .Iadd.performing, at the base station, a
discontinuous reception (DRX) operation for the terminal based on
the first parameter in an active state.Iaddend..
7. The .Iadd.communication .Iaddend.method as recited in claim 6,
wherein the .[.parameters include information of the predetermined
timer.]. .Iadd.first parameter comprises a first DRX cycle and a
first period of time, and the DRX operation is performed based on
the first DRX cycle during the first period of time.Iaddend..
8. The .Iadd.communication .Iaddend.method as recited in claim
.[.6.]. .Iadd.7.Iaddend., wherein .[.the preferred information is a
low power-consuming operation indicator preferred by the
terminal.]. .Iadd.the first parameter further comprises a second
period of time, and, after the first period of time, the DRX
operation is performed based on a second DRX cycle during the
second period of time, the second DRX cycle longer than the first
DRX cycle.Iaddend..
9. The .Iadd.communication .Iaddend.method as recited in claim 6,
.[.wherein the discontinuous reception.]. .Iadd.further comprising:
transmitting a third message to the terminal, wherein the third
message instructs the terminal to start DRX .Iaddend.operation.[.is
initiated when a discontinuous reception operation initiation
message is received by the terminal.]..
10. The .Iadd.communication .Iaddend.method as recited in claim 6,
wherein the .Iadd.first .Iaddend.parameters are received through a
broadcasting channel .[.from the base station.]. .Iadd.to the
terminal.Iaddend..
11. A method for discontinuous reception operation of a terminal in
wireless communication system, comprising of: transmitting
preferred information for low power-consuming operation to a base
station; receiving performing information of whether performing the
discontinuous reception operation from the base station; and
performing, in an active state, the discontinuous reception
operation based on the performing information, wherein messages
from the base station are monitored discontinuously according to a
discontinuous reception cycle, wherein uplink synchronization is
sustained until a predetermined time is expired and the uplink
synchronization is not sustained after the predetermined time is
expired in the active state, wherein the performing information is
configured by the base station based on the preferred
information.
12. The method as recited in claim 11, wherein the preferred
information is a low power-consuming operation indicator preferred
by the terminal.
13. A method for supporting discontinuous reception operation of a
terminal in a base station in wireless communication system,
comprising of: receiving preferred information for low
power-consuming operation from the terminal; configuring performing
information of whether performing the discontinuous reception
operation of the terminal which is capable of
transmitting/receiving data to/from the base station; transmitting
the configured performing information to the terminal; and
transmitting messages to the terminal, wherein the performing
information is configured to support discontinuous reception
operation by the terminal in an active state, wherein the messages
are discontinuously monitored according to a discontinuous
reception cycle by the terminal, wherein uplink synchronization is
sustained until a predetermined timer is expired and the uplink
synchronization is not sustained after the predetermined timer is
expired in the active state being capable of transmitting/receiving
data to/from the base station, wherein the performing information
is configured by the base station based on the preferred
information.
14. The method as recited in claim 13, wherein the preferred
information is a low power-consuming operation indicator preferred
by the terminal.
.Iadd.15. A communication apparatus comprising: a memory; and a
processor operably coupled to the memory, wherein the processor,
when executing program instructions stored in the memory, is
configured to: cause the communication apparatus to receive from a
terminal a first message comprising first information on a
preference of the terminal about implementing low power
consumption; determine a first parameter at least based on the
first information; cause the communication apparatus to transmit a
second message comprising the first parameter to the terminal; and
cause the communication apparatus to perform a discontinuous
reception (DRX) operation for the terminal based on the first
parameter in an active state..Iaddend.
.Iadd.16. The communication apparatus as recited in claim 15,
wherein the first parameter comprises a first DRX cycle and a first
period of time, and the DRX operation is performed based on the
first DRX cycle during the first period of time..Iaddend.
.Iadd.17. The communication apparatus as recited in claim 16,
wherein the first parameter further comprises a second period of
time, and, after the first period of time, the DRX operation is
performed based on a second DRX cycle during the second period of
time, the second DRX cycle longer than the first DRX
cycle..Iaddend.
.Iadd.18. The communication apparatus as recited in claim 15,
wherein the processor, when executing the program instructions, is
configured to cause the communication apparatus to transmit a third
message to the terminal, wherein the third message instructs the
terminal to start the DRX operation..Iaddend.
