WIRELESS COMMUNICATION DEVICE, BASE STATION, WIRELESS
5 COMMUNICATION MEHTOD, AND WIRELESS COMMUNICATION SYSTEM
Technical Field
[0001]
The present disclosure relates to a wireless communication device, a base
10 station, a wireless communication method, and a wireless communication system.
Background Art
[0002]
At present, the standardization of 4G wireless communication system is
15 being carried out in 3GPP (Third Generation Partnership Project). The 4G makes it
possible to use techniques such as a relay or carrier aggregation, thereby improving
the maximum communication speed and the quality at cell edges. Further, it also
has been studied to improve the coverage by introducing a base station other than
eNodeB (macrocell base station), such as HeNodeB (Home eNodeB, femtocell base
20 station, small base station for mobile phone) or RHH (Remote Radio Head).
[0003]
In such a wireless communication system, user equipments perform a
measurement of a reference signal included in a wireless signal transmitted from a
base station to evaluate the quality of wireless communication. More specifically,
25 the user equipment acquires measurement information by measuring multiple times
and averaging values obtained from the measurements to suppress the influence of a
fading. Then the user equipment reports the measurement information to the base
station as needed. Further, technology related to the measurement is described, for
example, in Patent Literature 1.
30 [0004]
Meanwhile, there has been a discussion concerning the MTC (Machine
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Type Communications) in 3GPP. As an application of MTC, a variety of
applications such as Metering for collecting information relevant to water systems or
power systems , Health for collecting information relevant to health care instruments,
or the like have been studied . The MTC terminal is a terminal designed specifically
5 for these applications.
[0005]
Furthermore, the MTC terminal, for example, has characteristics such as
Low Mobility, Time Controlled, Online Small Data Transmission, and Time Tolerant.
That is, the MTC terminal has a little movement, has a few connections to the base
10 station to communicate a small amount of data, and then again returns to an idle
mode. Further, sonic amount of delay is acceptable in data communication. Also,
the MTC terminal requires extra low power consumption.
Citation List
15 Patent Literature
[0006]
Patent Literature 1: JP 2010-062783A
Summary of Invention
20 Technical Problem
[0007]
However, measurements for obtaining measurement information are
repeatedly performed multiple times as described above. Thus, if each one of all
the MTC terminals performs a measurement, it would be difficult to achieve extra
25 low power consumption.
[0008]
Therefore, the present disclosure provides a novel and improved wireless
communication device, base station, wireless communication method, and wireless
communication system, capable of reducing power consumption of the wireless
30. communication device such as a MTC terminal.
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Solution to Problem
[0009]
SP264085W000
According to an embodiment of the present disclosure, there is provided a
wireless communication device including a receiving unit for receiving information
5 based on measurement of radio conditions transmitted from a base station in
association with identification information, and a control unit for controlling
communication by using the information received by the receiving unit when the
wireless communication device corresponds to the identification information
received by the receiving unit.
10 [0010]
The identification information may be position information, and the wireless
communication device corresponding to the identification information may be a
wireless communication device located within a range specified by the identification
information.
15 [0011]
The information may be information obtained by the measurement of radio
conditions within the range specified by the identification information.
[0012]
The wireless communication device may further include a position
20 information holding unit for holding position information, a measuring unit for
measuring radio conditions, and a transmitting unit for transmitting radio condition
measurement information obtained by the measuring unit to the base station in
association with position information held by the position information holding unit.
The control unit, when identification information corresponding to the wireless
25 communication device is not received by the receiving unit, may cause the measuring
unit to measure radio conditions.
[0013]
Further, according to an embodiment of the present disclosure, there is
provided a base station including a storage unit for storing identification information
30 and the radio condition measurement information in association with each other, and
a transmitting unit for transmitting the identification information and the radio
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condition measurement information in association with each other.
[0014]
SP264085WO00
The identification information may be position information, and the
identification information may be corresponded to a wireless communication device
located within a range specified by the identification information.
[0015]
The storage unit may further store acquisition time information of the radio
condition measurement information in association with the identification information
and the radio condition measurement information, and the transmitting unit may
10 transmit the identification information and the radio condition measurement
information when an elapsed time from acquisition time is within a predetermined
range.
[0016]
The base station may further include a control unit for designating at least
15 one wireless communication device corresponding to the identification information
as a recipient of requests for measurement of radio conditions and reporting of
measurement information, and the storage unit may store radio condition
measurement information reported from the wireless communication device
designated as the recipient.
20 [0017]
The control unit may designate two or more wireless communication
devices as recipients of a same request for measurement of radio conditions and
reporting of measurement information, and average measurement information
reported from the two or more wireless communication devices.
25 [0018]
The control unit may designate two or more wireless communication
devices as recipients of requests for measurement of radio conditions and reporting
of measurement information in different frequency bands, and integrate radio
condition measurement information of the respective frequency bands reported from
30 the two or more wireless communication devices.
[0019]
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The transmitting unit may transmit expiration information of the radio
condition measurement information stored in the storage unit to a wireless
communication device designated as a recipient of requests by the control unit.
[0020]
5 The base station may further include a control unit for determining whether
the plurality of wireless communication devices are to be changed over to a base
station or frequency and determining to which base station or frequency the plurality
of wireless communication devices are to be changed over. The transmitting unit,
when it is determined by the control unit that the plurality of wireless communication
to devices are to be changed over to a base station or frequency, may transmit the base
station or frequency determined to be changed over as radio condition measurement
information in association with the identification information.
[00211
The transmitting unit may broadcast the identification information and the
15 radio condition measurement information on a 13CCH.
[0022]
The transmitting unit may intermittently transmit the identification
information and the radio condition measurement information by using a dedicated
channel.
