2. The base station apparatus according to Claim 1, wherein the resource control means does not place a resource allocation upper-limit to a terminal device, which is an object of a QoS guarantee, but places the resource allocation upper-limit to a terminal device, which is not the object of the QoS guarantee.

3. The base station apparatus according to Claim 2, wherein when an unallocated resource is present with a result that the resource control means places the resource allocation upper-limit to allocate the resource to the terminal device, the resource control means eliminates the resource allocation upper-limit and adds 20 a resource allocated to the terminal device.

4. The base station apparatus according to any one of Claims 1 to 3, wherein the congestion degree estimation meails sets as the congestion degree, in the estimation of the congestion degree, one or more values of a value that a 25 network connected to the base station apparatus notifies of, the number of terminal devices connected to the base station apparatus, the number of terminal devices in which data to be transmitted is present in a downlink buffer in the base station apparatus, the number of terminal devices estimated that data to be transmitted is present in an uplink buffer in the base station apparatus, and a resource allocation 30 delay time in the base station apparatus.

5. The base station apparatus a c c o r d i ~ ~tog any one of Claims 1 to 3, wherein the congestion degree estimation means calculates the congestion degree, in the estimation of the congestion degree. based on at least one of a value that a network connected to the base station apparatus notifies of, the number of terininal devices connected to the base station apparatus, the number of terminal devices in which data to be transmitted is present in a downlink buffer in the base station apparatus, the number of terminal devices estimated that data to be transmitted is 5 present in an uplink buffer in the base station apparatus, and a resource allocation delay time in the base station apparatus.

6. The base station apparatus according to Claim 2 or 3, wherein the resource control means decides a value set to the base station apparatus by an 10 external device as a resource allocation upper-limit in deciding the resource allocation upper-limit to the terminal device based on the congestion degree.

7. The base station apparatus according to any one of Claims 1 to 6, wherein the base station apparatus notifies the network of the congestion degree 15 estimated by the congestion degree estimation means.

8. The base station apparatus according to any one of Claims 1 to 7, wherein the base station apparatus is a radio base station, the terminal device is a wireless terminal, and the resource is a radio resource.

9. A coinlnunication control method for allocating a resource for communication to a terminal device, wherein a congestion degree by communication of the terminal device is estimated, and a resource allocation amount to the terminal device is controlled based on the estimated congestion degree. 3 0

10. A non-transitory co~nputcrr eadable medium storing a communication control program for allocating a resource for communication to a terminal device in a basc station apparatus; thc colnrnunication control prograln making the base station apparatus execute: processillg of estimating a collgestioil degree by communicatioll of the terminal device; and processing of controlling a resource allocatiorl amount to the terminal device based on the estimated congestion degree.

[OOO I]
The present invention relates to a base station apparatus, a communication
10 control method, and a non-transitory computer readable medium storing a
communication control program and, in particular, to a technology to allocate a
resource for communication to a terminal device that performs communication
through the base station apparatus.
15 Background Art
[0002]
In a wireless communication system, a limited radio resource in a radio
base station is shared among a plurality of wireless terminals. The radio base
station communicates with the wireless terminals by allocating the radio resource
20 to the wireless terminals. As described above, it is called scheduling to decide
the wireless terminal to which the radio resource is allocated and to allocate the
radio resource to the decided wireless terminal.
[0003]
However, the radio resource is limited as mentioned above, and thus when
25 the radio base station is congested by increase in traffic or increase in the number
of wireless terminals, the radio resource becomes tight, and communication
becomes hard to perform. A state where communication is hard to perform due to
congestion as described above is generally called a congestion state.
[0004]
3 0 Here, a technology to perform scheduling according to a congestion degree
is disclosed in Patent Literature 1. The technology disclosed in Patent Literature
1 is the tecl~nology in which a strict priority difference is set between a terminal
with low priority and a terminal with high priority to thereby perforn~ scheduling
wlles~ a radio base station is congested, and in which a moderate priority difference
is set between the terminal with low priority and the terminal with 11igh priority to
thereby perform scheduling when the radio base station is not congested.
[0005]
However, since the technology disclosed in Patent Literature 1 is not the
5 scheduling in consideration of radio resource allocation delay due to congestion,
there is a problem that it takes time before the radio resource is allocated to the
wireless terminal when the radio base station is congested. The reason is that
when the number of wireless terminals to which the radio resource should be
allocated increases at the time of congestion of the radio base station, it takes time
10 before the radio resource is allocated to each wireless terminal, which is not taken
into consideration.