.Iadd.19. The communication apparatus as recited in claim 15,
wherein the first parameter is received through a broadcasting
channel to the terminal..Iaddend.
.Iadd.20. A communication method for a discontinuous reception
(DRX) operation by a terminal, the method comprising: transmitting,
by the terminal, a first message comprising first information on a
preference of the terminal about implementing low power
consumption; receiving, at the terminal, a second message
comprising a first parameter from the base station; and performing,
at the terminal, the DRX operation for the terminal based on the
first parameter in an active state..Iaddend.
.Iadd.21. The communication method as recited in claim 20, wherein
the first parameter comprises a first DRX cycle and a first period
of time, and the DRX operation is performed based on the first DRX
cycle during the first period of time..Iaddend.
.Iadd.22. The communication method as recited in claim 20, wherein
the first parameter is determined based on the first
information..Iaddend.
.Iadd.23. The communication method as recited in claim 20, further
comprising: receiving a third message from the base station,
wherein the DRX operation is performed in response to the third
message..Iaddend.
.Iadd.24. The communication method as recited in claim 20, wherein
the first parameter is received through a broadcasting channel from
the base station..Iaddend.
.Iadd.25. The communication method as recited in claim 21, wherein
the first parameter further comprises a second period of time, and,
after the first period of time, the DRX operation is performed
based on a second DRX cycle during the second period of time, the
second DRX cycle longer than the first DRX cycle..Iaddend.
.Iadd.26. A communication apparatus, comprising: a memory; and a
processor operably coupled to the memory, wherein the processor,
when executing program instructions stored in the memory, is
configured to: cause the communication apparatus to transmit, to a
base station, a first message comprising first information on a
preference of the communication apparatus about implementing low
power consumption; cause the communication apparatus to receive,
from the base station, a second message comprising a first
parameter; and cause the communication apparatus to perform a
discontinuous reception (DRX) operation based on the first
parameter in an active state..Iaddend.
.Iadd.27. The communication apparatus as recited in claim 26,
wherein the first parameter comprises a first DRX cycle and a first
period of time, and the DRX operation is performed based on the
first DRX cycle during the first period of time..Iaddend.
.Iadd.28. The communication apparatus as recited in claim 26,
wherein the first parameter is determined based on the first
information..Iaddend.
.Iadd.29. The communication apparatus as recited in claim 26,
wherein the processor, when executing the program instructions,
causes the communication apparatus to receive a third message from
the base station, and the DRX operation is performed in response to
the third message..Iaddend.
.Iadd.30. The communication apparatus as recited in claim 26,
wherein the first parameter is received through a broadcasting
channel from the base station..Iaddend.
.Iadd.31. The communication apparatus as recited in claim 27,
wherein the first parameter further comprises a second period of
time, and, after the first period of time, the DRX operation is
performed based on a second DRX cycle during the second period of
time, the second DRX cycle longer than the first DRX
cycle..Iaddend.
.Iadd.32. A communication device in a terminal, the communication
device comprising: a processor; and a memory operably coupled with
the processor, wherein the processor, when executing program
instructions stored in the memory, is configured to: cause the
terminal to transmit, to a base station, a first message comprising
first information on a preference of the terminal about
implementing low power consumption; cause the terminal to receive,
from the base station, a second message comprising a first
parameter; and cause the terminal to perform a discontinuous
reception (DRX) operation based on the first parameters in an
active state..Iaddend.
.Iadd.33. The communication device as recited in claim 32, wherein
the first parameter comprises a first DRX cycle and a first period
of time, and the DRX operation is performed based on the first DRX
cycle during the first period of time..Iaddend.
.Iadd.34. The communication device as recited in claim 32, wherein
the first parameter is determined based on the first
information..Iaddend.
.Iadd.35. The communication device as recited in claim 32, wherein
the processor, when executing the program instructions, is
configured to cause the terminal to receive a third message from
the base station, and the DRX operation is performed in response to
the third message..Iaddend.
.Iadd.36. The communication device as recited in claim 32, wherein
the first parameter is received through a broadcasting channel from
the base station..Iaddend.
.Iadd.37. The communication device as recited in claim 33, wherein
the first parameter further comprises a second period of time, and,
after the first period of time, the DRX operation is performed
based on a second DRX cycle during the second period of time, the
second DRX cycle longer than the first DRX cycle..Iaddend.