20 [0023]
Further, according to an embodiment of the present disclosure, there is
provided a wireless communication method including receiving, at a wireless
communication device, information based on measurement of a radio condition
transmitted from a base station in association with identification information, and
25 controlling communication by using the received information when the wireless
communication device corresponds to the received identification information.
[0024]
Further, according to an embodiment of the present disclosure, there is
provided a wireless communication method including storing identification
30 information and the radio condition measurement information in association with
each other, and transmitting the identification information and the radio condition
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measurement information in association with each other.
[0025]
sP264085WO00
Further, according to an embodiment of the present disclosure, there is
provided a wireless communication system including a base station including a
5 storage unit for storing identification information and the radio condition
measurement information in association with each other, and a transmitting unit for
transmitting the identification information and the radio condition measurement
information in association with each other, and a wireless communication device
including a receiving unit for receiving information based on measurement of radio
10 conditions transmitted from the base station in association with identification
information, and a control unit for controlling communication by using the
information received by the receiving unit when the wireless communication device
corresponds to the identification information received by the receiving unit.
15 Advantageous Effects of Invention
[0026]
According to the present disclosure as described above, the reduction of
power consumption of a wireless communication device such as a MTC terminal can
be done.
20
Brief Description of Drawings
[0027]
[Fig. 1] Fig. I is an explanatory diagram illustrating an exemplary configuration of a
wireless communication system.
25 [Fig. 2] Fig. 2 is a functional block diagram illustrating a configuration of a MTC
terminal according to an embodiment of the present disclosure.
[Fig. 3] Fig. 3 is an explanatory diagram illustrating a configuration of an eNodeB
according to an embodiment of the present disclosure.
[Fig. 4] Fig. 4 is an explanatory diagram illustrating a specific example of
30 information stored in a memory,
[Fig. 5] Fig. 5 is an explanatory diagram illustrating how a plurality of MTC
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terminals share measurement information.
[Fig. 6] Fig. 6 is a flowchart showing an operation of an eNodeB according to an
embodiment of the present disclosure.
[Fig. 7] Fig. 7 is a flowchart showing an operation of a MTC terminal according to
5 an embodiment of the present disclosure.
[Fig. 8] Fig. 8 is an explanatory diagram illustrating a specific example in which an
eNodeB designates a recipient of requests for performing measurement and reporting
of measurement information.
[Fig. 9] Fig. 9 is an explanatory diagram illustrating a specific example in which the
10 objects to be measured are distributed to a plurality of MTC terminals,
[Fig. 10] Fig. 10 is an explanatory diagram illustrating a specific example of
reducing the number of measurement times in each MTC terminal.
[Fig. 11] Fig. 11 is an explanatory diagram illustrating an exemplary configuration of
a measurement channel for transmitting measurement information.
1.5 [Fig. 12] Fig. 12 is an explanatory diagram illustrating a modified example of
information transmitted by an eNodeB.
Description of Embodiments
[0028]
20 Hereinafter, preferred embodiments of the present technology will be
described in detail with reference to the appended drawings. Note that, in this
specification and the drawings, elements that have substantially the same function
and structure are denoted with the same reference signs, and repeated explanation is
omitted.
25 [0029]
Also, in the specification and drawings, a plurality of structural elements
having substantially the same functional configuration may be distinguished from
each other by each having a different alphabetical letter added to the end of the same
reference numeral. For example, a plurality of structural elements having
30 substantially the same functional configuration may be distinguished from each other
as necessary, such as MTC terminals 20A., 20B, and 20C. However, if it is not
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particularly necessary to distinguish each of a plurality of structural elements having
substantially the same functional configuration, only the same reference numeral is
assigned. For example, if it is not particularly necessary to distinguish between the
MTC terminals 20A, 20B, and 20C, they are simply referred to as the MTC terminal
5 20.
[0030]
Furthermore, "Description of Embodiments" will be described according to
the following item order.
1. Overview of Wireless Communication System
1.0 1-1. Configuration of Wireless Communication System
1-2. Measurement
1-3. MTC Terminal
2. Configurations of MTC Terminal and eNodeB
3. Operations of MTC Terminal and eNodeB
15 4.. Modified Example
4-1. Designation of MTC Terminal to perform Measurement
4-2. Method of transmitting Measurement Information from
eNodeB
4-3. Modified Example of Method of transmitting from eNodeB
20 5. Conclusion
[0031]
<1. Overview of Wireless Communication System>
At present, the standardization of 4G wireless communication system is
being carried out in 3GPP. Embodiments of the present disclosure, as an illustrative
25 example, are applicable to the 4G wireless communication system, and thus
overview of 4G wireless communication system will be first described.
[0032]
[1-1. Configuration of Wireless Communication System]
Fig. 1 is an explanatory diagram illustrating an exemplary configuration of a
30 wireless communication system 1. As shown in Fig. 1, the wireless communication
system 1 includes an eNodeB 10, a core network, MTC terminals 20, and a MTC
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server 30. The core network includes a MME (Mobility Management Entity) 12, an
S-GW (Serving Gateway) 14, and a PDN (Packet Data Network)-GW 16.
[0033]
The eNodeB 10 is a radio base station that communicates with the MTC
5 terminal 20. Note that although only one eNodeB 10 is shown in Fig. 1, in practice
a plurality of eNodeBs are connected to the core network. In addition, although the
illustration is omitted in Fig. 1, the eNodeB 10 also communicates with wireless
communication devices other than the MTC terminal 20, for example, a user
equipment (UE: User Equipment). In the specification, the description is focused
10 on the MTC terminal 20 as an example of a wireless communication device, but the
present disclosure is also applicable to the user equipment.
