FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
“TRANSMISSION DEVICE, TRANSMISSION METHOD, RECEIVING DEVICE AND
RECEIVING METHOD”
SONY CORPORATION, of 1-7-1, Konan, Minato-ku, Tokyo 108-0075, Japan
The following specification particularly describes the invention and the manner in which it is to
be performed.
2
DESCRIPTION
TRANSMISSION DEVICE, TRANSMISSION METHOD, RECEPTION DEVICE,
AND RECEPTION METHOD
5 TECHNICAL FIELD
[0001]
The present technology relates to a transmission device,
a transmission method, a reception device, and a reception
method, and is particularly related to a transmission device,
10 a transmission method, a reception device, and a reception
method that are capable of executing a process related to
emergency warning information in DVB-T2 standard more quickly
at a low power consumption.
15 BACKGROUND ART
[0002]
Digital video broadcasting-terrestrial (DVB-T)
standard has been used as a terrestrial digital broadcasting
standard in Europe and all over the world. Further, these
20 days the DVB-T2 standard, which is an improved version of the
DVB-T standard, has been in practical use (for example, see
Non-Patent Document 1).
[0003]
Further, an emergency warning system (EWS) has been
25 defined as a method for sending a warning in a case of emergency
such as natural disasters or the like including earthquakes
and tsunami (for example, see Patent Document 1).
CITATION LIST
30 PATENT DOCUMENT
[0004]
3
Patent Document 1: Japanese Patent Application Laid-Open No.
2008-148230
NON-PATENT DOCUMENT
[0005]
Non-Patent Document 1: Digital Video Broadcasting 5 (DVB); Frame
structure channel coding and modulation for a second generation
digital terrestrial television broadcasting system (DVB-T2)
SUMMARY OF THE INVENTION
10 PROBLEMS TO BE SOLVED BY THE INVENTION
[0006]
Here, an Emergency Warning System has been also
introduced in the DVB standard and there is a demand to execute
a process related to emergency alert information more quickly
15 at a low power consumption.
[0007]
The present technology has been made in view of the above
situation and realizes an execution of a process related to
emergency warning information in the DVB-T2 standard more
20 quickly at a low power consumption.
SOLUTIONS TO PROBLEMS
[0008]
A transmission device according to a first aspect of
25 the present technology includes: an emergency warning
information acquisition unit configured to acquire emergency
warning information; a content acquisition unit configured
to acquire a content; a transmission frame generation unit
configured to generate a transmission frame that includes
30 emergency warning notification information indicating that
the emergency warning information is being transmitted in P1
4
signaling or L1-pre signaling, as a transmission frame,
according to the digital video broadcasting-terrestrial 2
(DVB-T2) standard, composed of a first preamble signal of the
P1 signaling, a second preamble signal of the L1-pre signaling,
and the content data; and a transmission 5 unit configured to
transmit the transmission frame as a digital broadcast signal.
[0009]
When included in the L1-pre signaling, the emergency
warning notification information may be placed in a reserved
10 bit of the L1-pre signaling.
[0010]
The emergency warning notification information may be
a 1-bit emergency warning flag, and the emergency warning
information may be transmitted using service information (SI)
15 information, an auxiliary stream, or a particular physical
layer pipe (PLP) which are defined in the DVB-T2 standard.
[0011]
When included in the P1 signaling, the emergency warning
notification information may be placed in a reserved bit of
20 the P1 signaling.
[0012]
the emergency warning notification information may be
a particular bit sequence, and the emergency warning
information may be transmitted using SI information, an
25 auxiliary stream, or a particular PLP which are defined in
the DVB-T2 standard.
[0013]
A signaling generation unit configured to generate the
P1 signaling and the L1-pre signaling may be further included.
30 [0014]
The transmission device may be an independent device
5
or an internal block that composes a device.
[0015]
The transmission method according to a first aspect of
the present technology is a transmission method for the
transmission device according to the first aspect 5 of the above
described present technology.