Description
.Iadd.CROSS REFERENCES TO RELATED APPLICATIONS.Iaddend.
.Iadd.This application is a reissue application of U.S. Pat. No.
8,560,025 issued Oct. 15, 2013, which is issued from U.S.
application Ser. No. 12/281,913 which is a national entry of
International Application No. PCT/KR2007/001094, filed Mar. 6,
2007, which claims priorities to and the benefits of Korea Patent
Application No. 10-2006-0021316 filed Mar. 7, 2006, Korean Patent
Application No. 10-2006-0022697 filed Mar. 10, 2006, and Korean
Patent Application No. 10-2007-0010883, filed Feb. 2, 2007 in the
Korean Intellectual Property Office, the contents of which are
incorporated herein by reference..Iaddend.
TECHNICAL FIELD
The present invention relates to a low power-consuming operation in
a cellular system; and, more particularly, to a low power-consuming
operation method of a terminal that can reduce the power
consumption of the terminal and extend a call waiting time in a
cellular system for packet transmission.
BACKGROUND ART
In a conventional cellular system, terminals have performed a low
power-consuming operation, i.e., a power-saving operation, by using
a sleep-mode operation based on a discontinuous reception (DRX)
cycle, which is a system parameter.
The WCDMA 3GPP system aims to provide circuit and packet services
in a circuit-based system. On the other hand, a Long-Term Evolution
(LTE), which is under standardization process to provide diverse
packet services, is a packet-based system aiming to provide only a
packet service.
Therefore, the LTE system which is devised to provide a packet
service having a burst characteristic requires an efficient low
power-consuming operation method for terminals.
In short, it is required to develop a method that can reduce power
consumption not only in idle-state terminals whose session for a
packet service is terminated, but also in active-state terminals in
a section where there is no data to be transmitted to provide a
packet service having a burst characteristic and diverse qualities
of service (QoS).
DISCLOSURE
Technical Problem
It is, therefore, an object of the present invention to provide a
method that can effectively reduce power consumption of a terminal
by using an indicator indicating whether the terminal needs to
perform a low power-consuming operation to control the low
power-consuming operation in a cellular system for transmitting
packets.
Other objects and advantages of the present invention can be
understood by the following description, and become apparent with
reference to the embodiments of the present invention. Also, it is
obvious to those skilled in the art to which the present invention
pertains that the objects and advantages of the present invention
can be realized by the means as claimed and combinations
thereof.
Technical Solution
In accordance with one aspect of the present invention, there is
provided a method for performing low power-consuming operation to
reduce power consumption of a terminal in a cellular system for a
packet service, including the steps of: a) establishing low
power-consuming operation parameters including a low
power-consuming operation indicator in a terminal operating in a
transmission suspension mode, which is a sub-state of an active
state; and b) performing the low power-consuming operation based on
the low power-consuming operation parameters in the terminal
according to a value of the low power-consuming operation
indicator.
Advantageous Effects
The method of the present invention can effectively reduce power
consumption of a terminal by using an indicator indicating whether
the terminal needs to perform a low power-consuming operation to
control the low power-consuming operation in a cellular system for
transmitting packets, when the terminal is in an active state.
DESCRIPTION OF DRAWINGS
FIG. 1 is a diagram illustrating a terminal state in a cellular
system to which the present invention is applied.
FIG. 2 is a view showing a low power-consuming operation based on
low power-consuming operation parameters in accordance with an
embodiment of the present invention.
FIG. 3 is a signaling flowchart between a base station and a
terminal that perform low power-consuming operation in accordance
with an embodiment of the present invention.
BEST MODE FOR THE INVENTION
Other objects and aspects of the invention will become apparent
from the following description of the embodiments with reference to
the accompanying drawings, which is set forth hereinafter.
Accordingly, those skilled in the art of the present invention can
easily implement the technological concept of the present
invention. Also, when it is considered that detailed description on
a prior art related to the present invention may obscure the points
of the present invention unnecessarily in the description of the
present invention, the description will not be provided.
Hereinafter, specific embodiments of the present invention will be
described in detail with reference to the accompanying
drawings.