[0034]
Furthermore, although Fig. I illustrates the eNodeB 10 as an example of a
base station, the present disclosure is also applicable to other base stations. For
15 example, the present disclosure is also applicable to. a relay node that relays
communication between the user equipment (MTC terminal 20) and the eNodeB 10,
and a base station such as Home eNodeB which is a small base station for home.
[0035]
The MME 12 is a device that controls the setup, opening and handover of
20 sessions for data communication. The MME 12 is connected to the eNodeB 10
through an interface called X2.
[0036]
The S-GW 14 is a device that performs the routing, transfer, and so on, of
user data. The PDN-GW 16 acts as a connection point to IP service network and
25 transfers user data from and to the IP service network.
[0037]
The MTC terminal 20 is a terminal designed specifically for applications for
MTC which has been studied in 3GPP and performs a wireless communication with
the eNodeB 10 depending on the applications. In addition, the MTC terminal 20
30 performs a bidirectional communication with the MTC server 30 through the core
network. A user executes a particular application by accessing the MTC server 30.
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The user normally does not directly access the MTC terminal 20. This MTC
terminal 20 will be described in detail in "1-3. MTC Terminal".
[0038]
[1-2. Measurement]
5 4G measurement closely related to the embodiments of the present
disclosure will be described below. Measurement is an operation performed in a
user equipment to evaluate the quality of a wireless communication. The user
equipment measures the reception quality using a reference signal or the like
included in a. signal transmitted from the eNodeB. In addition, the user equipment
10 acquires measurement information by measuring the reference signal multiple times
and averaging values obtained from the respective measurements so as to suppress
the influence of a fading or the like.
[0039]
(Measured Object and Measurement Method)
15 More specifically, the user equipment measures RSRP (Reference Signal
Receive Power) or RSSI (Received Signal Strength Indicator) in a state synchronized
with the eNodeB. The RSRP is a reception power of the reference signal
transmitted from the eNodeB, and the RSSI is a reception power measured in a form
that includes interference from a cell which is an interference source.
20 [0040]
The user equipment then obtains RSRQ (Rference Signal Received Quality)
based on the RSRP and RSSI. For example, the user equipment may obtain the
RSRP from the mathematical expression of RSRP/RSSI. The user equipment
determines cell reselection or handover based on this RSRP.
25 [0041]
In this case, final measurement information is calculated by repeatedly
measuring the RSRP multiple times and averaging the RSRP obtained by the
respective measurements . Accordingly, the measurement requires a corresponding
amount of time, and thus the user equipment spends a large power for the
30 measurement . Therefore, there is a need to suppress unnecessary measurement so
as to reduce power consumption in the user equipment.
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[0042]
SP264085WO00
Further, the user equipment reports the measurement. information to the
eNodeB periodically or when a trigger condition which is the quality relationship
between a Serving eNodeB and a new eNodeB is satisfied. In addition, the user
5 equipment does not report the measurement information in an idel mode and reflects
it in the operation of the terminal.
[0043]
(Case where Measurement is performed)
Measurement in the user equipment is performed in the following cases.
10 ° Case where the determination of an eNodeB to be connected is needed
after the user equipment is powered on (initial access).
Case where the quality of the eNodeB is monitored during the connection
(in order to determine the beginning of cell search).
Case where the quality of an eNodeB in other frequencies or neighboring
15 cells is needed, if the quality of the eNodeB is decreased during the connection (in
order to determine handover).
In an idle mode, a case where the quality of the eNodeB receiving a
paging is monitored. A paging channel is received at fixed intervals in an idle mode.
In the paging channel, each of a plurality of eNodeBs in a tracking area transmits the
20 same signal, but the user equipment receives a signal transmitted from one eNodeB
of the plurality of eNodeBs (in order to determine the beginning of cell search in the
idle mode).
In an idle mode, if the quality of the eNodeB which is receiving a paging
is decreased, a case where a candidate of the eNodeB for receiving a new paging
25 channel is searched (in order to change over the eNodeB for receiving a paging).
[0044]
(Summary of Measurement)
Main points of the above-mentioned measurement are summarized below.
° There are multiple types of cases that the measurement is performed.
30 ° The measurement is performed by a user equipment.
° The measurement information may be reported to the eNodeB or may not
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be reported to the eNodeB. If the measurement information is reported to the
eNodeB, the measurement information may be reported periodically or under certain
trigger conditions.
° The measurement is performed multiple times to obtain an average value,
5 and thus the power of the user equipment is consumed,
[0045]
[1-3. MTC Terminal]
The MTC terminal 20 is a terminal designed specifically for applications for
MTC which has been studied in 3GPP, as described above. Examples of the
10 applications for MTC are as follows:
[0046]
1. Security
2. Trcking & Tracing
3. Payment
15 4. Health
5. Remote Maintenace/Control
6. Metering
7. Consumer Devices
[0047]
20 As an example, the MTC terminal 20 may be an electrocardiogram
measuring device corresponding to "4. Health" in the list above. In this case, if a
user inputs a command for requesting the MTC server 30 to report electrocardiogram
measurements, the MTC server 30 requests the MTC terminal 20 to report the
electrocardiogram measurements, and then the electrocardiogram measurements are
25 reported from the MTC terminal 20 to the MTC server 30.
[0048]
As another example, the MTC terminal 20 may be a vending machine
corresponding to "3. Payment" in the list above. In this case, if a user inputs a
command for requesting the MTC server 30 to report the sales volume, the MTC
30 server 30 requests the MTC terminal 20 to report the sales volume, and then the sales
volume is reported from the MTC terminal 20 to the MTC server 30.
