U.S. patent application number 12/841353 was filed with the patent office on 2010-11-11 for transmission rate control method, radio base station and radio network controller.
This patent application is currently assigned to NTT DOCOMO, INC.. Invention is credited to Takehiro NAKAMURA, Anil UMESH, Masafumi USUDA.
Application Number | 20100284475 12/841353 |
Document ID | / |
Family ID | 37023775 |
Filed Date | 2010-11-11 |
United States Patent
Application |
20100284475 |
Kind Code |
A1 |
USUDA; Masafumi ; et
al. |
November 11, 2010 |
TRANSMISSION RATE CONTROL METHOD, RADIO BASE STATION AND RADIO
NETWORK CONTROLLER
Abstract
The present invention provides a transmission rate control
method for controlling the transmission rate of uplink user data,
including the step of; a radio network controller notifies to a
radio base station and a mobile station an effective period of an
absolute transmission rate control channel, when a call is
established or when a serving cell is changed; a radio base station
determines whether or not to transmit the absolute transmission
rate control channel to each of mobile stations which is performing
a communication with the radio base station; and each of the mobile
stations determines the transmission rate of the uplink user data,
based on a maximum allowable transmission rate mapped to the
absolute transmission rate control channel notified by the radio
base station.
Inventors: |
USUDA; Masafumi; (Tokyo,
JP) ; UMESH; Anil; (Yokohama, JP) ; NAKAMURA;
Takehiro; (Yokohama, JP) |
Correspondence
Address: |
MOTS LAW, PLLC
1629 K STREET N.W., SUITE 602
WASHINGTON
DC
20006-1635
US
|
Assignee: |
NTT DOCOMO, INC.
Tokyo
JP
|
Family ID: |
37023775 |
Appl. No.: |
12/841353 |
Filed: |
July 22, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11886869 |
Nov 5, 2007 |
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PCT/JP2006/305685 |
Mar 22, 2006 |
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12841353 |
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Current U.S.
Class: |
375/259 |
Current CPC
Class: |
H04W 28/22 20130101 |
Class at
Publication: |
375/259 |
International
Class: |
H04L 27/00 20060101
H04L027/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 22, 2005 |
JP |
2005-082784 |
Claims
1. (canceled)
2. A transmission rate control method for controlling a
transmission rate of uplink user data, comprising: determining, at
a radio base station, whether or not to transmit an absolute
transmission rate control channel to each of mobile stations which
is performing a communication with the radio base station, based on
a predetermined effective period; and determining, at each of the
mobile stations, the transmission rate of the uplink user data,
based on an allowable transmission rate mapped to the absolute
transmission rate control channel notified by the radio base
station.
3. (canceled)
4. A radio base station used in a transmission rate control method
for controlling a transmission rate of uplink user data,
comprising: a determination section configured to determine whether
or not to transmit an absolute transmission rate control channel to
each of mobile stations which is performing a communication with
the radio base station, based on a predetermined effective
period.
5. (canceled)
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a transmission rate control
method, a radio base station and a radio network controller for
controlling a transmission rate of uplink user data.
BACKGROUND ART
[0002] As described in Non-patent Document 1, an absolute
transmission rate control channel (E-AGCH: enhanced-absolute grant
channel) is defined as a channel used by a radio base station in
uplink enhancement to control a transmission rate of uplink user
data (data to be transmitted through EDCH/E-DPDCH) from a mobile
station.
[0003] Note that, in the uplink enhancement, the transmission rate
of uplink user data is specified by factors such as: a transmission
power ratio between an enhanced-dedicated physical data channel
(E-DPDCH) used for the uplink user data and a dedicated physical
control channel (DPCCH); a transmission power of the
enhanced-dedicated physical data channel (E-DPDCH) used for the
uplink user data; and a size of transmission data block of the
uplink user data.
[0004] In the uplink enhancement, a radio base station maps, to the
absolute transmission rate control channel, an absolute value of
the allowable transmission rate of uplink user data from a mobile
station. Then, the radio base station transmits the absolute value
to each mobile station, so that the mobile station can determine
the transmission rate of uplink user data based on the absolute
value.