[0006]
For example, there is LTE (Long Term Evolution) as a communication
scheme that is standardized by 3GPP (3rd Generation Partnership Project), and is
15 currently started to be commercially used. In the LTE, a radio base station can
instruct a wireless terminal to allocate a radio resource for each subframe (each 1
ms). Specifically, the radio resource is allocated to the wireless terminal for 1 ms
by one allocation. Accordingly, assuming that the number of wireless terminals
to which the radio resource is allocated for each I ms is one, and that the total
20 number of wireless terminals to which the radio resource should be allocated is
1000, it takes 1 seconds at the shortest before the radio resource is allocated to all
the wireless terminals at least once.
[0007]
When a large delay occurs as described above, in spite of a packet from the
25 wireless terminal having arrived at a transmission destination, an ACK
(Acknowledgement) of a TCP (Transmission Control Protocol) does not arrive in
time, and the wireless terminal detects time-out and retransmits the packet. As a
result, there are possibilities that communication efficiency becomes deteriorated,
an application executed in the wireless terminal does not operate as expected due
30 to communication delay, etc.
Citation List
Patent Literature
[OOOS]
Patent Literature 1 : Interilatiollal Patent Publication No. W020091116497
Summary of Invention
Technical Problem
5 [0009]
As mentioned above, there is a problem that allocatioil of the resource to
the terminal device in the base station apparatus is delayed when the base station
apparatus is congested.
[OO lo]
10 In order to solve the problem as mentioned above, an object of the present
invention is to provide a base station apparatus, a communication control method,
and a communication control program that can reduce resource allocation delay to
a terminal device even when the base station apparatus is congested.
Solution to Problem
[OO 111
A base station apparatus according to a first exemplary aspect of the
present invention that allocates a resource for communication to a terminal device,
including: congestioil degree estimation means for estimating a coiigestion degree
in the base station apparatus; and resource control means for controlling a resource
allocation amount to the terminal device based on the congestion degree estimated
by the coilgestioli degree estimation means.
[00121
2 5 A communication control method according to a second exemplary aspect
of the present invention for allocating a resource for commullication to a terminal
device, includes a step of estimating a congestion degree by communication of the
terminal device, and a step of controlling a resource allocation amount to the
termiiial device based on the estimated congestion degree.
[00 131
A communication control program according to a third exemplary aspect of
the present iilventioll for allocating a resource for communication to a terminal
device in a base station apparatus, the comnluilication control program ~nakingth e
base station apparatus execute: processing of estimating a congestion degree by
communication of the terminal device; and processing of controlling a resource
allocation amount to the terminal device based on the estimated congestion degree.
5 Advantageous Effects of Invention
[00 141
According to the above-mentioned each aspect of the present invention,
there can be provided the base station apparatus, the communication control
method, and the communication control program that can reduce resource
10 allocation delay to the terminal device even when the base station apparatus is
congested.
Brief Description of Drawings
[00 151
15 Fig. 1 is a block diagram showing a configuration of the wireless
communication system according to the embodiment of the present invention.
Fig. 2 is a diagram showing a functional block of the radio base station
according to the embodiment of the present invention.
Fig. 3 is a flow chart showing one example of operation of the scheduling
20 unit according to the embodiment of the present invention.
Fig. 4 is a diagram showing a functional block of the base station apparatus
according to the eilibodiment of the present invention.
Description of Embodiments
25 [O016]

Hereinafter, an embodiment of the present invention will be explained in
detail with reference to drawings. First, a wireless communication system 1
according to the embodiment of the present invention will be explained with
30 reference to Fig. 1. Fig. 1 is a block diagram showing a configuration of the
wireless communication system 1 according to the embodiment of the present
invention.
100 171
Thc wireless con~munication system 1 has: a plurality of wireless terminals
100; a radio base station 500; and a network 1000.
[00 181
The wireless terminal 100 is a device that wirelessly transmits and receives
data through the radio base station 500. The wireless terminal 100 is, for
5 example, a PHs (Personal Handyphone System) or a mobile phone. For example,
an other wireless terminal 100, an information processing device on the Internet
accessible through the network 1000, etc. correspond to devices that transmit and
receive data tolfrom the wireless terminal 100.
