Description
Title of Invention
COMMUNICATION CONTROL DEVICE, PROGRAM, COMMUNICATION
CONTROL METHOD, AND TERMINAL DEVICE
Technical Field
[0001]
The present disclosure relates to a communication control device, a program,
a communication control method, and a terminal device.
Background Art
[0002]
Currently, increasing data traffic in cellular systems caused by spread of
smartphones is a concern. For this reason, expanding communication capacities of
15 the cellular systems become more and more important for each cellular business
operator. In order to expand the communication capacities, the business operators
dispose, for example, small cells such as pico cells and femto cells within macro
cells. Accordingly, the business operators can gain more communication capacities
from advantages of cell splitting.
20 [0003]
Generally in a macro cell, system information of the macro cell is
transmitted from a base station of (he macro cell. Likewise in a small cell, system
information of the small cell is transmitted from a base station of the small cell.
Technologies pertaining to transmission methods of such system information of
25 small cells have also been proposed.
[0004]
For example, Patent Literature 1 discloses a technology in which a base
station of a femto cell transmits subframes that constitute a subframe set including a
plurality of kinds of subframes and are included in the subframe set in a
30 predetermined order, in order to prevent deterioration in performance of a system.
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Citation List
Patent Literature
[0005]
Patent Literature 1: JP 2012-523745T
5
Summary of Invention
Technical Problem
[0006]
According to the existing techniques for transmission of system information
10 including the technique disclosed in Patent Literature 1, however, system information
of small cells is transmitted only by base stations of the small cells. For this reason,
an area in which a terminal device can receive the system information of the small
cells is limited. Thus, there may be cases in which the terminal device has not
acquired the system information of the small cells when it has just entered or come
15 close to the small cells. As a result, spending much time in connection of the
terminal device in the small cells is a concern. For example, spending much time in,
for example, specifying a cell in a cell search, receiving system information thereof
after the cell search, and the like is a concern. Due to the fact that a small cell is
smaller than a macro cell, the frequency of the terminal device entering and exiting a
20 small cell is considered to be higher than the frequency of the terminal device
entering and exiting a macro cell, and thus spending much time as described above is
not favorable.
[0007]
Therefore, it is desirable to provide a mechanism in which a time taken for
25 connection of a terminal device in a small cell can be further shortened.
Solution to Problem
[0008]
According to the present disclosure, there is provided a communication
control device including an acquisition unit configured to acquire system information
30 of a frequency band that is used in a small cell that is partially or entirely overlapped
by a macro cell, and a control unit configured to control downlink transmission of the
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system information in the macro cell. The control unit notifies a terminal device
positioned within the macro cell of radio resource that is used in the downlink
transmission.
[0009]
5 In addition, according to the present disclosure, there is provided a program
causing a computer to function as an acquisition unit configured to acquire system
information of a frequency band that is used in a small cell that is partially or entirely
overlapped by a macro cell, and a control unit configured to control downlink
transmission of the system information in the macro cell. The control unit notifies a
10 terminal device positioned within the macro cell of radio resource that is used in the
downlink transmission.
[0010]
In addition, according to the present disclosure, there is provided a
communication control method including acquiring system information of a
15 frequency band that is used in a small cell that is partially or entirely overlapped by a
macro cell, controlling downlink transmission of the system information in the macro
cell, and notifying a terminal device positioned within the macro cell of radio
resource that is used in the downlink transmission.
[0011]
20 According to the present disclosure, there is provided a communication
control device including a generation unit configured to generate system information
of a frequency band that is used in a small cell that is partially ore entirely
overlapped by a macro cell, and a provision unit configured to provide the system
information to the device that is a device controlling downlink transmission of the
25 system information in the macro cell and notifying a terminal device positioned
within the macro cell of radio resource that is used in the downlink transmission.
[0012]
In addition, according to the present disclosure, there is provided a program
causing a computer to function as a generation unit configured to generate system
30 information of a frequency band that is used in a small cell that is partially or entirely
overlapped by a macro cell, and a provision unit configured to provide the system
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information to a device that is a device controlling downlink transmission of the
system information in the macro cell and notifying a terminal device positioned
within the macro cell of radio resource that is used in the downlink transmission.
[0013]
5 In addition, according to the present disclosure, there is provided a
communication control method including generating system information of a
frequency band that is used in a small cell that is partially or entirely overlapped by a
macro cell, and providing the system information to a device that is a device
controlling downlink transmission of the system information in the macro cell and
10 notifying a terminal device positioned within the macro cell of radio resource that is
used in the downlink transmission.
[0014]
According to the present disclosure, there is provided a terminal device
including a wireless communication unit configured to receive system information of
15 a frequency band that is used in a small cell that is partially or entirely overlapped by
a macro cell when the terminal device is positioned within the macro cell, and an
acquisition unit configured to acquire information transmitted using radio resource as
the system information when the terminal device is positioned within the macro cell
and the radio resource that is used in downlink transmission of the system
20 information is notified of.
[0015]
In addition, according to the present disclosure, there is provided a
communication control method including receiving system information of a
frequency band that is used in a small cell that is partially or entirely overlapped by a
25 macro cell when a terminal device is positioned within the macro cell, and acquiring
information transmitted using radio resource as the system information when the
terminal device is positioned within the macro cell and the radio resource that is used
in downlink transmission of the system information is notified of.
30 Advantageous Effects of Invention
[0016]
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According to the present disclosure as described above, it is possible to
further shorten a time taken for connection of a terminal device in a small cell.
Brief Description of Drawings
5 [0017]
[FIG. 1] FIG. 1 is an illustrative diagram for describing an example of a scenario in
which a macro cell and a small cell use different frequency bands.
[FIG. 2] FIG. 2 is an illustrative diagram for describing an example of PCCs of each
UE.
10 [FIG. 3] FIG 3 is an illustrative diagram for describing a physical broadcast channel
(PBCH) on which an MIB is transmitted.
[FIG. 4] FIG 4 is an illustrative diagram for describing subframes transmitted by SIB
1.
[FIG. 5] FIG. 5 is an illustrative diagram showing an example of a schematic
15 configuration of a wireless communication system according to an embodiment.
[FIG. 6] FIG. 6 is a block diagram showing an example of a configuration of a macro
eNodeB according to an embodiment.
[FIG. 7] FIG. 7 is an illustrative diagram for describing an example of information
transmitted for notification of radio resource used in transmission of system
20 information of a pico cell side.
[FIG. 8] FIG. 8 is an illustrative diagram for describing an example of
correspondences between LPSI and radio resource.
[FIG. 9] FIG. 9 is a block diagram showing an example of a configuration of a pico
eNodeB according to an embodiment.
25 [FIG. 10] FIG 10 is a block diagram showing an example of a configuration of a UE
according to an embodiment.
[FIG. 11] FIG. 11 is a sequence diagram showing an example of a schematic flow of a
communication control process according to an embodiment.
[FIG. 12] FIG. 12 is an illustrative diagram for describing an example of a position of
30 radio resource used in transmission of SIB 1.
[FIG. 13] FIG. 13 is an illustrative diagram for describing a first example of radio
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resource used in transmission of LPS1 according to a first modified example of an
embodiment.
[FIG. 14] FIG. 14 is an illustrative diagram for describing a first example of radio
resource used in transmission of LPSI according to a second modified example of an
5 embodiment.
[FIG. 15] FIG 15 is an illustrative diagram for describing a first example of radio
resource used in transmission of LPSI according to a third modified example of an
embodiment.
[FIG. 16] FIG. 16 is a sequence diagram showing an example of a schematic flow of
10 a communication control process according to the first modified example of an
embodiment.
[FIG. 17] FIG. 17 is an illustrative diagram for describing an example of information
transmitted for notification of updating of system information of a pico cell side.
[FIG. 18] FIG. 18 is an illustrative diagram for describing an example of
15 correspondences between pico system information and information transmitted to
notify of updating of the pico system information.
[FIG. 19] FIG 19 is a sequence diagram showing an example of a schematic flow of
a communication control process according to a second modified example of an
embodiment.
20
Description of Embodiments
[0018]
Hereinafter, preferred embodiments of the present disclosure will be
described in detail with reference to the appended drawings. Note that, in this
25 specification and the appended drawings, stiiictural elements that have substantially
the same function and structure are denoted with the same reference numerals, and
repeated explanation of these structural elements is omitted.
[0019]
Note that description will be provided in the following order.
30 1. Preface
1.1. Wireless communication technology of the 3 GPP
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1.2. Technical problem
2. Schematic configuration of a wireless communication system
3. Configurations of respective devices
3.1. Configuration of a macro eNodeB
5 3.2. Configuration of a pico eNodeB
3.3. Configuration of a UE
4. Process flow
5. Modified examples
5.1. First modified example
10 5.1.1. Overview
5.1.2. Configurations of respective devices
5.1.3. Process flow
5.2. Second modified example
5.2.1. Overview
15 5.2.2. Configurations of respective devices
5.2.3. Process flow
6. Conclusion
[0020]
<«l.Preface>»
20 First, a wireless communication technology of the 3rd Generation
Partnership Project (3GPP) and technical challenges thereof will be described.
[0021]
« 1 . 1 . Wireless communication technology of the 3GPP»
Hereinafter, the wireless communication technology of the 3GPP will be
25 described with reference to FIGS. 1 to 4.
[0022]
(Small cell of Release 10)
There is a mention in Release 10 as well as Release 11 of the 3GPP of small
cells (to be specific, pico cells). In Release 10 and Release 11, a base station is
30 referred to as an eNodeB, and particularly, an eNodeB of a macro cell is referred to
as a macro eNodeB, and an eNodeB of a pico cell is referred to as a pico eNodeB.
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[0023]
A pico cell is partially or entirely overlapped by a macro cell, and for
example, a macro eNodeB and a pico eNodeB use the same frequency band. Such a
network is referred to as a heterogeneous network (Het-Net). Reducing interference
5 between a macro eNodeB and a pico eNodeB in a Het-Net is an important task, and
thus the 3GPP has been vigorously discussed a technology for reducing such
interference. For example, providing a subframe that is called an almost blank
subfiame (ABS) in which most transmissions stop on a macro cell (macro eNodeB)
side and the like have been reviewed.