[0005] In the uplink enhancement, a radio base station generally
means a cell in the radio base station if not otherwise specified.
In addition, in the uplink enhancement, each mobile station UE is
configured to receive an absolute transmission rate control channel
(AGCH) from a serving cell of the mobile station UE.
[0006] Additionally, in the uplink enhancement, a transmission rate
generally includes a size of a transport block and a transmission
power ratio (ratio between the transmission power of E-DPDCH and
the transmission power of DPDCH).
[0007] At this time, an effective period of the absolute
transmission rate control channel (an effective period of an
absolute value of the allowable transmission rate mapped to the
absolute transmission rate control channel) is not particularly
set, and the absolute value is valid until the reception of the
next absolute transmission rate control channel.
[0008] Here, in the uplink enhancement, an effective period in
general may be set according to a time elapsed since receiving the
absolute transmission rate control channel (AGCH) (for example, 10
ms, 5 TTI (transmission time interval) or the like), or may be set
in HARQ process units.
[0009] In an example shown in FIG. 13, HARQ processes #4 to #8 are
set as an effective period of the absolute transmission rate
control channel (AGCH).
[0010] For this reason, for example, when a radio base station
desires a certain mobile station to stop transmitting uplink user
data, the radio base station has to transmit another absolute
transmission rate control channel such that the allowable
transmission rate of the uplink user data of the mobile station can
be set to "0 bps", to thereby cause the mobile station to stop
transmitting the uplink user data.
[0011] As a result, transmission power resource in the downlink is
overspent, which leads to deterioration in radio capacity.
[0012] [Non-Patent Document 1] 3GPP TSG-RAN TS25.309 V6.2.0
DISCLOSURE OF THE INVENTION
[0013] Hence, the present invention has been made in view of the
above-mentioned points. An object of the present invention is to
provide a transmission rate control method, a radio base station
and a radio network controller, the three of which are capable of
increasing the radio capacity in downlink by reducing, to 0 bps, an
allowable transmission rate of uplink user data of a mobile station
without transmitting the absolute transmission rate control
channel. Specifically, this is achieved by setting an effective
period of the absolute transmission rate control channel by layer 3
signaling, or by employing a fixed value in the system.
[0014] In addition, the present invention aims to provide a
transmission control method, a radio base station and a radio
network controller, which are capable of optimizing, according to
conditions, the trade-off between the load caused by a control
channel in the downlink and the accuracy in scheduling in the
uplink, by flexibly changing the effective period by layer 3
signaling.
[0015] A first aspect of the present invention is summarized as a
transmission rate control method for controlling a transmission
rate of uplink user data, including: notifying, at a radio network
controller, an effective period of an absolute transmission rate
control channel to a radio base station and a mobile station, when
a call is established or when a serving cell is changed;
determining, at the radio base station, whether or not to transmit
the absolute transmission rate control channel to each of mobile
stations which is performing a communication with the radio base
station, based on the effective period; and determining, at each of
the mobile stations, the transmission rate of the uplink user data,
based on an allowable transmission rate mapped to the absolute
transmission rate control channel notified by the radio base
station.
[0016] A second aspect of the present invention is summarized as a
transmission rate control method for controlling a transmission
rate of uplink user data, including: determining, at a radio base
station, whether or not to transmit an absolute transmission rate
control channel to each of mobile stations which is performing a
communication with the radio base station, based on a predetermined
effective period; and determining, at each of the mobile stations,
the transmission rate of the uplink user data, based on an
allowable transmission rate mapped to the absolute transmission
rate control channel notified by the radio base station.
[0017] A third aspect of the present invention is summarized as a
radio base station used in a transmission rate control method for
controlling a transmission rate of an uplink user data, including:
a determination section configured to determine whether or not to
transmit an absolute transmission rate control channel to each of
mobile stations which is performing a communication with the radio
base station, based on an effective period of an absolute
transmission rate control channel notified by a radio network
controller, when a call is established or when a serving cell is
changed.