[0019]
10 The radio base station 500 is an apparatus that wirelessly transmits and
receives data tolfrom the wireless terminal 100. The radio base station 500
enables transmission and reception of data tolfrom the wireless terminal 100 by
allocating a radio resource of the radio base station 500 to the wireless terminal
100 and utilizing the allocated radio resource. Here, the radio resource is, for
15 example, a resource block (RB). The resource block is configured with a
subcarrier, which is a unit of a resource on a frequency, and a symbol, which is a
unit of a resource on a temporal axis. More specifically, a time length of the
resource block is 0.5 Ins, and the resource block forms a pair on the temporal axis.
As a result, the radio resource can be allocated for each subframe (each 1 ms).
20 [0020]
'I'he network 1000 is connected to the radio base station 500. The network
1000 includes a higher apparatus of the radio base station 500.
[002 11
For example, when a wireless communication system to which LTE (Long
25 Term Evolution) has been applied is used as an object as the wireless
communication system 1, UE (User Equipment) corresponds to the wireless
terminal 100, an eNB (evolved Node B) corresponds to the radio base station 500,
and an EPC (Evolved Packet Core), which is a core network, corresponds to the
network 1000. In this case, for example, an MME (Mobility Management Entity),
30 an SGW (Serving Gateway), a PGW (Packet Data Network Gateway), etc.
correspond to higher apparatuses.
[0022]
Subsecluently, a configuration of the radio base station 500 according to the
elnbodiinent of the prcsent invention will be explained with reference to Fig. 2.
Fig. 2 is a diagram showing a functional block of the radio base station 500
according to the embodiment of the present invention.
[0023]
The radio base station 500 has a congestion degree estimation unit 5 10 and
5 a scheduling unit 520.
[0024]
The congestion degree estimation unit 5 10 estimates a congestion degree of
the radio base station 500, and notifies the scheduling unit 520 of the estimated
congestion degree.
10 [0025]
The congestion degree may be set to be at least one value of the following
values of (1) to (5).
( I ) A value that the network 1000 notifies of
(2) The number of wireless terminals 100 connected to the radio base station
15 500
(3) The number of wireless terminals 100 in which data to be transmitted is
present in a downlink buffer in the radio base station 500
(4) The number of wireless terminals 100 estimated that data to be transmitted
is present in an uplink buffer in the radio base station 500
20 (5) A radio resource allocation delay time in the radio base station 500
[0026]
Here, the downlink buffer retains downlink data sent from the network
1000 to the radio base station 500 until it is distributed and transmitted for each
wireless terminal 100. The congestion estimation unit 5 10 recognizes the number
25 of wireless terminals 100 in which data is present in the downlink buffer by
referring to the downlink buffer. Note that the downlink buffer is provided in a
storage device of the radio base station 500. The storage device is, for example, a
memory, a hard disk, etc.
[0027]
In addition, the uplink buffer retains data to be transmitted that is
generated in the wireless terminal 100. The uplink buffer is provided in a storage
device of the wireless terminal 100. The congestioil estimation unit 5 10
estimates a status of the uplink buffer of each wireless terminal 100 based 011 a
HSR (Buffer Status Report) from the wircless terminal 100.
100281
Here, the BSR is information indicating a content to be able to determine
whether or not data is retained (present) in the uplink buffer. For example, a
retention amount of the data in the uplink buffer of the wireless terminal 100 is
5 shown in the BSR. The congestion estimation unit 5 10 determines whether or not
the data is retained (present) in the uplink buffer in each of the wireless terminals
100 based on the BSR transmitted from each of the wireless terminals 100, and
thereby recognizes the number of wireless terminals 100 estimated that the data is
present in the uplink buffer.
10 [0029]
In addition, as values that the network 1000 notifies of, for example, a
value representing a load of a higher apparatus as a numerical value, or a
congestion degree of a line in the higher apparatus may be employed. More
specifically, as the value that the network 1000 notifies of, for example, a load or a
15 congestion degree is detected in the SGW that transfers data transmitted and
received tolfrom the radio base station 500, and information that indicates a value
representing the load or the congestion degree detected by the SGW is transmitted
to the radio base station 500. The congestion estimation unit 5 10 then recognizes
as the congestion degree the value representing the load or the congestion degree
20 indicated by the information transmitted from the SGW.
[0030]
In addition, the radio resource allocation dclay time in the radio base
station 500, for example, may be set to be at least one value of the followiilg (a) to
(f).