10 [0024]
(Small cell that is assumed in Release 12)
On the other hand, a scenario in which a macro eNodeB and a pico eNodeB
use different frequency bands is expected to be reviewed as a scenario of Release 12.
Hereinbelow, this point will be described in more detail with reference to FIG. 1.
15 [0025]
FIG. 1 is an illustrative diagram for describing an example of the scenario in
which a macro cell and a small cell use different frequency bands. Referring to FIG.
1, a macro cell 10 and a macro eNodeB 11 are shown. In addition, a pico cell 20
that is entirely overlapped by the macro cell 10 and a pico eNodeB 21 are shown.
20 Furthermore, a user equipment (UE) 31 that communicates with the macro eNodeB
and the pico eNodeB is shown. On such a network, for example, the macro
eNodeB 11 performs wireless communication with the UE 31 using a frequency band
of the 2 GHz band within the macro cell 10. In addition, for example, the pico
eNodeB 21 performs wireless communication with the UE 31 using a frequency
25 band of the 5 GHz band within the pico cell 20.
[0026]
(Carrier aggregation of Release 10)
[0027]
- Component carrier
30 In carrier aggregation of Release 10, up to five component carriers (CCs)
are bundled and used in a UE. Each CC is a bandwidth of up to 20 MHz. In
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carrier aggregation, CCs continuing in a frequency direction are used in some cases
and CCs separated in the frequency direction are used in some cases. In carrier
aggregation, the CCs to be used can be set for each UE.
[0028]
5 - Primary CC and secondary CC
In carrier aggregation, one of the plurality of CCs used by the UE is a
special CC. The one special CC is referred to as a primary component carrier
(PCC). Of the plurality of CCs, the remaining CCs are referred to as secondary
component carriers (SCCs). The PCC can differ for each UE. This point will be
10 described more specifically below with reference to FIG. 2.
[0029]
FIG. 2 is an explanatory diagram illustrating an example of the PCC of each
UE. A UE 31a, a UE 31b, and five CCs 1 to 5 are illustrated in FIG. 2. In this
example, the UE 31a uses two CCs, the CC 1 and the CC 2. The UE 31a uses the
15 CC 2 as the PCC. On the other hand, the UE 31b uses two CCs, the CC 2 and the
CC 4. The UE 31b uses the CC 4 as the PCC. In this way, each UE can use a
different CC as the PCC.
[0030]
Since the PCC is the most important CC among the plurality of CCs, the CC
20 for which communication quality is the stablest is preferable. Which CC is used as
the PCC actually depends the way in which they are installed.
[0031]
The CC with which a UE initially establishes connection is the PCC in the
UE. The SCC is added to the PCC. That is, the PCC is a main frequency band
25 and the SCC is an auxiliary frequency band. The SCC is changed by deleting the
existing SCC and adding a new SCC. The PCC is changed in an inter-frequency
handover sequence of the related art. In carrier aggregation, a UE may not use only
the SCC, but necessarily uses one PCC.
[0032]
30 The PCC is also referred to as a primary cell. The SCC is also referred to
as a secondary cell.
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[0033]
(System information)
[0034]
System information includes a master information block (MIB) and a
5 system information block (SIB). An MIB includes vital information for receiving
data in a first stage such as a bandwidth to be used, a system frame number (SFN), a
configuration of a hybrid ACK, and the like. In addition, an SIB includes other
system information. Information included in an MIB is more important information
than information included in an SIB.
10 [0035]
An MIB is transmitted on a physical broadcast channel (PBCH).
Hereinbelow, a PBCH on which an MIB is transmitted will be described in detail.
[0036]
FIG. 3 is an illustrative diagram for describing a physical broadcast channel
15 (PBCH) on which an MIB is transmitted. Referring to FIG. 3, radio resource of a
frequency band in a #0 subframe are shown. The #0 subframe is one of 10
subframes (#0 to #9 subframes) included in a 10 ms radio frame (Radio Frame).
Referring to FIG. 3, the subframe includes two slots. In addition, each slot includes
7 OFDM symbols. 1 to 3 OFDM symbols of the first slot are physical downlink
20 control channels (PDCCH), and 4 to 7 OFDM symbols of the first slot and the
second slot are physical downlink shared channels (PDSCH). In addition,
particularly in the #0 subframe, a PBCH is positioned in the range of 72 subcarriers
at the center of a frequency band in the frequency direction and 1 to 4 OFDM
symbols of the second slot in the time direction. In other words, a PBCH is
25 disposed over six resource blocks. An MIB is transmitted on this PBCH.
[0037]
In addition, an SIB is transmitted on a physical downlink shared channel
(Physical Downlink Shared Channel). Particularly, an SIB 1 of SIBs is transmitted
in a #5 subframe of a radio frame whose SFN is an even number. This will be
30 described in detail with reference to FIG. 4.
[0038]
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FIG. 4 is an illustrative diagram for describing a subframe in which the SIB
1 is transmitted. Referring to FIG. 4, two consecutive radio frames, i.e., a radio
frame whose SFN is an even number and a radio frame whose SFN is an odd number
are shown. In addition, the SIB 1 is transmitted in the #5 subframe of the radio
5 frame whose SFN is an even number. On the other hand, the SIB 1 is not
transmitted in the radio frame whose SFN is an odd number. The SIB 1 is
transmitted in a fixed subframe as above.
[0039]
Note that an MIB indicates at which position in the frequency direction of
10 the #5 subframe of the radio frame whose SFN is an even number the SIB 1 is
transmitted. For this reason, the SIB 1 is not transmitted completely at a fixed
position, but transmitted at a semi-fixed position, different from an MIB. Note that
a position in the time direction (i.e., an OFDM symbol) in the #5 subframe in which
the SIB 1 is transmitted is fixed.
15 [0040]
In addition, SIBs 2 to 11 among SIBs are not entirely transmitted in a fixed
subframe, like the SIB 1. The SIBs 2 to 11 are transmitted using the radio resource
represented by the SIB 1.
[0041]
20 (Paging)
[0042]
In LTE, there are an RRC connected (RRCConnected) mode and an RRC
idle (RRCIdle) mode as modes of a UE.
[0043]
25 When the mode of a UE is the RRC connected mode, connection between
the UE and an eNodeB is established, and thereby transmission and reception of
uplink signals and downlink signals are possible.
[0044]
On the other hand, when the mode of the UE is the RRC idle mode, the
30 eNodeB does not have information of the UE, and a tracking area in which the UE is
present is registered in a mobility management entity (MME). An MME is a node
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that is wire-connected to the eNodeB in an Sl-MME interface. A tracking area is
an area that includes dozens to hundreds of cells close to each other.
[0045]
When there is an incoming call to the UE, the MME performs calling-out at
5 a paging channel in all cells included in the tracking area of the UE. In other words,
the UE in the RRC idle mode monitors the paging channel, and when there is an
incoming call to the UE, the mode of the device transitions from the RRC idle mode
to the RRC connection mode.
[0046]
10 The UE in the RRC idle mode performs power saving such as stopping a
clock of hardware, stopping power supply, or the like in order to reduce power
consumption except for the time at which information is transmitted on the paging
channel. In addition, when the time at which information is transmitted on the
paging channel arrives, the UE turns the power on, receives the information on the
15 paging channel, and then performs power saving again after the reception.
[0047]
(Updating of system information)
Updating of system information (System Information Update) is notified of
on the paging channel. In addition, updating of system information is also notified
20 of by the SIB 1 of the system information.
[0048]
(System information in carrier aggregation and updating thereof)
In carrier aggregation, system information is provided by all component
carriers (CC), In addition, since the SIB 1 is transmitted by all CCs, updating of the
25 system information is notified of by all CCs. A UE applied to carrier aggregation,
however, can be aware of updating of the system information of all CCs by
monitoring only the PCC.
[0049]
«1.2. Technical challenge»
30 Next, a technical challenge that is also relevant to the above-described
technology will be described.
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[0050]
Generally in a macro cell, system information of the macro cell is
transmitted by a macro eNodeB. In addition, likewise in a pico cell, system
information of the pico cell is transmitted by a pico eNodeB. A technology relating
5 to a transmission method of system information of such a small cell has also been
proposed.
[0051]
JP 2012-523745A, for example, discloses a technology in which a base
station of a femto cell transmits subframes that constitutes a subframe set that
10 includes a plurality kinds of subframes and are included in the subframe set in a
predetermined order to prevent deterioration in performance of a system.
[0052]
According to the transmission method of system information of the related
art described above, however, system information of a pico cell is transmitted
15 entirely by a pico eNodeB. For this reason, due to low transmission electric power,
a high frequency band, or the like, for example, an area in which a UE can receive
the system information of the pico cell is limited. Thus, there are also cases in
which the UE has not yet acquired the system information of the pico cell when the
UE has just entered or come close to the pico cell. For example, the UE can fail to
20 acquire the system information of the pico cell when the UE enters the pico cell at a
high speed. As a result, spending much time in connection of a UE in a small cell is
a concern. A UE, for example, the UE, specifies a pico cell among all pico cell
candidates in a cell search based on a primary synchronization signal (PSS) and a
secondary synchronization signal (SSS), and thus specification of a cell can require
25 much time. In addition, since the UE newly receives system information after the
cell search, for example, the reception of the system information can take much time
as well. The frequency of a UE entering and exiting a small cell is higher than the
frequency of the UE entering and exiting a macro cell due to the fact that a small cell
is smaller than a macro cell, and thus spending much time as described above is not
30 favorable.
[0053]
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Therefore, embodiments of the present disclosure enable a time taken for
connection of a UE in a pico cell to be further shortened. Hereinbelow, details
thereof will be described in <«2. Schematic configuration of a wireless
communication system>», < « 3 . Configurations of respective devices>», < « 4 .
5 Process flow>», and < « 5 . Modified examples>».
[0054]
<«2. Schematic configuration of a wireless communication system>»
A schematic configuration of a wireless communication system according to
an embodiment of the present disclosure will be described with reference to FIG. 5.