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[0049]
SP264085W000
The characteristics of such MTC terminal 20 are described below. In
addition, the MTC terminal 20 is not necessary to have all of the characteristics
described below.
5 [0050]
1. Low Mobility
2. Time Controlled
3. Time Tolerant
4. Packet Switched Only
10 5. Online Small Data Transmissions
6. Offline Small Data Transmission
7. Mobile Originated Only
8. Infrequent Mobile Terminated
9. MTC Monitoring
15 10. Offline Indication
11. Jamming Indication
12. Priority Alarm Message
13. Extra Low Power Consumption
14. Secure Connection
20 1.5. Location Specific Trigger
16. Group based MTC Features
[0051]
Summarizing the above, the MTC terminal 20 has a little movement, has a
few connections to the eNodeB to communicate a small amount of data, and then
25 again returns to an idle mode. Further, some amount of delay is acceptable in data
communication. In addition, the MTC terminal 20 requires extra low power
consumption (13. Extra Low Power Consumption).
[0052]
In this regard, the number of the MTC terminals 20 to be used in the future
30 is expected. At present, nearly two billion and seven hundred million people out of
the world's population of more than six billion people are using cellular phones. On
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the other hand, in the situation that there are nearly five hundred trillion machines in
the world, nearly five hundred million machines are using cellular phones as the
MTC terminal 20.
[0053]
5 That is, although the MTC terminals 20 are not yet widely used at present,
on the order of one hundred trillion MTC terminals 20 would be more likely to be
accommodated in the cellular phones all over the world in the future. Consequently,
it is expected that an expanded number of MTC terminals 20 would be
accommodated in each eNodeB 10.
10 [0054]
(Why embodiments of the present disclosure are conceived)
As described in the item "1-3. MTC Terminal", the MTC terminal 20
requires extra low power consumption. However, if the measurement performed by
the user equipment described in the item "1-2. Measurement" is directly applied to
15 the MTC terminal 20, there is a problem that it is difficult to achieve extra low power
consumption.
[0055]
As described in the item "1-3. MTC terminal", it is expected that an
expanded number of MTC terminals 20 would be accommodated in each eNodeB 10
20 in the future. Thus, it is desired to reduce signaling between the eNodeB and the
MTC terminal 20.
[0056]
Moreover, a measurement result is varied depending on external factors
such as an interference suppression control by other mobile objects or eNodeBs even
25 in the same location, thus it is necessary to update measurement information.
[0057]
Therefore, the embodiments of the present disclosure have been designed by
considering the above-mentioned circumstances as a problem to be solved.
According to the embodiments of the present disclosure , it is possible to reduce
30 power consumption of the MTC terminal 20, suppress signaling between the MTC
terminal 20 and the eNodeB 10, and update measurement information of the MTC
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terminal 20. The eNodeB 10 and the MTC terminal 20 according to the
embodiments of the present disclosure will be described in detail below.
[0058]
<2. Configurations of MTC Terminal and eNodeB>
5 (Configuration of MTC Terminal)
Fig. 2 is a functional block diagram illustrating the configuration of the
MTC terminal 20 according to the embodiment of the present disclosure. As shown
in Fig. 2, the MTC terminal 20 includes a wireless communication unit 210, a
position information holding unit 220, a measurement information monitoring unit
10 230, and a control unit 240.
[0059]
The wireless communication unit 210 has a function as a receiving unit for
receiving a control signal, data, measurement information, and so on from the
eNodeB 10 and a function as a transmitting unit for transmitting a control signal, data,
15 measurement information, and so on to the eNodeB 10. Specifically, the wireless
communication unit 210 performs a wireless signal processing and an antenna signal
processing such as modulation or demodulation, and a mapping, de=mapping or
interleaving of signals. In addition, the wireless communication unit 210 has also a
function as a measuring unit that measures radio conditions.
20 [0060]
The position information holding unit 220 holds position information that
indicates a current position of the MTC terminal 20. The MTC terminal 20 may
acquire position information by using a GPS, and may acquire position information
obtained by estimation in the eNodeB 10.
25 [0061]
The measurement information monitoring unit 230 monitors signals
received from the eNodeB 10 by the wireless communication unit 210, and extracts
measurement information corresponding to the MTC terminal 20 from signals
received from the eNodeB 10.
30 [0062]
Specifically, the eNodeB 10 according to the embodiment of the present
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disclosure broadcasts measurement information in association with position
information. Thus, when a current position of the MTC terminal 20 is within a
range specified by the position information transmitted from the eNodeB 10, the
measurement information monitoring unit 230 extracts the measurement information
5 transmitted in association with the position information.
[0063]
In addition, the position information transmitted from the eNodeB 10 may
be latitude and longitude information that indicates a given point, and the range
specified by the position information may be a range within a predetermined distance
10 from the point indicated by the position information. Alternatively, the position
information transmitted from the eNodeB 10 may be information that indicates a
given range, and the range specified by the position information may be a range
indicated by the position information. Here, it is assumed that a plurality of the
MTC terminals 20 exist in the range specified by the position information, thus the
15 plurality of MTC terminals 20 are corresponding to the position information
transmitted from the eNodeB 10.
[0064]
In this way, in the embodiment of the present disclosure, although the
position information is used as identification information for identifying a specific
20 MTC terminal 20, the identification information is not limited to position
information. For example, when a plurality of MTC terminals 20 are grouped and
group ID is assigned to the respective groups, the group ID can also be used as
identification information. In this case, the measurement information monitoring
unit 230 of the MTC terminal 20 extracts measurement information based on
25 whether the group ID transmitted in association with the measurement information
from the eNodeB 10 is a group ID of a group to which the MTC terminal 20 belongs.