25 (a) A time spent until data to be transmitted reaches the downlink buffer, and
the radio resource is allocated in order to transmit the data
(b) A time spent until data to be transmitted is estimated to have reached the
uplink buffer, and the radio resource is allocated in order to transmit tlle data
(c) A time when each data to be transmitted is retained in the downlink buffer
30 (d) A time when each data to be transmitted is estiinated to be retained in the
uplink buffer
(e) A maxinlum value in calculated times obtained by calculatillg a time when
the radio resource is not allocated to the wireless terminal 100 for each wireless
terminal 100, while data to be t r a l ~ s ~ ~ ~ iitst reedta ined in the downlink buffer with
respect to the wireless terminal 100
(f) A maximum value in calculated times obtained by calculating a time when
the radio resource is not allocated to the wireless terminal 100 for each wireless
terminal 100, while data to be transmitted is estimated to be retained in the uplink
5 buffer with respect to the wireless terminal 100
[003 11
Namely, the congestion estimation unit 5 10 detects at least one time of the
above-described (a) to (f). Here, the radio base station 500 cannot directly
recognize the status of the buffer of the wireless terminal 100. Therefore, the
10 congestion estimation unit 510 may set the time of the above-described (b) to be a
time until the radio resource is allocated to the wireless terminal 100 after the BSR
is received from the wireless terminal 100. In addition, the congestion estimation
unit 5 10 may set the time of the above-described (d) to be a time until the data
stored in the uplink buffer is received from the wireless terminal 100 after the BSR
15 is received from the wireless terminal 100.
[0032]
In addition, as for the above-described (e) and (f), the congestion
estimation unit 5 10 may destroy a record of the maximum value in which a
predetermined time has elapsed after the maximum value is calculated, and may
20 newly acquire a maximum value according to a newest congestion condition.
[0033]
In addition, the congestioll degree may be estimated by calculation using at
least one value of the following values of (1) to (5). Note that the values of the
following ( I ) to (5) are similar to the values of the above-mentioned (1) to (5).
25 (1) A value that the network 1000 notifies of
(2) The number of wireless terminals 100 connected to the radio base station
500
(3) The number of wireless terminals 100 in which data to be transmitted is
present in the downlink buffer in the radio base station 500
30 (4) The number of wireless tcsinil~als 100 estimated that data to be transmitted
is present in thc uplink buffcr in the radio base station 500
(5) A radio resource allocation delay time in the radio base station 500
[0034]
The congestion degree calculated at this time may be calculated by any
calculation formula as long as it becomes larger as the values of the
above-described (1) to (5) become larger.
[003 51
In addition, the congestion degree or the calculated congestion degree may
5 be multivalued. In addition, a multiple value may also be set to be a binary for
representing two statuses of a congested status and an uncongested status, or may
also be a multiple value larger than two in order to represent a level of congestion
in stages. Namely, for example, a congestion degree C may be estimated by
calculation using the following Formula (1).
10 [0036]
[Formula 11
i 0 N - dl - user < N - lhreshold 1
C = 1 N - threshold 1 5 N - dl - user < N - threshold 2 . . . (1)
2 N - threshold 2 1 N - dl - user
15 [0037]
N - dl - user is the number of wireless terminals 100 ill which data to be
transmitted is present in the downlink buffer. N-threshold1 and N-threshold2 are
threshold values set to the radio base station 500 as parameters, respectively. A
fixed value of the parameter may be previously incorporated in the radio base
20 station 500. I11 this case, the parameter is, for example, previously stored in the
storage device of the radio base station 500. In addition, the parameter inay be
set to the radio base station 500 by a maintenance and management server (not
shown) that can colnmunicate with the radio base station 500. Specifically, when
an administrator inputs a parameter to the maintenance and management server
25 through an input device of the maintenance and management server, the
maintenance and management server transmits information indicating the input
parameter to the radio base station 500. Subsequently, the radio base station 500
sets as the parameter the parameter indicated by the infornlation transmitted from
the ~ ~ ~ a i ~ ~ t eannad nmcaen agement server. Note that the input device is, for
30 example, a mouse, a keyboard, a touch panel, etc.
[003 81
In addition, the congestion estimation unit 51 0 may calculate a congestioi~
degree according to the number of wireless ter~ninals 100 in which data is present
in the buffer in each of the uplink and the downlink, and may notify the scheduling
unit 520 of an uplink congestion degree and a downlink congestion degree. In
addition, when the radio base station 500 has a plurality of sectors, a congestion
5 degree may be estimated in each sector to apply to the each sector. Namely, the
congestion estimation unit 5 10 may estimate the congestion degree for each sector
to notify the scheduling unit 520 of the congestion degree, and the scheduling unit
520 may control a radio resource amount allocated to the wireless terminal 100 in
the notified sector according to the congestion degree of the sector.