10 FIG. 5 is an illustrative diagram showing an example of the schematic configuration
of the wireless communication system according to the present embodiment. The
wireless communication system is a wireless communication system based on, for
example, LTE. Referring to FIG. 5, the wireless communication system includes a
macro eNodeB 100 of the macro cell 10 and a pico eNodeB 200 of the pico cell 20,
15 and a UE 300.
[0055]
The macro eNodeB 100 wirelessly communicates with the UE 300 within
the macro cell 10. As an example, a frequency band of the 2 MHz band is used
within the macro cell 10 for wireless communication between the macro eNodeB 100
20 and the UE 300.
[0056]
The pico eNodeB 200 wirelessly communicates with the UE 300 within the
pico cell 20. The pico cell 20 is partially or entirely overlapped by the macro cell
10. Within the pico cell 20, for example, a different frequency band from the
25 frequency band used in the macro cell 10 is used. To be specific, a frequency band
used within the pico cell 20, for example, is a higher frequency band than the
frequency band used within the macro cell 10. As an example, a frequency band of
the 5 MHz band is used in wireless communication between the pico eNodeB 200
and the UE 300 within the pico cell 20.
30 [0057]
The UE 300 wirelessly communicates with the macro eNodeB 100 within
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the macro cell 10. In addition, the UE 300 wirelessly communicates with the pico
eNodeB 200 within the pico cell 20.
[0058]
< « 3 . Configurations of respective devices>»
5 Next, examples of respective configurations of the macro eNodeB 100, the
pico eNodeB 200, and the UE 300 will be described with reference to FIGS. 6 to 10.
[0059]
« 3 . 1 . Configuration of a macro eNodeB»
First, an example of a configuration of the macro eNodeB 100 will be
10 described with reference to FIGS. 6 to 8. FIG. 6 is a block diagram showing the
example of the configuration of the macro eNodeB 100 according to the present
embodiment. Referring to FIG. 6, the macro eNodeB 100 is provided with an
antenna unit 110, a wireless communication unit 120, a network communication unit
130, a storage unit 140, and a control unit 150.
15 [0060]
(Antenna unit 110)
The antenna unit 110 receives a radio signal and outputs the received radio
signal to the radio communication unit 120. The antenna unit 110 transmits a
transmission signal output by the radio communication unit 120.
20 [0061]
(Wireless communication unit 120)
The wireless communication unit 120 wirelessly communicates with the UE
300 that is positioned within the macro cell 10. As an example, the wireless
communication unit 120 wirelessly communicates with the UE 300 using a
25 frequency band of the 2 MHz band. The wireless communication unit 120 includes,
for example, a radio frequency (RF) circuit and other circuits.
[0062]
(Network communication unit 130)
The network communication unit 130 communicates with other devices.
30 For example, the network communication unit 130 communicates with the pico
eNodeB 200. The network communication unit 130 includes, for example, a
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communication interface for any type of wired communication.
[0063]
(Storage unit 140)
The storage unit 140 stores programs and data for operations of the macro
5 eNodeB 100. The storage unit 140 includes a storage medium, for example, a hard
disk, a semiconductor memory, or the like.
[0064]
(Control unit 150)
The control unit 150 provides various functions of the macro eNodeB 100.
10 For example, the control unit 150 corresponds to a processor such as a CPU or a DSP,
and provides the various functions by causing programs stored in the storage unit 140
or other storage media to be executed. The control unit 150 includes an information
acquisition unit 151 and a communication control unit 153.
[0065]
15 (Information acquisition unit 151)
The information acquisition unit 151 acquires system information of a
frequency band that is used in the pico cell 20 (which will be referred to hereinafter
as "pico system information"). When, for example, the network communication
unit 130 receives pico system information transmitted by the pico eNodeB 200, the
20 information acquisition unit 151 acquires the pico system information.
[0066]
(Communication control unit 153)
The communication control unit 153 controls wireless communication
within the macro cell 10.
25 [0067]
- Transmission of system information of a pico cell side
Particularly in the present embodiment, the communication control unit 153
controls downlink transmission of the pico system information in the macro cell 10.
For example, the wireless communication unit 153 causes the wireless
30 communication unit 120 to perform downlink transmission of the pico system
information in the macro cell 10. In other words, the wireless communication unit
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153 causes the wireless communication unit 120 to transmit the pico system
information in the macro cell 10.
[0068]
Radio resource to be used in the downlink transmission of the pico system
5 information (which will be referred to hereinafter as "resource for pico system
information) is resource of a frequency band used in the macro cell 10. In addition,
the resource for pico system information is resource that are not used in transmission
of system information of the frequency band used in the macro cell 10 (which will be
referred to hereinafter as "macro system information"). In other words, the
10 communication control unit 153 causes the wireless communication unit 120 to
transmit the pico system information using different radio resource from radio
resource used in transmission of the macro system information.
[0069]
In addition, for example, there are a plurality of pico cells 20 in the macro
15 cell 10. In this case, the resource for pico system information are not used in
transmission of system information of a frequency band used in another pico cell 20
(in other words, pico system information of another pico cell 20) either. In other
words, the communication control unit 153 causes the wireless communication unit
120 to transmit pico system information of each pico cell 20 using discrete radio
20 resource.
[0070]
In addition, as an example, the resource for pico system information is
resource of a physical downlink shared channel (PDSCH).
[0071]
25 Note that the communication control unit 153 also controls, for example,
downlink transmission of the macro system information in the macro cell 10. The
communication control unit 153 generates, for example, macro system information.
Then, the communication control unit 153 causes the wireless communication unit
120 to transmit the macro system information in the macro ceil 10.
30 [0072]
- Notification of radio resource used in transmission of system information of a pico
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cell side
In addition, the communication control unit 153 notifies the UE 300
positioned within the macro cell 10 of the resource for pico system information in the
present embodiment. To be more specific, for example, the communication control
5 unit 153 causes the wireless communication unit 120 to transmit information for
specifying resource for pico system information to the UE 300 positioned within the
macro cell 10. The information is, for example, information representing a position
of the resource for pico system information in a frequency direction and a time
direction (which will be referred to hereinafter as "location of pico system
10 information (LPSI)"). LPSI includes, for example, a cycle, a subframe number, a
position of a resource block in a frequency direction and a time direction, and the
like.
[0073]
In addition, the communication control unit 153 also notifies the UE of, for
15 example, a pico cell ID for identifying the pico cell 20 along with the resource for
pico system information. To be specific, for example, the communication control
unit 153 causes the wireless communication unit 120 to transmit a combination of a
pico cell ID and LPSI. Hereinbelow, a specific example of this will be described
with reference to FIGS. 7 and 8.
20 [0074]
FIG. 7 is an illustrative diagram for describing an example of information
transmitted for notification of radio resource used in transmission of system
information of a pico cell side. Referring to FIG 7, three combinations of pico cell
IDs and LPSI are shown. When there are three pico cells 20 in the macro cell 10,
25 for example, a pico cell ID and LPSI are transmitted to the three respective pico cells
20.
[0075]
FIG 8 is an illustrative diagram for describing an example of
correspondences between LPSI and radio resource. Referring to FIG. 8,
30 correspondences between the combinations of pico cell IDs and LPSI shown in FIG.
7 and radio resource represented by the LPSI are shown. In the radio resource
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represented by LPSI, system information including MIBs and SIBs is transmitted.
With the LPSI with respect to each pico cell 20, the UE 300 can specify where pico
system information of each pico cell is.
[0076]
5 In addition, the resource for pico system information are notified of, for
example, through signaling to the UE 300 that is in a connected state in the macro
cell 10. To be more specific, for example, the communication control unit 153
causes the wireless communication unit 120 to transmit the combinations of the pico
cell IDs and LPSI through RRC signaling to the UE 300 that is in the RRC
10 connection mode in the macro cell 10. The communication control unit 153 may
cause the wireless communication unit 120 to transmit the respective combinations
of the pico cell IDs and LPSI separately from each other, or to transmit two or more
of the combinations as a whole.
[0077]
15 «3.2. Configuration of a pico eNodeB»
Next, an example of a configuration of the pico eNodeB 200 will be
described with reference to FIG. 9. FIG. 9 is a block diagram showing the example
of the configuration of the pico eNodeB 200 according to the present embodiment.
Referring to FIG. 9, the pico eNodeB 200 is provided with an antenna unit 210, a
20 wireless communication unit 220, a network communication unit 230, a storage unit
240, and a control unit 250.
[0078]
(Antenna unit 210)
The antenna unit 210 receives a radio signal and outputs the received radio
25 signal to the radio communication unit 220. The antenna unit 210 transmits the
transmitted signal output by the radio communication unit 220.
[0079]
(Wireless communication unit 220)
The wireless communication unit 220 wirelessly communicates with the UE
30 300 that is positioned within the pico cell 20. As an example, the wireless
communication unit 220 wirelessly communicates with the UE 300 using a
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frequency band of the 5 MHz band. The wireless communication unit 120 includes,
for example, an RF circuit and other circuits.
[0080]
(Network communication unit 230)
5 The network communication unit 230 communicates with other devices.
For example, the network communication unit 230 communicates with the macro
eNodeB 100. The network communication unit 230 includes, for example, a
communication interface for any type of wired communication.
[0081]
10 (Storage unit 240)
The storage unit 240 stores programs and data for operations of the pico
eNodeB 200. The storage unit 240 includes a storage medium, for example, a hard
disk, a semiconductor memory, or the like.
[0082]
15 (Control unit 250)
The control unit 250 provides various functions of the pico eNodeB 200.
For example, the control unit 250 corresponds to a processor such as a CPU or a DSP,
and provides the various functions by causing programs stored in the storage unit 240
or other storage media to be executed. The control unit 250 includes a
20 communication control unit 251 and an information provision unit 253.
[0083]
(Communication control unit 251)
The communication control unit 251 controls wireless communication
within the pico cell 20. Specifically, for example, the communication control unit
25 251 generates system information of a frequency band used in the pico cell 20 (in
other words, pico system information). The system information includes, for
example, an MIB and an SIB. The communication control unit 251 outputs the
generated pico system information to the information provision unit 253.