[0016]
In the transmission device and transmission method
according to the first aspect of the present technology,
10 emergency warning information is acquired, a content is
acquired, a transmission frame including emergency warning
notification information indicating the emergency warning
information is being transmitted in the P1 signaling or the
L1-pre signaling, as a transmission frame according to the
15 DVB-T2 standard, composed of a first preamble signal including
the P1 signaling, a second preamble signal including the L1-pre
signaling, and the content data, and the transmission frame
is transmitted as a digital broadcast signal.
[0017]
20 A reception device according to a second aspect of the
present technology includes: a reception unit configured to
receive, as a digital broadcast signal, a transmission frame,
according to DVB-T2 standard, composed of a first preamble
signal including P1 signaling, a second preamble signal
25 including L1-pre signaling, and content data; and a
demodulation unit configured to demodulate the first preamble
signal, or the first preamble signal and the second preamble
signal and monitor emergency warning notification information
indicating that emergency warning information is being
30 transmitted in the P1 signaling included in the first preamble
signal or the L1-pre signaling included in the second preamble
6
signal.
[0018]
When included in the L1-pre signaling, the emergency
warning notification information may be placed in a reserved
bit of the 5 L1-pre signaling.
[0019]
The emergency warning notification information may be
a 1-bit emergency warning flag, the emergency warning
information may be transmitted using SI information, an
10 auxiliary stream, or a particular PLP which are defined by
the DVB-T2 standard, and a control unit configured to be
activated when the emergency warning notification information
indicates that the emergency warning information is being
transmitted, and acquire the emergency warning information
15 transmitted using the SI information, the auxiliary stream,
or the particular PLP may be further included.
[0020]
When included in the P1 signaling, the emergency warning
notification information may be placed in a reserved bit of
20 the P1 signaling.
[0021]
The emergency warning notification information may be
a particular bit sequence, the emergency warning information
may be transmitted using SI information, an auxiliary stream,
25 or a particular PLP, which are defined in the DVB-T2 standard,
and a control unit configured to be activated when the emergency
warning notification information indicates that the emergency
warning information is being transmitted, and acquire the
emergency warning information transmitted using the SI
30 information, the auxiliary stream, or the particular PLP may
be further included.
7
[0022]
The reception device may be an independent device or
an internal block that composes a device.
[0023]
The reception method according to 5 a second aspect of
the present technology is a reception method for the reception
device according to the second aspect of the above described
present technology.
[0024]
10 In the reception device and reception method according
to the second aspect of the present technology, a transmission
frame according to the DVB-T2 standard, which is composed of
a first preamble signal including P1 signaling, a second
preamble signal including L1-pre signaling, and content data
15 is received as a digital broadcast signal, the first preamble
signal, or the first preamble signal and the second preamble
signal are demodulated, and emergency warning notification
information indicating that emergency warning information is
being transmitted is monitored in the P1 signaling included
20 in the first preamble signal or the L1-pre signaling included
in the second preamble signal.
EFFECTS OF THE INVENTION
[0025]
25 According to the first aspect and second aspect of the
present technology, a process related to emergency warning
information can be executed in the DVB-T2 standard more quickly
at a low power consumption.
[0026]
30 Here, the above described effects are not always limited
and may be any one of the effects described in this disclosure.
8
BRIEF DESCRIPTION OF DRAWINGS
[0027]
Fig. 1 is a diagram to explain an outline of an Emergency
Warning System according 5 to DVB standard.
Fig. 2 is a diagram illustrating a format of a T2 frame.
Fig. 3 is a diagram illustrating a detailed configuration
of L1-pre signaling.
Fig. 4 is a diagram to explain power consumption in a
10 case that an L1-pre signaling transmission method is employed.
Fig. 5 is a diagram to explain processing speed in a
case that the L1-pre signaling transmission method is employed.
Fig. 6 is a diagram illustrating a transmission method
of an auxiliary stream.
15 Fig. 7 is a diagram illustrating a loop of the auxiliary
stream included in L1-post signaling.
Fig. 8 is a diagram illustrating a configuration example
of AUX_STREAM_TYPE.