10 [0039]
In addition, the congestion degree estimation unit 5 10 may notify the
network 1000 of the estimated congestion degree. The network 1000 changes
setting of QoS (Quality of Service) to the wireless terminal 100 in the network
1000 or limits data transmitted from the network 1000 to the radio base station 500
15 by getting to know the congestion degree, and thereby it becomes possible to
suppress the congestion degree of the radio base station 500. For example, the
congestion degree estimation unit 5 10 notifies the higher apparatus of the network
1000 of the congestion degree, and the higher apparatus transmits data more
preferentially to the radio base station 500 having a small congestion degree than
20 the radio base station 500 having a large congestion degree based on the
congestion degrees that the plurality of radio base stations 500 have notified of.
For example, in QoS control, the PGW lowers a priority of data transmitted and
received tolfrom the radio base station 500 having the large congestion degree and
raises the priority of data transmitted and received tolfrom the radio base station
25 500 having the small congestion degree.
[0040]
The scheduling unit 520 controls the radio resource amount to be allocated
based on the congestion degree that the congestion degree estimation unit 5 10 has
notified of, and allocates the radio resource to each wireless terminal 100.
30 Specifically, the scheduling unit 520 sets to be s~nalla n upper-limit value of the
radio resource allocated to the wireless terminal 100 when the congestion degree is
large, and sets to be large thc upper-limit value of the radio resource allocated to
the wireless terminal 100 when the congestion degree is small. Namely, the
scheduling unit 520 sets the uppes-limit value of the radio resource so that the
upper-limit value of the radio resource becomes smaller as the congestion degree
becomes larger.
[004 11
According to the above, since the upper-limit value of the radio resource
5 allocated to the wireless terminal 100 is set to be small when the radio base station
500 is congested, a radio resource amount consumed by the radio resource
allocation to the wireless terminal 100 can be reduced. Accordingly, the radio
resource is allocated to a number of wireless terminals 100 little by little under a
situation where the radio base station 500 is congested, and thereby radio resource
10 allocation delay can be reduced. Namely, it can be prevented that the radio
resource is allocated to one wireless terminal 100 without limitation, and that it
takes time before the radio resource is allocated to the other wireless terminals
100.
[0042]
15 Subsequently, one example of operation of the scheduling unit 520 will be
explained with reference to Fig. 3. Fig. 3 is a flow chart showing one example of
operation of the scheduling unit according to the embodiment of the present
invention.
[0043]
2 0 The scheduling unit 520 selects a wireless terminal 100 to which a radio
resource is allocated ( S l ) . For example, as a method to select the wireless
terminal 100, Round Robin or Proportional Fairness known as scheduling schemes
may be used.
[0044]
2 5 The scheduling unit 520 determines whether or not the selected wireless
terminal 100 is an object of a QoS guarantee (S2). If the selected wireless
terminal 100 is the object of the QoS guarantee, processing proceeds to step S4
(S2: Yes).
[0045]
3 0 Meanwhile, if the selected wireless terminal 100 is not the object of the
QoS guarantee, processing proceeds to step S3 (S2: No). The scheduling unit 520
sets an upper-limit value of the radio resource allocated to the wireless terillinal
100 based on a congestion degree (S3).
(00461
Here, as a setting method of the upper-limit value of the radio resource, for
example, in a case where notification of the number of wireless terminals 100 in
which data to be transmitted is present in the downlink buffer in the radio base
station 500, and a radio resource allocation delay time in the radio base station 500
5 have been performed as the congestion degree, when the i~umbero f wireless
termillals 100 in which data to be transmitted is present in the downlink buffer is
not less than a threshold value set by a parameter, a value R-u calculated by the
following Formula (2) is set to be the upper-limit value of the radio resource to be
allocated.
10 LO0471
[Formula 21
t threshold
R - all- - 1 t delay > t threshold
t delay R - u= - - - (2)
(R - aN t - delay 5 t - threshold
15 [0048]
K - all is a threshold value set as the whole number of radio resources,
t - delay is as a radio resource allocation delay time, and t-thresl~old is as a
parameter. A fixed value of the parameter may be previously incorporated in the
radio base station 500. In this case, the parameter is, for example, previously
20 stored in the storage device of the radio base station 500. In addition, the
parameter may be set to the radio base station 500 by the maintenance and
management server as mentioned above. In addition, ail upper-limit value R-u of
the radio resource may be calculated separately for the uplink and the downlink.