[0065]
The control unit 240 controls the overall operation of the MTC terminal 20.
For example, the control unit 240 performs determination of whether or not
30 measurement is performed, a process related to a. series of measurements, a
communication control based on measurement information, and so on. When the
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measurement information corresponding to the MTC terminal 20 is extracted by the
measurement information monitoring unit 230, the control unit 240 avoids the need
for performing measurement by using the measurement information. In addition,
when measurement is performed, the control unit 240 transmits the measurement
5 information along with the position information held in the position information
holding unit 220 to the eNodeB 10.
[0066]
In addition, the control unit 240 may be incorporated with a portion of the
measurement method performed by the user equipment described in the item "1-2.
10 Measurement". For example, the control unit 240 may measure RSRP and RSSI,
and obtain RSRP from the RSRP and RSSI.
[0067]
(Configuration of eNodeB)
Fig. 3 is an explanatory diagram illustrating the configuration of the
15 eNodeB 10 according to the embodiment of the present disclosure. As shown in
Fig. 3, the eNodeB 10 includes a wireless communication unit 110, a memory 120, a
time management unit 130, and a measurement information management unit 140.
[0068]
The wireless communication unit 110 has a function as a receiving unit for
20 receiving a control signal, data, measurement information, and so on from the MTC
terminal 20 and a function as a transmitting unit for transmitting a control signal,
data, measurement information, and so on to the MTC terminal 20. Specifically, the
wireless communication unit 110 performs a wireless signal processing and an
antenna signal processing such as modulation or demodulation, and a mapping, de-
25 mapping or interleaving of signals.
[0069]
The memory 120 is a storage unit for storing position information,
measurement information, and acquisition time information of the measurement
information in association with one another. For example, the memory 120 holds
30 position information of a given MTC terminal 20 received from the MTC terminal 20
and measurement information measured by the MTC terminal 20 in association with
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each other. Further, the measurement information held in the memory 120 may be
measurement information obtained by measurement in any wireless communication
device other than the MTC terminal 20. A specific example of information stored
in the memory 120 will be described below with reference to Fig. 4.
5 [0070]
Fig. 4 is an explanatory diagram illustrating a specific example of
information stored in the memory 120. As shown in Fig. 4, measurement
information stored in association with position information (Position N) and
acquisition time information (Time M) includes not only information on a Serving
10 eNodeB connected to the MTC terminal 20 which performs measurement but also
information on other eNodeBs.
[0071]
For example, the measurement information associated with position
information Position 0 includes measurement information 0 related to a Serving
15 eNode£i, and measurement information I and 2 related to other eNodeBs or
frequencies. Further, the acquisition time indicated by acquisition time information
(Time M) may be the time at which the eNodeB 10 receives measurement
information from the MTC terminal 20, the time at which measurement information
is stored in the memory 120, or the time at which the MTC terminal 20 acquires
20 measurement information.
[0072]
The time management unit 130 manages a current time, an elapsed time
from the time indicated by each piece of acquisition time information stored in the
memory 120, and so on.
25 [0073]
The measurement information management unit 140 (control unit) manages
transmission of measurement information held in the memory 120. For example,
the measurement information management unit 140 controls so that measurement
information and position information held in the memory 120 may be transmitted on
30 the BCCFI (broadcast channel).
[0074]
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With this configuration, the MTC terminal 20 which receives measurement
information corresponding to the current position can avoid the need for performing
measurement by using the measurement information. As a result, it is possible to
reduce power consumption of the MTC terminal 20. In addition, the MTC terminal
5 20 may not transmit measurement information to the eNodeB 10, thus it is possible
to suppress signaling of measurement information from the MTC terminal 20 to the
eNodeB 10.
[0075]
For example, as shown in Fig. 5, if a MTC terminal 20A performs
10 measurement and reports measurement information to an eNodeB 10 (step 1), the
eNodeB 10 broadcasts the measurement information (step 2). Thus, MTC terminals
20B and 20C existed in the vicinity of the MTC terminal 20A can avoid the need for
performing measurement by using the broadcasted measurement information, that is,
by sharing measurement information with the MTC terminal 20A. Therefore, the
15 power consumption of the MTC terminal 20B and 20C can be reduced. In addition,
the MTC terminals 20B and 20C may not transmit measurement information to the
eNodeB 10, thus it is possible to suppress signaling of measurement information
from the MTC terminal 20 to the eNodeB 10.
[0076]
20 Furthermore, the measurement information management unit 140 may not
transmit the measurement information in which an elapsed time from the acquisition
time is outside of a predetermined range based on the acquisition time information
associated with each piece of measurement information. Alternatively, the
measurement information management unit 140 may control so that acquisition time
25 information is transmitted along with the measurement information on the BCCII.
In this case, the MTC terminal 20 which extracts the measurement information
having the acquisition time earlier than others performs the measurement on behalf
of neighboring MTC terminals and reports new measurement information to the
eNodeB 10. With this configuration, it can be prevented that the measurement is
30 performed by all of the MTC terminals around the MTC terminal 20. In addition, it
also can be prevented that the measurement information becomes expired.
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[0077]
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<3. Operations of MTC Terminal. andeNodeB>
The configurations of the MTC terminal 20 and the eNodeB 10 according to
the embodiment of the present disclosure have been described above. Next, the
5 operations of the MTC terminal 20 and the eNodeB 10 according to the embodiment
of the present disclosure will be described.
[0078]
(Operation of eNodeB)
Fig. 6 is a flowchart showing the operation of the eNodeB 10 according to
10 the embodiment of the present disclosure. As shown in Fig. 6, the eNodeB 10
broadcasts position information and measurement information held in the memory
120 in association with each other (S310).