Fig. 9 is a diagram illustrating a format of a T2 frame.
20 Fig. 10 is a diagram illustrating a detailed
configuration of an S1 field.
Fig. 11 is a diagram illustrating a detailed
configuration of an S2 field.
Fig. 12 is a diagram illustrating a detailed
25 configuration of the S1 field.
Fig. 13 is a diagram illustrating a detailed
configuration of the S2 field.
Fig. 14 is a diagram illustrating a detailed
configuration of the S1 field.
30 Fig. 15 is a diagram to explain power consumption in
a case that a P1 signaling transmission method is employed.
9
Fig. 16 is a diagram to explain a transmission using
a particular PLP.
Fig. 17 is a diagram to explain a configuration example
of an emergency warning information transmission system to
which the present technology 5 is applied.
Fig. 18 is a diagram illustrating a configuration example
of a transmission device.
Fig. 19 is a diagram illustrating a configuration example
of a reception device.
10 Fig. 20 is a flowchart to explain a flow of an emergency
warning information transmission process.
Fig. 21 is a flowchart to explain a flow of an emergency
warning information reception process.
Fig. 22 is a diagram illustrating a configuration example
15 of a computer.
MODE FOR CARRYING OUT THE INVENTION
[0028]
Hereinafter, embodiments of the present technology will
20 be explained with reference to the drawings. Here, the
explanation will be made in the following order.
[0029]
1. Outline of Emergency Warning System
2. First embodiment (L1-pre signaling transmission method)
25 3. Second embodiment (P1 signaling transmission method)
4. System configuration
5. Process flow in each device
6. Computer configuration
[0030]
30 <1. Outline of Emergency Warning System>
[0031]
10
People's lives are exposed to various dangerous events
such as natural disasters including earthquakes, tsunami
caused by earthquakes, typhoons, heavy rains, stormy winds,
tornados, floods, and wildfire. When such an event occurs,
emergency warning information needs to be 5 informed to people
as soon as possible to urge them to evacuate. Emergency warning
information in case of a natural disaster is provided by a
government agency for example. Further, for the notification
of emergency warning information, broadcasting service may
10 be used.
[0032]
Fig. 1 is a diagram illustrating an outline of emergency
warning system (DVB-EWS) of DVB standard. Fig. 1
schematically illustrates current service and announcement
15 service provided by digital broadcasting according to the DVB
standard.
[0033]
As the current service, video and sound streams, which
compose content such as a program, are transmitted by a
20 transmitter. With this, a receiver can output the video and
sound of the program. In the announcement service, a
transmitter can transmit sound data for example as emergency
warning information using service information (SI)
information.
25 [0034]
Here, in the receiver, an announcement flag (AF) in a
TS header (TS HDR) in the announcement service is monitored
while video and sound streams of a normal program as a current
service are being received. Then, when the announcement flag
30 changes from "0" to "1," the announcement service becomes
active and the sound stream of the normal program received
11
by the receiver is switched to sound data of the emergency
warning information.
[0035]
With this, warning in an emergency of a natural disaster
such has earthquake and tsunami for example 5 can be given to
a user near the receiver. Here, the sound data of the emergency
warning information is kept received while the announcement
flag is "1," then, is ended when the announcement flag returns
to "0," and switched to the sound stream of the normal program.
10 [0036]
The Emergency Warning System according to the DVB
standard (DVB-EWS) has been performed as described above and,
since the SI information is transmitted in an level upper than
a physical layer, the receiver cannot obtain the emergency
15 warning information until the signal passes a system on a chip
(SoC) which is provided at a later part of a tuner and a
demodulator (demodulation unit). Thus, a certain period of
time has been needed until analysis of the emergency warning
information is completed. Further, since the analysis of the
20 emergency warning information cannot be executed without
operating the system on a chip, this increases the power
consumption by a corresponding amount. Specifically, since
the system on a chip consumes much power, it is preferable
to suppress the power consumption as much as possible.