Consequently, the above-mentioned parameter regarding the uppcr-limit value of
25 the radio resource allocation may also be set separately by a calculation formula of
the upper-limit value R-u of the uplink radio resource and a calculation formula of
the upper-limit value R-u of the downlink radio resource.
100491
As mentioned above, when the number of wireless terminals 100 ill which
30 data to be transmitted is present in the dow~lli~lbku ffer is not less thal~th e
tllreshold value, the upper-limit value R - u of the radio resource is decided by
Formula (2). Namely, w l ~ etlh~e number of wireless termil~als1 00 in which data
to be transmitted is present in the downlink buffer is less than the threshold value,
the whole number of radio resources R-all may be set to be the upper-limit value
R - u of the radio resource. Additionally, when the radio resource allocation delay
time t - delay is not more than the threshold value t-threshold in Formula (2), the
5 whole number of radio resources R - all is set to be the upper-limit value R - u of the
radio resource. Namely, when the whole number of radio resources R-all is set to
be the upper-limit value R - u of the radio resource, substantially, the upper-limit
value of the radio resource is not placed. Meanwhile, when the radio resource
allocation delay time t-delay is larger than the threshold value t-threshold in
10 Formula (2), a value obtained by multiplying the whole number of radio resources
R - all by a value obtained by dividing the threshold value t-threshold by the radio
resource allocation delay time t - delay is set as the upper-limit value R - u of the
radio resource.
[0050]
15 According to the above, when the congestion degree (the number of
wireless terminals 100 in which data to be transmitted is present in the downlink
buffer, and the radio resource allocation delay time t-delay) of the radio base
station 500 is small, the upper-limit value of the radio resource allocated to the
wireless terminal 100 is set to be large, while when the congestion degree of the
20 radio base station 500 is large, the upper-limit value of the radio resource allocated
to the wireless terminal 100 is set to be small.
[005 11
In addition, as the setting method of the upper-limit value of the radio
resource, for example, when the congestion degree that the congestion degree
25 estimation unit 510 notifies of is one value, and is a binary of a congested status
and an uncongested status, the upper-limit value of the radio resource allocation
may be set in the congested status, and the upper-limit value of the radio resource
allocation may not be set in the uncongested status (the whole number of radio
resources R - all is set as the upper-limit value). Note that an arbitrary value can
30 be set to be the upper-limit value of the radio resource allocation in the congested
status as a parameter previously or by the mai~~tenancaen d management server as
mentioned above.
[0052]
When the congestion degree that the congestion degree e s t i m a t i o ~u~ni t 5 10
notifies of is one value, and is a multiple value larger than the binary, a plurality of
upper-limit values of radio resource allocation can be set as parameters so as to
correspond to each of values that the multiple value can take, and the upper-limit
value of the radio resource is set to be smaller as the congestion degree indicates a
5 more congested status. The fixed value may be previously incorporated in the
radio base station 500 as the parameter of the upper-limit value of the radio
resource allocation as mentioned above, or the parameter may be set to the radio
base station 500 by the maintenance and management server. In addition, the
parameter of the upper-limit value of the radio resource allocation may be set
10 separately for the uplink and the downlink.
[0053]
The upper-limit value of the radio resource allocation is set according to
the congestion degree as described above, whereby the number of wireless
terminals 100 to which the radio resource is allocated for each radio resource
15 allocation opportunity can be increased, and delay can be suppressed. In addition,
in a case of a wireless system using FDMA (Frequency Division Multiple Access),
transmission power per frequency can be increased by limiting the radio resource
allocated to one wireless terminal 100, and thereby efficient communication can
also be performed.
20 [0054]
In addition, the upper-limit value of the radio resource allocation is set
only to the wireless terminal 100, which is not the object of the QoS guarantee, and
thereby it becomes possible to rnailltaill the QoS guarantee to the wireless terminal
100, which is the object of the QoS guarantee, also in the radio base station 500
25 being congested.
[0055]
The scheduling unit 520 allocates the radio resource to the selected
wireless termiilal 100 (S4). For example, a smaller value of a radio resource
amount to be able to finish transmitting data to be transmitted retained in the
30 buffer, and the uppcr-limit value of the radio resource allocation may be used as a
radio resource amount to be allocated.