[0084]
30 In addition, for example, the pico system information is not transmitted in
the pico cell 20. In other words, the communication control unit 251 does not cause
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the wireless communication unit 220 to transmit pico system information in the pico
cell 20.
[0085]
(Information provision unit 253)
5 The information provision unit 253 provides the pico system information to
the macro eNodeB 100. To be specific, when the pico system information is output
by the communication control unit 251, the information provision unit 253 acquires
the pico system information. Then, the information provision unit 253 causes the
network communication unit 230 to transmit the pico system information to the
10 macro eNodeB 100.
[0086]
« 3 . 3 . Configuration of a U E »
Next, an example of a configuration of the UE 300 will be described with
reference to FIG. 10. FIG. 10 is a block diagram showing the example of the
15 configuration of the UE 300 according to the present embodiment. Referring to FIG.
10, the UE 300 is provided with an antenna unit 310, a wireless communication unit
320, a storage unit 330, and a control unit 340.
[0087]
(Antenna unit 310)
20 The antemia unit 310 receives a radio signal and outputs the received radio signal to
the radio communication unit 220. The antenna unit 310 transmits a transmission
signal output by the radio communication unit 320.
[0088]
(Wireless communication unit 320)
25 The wireless communication unit 320 wirelessly communicates with the
macro eNodeB 100 when it is positioned within the macro cell 10. In addition, the
wireless communication unit 320 wirelessly communicates with the pico eNodeB
200 when it is positioned within the pico cell 20.
[0089]
30 Particularly in the present embodiment, when the UE 300 is positioned
within the macro cell 10, the wireless communication unit 320 receives system
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information of a frequency band used in the pico cell 20 (i.e., pico system
information). To be more specific, for example, when the UE 300 is positioned
within the macro cell, the wireless communication unit 320 receives pico system
information transmitted by the macro eNodeB 100.
5 [0090]
In addition, when, for example, the UE 300 is positioned within the macro
cell 10, the wireless communication unit 320 receives information for specifying
resource for pico system information. The information is, for example, LP SI. In
addition, the wireless communication unit 320 also receives a pico cell ID along with
10 the LPSI.
[0091]
(Storage unit 330)
The storage unit 330 stores programs and data for operations of the UE 300.
The storage unit 330 includes a storage medium, for example, a hard disk, a
15 semiconductor memory, or the like.
[0092]
(Control unit 340)
The control unit 340 provides various functions of the UE 300. For
example, the control unit 340 corresponds to a processor such as a CPU or a DSP,
20 and provides the various functions by causing programs stored in the storage unit 330
or other storage media to be executed.
[0093]
For example, the control unit 340 acquires control information transmitted
by the macro eNodeB 100 and the pico eNodeB 200. To be more specific, for
25 example, the control unit 340 acquires the control information when the wireless
communication unit 320 receives the control information. As an example, a
position of radio resource in a frequency direction and a time direction in which each
piece of control information is transmitted is known to the control unit 340.
Therefore, the control unit 340 acquires information transmitted using the radio
30 resource at the known position as control information.
[0094]
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Particularly, in the present embodiment, when the UE 300 is positioned
within the macro cell 10 and radio resource used in downlink transmission of pico
system information are notified of, the control unit 340 acquires information
transmitted using the radio resource as the pico system information.
5 [0095]
To be more specific, for example, when the UE 300 is positioned within the
macro cell 10 and the wireless communication unit 320 receives a pico cell ID and
LPSI, the control unit 340 acquires the pico cell ID and the LPSI. Accordingly, the
control unit 340 can know radio resource that is used to transmit pico system
10 information of the pico cell 20. Then, when the information transmitted using the
radio resource is received by the wireless communication unit 320, the control unit
340 acquires the information as pico system information. In this way, the control
unit 340 acquires the pico system information of the pico cell 20.
[0096]
15 Note that, since the UE 300 can know the pico cell ID from a PSS and an
SSS of the pico cell 20 in a cell search, the pico cell 20 found as a result of the cell
search can be associated with the system information acquired based on the LPSI
using the pico cell ID.
[0097]
20 <«4. Process f l o w >»
Next, an example of a communication control process according to the
present embodiment will be described with reference to FIG. 11. FIG. 11 is a
sequence diagram showing an example of a schematic flow of the communication
control process according to the present embodiment.
25 [0098]
In Step S401, the UE 300 is in the RRC connection mode with the macro
eNodeB 100.
[0099]
In Step S403, the communication control unit 153 of the macro eNodeB 100
30 causes the wireless communication unit 120 to transmit a combination of a pico cell
ID and LPSI. To be more specific, the communication control unit 153 causes the
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wireless communication unit 120 to transmit the combination of the pico cell ID and
the LPSI through RRC signaling to the UE 300 that is in the RRC connection mode
in the macro cell 10. Then, the wireless communication unit 320 of the UE 300
receives the combination of the pico cell ID and the LPSI, and the control unit 340 of
5 the UE 300 acquires the combination of the pico cell ID and the LPSI.
[0100]
In Step S405, the communication control unit 251 of the pico eNodeB 200
generates system information of a frequency band used in the pico cell 20 (i.e., pico
system information). After that, in Step S407, the information provision unit 253 of
10 the pico eNodeB 200 causes the network communication unit 230 to transmit the
pico system information to the macro eNodeB 100. Then, the network
communication unit 130 of the macro eNodeB 100 receives the pico system
information and the information acquisition unit 151 acquires the pico system
information.
15 [0101]
In Step S409, the communication control unit 153 of the macro eNodeB 100
causes the wireless communication unit 120 to transmit the pico system information
in the macro cell 10 using radio resource represented by the LPSI. Then, the
wireless communication unit 320 of the UE 300 receives the pico system information
20 using the radio resource represented by the LPSI.
[0102]
After that, in Step S411, the control unit 340 of the UE 300 acquires the
information transmitted and received using the radio resource represented by the
LPSI as the pico system information.
25 [0103]
The configurations of the respective devices and the process flow of the
present embodiment have been described above. As described above, the UE 300 is
notified of radio resource of the macro cell 10, then pico system information is
transmitted in the macro cell 10 using the radio resource, and accordingly, the UE
30 300 can acquire the pico system information in the macro cell 10. In other words,
an area in which the pico system information can be acquired is not limited to the
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pico cell 20, but expands to the macro cell 10. Thus, the UE 300 can acquire the
pico system information of the pico cell 20 before the UE comes close to the pico
cell 20. As a result, a time taken for connection of the UE 300 in the pico cell is
shortened. For example, the UE 300 specifies the pico cell 20 in a cell search based
5 on a PSS and an SSS from limited pico cells 20 corresponding to pico system
information that has been acquired beforehand. For this reason, a time taken to
specify a cell is shortened. In addition, for example, it is not necessary for the UE
300 to receive system information again after the cell search. For this reason, a
time taken for connection in the pico cell 20 is shortened more.
10 [0104]
Note that PDCCHs, each of which is a control channel in the macro cell 10
and the pico cell 20, for example, are present in both of the macro cell 10 and the
pico cell 20 as in the related art. Mainly on the PDCCHs, release assignment
information (i.e., scheduling information) is transmitted. The scheduling
15 information includes downlink assignment (Downlink Assignment) and an uplink
grant (Uplink Grant). The downlink assignment indicates which resource block
(RB) among downlink RBs is the RB that a UE should receive. On the other hand,
the uplink grant indicates which RB among uplink RBs is the RB that a UE should
use in transmission. The reason is that deciding this scheduling information in each
20 of eNodeBs (i.e., each macro eNodeB 100 and each pico eNodeB 200) simplifies
implementation of the wireless communication system. When the pico eNodeB 200
is implemented as a remote radio head (RRH), transmission of scheduling
information of the pico eNodeB side may also be possible on the PDCCH of the
macro eNodeB side. When the pico eNodeB 200 is not implemented as an RRH,
25 however, the presence of the PDCCHs in each cell (i.e., each macro cell and each
pico cell) is considered to be natural.
[0105]
In addition, in order to secure synchronization in a pico cell, transmission of
synchronization signals of PSSs and SSSs by the pico eNodeB 200 is also considered
30 to be natural.
[0106]
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On the other hand, taking the small area of the pico cell 20, transmission of
system information of the pico cell 20, system information updating, paging channels,
and the like in the macro cell 10 rather than the pico cell 20 is considered to be
natural. In addition, signaling to the UE via the macro eNodeB 100 is considered to
5 be desirable. This is because the pico eNodeB 200 should concentrate on
transmission and reception of user data.
[0107]
< « 5 . Modified examples>»
Next, a first modified example and a second modified example according to
10 the present embodiment will be described with reference to FIGS. 12 to 19.
[0108]
« 5 . 1 . First modified example»
First, the first modified example according to the present embodiment will
be described with reference to FIGS. 12 to 16.
15 [0109]
<5.1.1. Overview>
In the examples of the present embodiment described above, radio resource
that is used in transmission of pico system information (i.e., resource for pico system
information) are notified of through signaling (for example, RRC signaling) to the
20 UE 300 that is in a connection state in the macro cell 10. In this case, the UE 300
that is not in a connection state in the macro cell 10 (i.e., the UE 300 in an idle state)
does not receive a notification through signaling, and thus fails to acquire pico
system information. For this reason, it is not possible to cause the above-described
examples to correspond to a case in which, for example, the UE 300 intends to
25 perform wireless communication in a specific pico cell 20 and then is in a connection
state in the macro cell 10.
[0110]
Thus, in the first modified example of the present embodiment, resource for
pico system information are notified of using radio resource for notification that have
30 a predetermined positional relation with other radio resource that is used in
transmission of a predetermined information block included in macro system
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information. To be specific, for example, LPSI is transmitted using radio resource
for notification that have a predetermined positional relation with other radio
resource that is used in transmission of a predetermined information block included
in macro system information.
5 [0111]
Even a UE 300 that is not in a connection state in the macro cell 10 can
acquire system information of the macro cell 10. Thus, according to the first
modified example, when the UE 300 that is not in a connection state in the macro
cell 10 acquires the predetermined information block, information transmitted with
10 radio resource that has a predetermined positional relation with radio resource for
transmission of the information block can be acquired as information that represents
resource for the pico system information (i.e., LPSI). Then the UE 300 can acquire
information transmitted with the resource for pico system information represented by
the information as pico system information. In other words, the UE 300 can acquire
15 pico system information even when it is not in a connection state in the macro cell 10.