FIG. 1 is a diagram illustrating terminal states in a cellular
system to which the present invention is applied.
A cellular system providing a packet service defines and manages
the state of a terminal as shown in FIG. 1 to efficiently operate
limited radio resources in nodes over a base station, i.e., a node
B.
When a terminal is registered on a network through a base station,
the state of the terminal is defined as an attached mode 1. When a
terminal is not recognized on a cellular network and the base
station, or when the terminal is not registered, the state of the
terminal is defined as a detached mode 2.
Terminals in the attached mode 1 are divided into those of an
active state 3 and those of an idle state 4 according to whether or
not a packet service is provided.
The active state 3 is a state where a terminal can be allocated
with radio resources for transmitting/receiving packet data under
the control of a scheduling unit disposed in a base station.
The active state 3 is divided into a transmission mode (Tx on) 5
and a transmission suspension mode (Tx off) 6 according to whether
radio resources for transmitting packet data are allocated.
A conventional terminal performs a low power-consuming operation,
which is so-called a power-saving operation, by maintaining only
the least control channel with a base station only in the idle
state 4 where there is no data to be transmitted/received based on
the burst property of packet data. The terminal may enter the idle
state 4 by a scheduling unit of a base station, regardless of the
state of the terminal.
In the transmission suspension mode 6 of the active state 3, the
scheduling unit operates in the transmission suspension mode
because there are no data to be transmitted or received due to the
burst characteristic of packet data or other reasons and does not
allocate the radio resources for transmitting/receiving packet data
and control information. The terminals need to efficiently perform
the low power-consuming operation in a transmission suspension mode
duration to minimize the power consumption of the terminal.
According to the embodiment of the present invention, terminals
performs low power-consuming operation based on a discontinuous
reception (DRX) cycle established between the terminals and the
base station in a duration of the transmission suspension mode 6,
which is a sub-state of the active state 3, while maintaining the
least power for a control channel.
FIG. 2 is a view showing a low power-consuming operation based on
low power-consuming operation parameters in accordance with an
embodiment of the present invention.
Referring to FIG. 2, the low power-consuming operation of a
terminal is controlled based on low power-consuming operation
parameters in the transmission suspension mode 8 of the active
state.
The low power-consuming operation parameters include an
active-state initial DRX cycle length 10, a DRX cycle augmentation
coefficient, a DRX duration 11, the number of DRX durations 12,
active dwelling time (Active_dwell_time) 13, low power consuming
operation indicator, i.e., a power-saving indicator, and a physical
layer uplink sync sustaining time (L1_UL_Sync_keep_time) 16.
The active-state initial DRX cycle length 10 is the minimum value
of a DRX cycle length for a terminal in the transmission suspension
mode to perform low power-consuming operation. The DRX cycle
augmentation coefficient is an increased amount of the DRX cycle
length that performs DRX operation. The DRX duration 11 is a
section to which a DRX is applied. It is established as a counter
number or time. When one DRX duration ends, another DRX cycle which
is obtained by increasing the DRX cycle as much as the DRX cycle
augmentation coefficient parameters in the next DRX duration.
The number of DRX durations 12 is the number of DRX durations
needed for a terminal to perform the low power-consuming operation.
The active dwelling time (Active_d-well_time) 13 is a threshold
value of time for which a terminal can remain in the active state
without having packet data to be transmitted to a transmission
buffer.
The low power-consuming operation indicator, i.e., a power-saving
indicator indicates whether to perform the low power-consuming
operation in a terminal. When the low power-consuming operation
indicator is set "on," the base station and terminal performs low
power-consuming operation when the terminal enters the transmission
suspension mode. When the low power-consuming operation indicator
is set "off," the low power-consuming operation is not performed in
the terminal.
The physical layer uplink sync sustaining time
(L1_UL_Sync_keep_time) 16 is a threshold value of time for which
uplink synchronization should be sustained in a physical layer
while a terminal operates in the transmission suspension mode.
As aforementioned, the low power-consuming operation parameters are
established through negotiation between the base station and the
terminal. The active-state initial DRX cycle length parameter may
differ according to the quality of service (QoS) attributes of a
provided packet service.