25 [0037]
In this manner, in the Emergency Warning System according
to the DVB standard, there has been a demand to execute a process
related to the emergency alert information more promptly and
at a low power consumption. In view of the above, according
30 to the present technology, the following two methods will be
proposed to realize an execution of the process related to
12
the emergency warning information according to the DVB-T2
standard more promptly and at a lower power consumption. Here,
to distinguish from the two methods of the present technology,
the method of the Emergency Warning System according to the
DVB standard in Fig. 1 will be referred to as a 5 "DVB-EWS existing
method" in the following explanation.
[0038]
<2. First embodiment>
[0039]
10 In the first embodiment, a method for placing, in the
L1-pre signaling, emergency warning notification information
indicating that emergency warning information is being
transmitted to transmit (hereinafter, referred to as an "L1-pre
signaling transmission method") will be explained.
15 [0040]
(T2 frame)
Fig. 2 is a diagram illustrating a format of a T2 frame.
[0041]
According to the DVB-T2 standard, a frame called T2 frame
20 is defined and data is transmitted in the unit of T2 frames.
The T2 frame includes two types of preamble signals called
P1 and P2, and the preamble signals include information
required in a process such as demodulation of an orthogonal
frequency division multiplexing (OFDM) signal.
25 [0042]
In the T2 frame, a P1 symbol, a P2 symbol, and data symbols
are included in order.
[0043]
The P1 symbol is a symbol to transmit P1 signalling and,
30 in the P1 signaling, a transmission type and basic transmission
parameters are included.
13
[0044]
The P2 symbol is a symbol to transmit L1-pre signalling
and L1-post signalling. The L1-pre signaling includes
information required by the receiver which receives the T2
frame to receive and decode the L1-post signaling. 5 The L1-post
signaling includes a parameter required by the receiver to
access a physical layer pipes (PLP).
[0045]
The L1-post signaling is composed of two types of a
10 configurable field and a dynamic field, and an optional
extension field is prepared. Further, a cyclic redundancy
check (CRC) and L1 padding are placed in order.
[0046]
Here, according to the DVB-T2 standard, a frame, which
15 is called a future extension frame (FEF), having a structure
different from the T2 frame is multiplexed and transmitted
in a temporal direction between the T2 frames to be transmitted.
[0047]
Further, as the T2 frame, there are two types, which
20 are a T2-base frame for a receiver such as a fixed television
and a T2-Lite frame for a receiver such as a mobile device,
they are classified according to profiles, and the structures
of the T2 frames are in common regardless of the types of the
profile.
25 [0048]
(L1-pre signaling)
Fig. 3 is a diagram illustrating a detailed configuration
of the L1-pre signaling of Fig. 2.
[0049]
30 Fig. 3 illustrates information included in the L1-pre
signaling. TYPE is an 8-bit field that defines a type of a
14
stream to be transmitted. BWT_EXT is a 1-bit field that defines
whether or not an expansion career mode is used. S1 is a 3-bit
field that defines a value same as an S1 field of the P1 signaling.
S2 is a 4-bit field that defines a value same as an S2 field
of 5 the P1 signaling.
[0050]
L1_REPETITION_FLAG is a 1-bit field that defines a
provision of the dynamic field of the L1-post signaling.
GUARD_INTERVAL is a 3-bit field that defines a guard interval.
10 PAPR is a 4-bit field that defines a peak to average power
ratio (PAPR). L1_MOD is a 4-bit field that defines a
constellation of the L1-post signaling. L1_COD is a 2-bit
field that defines a code rate of the L1-post signaling.
[0051]
15 L1_FEC_TYPE is a 2-bit field that defines a type of a
forward error correction (FEC) of the L1-post signaling.
L1_POST_SIZE is an 18-bit field that defines a size of a data
block of encoded and modulated L1-post signaling.
L1_POST_INFO_SIZE is an 18-bit field that defines a size of
20 a part of information in the data block of the L1-post signaling.
PILOT_PATTERN is a 4-bit field that defines a type of a pilot
pattern of an OFDM symbol. TX_ID_AVAILABILITY is an 8-bit
field that defines an availability of a transmitter ID.