[0112]
<5.1.2. Configurations of respective devices>
Next, configurations of respective devices according to the first modified
example of the present embodiment will be described with reference to FIGS. 12 to
20 15. Herein, only changes from the content that has already been described with
reference to FIGS. 6, 9, and 10 will be described.
[0113]
(Macro cNodeB 100)
- Communication control unit 153
25 As described above, resource for pico system information are notified of
using radio resource for notification that have a predetermined positional relation
with other radio resource that is used in transmission of a predetermined information
block included in macro system information. To be specific, the communication
control unit 153 causes the wireless communication unit 120 to transmit a pico cell
30 ID and LPSI using radio resource for notification that have a predetermined
positional relation with other radio resource that is used in transmission of a
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predetermined information block included in macro system information.
[0114]
The other radio resource used in transmission of the predetermined
information block included in the macro system information is, for example, resource
5 positioned within a predetermined range of a time direction and a frequency direction.
As an example, the predetermined information block is the SIB 1 among system
information blocks (SIBs). In addition, the other radio resource is resource used in
transmission of the SIB 1. In other words, the communication control unit 153
causes the wireless communication unit 120 to transmit the pico cell ID and LPSI
10 using radio resource that has a predetermined positional relation with the radio
resource used in transmission of the SIB 1. Hereinbelow, the position of the radio
resource used in transmission of the SIB I will be described with reference to FIG.
12.
[0115]
15 FIG 12 is an illustrative diagram for describing an example of a position of
radio resource used in transmission of the SIB 1. Referring to FIG. 12, two
consecutive radio frames, i.e., a radio frame whose SFN is an even number and a
radio frame whose SFN is an odd number, are shown. In addition, the SIB 1 is
transmitted in a #5 subframe of the radio frame whose SFN is an even number. To
20 be more specific, the SIB I is transmitted on a PDSCH in the #5 subfi-ame. To be
more specific, the position of the SIB 1 is fixed in the time direction in the #5
subframe, but variable in the frequency direction. The position of the SIB 1 in the
frequency direction is notified of using an MIB 1. In the first modified example of
the present embodiment, LPSI is transmitted with radio resource thai has a
25 predetermined positional relation with semi-fixed radio resource used in transmission
of the SIB 1.
[0116]
In addition, the predetermined positional relation is a positional relation that
has a predetermined offset with the other radio resource in the time direction and the
30 frequency direction. As an example, the predetermined positional relation is a
positional relation that has a predetermined offset with the radio resource used in the
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transmission of the SIB 1 in the time direction and the frequency direction. In other
words, the communication control unit 153 causes the wireless communication unit
120 to transmit the pico cell ID and the LPSI using radio resource that has a
predetermined offset with the radio resource used in the transmission of the SIB 1 in
5 the time direction and the frequency direction. Hereinbelow, a specific example of
radio resource that has a predetermined offset will be described with reference to
FIGS. 13 to 15.
[0H7]
FIG. 13 is an illustrative diagram for describing a first example of radio
10 resource used in transmission of LPSI according to the first modified example of the
present embodiment. Referring to FIG. 13, radio resource of the macro cell 10 in
the #5 subframe of the radio frame whose SFN is an even number are shown. As
shown in FIG. 13, for example, the radio resource used in transmission of LPSI have
a predetermined offset with radio resource used in transmission of the SIB 1 in the
15 frequency direction.
[0118]
FIG. 14 is an illustrative diagram for describing a second example of the
radio resource used in transmission of LPSI according to the first modified example
of the present embodiment. Referring to FIG. 14, radio resource of the macro cell
20 10 in the #5 subframe of the radio frame whose SFN is an even number are shown.
As shown in FIG. 14, for example, the radio resource used in transmission of the
LPSI has a predetermined offset with the radio resource used in transmission of the
SIB 1 in the time direction. To be more specific, the radio resource used in
transmission of the LPSI are transmitted in the #5 subframe, and transmitted using an
25 OFDM symbol different from that of the radio resource used in transmission of the
SIB 1.
[0119]
FIG. 15 is an illustrative diagram for describing a third example of the radio
resource used in transmission of LPSI according to the first modified example of the
30 present embodiment. Referring to FIG. 15, two consecutive radio frames, i.e., a
radio frame whose SFN is an even number and a radio frame whose SFN is an odd
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number, are shown. In addition, the SIB 1 is transmitted in the #5 subframe whose
SFN is an even number. On the other hand, the LPSI is transmitted in the #5
subframe whose SFN is an odd number. The radio resource used in transmission of
the LPSI have an offset of one radio frame with respect to the radio resource used in
5 transmission of the SIB 1 in the time direction.
[0120]
Note that the radio resource used in transmission of the LPSI have
predetermined offsets with the radio resource used in transmission of the SIB 1 in the
frequency direction and the time direction as above. Note that the predetermined
10 offset is not limited to the above-described example, and various offsets can be
applied. In addition, the predetermined offset is not limited to one offset of those in
the frequency direction and the time direction, and predetermined offsets in both of
the frequency direction and the time direction can be applied.
[0121]
15 Note that, for example, the pico cell ID also is transmitted using radio
resource that has the predetermined offset along with the LSPI.
[0122]
(UE 300)
- Control unit 340
20 If radio resource used in downlink transmission of pico system information
(i.e., resource for pico system information) are notified of when the UE 300 is
positioned within the macro cell 10, the control unit 340 acquires information
transmitted using the radio resource as (he pico system information. Particularly in
the first modified example of the present embodiment, the resource for pico system
25 information is notified of using radio resource for notification that have a
predetermined positional relation with other radio resource that is used in
transmission of a predetermined information bock included in macro system
information. In other words, the control unit 340 receives a notification of the
resource for pico system information using the radio resource for notification. To
30 be specific, for example, a pico cell ID and LSPI transmitted using radio resource
that have a predetermined positional relation with the radio resource used in
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transmission of the SIB 1 are received by the wireless communication unit 320.
Then, the control unit 340 acquires information transmitted using the radio resource
that has the predetermined positional relation as the pico cell ID and the LSPI.
Note that details of the predetermined positional relation are as described above.
5 [0123]
<5.1.3. Process flow>
Next, an example of a communication control process according to the first
modified example of the present embodiment will be described with reference to FIG.
16. FIG. 16 is a sequence diagram showing an example of a schematic flow of the
10 communication control process according to the first modified example of the
present embodiment.
[0124]
In Step S501, the communication control unit 153 of the macro eNodeB 100
generates macro system information.
15 [0125]
Then, in Step S503, the communication control unit 153 of the macro
eNodeB 100 causes the wireless communication unit 120 to transmit the macro
system information in the macro cell 10. In addition, the communication control
unit 153 causes the wireless communication unit 120 to transmit the pico cell ID and
20 the LPSI using radio resource that has a predetermined offset with radio resource that
is used in transmission of the SIB 1 of the macro system information. On the other
hand, the wireless communication unit 320 of the UE 300 receives the macro system
information, and receives the pico cell ID and the LPSI using the radio resource that
has the predetermined offset.
25 [0126]
In Step S505, the control unit 340 of the UE 300 acquires the macro system
information. In addition, in Step S507, the control unit 340 acquires the pico cell
ID and the LPSI. To be specific, for example, the control unit 340 acquires
information transmitted using the radio resource that has the predetermined offset
30 with the radio resource used in transmission of the SIB 1 as the pico cell ID and the
LPSI.
SP349821WO00
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[0127]
In Step S509, the communication control unit 251 of the pico eNodeB 200
generates pico system information. Then, in Step S511, the information provision
unit 253 of the pico eNodeB 200 causes the network communication unit 230 to
5 transmit the pico system information to the macro eNodeB 100. Then, the network
communication unit 130 of the macro eNodeB 100 receives the pico system
information, and the information acquisition unit 151 thereof acquires the pico
system information.
[0128]
10 In Step S513, the communication control unit 153 of the macro eNodeB 100
causes the wireless communication unit 120 to transmit the pico system information
in the macro cell 10 using radio resource represented by the LPSI. Then, the
wireless communication unit 320 of the UE 300 receives the pico system information
using the radio resource represented by the LPSI.
15 [0129]
Then, in Step S515, the control unit 340 of the UE 300 acquires the
information transmitted and received using the radio resource represented by the
LPSI as the pico system information.
[0130]
20 «5.2. Second modified example»
Next, the second modified example according to the present embodiment
will be described with reference to FIGS. 17 to 19.
[0131]
<5.2.L Overview>
25 As described above, pico system information is transmitted by the macro
eNodeB 100 in the embodiment and the first modified example of the embodiment,
For this reason, updating of system information is also basically transmitted by the
macro eNodeB 100. In such a case, if updating of both of macro system
information and pico system information is notified of as notification of system
30 information updating, the frequency of system information updating becomes very
high. For example, if there are 20 pico cells 20 within the macro cell 10, updating
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SP349821WO00
of system information is frequently performed. Then, a process on the UE 300 side
occurs each time system information is updated. As a result, the UE 300
increasingly consumes power.
[0132]
5 Thus, in the second modified example of the embodiment, updating of
system information of a frequency band used in the pico cell 20 (i.e., pico system
information) is notified of independently of updating of system information of the
frequency band used in the macro cell 10 (i.e., macro system information). For
example, updating of pico system information is notified of along with resource for
10 pico system information. To be more specific, for example, information
representing updating of pico system information is transmitted along with LPSI.
[0133]
When updating of macro system information together with pico system
information is set to be notified of, if one of the macro system information and pico
15 system information is updated, it is notified of as updating of system information.
Thus, the UE 300 that wirelessly communicates only in the macro cell 10 checks
updating of system information even when only pico system information has been
updated. As a result, a load of the UE 300 increases. Thus, by setting updating of
macro system information to be notified of separately from updating of pico system
20 information as described above, the UE 300 that wirelessly communicates only in the
macro cell 10 can check updating of system information only when the macro system
information has been updated. As a result, the frequency of the UE 300 that
wirelessly communicates only in the macro cell 10 checking updating of system
information can be suppressed.