The base station may inform the generation of downlink traffic in a
monitoring section 9 at a termination moment of a DRX cycle or it
may transmit radio resource allocation information for reporting or
a radio resource allocation request through the uplink. A terminal
operating in the transmission suspension mode recognizes the
presence of downlink traffic transmitted through a downlink traffic
notification channel in the monitoring section and determines
whether to receive the downlink packet data or not. Otherwise, the
terminal operating in the transmission suspension mode recognizes
uplink radio resource allocation information transmitted through a
downlink control channel and transmits control information, such as
measurement information or a radio resource allocation request
through the uplink.
When there is no downlink traffic or when packet data to be
transmitted through the uplink is not transmitted from the upper
layer of a terminal, the terminal performs the low power-consuming
operation in DRX cycles until the next monitoring section. In the
low power-consuming operation, the terminal does not receive
downlink signals and does not transmit signals through the uplink,
either.
The DRX cycle length for low power-consuming operation is
determined by a base station to efficiently operate the system.
When one DRX cycle ends without setting up an additional parameter,
the base station may determine the next DRX cycle based on the
control information transmitted in the monitoring section 9 and
notify terminals of the next DRX cycle. Herein, the scheduling unit
of the base station may change the DRX cycle according to the QoS
attributes of the provided packet service and loads applied to the
system.
Meanwhile, when the low power-consuming operation is performed
based on the low power-consuming operation parameters determined
through negotiation between the base station and the terminals, a
DRX cycle is applied to one DRX duration. When one DRX duration
ends, the base station and the terminals can negotiate and
re-establish the next DRX duration.
A DRX cycle is determined in the following algorithm based on the
parameters determined through the negotiation between the base
station and the terminals.
When n>0 and n mod DTX/DRX duration is equal to 0,
DRX cycle(n+1)=DRX cycle (n)*DRX cycle augmentation
coefficient.
In other cases,
DRX cycle(n+1)=DRX cycle (n)
where n=0, 1, 2, 3 . . .
DRX cycle(0)=DRX cycle initial value
DRX cycle augmentation coefficient=1, 2, 3 . . . , j
DRX duration=time duration (or a threshold value of a counter) to
which the same DRX cycle is applied
The terminals perform the low power-consuming operation based on
the low power-consuming operation parameters determined as
above.
When data to be transmitted or received are not generated until the
moment 14 that the time determined based on the DRX duration and
the number of DRX durations ends, the scheduling unit in the base
station shifts the terminal into the idle state or re-establishes
the low power-consuming operation parameters.
Meanwhile, when data to be transmitted or received are not
generated until the moment 15 when an additional timer is provided
and an active dwelling time (Active_dwell_time) is achieved, the
scheduling unit of the base station shifts the terminal into the
idle state or re-establishes the low power-consuming operation
parameters.
The scheduling unit and the terminal may include a timer for a
physical layer uplink sync sustaining time (L1_UL_Sync_keep_time)
and, when data to be transmitted or received are not generated
until the moment 17 when a physical layer uplink sync sustaining
time is achieved, they operate the terminal not to sustain the
physical layer sync for the uplink and reduce the power consumption
of the terminal.
FIG. 3 is a signaling flowchart between a base station and a
terminal that perform low power-consuming operation in accordance
with an embodiment of the present invention.
The base station determines low power-consuming operation
parameters based on the QoS of the packet service, generates system
information including the low power-consuming operation parameters,
and transmits it through a broadcasting channel at step S311.
The low power-consuming operation parameters included in the system
information are the active-state initial DRX cycle length 10, the
DRX cycle augmentation coefficient, the DRX duration 11, the number
12 of DRX durations, and the active dwelling time
(Active_dwell_time) 13.
At step S312, when packet data are generated, the base station
attempts to provide a service corresponding to the packet data.
Herein, the base station attempts to provide the service through
paging, and the terminal receives the system information during a
paging monitoring section and attempts to access in a random access
method to receive the service corresponding to the generated packet
data.
The base station shifts the terminal into the active state at step
S313, and the terminal shifts into the active state and operates in
the transmission mode at step S314. When the terminal shifts from
the idle state into the active state, the base station and the
terminal establish a session though negotiation.
Meanwhile, the base station and the terminal perform an Radio
Resource Control (RRC) connection through the session establishment
to transmit/receive packet data, and they set up basic parameters
of the upper layer for it.