[0056]
The schcdulil~gu nit 520 determines whethcr or not an unallocated radio
resource is present (S5). If the unallocated radio resource is present, processing
proceeds to step S6 (S5: No), and if the unallocated radio resource is not present,
radio resource allocation is ended.
[0057]
The scheduling unit 520 determines whether or not the wireless terminal
5 100 to which the radio resource has not been allocated is present (S6). If the
wireless terminal 100 to which the radio resource has not been allocated is present
(S6: Yes), processing proceeds to step S1, and the scheduling unit 520 reselects the
wireless terminal 100 to which the radio resource is allocated. Meanwhile, if the
wireless terminal 100 to which the radio resource has not been allocated is not
10 present (S6: No), processing proceeds to step S7.
[0058]
The scheduling unit 520 eliminates the upper-limit value of radio resource
allocation with respect to the wireless terminal 100 in which the radio resource
allocation has been limited, and adds the radio resource to the wireless terminal
15 100 (S7). As a method to add the radio resource, for example, the wireless
ter~ninal 100 is selected in the order that the radio resource has been allocated in
step S4, and the radio resource is added to the wireless terminal 100 until the radio
resource is used up, or the radio resource amount reaches the amount to be able to
finish transmitting the data to be transmitted retained in the buffer. When the
20 unallocated radio resource is present, and the wireless terminal 100 to which the
radio resource has not been allocated is not present, the upper-limit value of radio
resource allocation is eliminated from and the radio resource is additionally
allocated to the wireless terminal 100 to which the upper-limit value has been set
and the radio resource has been allocated, whereby the unallocated radio resource
25 caused due to excessive limit of the radio resource to be allocated can be
eliminated, and thus efficient communication can be achieved.
LO0591
As explained above, the radio base station 500 according to the
embodiment controls the radio resource amount allocated to the wireless terminal
30 100 based on the congestion degree. Accordii~gto the above, even when the radio
base station 500 is congested, the radio resource amount allocated to the individual
wirelcss terminal 100 is reduced, and occurreilce of the wireless terminal 100
waiting for radio resource allocatioll call be suppressed. Namely, delay until the
radio rcsource is allocated to the wireless tern~inal 100 can be suppressed. In
addition, accordi~lgt o the above, it becomes possible to perform efficient
communication by suppressing the delay.
[0060]

5 Subsequently, a base station apparatus 50 serving as a summary of the radio
base station 500 according to the embodiment of the present invention will be
explained with reference to Fig. 4. Fig. 4 is a diagram showing a functional block
of the base station apparatus according to the embodiment of the present invention.
[0061]
10 The base station apparatus 50 has a congestion degree estimation unit 51
and a resource control unit 52. The base station apparatus 50 is the apparatus that
allocates a resource for communication to a terminal device.
[0062]
The congestion degree estimation unit 51 estimates a congestion degree in
15 the base station apparatus 50. The congestion degree estimation unit 51
corresponds to the congestion degree estimation unit 5 10.
[0063]
The resource control unit 52 controls a resource allocation amount to the
terminal device based on the congestion degree estimated by the congestion degree
20 estimation unit 51. The resource control unit 52 corresponds to the scheduling
unit 520.
[0064]
Note that the present invention is not limited to the above-described
embodiment, and that the embodiment can be appropriately changed without
25 departing from the spirit of the invention.
[0065]
For example, although in the above-mentioned embodiment, a case has
been exemplified where the wireless terminal 100 is used as an object as the
terminal device, and where the radio base station 500 is used as an object as the
30 base station apparatus, the present invention is not limited to this. For example,
the present invention may be applied to a system in which a terminal device and a
base station apparatus communicate with each other by wire. In addition, not
only wireless comlnunication but wircd communication may be mixedly used in the
above-mentioned wireless communicatioli system 1.
[0066]
The radio base station 500 accordiilg to the embodimeilt of the present
invention call be configured by a computer (the radio base station 500) or a
processor of the computer executing a program that achieves the function of the
5 above-mentioned embodiment.