[0018] A fourth aspect of the present invention is summarized as a
radio base station used in a transmission rate control method for
controlling a transmission rate of uplink user data, including a
determination section configured to determine whether or not to
transmit an absolute transmission rate control channel to each of
mobile stations which is performing a communication with the radio
base station, based on a predetermined effective period.
[0019] A fifth aspect of the present invention is summarized as a
radio network controller used in a transmission rate control method
for controlling a transmission rate of uplink user data, including
a notification section configured to notify an effective period of
an absolute transmission rate control channel transmitted to each
of mobile stations which is performing a communication with a radio
base station, when a call is established or when a serving cell is
changed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a configuration block diagram of a transmission
rate control system according to an embodiment of the present
invention.
[0021] FIGS. 2(a) to 2(c) are diagrams for explaining data
transmission from mobile stations according to the embodiment of
the present invention.
[0022] FIG. 3 is a sequence diagram showing a transmission rate
control method according to the embodiment of the present
invention.
[0023] FIG. 4 is a configuration block diagram of a mobile station
radio communications function section according to the embodiment
of the present invention.
[0024] FIG. 5 is a configuration block diagram of a baseband signal
processing section according to the embodiment of the present
invention.
[0025] FIG. 6 is a configuration block diagram of a MAC-e section
according to the embodiment of the present invention.
[0026] FIG. 7 is a configuration block diagram of a radio base
station according to the embodiment of the present invention.
[0027] FIG. 8 is a configuration block diagram of a baseband signal
processing section according to the embodiment of the present
invention.
[0028] FIG. 9 is a configuration block diagram of a MAC-e function
section according to the embodiment of the present invention.
[0029] FIG. 10 is a configuration block diagram of a radio network
controller according to the embodiment of the present
invention.
[0030] FIG. 11 is a flowchart showing a transmission rate control
method according to the embodiment of the present invention.
[0031] FIG. 12 is a flowchart showing the transmission rate control
method according to the embodiment of the present invention.
[0032] FIG. 13 is a diagram showing an example of a HARQ of which
an effective period is set, in a general mobile communication
system employing EUL.
BEST MODES FOR CARRYING OUT THE INVENTION
[0033] Hereinafter, an explanation will be given for an embodiment
of the present invention with reference to the drawings. The same
or similar reference numerals are given to the same or similar
portions in the drawings below. Note that the drawings are
expressed schematically.
First Embodiment
[0034] An explanation will be given for a transmission rate control
system according to a first embodiment of the present invention
with reference to FIGS. 4 to 12.
[0035] As shown in FIG. 4, a mobile station radio communications
function section provided in a mobile station of the transmission
rate control system according to the first embodiment of the
present invention includes a bus interface, a call processing
section, a baseband signal processing section and an RF
section.
[0036] Additionally, as shown in FIG. 5, the baseband signal
processing section includes a RLC processing section, a MAC-d
processing section, a MAC-e processing section and a layer 1
processing section.
[0037] Moreover, as shown in FIG. 6, the MAC-e processing section
includes an E-TFC selecting section and a HARQ processing
section.
[0038] Here, the E-TFC selecting section is configured to receive
scheduling signals such as an absolute transmission rate control
channel (E-AGCH) and a relative transmission rate control channel
(E-RGCH) transmitted from radio base station (cell), and to control
the transmission rate of uplink user data of a mobile station
(specifically, to select a transmission format (E-TFC)). The E-TFC
selecting section controls the transmission rate based on an
absolute value of the maximum allowable transmission rate of uplink
user data of the mobile station included in the E-AGCH, and a
relative value (Up/Down/Keep) of the maximum allowable transmission
rate of uplink user data of the mobile station included in the
E-RGCH.
[0039] As shown in FIG. 7, the radio base station (corresponding to
each cell) in the transmission rate control system according to the
first embodiment of the present invention includes a HWY interface,
a baseband signal processing section, a call control section, a
transmitter-receiver section and an amplifier section. Here, FIG. 8
shows a specific configuration example of the baseband signal
processing section related to the present invention.