25 [0134]
<5.2.2. Configurations of respective devices>
Next, configurations of the respective devices according to the second
modified example of the embodiment will be described with reference to FIGS. 17
and 18. Herein, only changes from the first modified example of the embodiment
30 will be described.
[0135]
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SP349821WO00
(Macro eNodeB 100)
- Communication control unit 153
The communication control unit 153 performs notification of updating of
system information. For example, the communication control unit 153 performs
5 notification of macro system information. To be more specific, the communication
control unit 153 performs notification of updating of macro system information using
a paging channel. In addition, the communication control unit 153 performs
notification of updating of macro system information using the SIB 1 of the macro
system information.
10 [0136]
Particularly, in the second modified example of the embodiment, the
communication control unit 153 performs updating of pico system information
independently of updating of macro system information. To be more specific, for
example, the communication control unit 153 does not perform notification of
15 updating of pico system information using the paging channel and the SIB 1.
[0137]
In addition, updating of system information of a frequency band used in the
pico cell 20 (i.e., pico system information), for example, is notified of independently
of updating of system information of a frequency band used in another pico cell 20
20 (i.e., pico system information of another cell 20). In other words, the
communication control unit 153 separately perforins notification of updating of pico
system information for each pico cell 20.
[0138]
In addition, for example, updating of pico system information is notified of
25 along with radio resource used in the downlink transmission of the pico system
information (i.e., resource for the pico system information). In other words, the
communication control unit 153 performs notification of updating of pico system
information along with resource for the pico system information. To be more
specific, for example, the communication control unit 153 transmits information
30 indicating whether or not pico system information has been updated (which will be
referred to hereinafter as "pico system information updating information") to the
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wireless communication unit 120 along with a cell ID and LPSI. Hereinbelow, this
will be described in detail with reference to FIGS. 17 and 18.
[0139J
FIG. 17 is an illustrative diagram for describing an example of information
5 transmitted for notification of updating of system information of a pico cell side.
Referring to FIG. 17, three combinations each having a pico cell ID, LPSI, and pico
system information updating information (UPDATE INFO) are shown. When, for
example, there are three pico cells 20 in the macro cell 10, pico cell IDs, LPSI, and
pico system information updating information of the three respective pico cells 20
10 are transmitted.
[0140]
FIG. 18 is an illustrative diagram for describing an example of
correspondences between pico system information and information transmitted to
notify of updating of the pico system information. Referring to FIG. 18, the
15 correspondences between the combinations of the pico cell IDs, LPSI, and pico
system information updating information shown in FIG. 17 and radio resource
represented by the LPSI are shown. In the radio resource represented by the LPSI,
system information including MIBs and SIBs is transmitted. With the pico system
information updating information of each of the pico cells 20, the UE 300 can know
20 whether or not individual pico system information of each pico cell 20 has been
updated.
[0141]
Note that, as described as the first modified example of the present
embodiment, for example, resource for pico system information are notified of using
25 radio resource for notification that have a predetermined positional relation with
other radio resource that is used in transmission of a predetermined information
block included in macro system information. Thus, updating of the pico system
information is also notified of using the radio resource for notification that have a
predetermined positional relation with the other radio resource that is used in
30 transmission of the predetermined information block. To be specific, for example,
the communication control unit 153 causes the wireless communication unit 120 to
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transmit the pico cell IDs, LPSI, and pico system information updating information
using the radio resource for notification that have the predetermined positional
relation with the other radio resource that is used in transmission of the
predetermined information block.
5 [0142]
As an example, the predetermined information block is, for example, the
SIB 1 of the macro system information. In addition, the predetermined positional
relation is a positional relation that has a predetermined offset with the other radio
resource used in transmission of the predetermined information block in the time
10 direction or the frequency direction. In other words, the communication control
unit 153 causes the wireless communication unit 120 to transmit the pico cell IDs,
LPSI, and pico system information updating information using the radio resource
that have the predetermined offset with the radio resource that is used in transmission
of the SIB 1 of the macro system information.
15 [0143]
(UE 300)
- Control unit 340
The control unit 340 is notified of updating of system information by the
macro eNodeB. For example, the control unit 340 is notified of updating of macro
20 system information. To be more specific, for example, the control unit 340 is
notified of updating of macro system information using a paging channel and the SIB
1 of the macro system information.
[0144]
Particularly in the second modified example of the present embodiment, the
25 control unit 340 is notified of updating of pico system information independently of
updating of the macro system information. To be more specific, for example, the
control unit 340 is not notified of updating of pico system information using the
paging channel and the SIB 1. In addition, for example, the control unit 340 is
separately notified of updating of pico system information for each pico cell 20.
30 [0145]
In addition, for example, the control unit 340 is notified of updating of pico
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system information along with resource for pico system information. To be more
specific, for example, when pico system information updating information is
received by the wireless communication unit 320 along with a cell ID and LPSI, the
control unit 340 acquires the pico system information updating information along
5 with the cell ID and the LPSI.
[0146]
To be more specific, for example, the cell ID, the LPSI, and the pico system
information updating information are transmitted using, for example, radio resource
that have a predetermined positional relation with the radio resource used in
10 transmission of the SIB 1, and then received by the wireless communication unit 320.
Then, the control unit 340 acquires the information transmitted using the radio
resource that has the predetermined positional relation as the pico cell ID, the LSPI,
and the pico system information updating information.
[0147]
15 <5.2.3. Process flow>
Next, an example of a communication control process according to the
second modified example of the embodiment will be described with reference to FIG.
19. FIG. 19 is a sequence diagram showing an example of a schematic flow of the
communication control process according to the second modified example of the
20 embodiment. Here, only Steps S521, S523, S525, and S527 which are differences
between the example of the schematic flow of the communication control process
according to the first modified example shown in FIG. 16 and the example of the
schematic flow of the communication control process according to the second
modified example shown in Fig. 19 will be described.
25 [0148]
In Step S521, the communication control unit 153 of the macro eNodeB 100
causes the wireless communication unit 120 to transmit macro system information in
the macro cell 10. In addition, the communication control unit 153 causes the
wireless communication unit 120 to transmit a pico cell ID, LPSI, and pico system
30 information updating information using radio resource that has a predetermined
offset with radio resource that is used in transmission of the SIB 1 of the macro
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system information. On the other hand, the wireless communication unit 320 of the
UE 300 receives the macro system information, and receives the pico cell ID, the
LPSI, and the pico system information updating information using the radio resource
that has the predetermined offset.
5 [0149]
In Step S523, the control unit 340 of the UE 300 acquires the pico cell ID,
the LPSI, and the pico system information updating information. To be specific, for
example, the control unit 340 acquires information transmitted using the radio
resource that has the predetermined offset with the radio resource used in
10 transmission of the SIB 1 as the pico cell ID, the LPSI, and the pico system
information updating information.
[0150]
In Step S525, the control unit 340 of the UE 300 checks whether or not the
pico system information has been updated from the pico system information updating
15 information.
[0151]
In Step S527, the control unit 340 of the UE 300 checks the updated spot of
the pico system information when the pico system information has been updated.
[0152]
20 «<6. Conclusion»
Hereinabove, the communication devices and processes according to
embodiments of the present disclosure have been described using FIGS. 1 to 19.
According to the embodiments relating to the present disclosure, system information
of a frequency band that is used in the pico cell 20 (i.e., pico system information) is
25 acquired, and downlink transmission of the pico system information in the macro cell
10 is controlled. In addition, the UE 300 that is positioned within the macro cell 10
is notified of radio resource that is used in the downlink transmission of the pico
system information (i.e., resource for the pico system information).
[0153]
30 By notifying the UE 300 of the radio resource in the macro cell 10 and
transmitting the pico system information in the macro cell 10 using the radio
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resource as described above, the UE 300 can acquire the pico system information in
the macro cell 10. In other words, an area in which the pico system information can
be acquired is not limited to the pico cell 20, and expands to the macro cell 10.
Thus, the UE 300 acquires the pico system information of the pico cell 20 before it
5 comes close to the pico cell 20. As a result, a time taken for connection of the UE
300 in the pico cell becomes short. For example, the UE 300 specifies a pico cell
20 based on a PSS and an SSS from limited pico cells 20 which correspond to pico
system information acquired in advance in a cell search. For this reason, a time
necessary for specifying a cell is shortened. In addition, for example, it is not
10 necessary for the UE 300 to receive system information again after the cell search.
For this reason, a time taken for connection in the pico cell 20 is shortened more.
[0154]
In addition, for example, the radio resource that is used in the downlink
transmission of the pico system information (i.e., the resource for the pico system
15 information) is resource of a frequency band that is used in the macro cell 10. In
addition, the resource for the pico system information is resource that is not used in
transmission of the system information of the frequency band that is used in the
macro cell 10.
[0155]
20 Radio resource that is used in transmission of macro system information
(particularly, radio resource that is used in transmission of the MIB and SIB 1) have
no spare bits with which other information is transmitted. Thus, when pico system
information is also transmitted with the radio resource, there can be cases in which
the radio resource is insufficient. That is to say, the radio resource should be
25 expanded. Thus, if macro system information and pico system information are
transmitted separately from each other as described above, there will not be such a
case in which radio resource that is used in transmission of the macro system
information are insufficient. Moreover, there is no need to expand the radio
resource.
30 [0156]
In addition, when macro system information and pico system information
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are transmitted separately from each other and only one of the macro system
information and the pico system information is desired to be acquired, only the one
can be selectively acquired. Thus, it is good for the UE 300 to acquire only
necessary system information, and accordingly, a load of the UE 300 can be
5 suppressed.
[0157]
In addition, if pico system information is included as a part of macro system
information, the frequency of updating the macro system information becomes high.
In other words, when pico system information of any pico cell 20 is updated, the
10 macro system information is updated. As a result, the UE 300 which wirelessly
communicates only in the macro cell 10 checks updating of the system information
more often than necessary, and a load of the UE 300 increases accordingly.