At step S316, the terminal reports a low power-consuming operation
indicator preferred according to the power setup environment of the
terminal to the base station. When the terminal is connected to an
external power source or it does not need to perform the low
power-consuming operation for other reasons, the terminal reports a
low power-consuming operation indicator set to be `off` to the base
station to inform the base station that the terminal does not need
to perform the low power-consuming operation. In the other cases,
the terminal reports a low power-consuming operation set to be `on`
which informs the base station that it needs to perform the low
power-consuming operation. Also, the terminal may receive a signal
directly from a user and set up a needed low power-consuming
operation indicator.
At step S317, when the terminal enters the transmission suspension
mode in the active state, the base station determines a low
power-consuming operation indicator to be applied to the terminal
based on the low power-consuming operation indicator reported by
the terminal and the environment of the base station.
At step S321, the terminal is shifted into the active state by
controlling the state shift, and the terminal whose mode is shifted
into the active state operates in the transmission mode at step
S722, and the base station and terminal establishes session for the
packet data service at step S723.
When the base station determines the low power-consuming operation
value to be applied to the terminal to be `on`, it negotiates and
sets up the low power-consuming operation parameters at step
S318.
To be specific, at the step S318, the terminal negotiates the low
power-consuming operation parameters, such as the physical layer
uplink sync sustaining time, the active-state initial DRX cycle
length, the DRX cycle augmentation coefficient, the DRX duration,
the number of DRX durations, and the active dwelling time, through
negotiation with the base station, or establishes the parameters
based on the system information transmitted through a broadcasting
channel without negotiation.
Subsequently, at step S319, the terminal enters the transmission
suspension mode and performs low power-consuming operation based on
the established low power-consuming operation parameters.
Through the process described above, the base station can not only
apply an appropriate DRX cycle in consideration of the QoS of the
provided packet service, but also divide the terminals within the
service coverage into those in need of the low power-consuming
operation and those that do not need the low power-consuming
operation based on the low power-consuming operation indicator.
The scheduling unit of the base station can inform generation of
downlink traffic to the terminals operating in the transmission
suspension mode of the active state and having a low
power-consuming operation indicator of `off`, whenever it needs to
do, regardless of the value of the low power-consuming operation
parameters, such as the DRX cycle length. The scheduling unit can
also transmit a report or radio resource allocation information for
requesting resources through the uplink. However, when the low
power-consuming operation indicator is set up to be `on`, the
scheduler sets up the low power-consuming operation parameters
according to the QoS of the provided packet service, and performs
low power-consuming operation.
Meanwhile when the terminal operating in the low power-consuming
operation sets up and reports its low power-consuming operation
indicator to be `off`, and the base station determines and changes
the low power-consuming operation indicator from on into off and
notifies the change to the terminal to there by control the
terminal operate in the active state without performing the low
power-consuming operation. In other words, the base station
determines the low power-consuming operation indicator in
consideration of the low power-consuming operation indicator
reported by the terminal and the base station environment, and
informs the terminal of the determined low power-consuming
operation indicator.
Subsequently, the base station transmits information informing the
generation of downlink traffic in a monitoring section 9 where a
downlink signal is received, or it transmits radio resource
allocation information for transmitting uplink control information
to make a report or request for radio resources through the uplink
at step S320.
Subsequently, when data to be transmitted are generated when the
terminal is in the transmission suspension mode, the terminal
changes its mode into the transmission mode upon the state shift
control, which is performed in the base station at step S321, at
step S322. At step S323, the terminal transmits packet data or
attempts to provide a new service. When the packet data service
ends, the terminal cancels a session.
The method of the present invention may be realized as a program
and stored in computer-readable recording media, such as CD-ROM,
RAM, ROM, floppy disks, hard disks, and magneto-optical disks.
Since the present invention can be easily implemented by those of
ordinary skill in the art of the present invention, detailed
description on it will not be provided herein.
The method of the present invention can effectively reduce the
power consumption of a terminal by controlling the terminal to
perform the low power-consuming operation in the active state with
an low power-consuming operation indicator, which indicates whether
the terminal is in need of performing the low power-consuming
operation, in a cellular system for transmitting packets.
While the present invention has been described with respect to
certain preferred embodiments, it will be apparent to those skilled
in the art that various changes and modifications may be made
without departing from the scope of the invention as defined in the
following claims.
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