[0040] In addition, as shown in FIG. 9, a MAC-e function section
provided in the baseband signal processing section includes a HARQ
processing section, a scheduling section and a receive processing
command section.
[0041] Here, the scheduling section is configured to control the
transmission rate of uplink user data of each mobile station, by
transmitting, to each mobile station, the above-mentioned absolute
transmission rate control channel or the relative transmission rate
control channel.
[0042] In addition, the scheduling section is configured to
determine whether or not to transmit the absolute transmission rate
control channel to each mobile station which is performing a
communication with the radio base station (cell) that the
scheduling section itself belongs to. The scheduling section makes
the determination based on an effective period of the absolute
transmission rate control channel, the effective period notified by
the radio network controller when a call is established or when a
serving cell is changed.
[0043] Otherwise, the scheduling section may be configured to
determine whether or not to transmit the absolute transmission rate
control channel to each mobile station which is performing a
communication with the radio base station (cell) to which the
scheduling section itself belongs, based on an effective period
determined in advance in the transfer rate control system.
[0044] Note that the effective period may be designated in time
units (for example, 10 seconds or the like), be designated in TTI
units (for example, 3 TTIs or the like), be designated by use of a
start time and an end time, or be designated in a format indicating
a time when a certain condition is satisfied.
[0045] As shown in FIG. 10, the radio network controller includes a
radio base station interface, an exchange interface, a media signal
processing section, a MAC layer processing section, a call control
section and an RLC layer processing section.
[0046] The call control section is configured to notify an
effective period of the absolute transmission rate control channel,
which is transmitted to each mobile station which is performing a
communication with each of the radio base stations (cells), when a
call is established or when a serving cell is changed.
[0047] FIG. 3 shows a sequence example of the transmission rate
control method according to the present invention. Although FIG. 3
shows an example of the mobile station originating a call, the
mobile station receiving a call can also be considered as an
example.
[0048] In step (1), the mobile station requests the radio network
controller to start communications by use of the EDCH (that is, to
establish a call).
[0049] In step (2), in response to the request, the radio network
controller transmits a request to establish a connection using the
EDCH to the radio base station that controls the mobile station.
Then in step (3), if the connection is successfully established,
the radio base station returns a connection establishment response
indicating the success to the radio network controller.
[0050] In step (4), the radio network controller transmits, to the
mobile station, a control channel connection establishment request
for an establishment of the control channel. This control channel
is used for transmitting and receiving information related to call
types, the release numbers of mobile stations, and the transmission
rates of transmittable and receivable user data.
[0051] If the control channel is established in accordance with the
control channel connection establishment request, the mobile
station notifies the radio network controller of a control channel
connection establishment response indicating the establishment in
step (5).
[0052] After the establishment of the control channel, in step (7),
various parameters related to the EDCH (such an amplitude ratio for
each format) are exchanged between the radio network controller and
the mobile station, and thus the transmission of uplink user data
is started. During this exchanging process, the radio network
controller performs signaling to notify the mobile station of the
effective period of the absolute transmission rate control
channel.
[0053] Also in step (6), various parameters related to the EDCH
(such an amplitude ratio for each format) are exchanged between the
radio network controller and the radio base station. In this step,
the radio network controller also performs signaling to notify the
radio base station of the effective period of the absolute
transmission rate control channel.
[0054] With reference to FIG. 3, the example has been described of
a case where the transmission rate control method of the present
invention is applied when a call is established. However, it should
be noted that the present invention is not limited to this case,
and that the method may also be similarly applied when a serving
cell is changed.
[0055] Incidentally, when the radio network controller judges,
based on a measurement report on the mobile cell, that the serving
cell of the mobile station should be changed, the serving cell is
changed to another cell by establishing the EDCH between the mobile
station and the cell to serve as the serving cell after the change,
and then by releasing the EDCH between the mobile station and the
cell having served as the serving cell before the change.