Therefore, by transmitting the macro system information and the pico system
information separately from each other as described above, the frequency of updating
15 the macro system information can be suppressed. As a result, the frequency of the
UE 300 that wirelessly communicates only in the macro cell 10 checking updating of
system information can be suppressed.
[0158]
In addition, for example, the resource for the pico system information are
20 not used in transmission of system information of a frequency band that is used in
another pico cell 20 (i.e., pico system information of another pico cell 20) either.
[0159]
Accordingly, necessary pico system information can be selectively acquired
from pico system information of a plurality of pico cells 20. Thus, it is good for the
25 UE 300 to acquire only necessary pico system information, and accordingly, a load
of the UE 300 can be suppressed.
[0160]
In addition, when pico system information of a plurality of pico cells 20 is
collectively transmitted, if pico system information of any pico cell 20 is updated, the
30 updating of the pico system information is notified of. As a result, the UE 300
checks updating of pico system information each time pico system information of
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any pico cell 20 is updated regardless of whether pico system information of the pico
cell 20 that relates to the device itself is updated. Accordingly, a load of the UE 300
increases. Therefore, by individually transmitting pico system information of each
pico cell 20, a frequency of the UE 300 checking updating of pico system
5 information can be suppressed.
[0161]
In addition, for example, the resource for the pico system information is
resource of a physical downlink shared channel.
[0162]
10 Accordingly, the necessary amount of resource of pico system information
can be secured, and thus even if the number of pico cells 20 increases, pico system
information can be transmitted in the macro cell 10. In addition, if pico system
information is transmitted on a physical downlink shared channel, a UE that need not
acquire pico system information is not affected thereby at all, and therefore it gives
15 no load to the UE.
[0163]
In addition, for example, the resource for the pico system information is
notified of through signaling to the UE 300 that is in a comiection state in the macro
cell 10.
20 [0164]
Accordingly, the resource for the pico system information can be specified
without a special operation of the UE 300 being performed.
[0165]
In addition, for example, a pico cell ID for identifying the pico cell 20 is
25 also notified of, along with the resource for the pico system information.
[0166]
Accordingly, the UE 300 can know corresponding pico system information
of pico cells 20 for all resource for the pico system information that are notified of.
Thus, the UE 300 can easily acquire pico system information of a desired pico cell
30 20.
[0167]
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In addition, for example, pico system information of a frequency band used
in a pico cell 20 is not transmitted in the pico cell.
[0168]
Accordingly, more radio resource can be used in transmission of user data in
5 the pico cell 20.
[0169]
In addition, according to the first modified example of the embodiment
relating to the present disclosure, resource for pico system information are notified of
using radio resource for notification that has a predetermined positional relation with
10 other radio resource that is used in transmission of a predetermined information
block included in macro system information.
[0170]
Even a UE 300 that is not in a connection state in the macro cell 10 can
acquire system information of the macro cell 10. Thus, according to the first
15 modified example, when acquiring the predetermined information block, the UE 300
that is not in a connection state in the macro cell 10 can acquire information
transmitted with radio resource that has the predetermined positional relation with
the radio resource for transmission of the information block as information
representing the resource for pico system information (i.e., LPSI). Then, the UE
20 300 can acquire information transmitted with the resource for the pico system
information represented by the information as pico system information. In other
words, the UE 300 can acquire pico system information even when the UE is not in a
connection state in the macro cell 10.
[0171]
25 In addition, for example, the other radio resource that is used in the
transmission of the predetermined information block included in the macro system
information is resource positioned within a predetermined range in a time direction
and a frequency direction.
[0172]
30 When the position of the radio resource used in transmission of the
information block (for example, the SIB 1) significantly changes, the radio resource
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that has the predetermined positional relation (for example, the radio resource used in
transmission of the LPSI) are not necessarily radio resource that can be freely used.
For example, there is also a possibility of the radio resource that has the
predetermined positional relation being radio resource to be used in transmission of
5 another information block or other important control information. Thus, if the radio
resource used in transmission of the information block is resource for transmission at
a semi-fixed position as described above, the predetermined positional relation can
be set so that the radio resource that has the predetermined positional relation is
freely usable resource.
10 [0173]
In addition, for example, the predetermined positional relation is a
positional relation that has a predetermined offset with the other radio resource in the
time direction or the frequency direction.
[0174]
15 Accordingly, the UE 300 can easily specify the position of the radio
resource that has the predetermined positional relation (for example, the radio
resource used in transmission of the LPSI) from the position of the radio resource
used in transmission of the information block (for example the SIB 1).
[0175]
20 In addition, according to a third modified example of the embodiment
relating to the present disclosure, updating of system information of a frequency
band used in a pico cell 20 (i.e., pico system information) is notified of
independently of updating of system information of the frequency band used in a
macro cell 10 (i.e., macro system information).
25 [0176]
When updating of macro system information and pico system information
are collectively notified of, if one of the macro system information and the pico
system information is updated, it is notified of as updating of system information.
Thus, the UE 300 that wirelessly communicates only in the macro cell 10 checks the
30 updating of system information even when only the pico system information is
updated. As a result, a load of the UE 300 increases. Thus, by notifying of
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SP349821WO00
updating of the macro system information and updating of the pico system
information separately from each other as described above, the UE 300 that
wirelessly communicates only in the macro cell 10 can check updating of system
information only when the macro system information has been updated. As a result,
5 the frequency of the UE 300 that wirelessly communicates only in the macro cell 10
checking updating of system information can be suppressed.
[0177]
In addition, for example, updating of system information of a frequency
band used in a pico cell 20 (i.e., pico system information) is notified of
10 independently of updating of system information of a frequency band used in another
pico cell 20 (i.e., pico system information of another cell 20).
[0178]
When updating of pico system information of a plurality of pico cells 20 is
collectively notified of, if pico system information of any pico cell 20 among the
15 plurality of pico cells 20 is updated, it is notified of as updating of system
information. Thus, the UE 300 checks updating of pico system information even
when pico system information of a pico cell 20 that is irrelevant to the device itself
has been updated. As a result, a load of the UE 300 increases. Thus, as updating
of pico system information of each pico cell 20 is individually notified of, the UE
20 300 can check updating of system information only when pico system information of
a pico cell 20 that relates to the device itself has been updated. As a result, the
frequency of the UE 300 checking updating of system information can be suppressed.
[0179]
In addition, for example, updating of pico system information is notified of
25 along with radio resource used in the downlink transmission of the pico system
information (i.e., resource for the pico system information).
[0180]
Accordingly, it is possible to check whether or not the pico system
information has been updated like the pico system information resource.
30 [0181]
The preferred embodiments of the present disclosure have been described
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SP349821WO00
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 art may find
various alterations 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
5 present disclosure.
[0182]
Although, for example, the example in which the LPSI and the pico system
information updating information are transmitted using radio resource that has a
predetermined offset with radio resource used in transmission of the SIB 1 has been
10 described in the second modified example as in the first modified example, the
present disclosure is not limited thereto. For example, the LPSI and the pico system
information updating information may be transmitted through RRC signaling.
[0183]
In addition, although the example in which one frequency band is used in
15 each of a macro cell and a pico cell has been described as an example, the present
disclosure is not limited thereto. A plurality of frequency bands may be used in one
or both of the macro cell and pico cell. As an example, a carrier application may be
applied to a pico cell. In addition, system information of each CC used in a pico
cell may be transmitted using a frequency band used in a macro cell. In addition,
20 pico system information of each of CCs may be collectively transmitted in units of
pico cells. In such a case, LPSI may represent the position of radio resource used to
collectively transmit the pico system information in units of pico cells.
Alternatively, pico system information of each of CCs may be individually
transmitted in units of CCs. In this case, the LPSI may represent the position of the
25 radio resource used to individually transmit the pico system information in units of
CCs. Note that, as another example, a carrier application may be applied to a macro
cell. In addition, system information of a frequency band used in a pico cell may be
transmitted using any CC used in a macro cell.
[0184]
30 In addition, although the example in which a CC used in a macro cell is a
frequency band of the 2 MHz band and a frequency band used in a pico cell is a
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frequency band of the 5 GHz band has been described as an example, the present
disclosure is not limited thereto. For example, a frequency band of the same band
(for example, the 2 GHz band) may be used in both of a macro cell and a pico cell.
In addition, a frequency band used in a macro cell and a frequency band used in a
5 pico cell may be different frequency bands, or the same frequency band.
[0185]
In addition, although the example in which the macro eNodeB and the pico
eNodeB perform wired communication has been described, the present disclosure is
not limited thereto. Instead of wired communication, wireless communication (for
10 example, microwave communication) may be performed.
[0186]
In addition, although the example in which the pico eNodeB is a normal
eNodeB has been described, the present disclosure is not limited thereto. The pico
eNodeB may be implemented as an RRH. In such a case, for example, a control
15 unit of the pico eNodeB may be provided in a macro eNodeB or another
communication control device.
[0187]
In addition, the macro eNodeB may be configured by a plurality of devices
rather than one device. For example, the macro eNodeB may include a
20 communication control device that includes at least a control unit as one of the
plurality of devices.
[0188]
In addition, although the example of the wireless communication system
based on LTE has been described, the present disclosure is not limited thereto. The
25 technology relating to the present disclosure can also be applied to a wireless
communication system of another communication standard in which transmission of
system information is performed. Also, although description has been provided
using the eNodeB as an example of a base station and the UE as an example of a
terminal device, the present disclosure is not limited thereto. The technology
30 relating to the present disclosure can also be applied to a base station and a terminal
device that are based on another communication standard.
SP349821WO00
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[0189]
In addition, although the example in which a small cell that is partially or
entirely overlapped by a macro cell is a pico cell lias been described, the present
disclosure is not limited thereto. The small cell may be, for example, a femto cell, a
5 nano cell, or a micro cell.
[0190]
Also, the processing steps in a communication control process in this
specification are not strictly limited to being executed in a time series following the
sequence described in a flowchart. For example, the processing steps in a
10 communication control process may be executed in a sequence that differs from a
sequence described herein as a flowchart, and furthermore may be executed in
parallel.
[0191]
In addition, it is possible to create a computer program for causing hardware
15 such as a CPU, ROM, and RAM built into a communication control device or a
terminal device to exhibit functions similar to each structural element of the
foregoing communication control device or terminal device.