[0079]
Then, when the eNodeB 10 receives position information and measurement
15 information from the MTC terminal 20 (S320), the eNodeB 10 updates information
held in the memory 120 with the received position information and measurement
information (S330). For example, the eNodeB 10 retrieves the received position
information and the position information that indicates a position within the
predetermined range from the memory 120, and rewrites the measurement
20 information associated with the retrieved position information to the received
measurement information.
[0080]
(Operation of MTC Terminal)
Fig.7 is a flowchart showing an operation of the MTC terminal 20 according
25 to the embodiment of the present disclosure. As shown in Fig. 7, the MTC terminal
20 first acquires its own position information (S410). Then, the MTC terminal 20,
when measurement information is required (S420), determines whether position
information close to its own current location indicated by the position information
acquired in 5410 is included in the position information broadcasted along with
30 measurement information from the eNodeB 10 (S430).
[0081]
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Moreover, examples of the case in which the measurement information is
needed include when it is determined that MTC terminal 20 is connected to which
eNodeB after the MTC terminal 20 is powered on, when the quality of the eNodeB
10 is monitored during the connection, and when the quality of other frequencies or
5 neighboring cells is needed.
[0082]
When it is determined that the position information corresponding to the
MTC terminal 20 is included in the broadcast signal in S430, the MTC terminal 20
acquires measurement information associated with the above-mentioned position
10 information from the broadcast signal (S440). On the other hand, if the position
information corresponding to the MTC terminal 20 is not included in the broadcast
signal, then the MTC terminal 20 performs measurement (S450), and transmits the
measurement information and the position information indicating a. current position
to the eNodeB 10 (S460).
15 [0043]
The MTC terminal 20, after acquiring the measurement information in S440
or 5460, controls the communication using the acquired measurement information
(S470). For example, the MTC terminal 20 controls handover, frequency change
over or the like, when there are an eNodeB 10 or frequency having better quality
20 than an eNodeB 10 or frequency which is currently being used, on the basis of the
acquired measurement. information.
[0084]
As described above, the MTC terminal 20 can suppress the number of times
required to perform measurement by using measurement information broadcasted
25 from the eNodeB 10, thereby reducing power consumption.
[0085]
It should be noted that the above--mentioned method is a way how a plurality
of MTC terminals 20 located in the vicinity share the same measurement information.
In this regard, if its position is varied even a little, actual radio conditions are
30 changed accordingly. Thus, the accuracy of measurement information being shared
by the plurality of MTC terminal 20 would be not perfect. However, the MTC
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terminal 20 is assumed to perform a low-speed communication at a low frequency.
For this reason, it is considered that a modulation method to be used becomes a
modulation method with a low data rate such as QPSK. Therefore, even if the
measurement information with a low accuracy is used, it may be said that actual
operational problems are restrictive.
[0086]
<4. Modified Example>
The basic configuration according to the embodiment of the present
disclosure has been described above. Next, a modified example of the embodiment
to of the present disclosure will be described.
[0087]
[4-1. Designation of MTC Terminal to perform Measurement]
In the description described above, the example of determining whether or
not the MTC terminal 20 performs measurement has been described. Asa modified
15 example, the eNodeB 10 may designate a recipient of requests for performing
measurement and reporting of measurement information. A specific example in
which the eNodeB 10 designates a recipient of requests for performing measurement
and reporting of measurement information will be described below.
[0088]
20 Fig. 8 is an explanatory diagram illustrating a specific example in which the
eNodeB designates a recipient of requests for performing measurement and reporting
of measurement information. As shown in Fig. 8, when a plurality of MTC
terminals 20 is included fir each of areas A to D, the measurement information
management unit 140 of the eNodeB 10 requests the MTC terminals 20 in each area
25 to perform measurement and report measurement information.
[0089]
For example, as shown in Fig. 8, the measurement information management
unit 140 of the eNodeB 10 designates a MTC 20P of the plurality of MTC terminals
20 located in the area A as a recipient of requests for performing measurement and
30 reporting of measurement information. With this configuration, the measurement
information is reported from the MTC 20P to the eNodeB 10, and thus it is possible
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to cause the multiple MTC terminals 20 in the area A to share the measurement
information of the MTC 20P by broadcasting the measurement information.
[0090]
Further, the measurement information management unit 140 of the eNodeB
5 10 may designate two or more MTC terminals 20 of the plurality of MTC terminals
20 located in the same area as a recipient of requests for performing measurement
and reporting of measurement information.
[0091]
For example, if one thousand MTC terminals 20 are located in the area A,
10 performing measurement and reporting of measurement information may be
requested to ten MTC terminals 20 in the area A. In a case where performing
measurement and reporting of measurement information are requested to only one
MTC terminal 20 in the area, if this MTC terminal 20 fails to perform measurement,
then all of the MTC terminals 20 in the area will not acquire measurement
15 information. On the other hand, If two or more MTC terminals 20 in the area are
designated as a recipient of requests for performing measurement and reporting of
measurement information as described above, then it is possible to reduce the
adverse effects occurred in the case where the MTC terminal 20 which is a recipient
of the requests fails to perform the measurement.
20 [0092]
Furthermore, the eNodeB 10 can designate one or more MTC terminals 20
in each area as the recipient of a request for measurement as described above by
collecting position information of each MTC terminal 20 and grouping the MTC
terminals 20 located in the substantially same position.
25 [0093]
(Distribution of Measured Object)
In addition, the eNodeB 10, when requesting two or more MTC terminals
20 to perform measurement, may distribute the measured object such as a frequency
band to two or more MTC terminals 20 and integrate the measurement information
30 reported from the two or more MTC terminals 20. The specific example will be
described below.