[0056] FIG. 11 shows a flowchart of operations of the mobile
station in the transmission rate control method according to the
present invention.
[0057] After completion of the connection processing for EDCH
(processing for establishing the call or processing for changing
the serving cell), the mobile station starts transmitting the
uplink user data through the EDCH in step S101 when having user
data to be transmitted.
[0058] Then, in a case of receiving the AGCH in step S103, the
mobile station resets a timer in step S105, and transmits uplink
user data in step S106, based on the allowable transmission rate
mapped to the AGCH.
[0059] Alternatively, in the case of not receiving the AGCH in step
S103, the mobile station increments the timer.
[0060] Thereafter, if the timer has not expired (that is, if the
time is within the effective period of the AGCH received most
recently) in step S107, the mobile station continues to transmit
the uplink user data based on the allowable transmission rate (the
absolute value of the transmission rate of the uplink user data)
mapped to the AGCH (step S101).
[0061] In contrast, if the timer has expired (that is, if the time
is not within the effective period of the AGCH received most
recently) in step S107, the mobile station invalidates the
allowable transmission rate mapped to the AGCH, in step S108.
[0062] In step S108, if the minimum allowable transmission rate is
set in advance, the mobile station transmits the uplink user data
at the minimum allowable transmission rate. If the minimum
allowable transmission rate is not set, the mobile station stops
transmitting the uplink user data.
[0063] FIG. 12 shows a flowchart of operations of the radio base
station in the transmission rate control method according to the
present invention.
[0064] In a case of connecting the EDCH (after completion of
processing for establishing the call or processing for changing the
serving cell), the radio base station (the serving cell of each
mobile station) transmits the AGCH in step S204 if the allowable
transmission rate in each mobile station needs to be changed in
step S201.
[0065] Meanwhile, in a case where in step S201 the allowable
transmission rate in each mobile station does not need to be
changed, such as a case where the AGCH is already transmitted, the
radio base station increments the timer in step S202.
[0066] If the timer has expired (that is, if the time is not within
the effective period of the AGCH) in step S203, the radio base
station transmits the AGCH again in step S204.
[0067] As has been described, according to the transmission rate
control method according to the present embodiment, the radio
capacity in the downlink can be increased by reducing, to 0 bps,
the transmission rate of uplink user data of a mobile station,
without transmission of the AGCH. Specifically, this is achieved by
employing an effective period of the AGCH set by layer 3 signaling,
or a fixed effective period of the AGCH in the system.
[0068] Additionally, according to the transmission rate control
method according to the present embodiment, the trade-off between
the load caused by a control channel in the downlink and the
accuracy in scheduling in the uplink can be optimized, as needed,
by flexibly changing the effective period by layer 3 signaling.
[0069] Hereinabove, the present invention has been explained in
detail with reference to the embodiment. However, it is obvious to
those skilled in the art that the present invention is not limited
to the embodiment described in the present application. An
apparatus of the present invention can be implemented as an
embodiment modified and improved without departing from the spirit
and scope of the present invention, defined by the description in
the scope of claims. Accordingly, the description in the present
application aims for exemplar illustration, and is not intended at
all to limit the present invention.
INDUSTRIAL APPLICABILITY
[0070] As described above, the present invention can provide a
transmission rate control method, a radio base station and a radio
network controller, the three of which are capable of increasing
the radio capacity in downlink by reducing, to 0 bps, an allowable
transmission rate of uplink user data of a mobile station without
transmitting the absolute transmission rate control channel.
Specifically, this is achieved by setting an effective period of
the absolute transmission rate control channel by layer 3
signaling, or by employing a fixed value in the system.
[0071] In addition, the present invention aims to provide a
transmission control method, a radio base station and a radio
network controller, which are capable of optimizing, according to
conditions, the trade-off between the load caused by a control
channel in the downlink and the accuracy in scheduling in the
uplink, by flexibly changing the effective period by layer 3
signaling.
* * * * *