COO671
In addition, the program is stored using various types of non-transitory
computer readable media, and can be supplied to the computer. The
non-transitory computer readable medium includes various types of tangible
10 storage media. Examples of the non-transitory computer readable medium
includes: a magnetic recording medium (for example, a flexible disk, a magnetic
tape, a hard disk drive); a magnetic optical recording medium (for example, a
magnetic optical disk); a CD-ROM (Read Only Memory); a CD-R; a CD-RIW; and
a semiconductor memory (for example, a mask ROM, a PROM (Programmable
15 ROM), an EPROM (Erasable PROM), a flash ROM, an RAM (Random Access
Memory)). In addition, the program may be supplied to the computer by various
types of transitory computer readable media. Examples of the transitory
computer readable medium include an electrical signal, an optical signal, and an
electrornagiletic wave. The transitory computer readable medium can supply the
20 program to the computer through a wired communication channel, such as an
electric wire and an optical fiber, or a wireless communication channel.
[0068]
Hereinbefore, although the invention in the present application has been
explained with reference to the embodiment, the invention in the present
25 applicatiotl is not limited by the above. Various changes that can be understood
by those skilled in the art within the scope of the invention can be made to a
configuration and a detail of the invention in the present application.
[0069]
This application claims priority based on Japanese Patent Application No.
30 2012-152624 filed on July 6, 2012, and the entire disclosure thereof is
incorporated herein.
Reference Signs List
[0070 1
base station apparatus
congestion degree estimation unit
resource control unit
wireless terminal
radio base station
congestion degree estimation unit
scheduling unit
network

WE CLAIMS:-
1 . A base station apparatus that allocates a resource for communication to
a terminal device, comprising:
5 congestion degree estimation means for estimating a congestion degree in
the base station apparatus; and
resource control means for controlling a resource allocation amount to the
terminal device based on the congestion degree estimated by the congestion degree
estimation means.
10
2. The base station apparatus according to Claim 1, wherein the resource
control means does not place a resource allocation upper-limit to a terminal device,
which is an object of a QoS guarantee, but places the resource allocation
upper-limit to a terminal device, which is not the object of the QoS guarantee.
3. The base station apparatus according to Claim 2, wherein when an
unallocated resource is present with a result that the resource control means places
the resource allocation upper-limit to allocate the resource to the terminal device,
the resource control means eliminates the resource allocation upper-limit and adds
20 a resource allocated to the terminal device.
4. The base station apparatus according to any one of Claims 1 to 3,
wherein the congestion degree estimation meails sets as the congestion degree, in
the estimation of the congestion degree, one or more values of a value that a
25 network connected to the base station apparatus notifies of, the number of terminal
devices connected to the base station apparatus, the number of terminal devices in
which data to be transmitted is present in a downlink buffer in the base station
apparatus, the number of terminal devices estimated that data to be transmitted is
present in an uplink buffer in the base station apparatus, and a resource allocation
30 delay time in the base station apparatus.
5. The base station apparatus a c c o r d i ~ ~tog any one of Claims 1 to 3,
wherein the congestion degree estimation means calculates the congestion degree,
in the estimation of the congestion degree. based on at least one of a value that a
network connected to the base station apparatus notifies of, the number of terininal
devices connected to the base station apparatus, the number of terminal devices in
which data to be transmitted is present in a downlink buffer in the base station
apparatus, the number of terminal devices estimated that data to be transmitted is
5 present in an uplink buffer in the base station apparatus, and a resource allocation
delay time in the base station apparatus.
6. The base station apparatus according to Claim 2 or 3, wherein the
resource control means decides a value set to the base station apparatus by an
10 external device as a resource allocation upper-limit in deciding the resource
allocation upper-limit to the terminal device based on the congestion degree.
7. The base station apparatus according to any one of Claims 1 to 6,
wherein the base station apparatus notifies the network of the congestion degree
15 estimated by the congestion degree estimation means.
8. The base station apparatus according to any one of Claims 1 to 7,
wherein
the base station apparatus is a radio base station,
the terminal device is a wireless terminal, and
the resource is a radio resource.
9. A coinlnunication control method for allocating a resource for
communication to a terminal device, wherein
a congestion degree by communication of the terminal device is estimated,
and
a resource allocation amount to the terminal device is controlled based on
the estimated congestion degree.
3 0
10. A non-transitory co~nputcrr eadable medium storing a communication
control program for allocating a resource for communication to a terminal device
in a basc station apparatus; thc colnrnunication control prograln making the base
station apparatus execute:
processillg of estimating a collgestioil degree by communicatioll of the
terminal device; and
processing of controlling a resource allocatiorl amount to the terminal
device based on the estimated congestion degree.