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[0094]
SP264085WO00
Fig. 9 is an explanatory diagram illustrating a specific example of
distributing the measured object to a plurality of MTC terminals 20. As shown in
Fig. 9, when the eNodeB 10 requests MTC terminals 20P and 20Q in the area A to
5 perform measu renment, the eNodeB 10 may request the MTC terminal 20P to perform
the measurement of a frequency band fl, and request the MTC terminal 20Q to
perform the measurement of a frequency band 12.
[0095]
In this case, measurement information related to the frequency band fl is
10 reported from the MTC terminal 20P, and measurement information related to the
frequency band f2_ is reported from the MTC terminal 20Q. Thus, the eNodeB 10
acquires final measurement information by integrating measurement information
reported from the MTC terminals 20P and 20Q.
[0096]
15 With this configuration, the load due to measurement can be distributed to
two or more MTC terminals 20, thereby reducing power consumption caused by one
MTC terminal 20.
[0097]
(Averaging of Measurement Information)
20 A normal measurement process, as described in the item "1n2.
Measurement", performs measurement in one terminal multiple times, and acquires
measurement information by averaging values obtained by each measurement.
Thus, the time taken to perform multiple measurements until completing the
measurement process is required.
25 [0098]
Therefore, the eNodeB 10, when requesting two or more MTC terminals 20
to perform measurement, may acquire the final measurement information by
reducing the number of measurement times performed in each MTC terminal 20 and
averaging measurement information reported from each MTC terminal 20. The
30 specific example will be described below.
[0099]
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Fig. 10 is an explanatory diagram illustrating a specific example of reducing
the number of measurement times in each MTC terminal 20. As shown in the upper
portion of Fig. 10, normally one MTC terminal 20 performs measurement multiple
times and averages values obtained by each measurement, and thus final
5 measurement information is calculated.
[0100]
Meanwhile, as shown in the lower portion of Fig. 10 as a modified example,
in the eNodeB 10, the final measurement information may be calculated by causing
the number of measurement times performed by two or more MTC terminals 20P to
10 20Q designated as a recipient of requests to be less than usual and average ng values
obtained from the MTC terminals 20P to 20Q.
[0101]
With this configuration, the number of measurement times in the MTC
terminal 20 designated as a recipient of requests is reduced, and thus the time
15 required for the eNodeB 10 to acquire the final measurement information can be
reduced. In addition, it is also possible to reduce power consumption in each MTC
terminal 20.
[0102]
[4-2. Method of transmitting Measurement Information from eNodeB]
20 Although the example in which the eNodeB 10 broadcasts measurement
information on the BCCH has been described above, embodiments of the present
disclosure are not limited to this example. For example, as described with reference
to Fig. 11, the eNodeB 10 may transmit measurement information using a dedicated
channel.
25 [0103]
Fig. 11 is an explanatory diagram illustrating an exemplary configuration of
a measurement channel for transmitting measurement information. The eNodeB 10,
as shown in Fig. 11, transmits the measurement channel at a DRX (Discontinuas
Reception) interval.
30 [0104]
This measurement channel, as shown in Fig, 11, consists of PDCCH and
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PDSCH. The PDSCH includes measurement information, and PDCCH includes
position information corresponding to measurement information included in the
PDSCH.
[0105]
5 Therefore, the MTC terminal 20 intermittently receives the measurement
channel, and thus it is possible to extract the measurement information from the
PDSCH only when the position information corresponding to the MTC terminal 20 is
not included in the PDCCH.
[0106]
10 [4-3. Modified Example of Method of transmitting from eNodeB]
Although the example in which the eNodeB 10 transmits measurement
information has been described above, embodiments of the present disclosure are not
limited to this example. For example, the eNodeB 10 may transmit an eNodeB,
frequency, or the like to be changed over, instead of measurement information, to the
15 MTC terminal 20, when the MTC terminal 20 needs to change over to a different
eNodeB10 or frequency.
[0107]
Specifically, the measurement information management unit 140 of the
eNodeB 10 determines a position where the MTC terminal 20 to be changed over
20 into a different eNodeB 10 or frequency is located, on the basis of the measurement
information stored in the memory 120. For example, when measurement
information better than measurement information of a Serving eNodeB is associated
with certain position information, the measurement information management unit
140 of the eNodeB 10 extracts an eNodeB or frequency band which provides the
25 position information and the better measurement information.
[0108]
Then, the wireless communication unit 110 of the eNodeB 10, as shown in
Fig. 12, transmits the position information and an eNodeB or frequency band
(Recommendation of Next eNodeB and Frequency) extracted by the measurement
30 information management unit 140. In this case, the MTC terminal 20 extracts
information indicating the eNodeB or frequency band associated with the position
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information corresponding to the MTC terminal 20, and uses the extracted eNodeB
or frequency band. With this configuration, it is possible to suppress the amount of
information transmitted from the eNodeB 10.
[0109]
5 <5. Conclusion
As described above, according to the embodiments of the present disclosure,
the MTC terminal 20 which receives measurement information corresponding to
current position can avoid the need for performing measurement by using the
measurement information. Therefore, it is possible to reduce power consumption of
10 the MTC terminal 20, In addition, because the MTC terminal 20 may not transmit
the measurement information to the eNodeB 10, it is possible to suppress signaling
of measurement information from the MTC terminal 20 to the eNodeB 10, and to
prevent loss of throughput in a normal communication.
[0110]
15 The preferred embodiments of the present disclosure have been described
above with reference to the accompanying drawings, whilst the present disclosure is
not limited to the above examples, of course. A person skilled in the all may find
various alternations and modifications within the scope of the appended claims, and
it should be understood that they will naturally come under the technical scope of the
20 present disclosure.