[0192]
Additionally, the present technology may also be configured as below.
20 (1)
A communication control device including:
an acquisition unit configured to acquire system information of a frequency
band that is used in a small cell that is partially or entirely overlapped by a macro
cell; and
25 a control unit configured to control downlink transmission of the system
information in the macro cell,
wherein the control unit notifies a terminal device positioned within the
macro cell of radio resource that is used in the downlink transmission.
(2)
30 The communication control device according to (1), wherein the radio
resource is resource of a frequency band that is used in the macro cell and the
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resource that is not used in transmission of the system information of the frequency
band.
(3)
The communication control device according to (2), wherein the radio
5 resource is not used in transmission of system information of a frequency band that is
used in another small cell either.
(4)
The communication control device according to (2) or (3), wherein the radio
resource is resource of a physical downlink shared channel.
10 (5)
The communication control device according to any one of (2) to (4),
wherein updating of the system information of the frequency band that is used in the
small cell is notified of independently of updating of the system information of the
frequency band that is used in the macro cell.
15 (6)
The communication control device according to (5), wherein updating of the
system information of the frequency band that is used in the small cell is also notified
of independently of updating of system information of a frequency band that is used
in another small cell.
20 (7)
The communication control device according to (5) or (6), wherein, for the
updating of the system information of the frequency band that is used in the small
cell, information pertaining to the updating is notified of along with the radio
resource.
25 (8)
The communication control device according to any one of (2) to (7),
wherein the radio resource is notified of using radio resource for notification that has
a predetermined positional relation with another radio resource that is used in
transmission of a predetermined information block included in the system
30 information of the frequency band used in the macro cell.
(9)
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The communication control device according to (8), wherein the another
radio resource is resource positioned within a predetermined range in a time direction
and a frequency direction.
(10)
5 The communication control device according to (8) or (9), wherein the
predetermined positional relation is a positional relation that has a predetermined
offset with the another radio resource in a time direction or a frequency direction.
( i i)
The communication control device according to any one of (2) to (7),
10 wherein the radio resource is notified of through signaling to a terminal device that is
in a connection state in the macro cell.
(12)
The communication control device according to any one of (2) to (11),
wherein the control unit also notifies small cell identification information for
15 identifying the small cell along with the radio resource.
(13)
The communication control device according to any one of (1) to (12),
wherein the system information of the frequency band that is used in the small cell is
not transmitted in the small cell.
20 (14)
A program causing a computer to function as:
an acquisition unit configured to acquire system information of a frequency
band that is used in a small cell that is partially or entirely overlapped by a macro
cell; and
25 a control unit configured to control downlink transmission of the system
information in the macro cell,
wherein the control unit notifies a terminal device positioned within the
macro cell of radio resource that is used in the downlink transmission.
(15)
30 A communication control method including:
acquiring system information of a frequency band that is used in a small cell
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that is partially or entirely overlapped by a macro cell;
controlling downlink transmission of the system information in the macro
cell; and
notifying a terminal device positioned within the macro cell of radio
5 resource that is used in the downlink transmission.
(16)
A communication control device including:
a generation unit configured to generate system information of a frequency
band that is used in a small cell that is partially ore entirely overlapped by a macro
10 cell; and
a provision unit configured to provide the system information to the device
that is a device controlling downlink transmission of the system information in the
macro cell and notifying a terminal device positioned within the macro cell of radio
resource that is used in the downlink transmission.
15 (17)
A program causing a computer to function as:
a generation unit configured to generate system information of a frequency
band that is used in a small cell that is partially or entirely overlapped by a macro
cell; and
20 a provision unit configured to provide the system information to a device
that is a device controlling downlink transmission of the system information in the
macro cell and notifying a terminal device positioned within the macro cell of radio
resource that is used in the downlink transmission.
(18)
25 A communication control method including:
generating system information of a frequency band that is used in a small
cell that is partially or entirely overlapped by a macro cell; and
providing the system information to a device that is a device controlling
downlink transmission of the system information in the macro cell and notifying a
30 terminal device positioned within the macro cell of radio resource that is used in the
downlink transmission.
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(19)
A terminal device including:
a wireless communication unit configured to receive system information of
a frequency band that is used in a small cell that is partially or entirely overlapped by
5 a macro cell when the terminal device is positioned within the macro cell; and
an acquisition unit configured to acquire information transmitted using radio
resource as the system information when the terminal device is positioned within the
macro cell and the radio resource that is used in downlink transmission of the system
information is notified of.
10 (20)
A communication control method including:
receiving system information of a frequency band that is used in a small cell
that is paitially or entirely overlapped by a macro cell when a terminal device is
positioned within the macro cell; and
15 acquiring information transmitted using radio resource as the system
information when the terminal device is positioned within the macro cell and the
radio resource that is used in downlink transmission of the system information is
notified of.
20 Reference Signs List
[0193]
10
20
100
110
120
130
140
150
151
153
macro cell
pico cell
macro cNodeB
antenna unit
wireless communication unit
network control unit
storage unit
control unit
information acquisition unit
communication control unit
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200
210
220
230
240
250
251
253
300
310
320
330
340
pico eNodeB
antenna unit
wireless communication unit
network control unit
storage unit
control unit
communication control unit
information provision unit
pico eNodeB
antenna unit
wireless communication unit
storage unit
control unit

CLAIMS
Claim 1
A communication control device comprising:
an acquisition unit configured to acquire system information of a frequency
5 band that is used in a small cell that is partially or entirely overlapped by a macro
cell; and
a control unit configured to control downlink transmission of the system
information in the macro cell,
wherein the control unit notifies a terminal device positioned within the
10 macro cell of radio resource that is used in the downlink transmission.
Claim 2
The communication control device according to claim 1, wherein the radio
resource is resource of a frequency band that is used in the macro cell and the
15 resource that is not used in transmission of the system information of the frequency
band.
Claim 3
The communication control device according to claim 2, wherein the radio
20 resource is not used in transmission of system information of a frequency band that is
used in another small cell either.
Claim 4
The communication control device according to claim 2, wherein the radio
25 resource is resource of a physical downlink shared channel.
Claim 5
The communication control device according to claim 2, wherein updating
of the system information of the frequency band that is used in the small cell is
30 notified of independently of updating of the system information of the frequency
band that is used in the macro cell.
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Claim 6
The communication control device according to claim 5, wherein updating
of the system information of the frequency band that is used in the small cell is also
5 notified of independently of updating of system information of a frequency band that
is used in another small cell.
Claim 7
The communication control device according to claim 5, wherein, for the
10 updating of the system information of the frequency band that is used in the small
cell, information pertaining to the updating is notified of along with the radio
resource.
Claim 8
15 The communication control device according to claim 2, wherein the radio
resource is notified of using radio resource for notification that has a predetermined
positional relation with another radio resource that is used in transmission of a
predetermined information block included in the system information of the frequency
band used in the macro cell.
20
Claim 9
The communication control device according to claim 8, wherein the
another radio resource is resource positioned within a predetermined range in a time
direction and a frequency direction.
25
Claim 10
The communication control device according to claim 8, wherein the
predetermined positional relation is a positional relation that has a predetermined
offset with the another radio resource in a time direction or a frequency direction.
30
Claim 11
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The communication control device according to claim 2, wherein the radio
resource is notified of through signaling to a terminal device that is in a connection
state in the macro cell.
5 Claim 12
The communication control device according to claim 2, wherein the control
unit also notifies small cell identification information for identifying the small cell
along with the radio resource.
10 Claim 13
The communication control device according to claim 1, wherein the system
information of the frequency band that is used in the small cell is not transmitted in
the small cell.
15 Claim 14
A program causing a computer to function as:
an acquisition unit configured to acquire system information of a frequency
band that is used in a small cell that is partially or entirely overlapped by a macro
cell; and
20 a control unit configured to control downlink transmission of the system
information in the macro cell,
wherein the control unit notifies a terminal device positioned within the
macro cell of radio resource that is used in the downlink transmission.
25 Claim 15
A communication control method comprising:
acquiring system information of a frequency band that is used in a small cell
that is partially or entirely overlapped by a macro cell;
controlling downlink transmission of the system information in the macro
30 cell; and
notifying a terminal device positioned within the macro cell of radio
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resource that is used in the downlink transmission.
Claim 16
A communication control device comprising:
5 a generation unit configured to generate system information of a frequency
band that is used in a small cell that is partially ore entirely overlapped by a macro
cell; and
a provision unit configured to provide the system information to the device
that is a device controlling downlink transmission of the system information in the
10 macro cell and notifying a terminal device positioned within the macro cell of radio
resource that is used in the downlink transmission.
Claim 17
A program causing a computer to function as:
15 a generation unit configured to generate system information of a frequency
band that is used in a small cell that is partially or entirely overlapped by a macro
cell; and
a provision unit configured to provide the system information to a device
that is a device controlling downlink transmission of the system information in the
20 macro cell and notifying a terminal device positioned within the macro cell of radio
resource that is used in the downlink transmission.
Claim 18
A communication control method comprising:
25 generating system information of a frequency band that is used in a small
cell that is partially or entirely overlapped by a macro cell; and
providing the system information to a device that is a device controlling
downlink transmission of the system information in the macro cell and notifying a
terminal device positioned within the macro cell of radio resource that is used in the
30 downlink transmission.
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Claim 19
A terminal device comprising:
a wireless communication unit configured to receive system information of
a frequency band that is used in a small cell that is partially or entirely overlapped by
5 a macro cell when the terminal device is positioned within the macro cell; and
an acquisition unit configured to acquire information transmitted using radio
resource as the system information when the terminal device is positioned within the
macro cell and the radio resource that is used in downlink transmission of the system
information is notified of.
10
Claim 20
A communication control method comprising:
receiving system mformation of a frequency band that is used in a small cell
(hat is partially or entirely overlapped by a macro cell when a terminal device is
15 positioned within the macro cell; and
acquiring information transmitted using radio resource as the system
information when the terminal device is positioned within the macro cell and the
radio resource that is used in downlink transmission of the system information is
notified of.