[0111]
For example, each step in the process of the eNodeB 10 or the MTC
terminal 20 of the present specification do not necessarily have to be processed in a
time series according to the order described as the sequence diagrams or flowcharts.
25 For example, each step in the process of the eNodeB 10 or MTC terminal 20 may be
processed in an order different from the order described as flowcharts, or may be
processed in parallel.
[0112]
Furthermore, a computer program for causing hardware such as CPU, ROM
30 and RAM, embedded in the eNodeB 10 or the MTC terminal 20 to realize an
equivalent function as each element of the above-mentioned eNodeB 10 or MTC
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terminal 20 can also be created. Moreover, a storage medium having the computer
program stored thereon is also provided.
Reference Signs List
5 [0113]
10 eNodeB
12 MME
14 S-GW
16 PDN-GW
10 20 MTC terminal
30 MTC server
110, 210 Wireless communication unit
120 Memory
130 Time management unit
15 140 Measurement information management unit
220 Position information holding unit
230 Measurement information monitoring unit
240 Control unit
20
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CLAIMS
Claim 1
SP264085W®00
A wireless communication device comprising:
a receiving unit for receiving information based on measurement of radio
5 conditions transmitted from a base station in association with identification
information; and
a control unit for controlling communication by using the information
received by the receiving unit when the wireless communication device corresponds
to the identification information received by the receiving unit.
10
Claim 2
The wireless communication device according to claim 1, wherein the
identification information is position information, and
wherein the wireless communication device corresponding to the
15 identification information is a wireless communication device located within a range
specified by the identification information.
Claim 3
The wireless communication device according to claim 2, wherein the
20 information is information obtained by the measurement of radio conditions within
the range specified by the identification information.
Claim 4
The wireless communication device according to claim 3, further
25 comprising:
a position information holding unit for holding position information;
a measuring unit for measuring radio conditions; and
a transmitting unit for transmitting radio condition measurement
information obtained by the measuring unit to the base station in association with
30 position information held by the position information holding unit,
wherein the control unit, when identification information corresponding to
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the wireless communication device is not received by the receiving unit, causes the
measuring unit to measure radio conditions.
Claim 5
5 A base station comprising:
a storage unit for storing identification information and the radio condition
measurement information in association with each other; and
a transmitting unit for transmitting theidentification information and the
radio condition measurement information in association with each other.
10
Claim 6
The base station according to claim 5, wherein the identification information
is position information, and
wherein a wireless communication device located within a range specified
15 by the identification information corresponds to the identification information.
Claim 7
The base station according to claim 6, wherein the storage trait further stores
acquisition time information of the radio condition measurement information in
20 association with the identification information and the radio condition measurement
information, and
wherein the transmitting unit transmits the identification information and the
radio condition measurement information when an elapsed time from acquisition
time is within a predetermined range.
25
Claim 8
The base station according to claim 6, further comprising:
a control unit for designating at least one wireless communication device
corresponding to the identification information as a recipient of requests for
30 measurement of radio conditions and reporting of measurement information, and
wherein the storage unit stores radio condition measurement information
SP2,64085W000
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reported from the wireless communication device designated as the recipient.
Claim 9
The base station according to claim 8, wherein the control unit designates
5 two or more wireless communication devices as recipients of a same request for
measurement of radio conditions and reporting of measurement information, and
averages measurement information reported from the two or more wireless
communication devices.
10 Claim 10
The base station according to claim 8, wherein the control unit designates
two or more wireless communication devices as recipients of requests for
measurement of radio conditions and reporting of measurement information in
different frequency bands, and integrates radio condition measurement information
15 of the respective frequency bands reported from the two or more wireless
communication devices.
Claim 11
The base station according to claim 8, wherein the transmitting unit
20 transmits expiration information of the radio condition measurement information
stored in the storage unit to a wireless communication device designated as a
recipient of requests by the control unit.
Claim 12
25 The base station according to claim 5, further comprising:
a control unit for determining whether the plurality of wireless
communication devices are to be changed over to a base station or frequency and
determining to which base station or frequency the plurality of wireless
communication devices are to be changed over, and
30 wherein the transmitting unit, when it is determined by the control unit that
the plurality of wireless communication devices are to be changed over to a base
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station or frequency, transmits the base station or frequency determined to b.
changed over as radio conditionmeasurement -information in association with the
identification information.
5 Claim 13
The base station according to claim 5, wherein the transmitting unit
broadcasts the identification information and the radio condition measurement
information on a BCCH. -
10 Claim 14
The base station according to claim 5, wherein the transmitting unit
intermittently transmits the identification information and the radio condition
measurement information by using a dedicated channel.
15 Claim 15
A wireless communication method comprising:
receiving, at a wireless communication device, information based on
measurement of a radio condition transmitted from a base station in association with
identification information; and
20 controlling communication by using the received information when the
wireless communication device corresponds to the received identification
information.
Claim 16
25 A wireless communication method comprising:
storing identification information and the radio condition measurement
information in association with each other; and
transmitting the identification information and the radio condition
measurement information in association with each other.
30
Claim 17
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A wireless cormunication system comprising:
a base station including
a storage unit for storing identification information and the radio
condition measurement information in association with each other; and
5 a transmitting unit for transmitting the identification information
and the radio condition measurement information in association with each other; and
a wireless communication device including
a receiving unit for receiving information based on measurement of
radio conditions transmitted from the base station in association with identification
10 information; and
a control unit for controlling communication by using the
information received by the receiving unit when the wireless communication device
corresponds to the identification information received by the receiving unit.