[0052]
25 CELL_ID is a 16-bit field that defines a cell ID for
identifying a geographical cell in a DVB network. NETWORK_ID
is a 16-bit field that defines a network ID for identifying
the current DVB network. T2_SYSTEM_ID is a 16-bit field that
defines a T2 system ID for identifying a T2 system in the DVB
30 network identified by the network ID.
[0053]
15
NUM_T2_FRAMES is an 8-bit field that defines the number
of T2 frames of each super frame composed of a T2 frame and
an FEF. NUM_DATA_SYMBOLS is a 12-bit field that defines the
number of OFDM symbols in each T2 frame. REGEN_FLAG is a 3-bit
field that defines the number of regeneration 5 of the signal
according to the DVB-T2 standard. L1_POST_EXTENSION is a
1-bit filed that defines an existence of an extension field
of the L1-post signaling.
[0054]
10 NUM_RF is a 3-bit field that defines a frequency of the
current T2 system. CURRENT_RF_IDX is a 3-bit field that
defines an index of the current RF channel when time frequency
slicing (TFS) is supported. T2_VERSION is a 4-bit field that
defines a latest version related to a transmission signal.
15 L1_POST_SCRAMBLED is a 1-bit field that defines whether the
L1-post signaling is being scrambled. T2_BASE_LITE is a 1-bit
field that defines whether the profile of the current T2-base
frame is compatible with the profile of the T2-Lite frame.
[0055]
20 RESERVED is a 4-bit field for future expansion. In the
L1-pre signaling transmission method, one of the four reserved
bits is allocated to emergency warning notification
information (an emergency warning flag) that indicates that
emergency warning information is being transmitted and other
25 three bits are used as reserved bits. The name of the 1-bit
emergency warning flag may be, for example,
"EMERGENCY_WARNING"; however, other names may be employed.
CRC-32 is a 32-bit field that defines an error-detecting code
of the L1-pre signaling.
30 [0056]
As described above, in the L1-pre signaling transmission
16
method, since a 1-bit emergency warning flag (emergency warning
notification information) is placed in the reserved bit of
the L1-pre signaling, the receiver can monitor the emergency
warning flag and acquires and output emergency warning
information transmitted from the transmitter 5 when the
emergency warning flag changes from "0" to "1" for example.
[0057]
(Comparison between DVB-EWS existing method and L1-pre
signaling transmission method)
10 Next, with reference to Figs. 4 and 5, power consumption
and processing speed in the DVB-EWS existing method and L1-pre
signaling transmission method are compared. Here, the
receiver which is capable of receiving a digital broadcasting
signal according to the DVB-T2 standard is generally composed
15 of three chips of a tuner, a demodulator (demodulation unit),
and a system on a chip (SoC).
[0058]
In Fig. 4, when the DVB-EWS existing method (Fig. 1)
is employed, the receiver cannot monitor (analyze) an
20 announcement flag (AF) until signals are supplied to the system
on a chip (SoC) which is provided at a section later than the
tuner and demodulation unit. In this case, the receiver
consumes hundreds of mW to activate the tuner and demodulation
unit respectively and also consumes power of several W to the
25 system on a chip.
[0059]
On the other hand, when the L1-pre signaling transmission
method (Figs. 2 and 3) is employed, the demodulation unit
demodulates P1 and P2 symbols that compose the T2 frame and
30 monitors (analyzes) an emergency warning flag
(EMERGENCY_WARNING) placed in the reserved bit of the L1-pre
17
signaling included in the P2 symbol. In this case, since the
demodulation unit before the system on a chip (SoC) monitors
(analyzes) the emergency warning flag, only power of several
dozens of mW is consumed to activate the tuner and demodulation
unit, and the system on a chip with a high 5 power consumption
does not have to be activated. Here, in this case, the power
consumption of the tuner and demodulation unit can be reduced
by executing a time splitting operation.
[0060]
10 In this manner, to monitor (analyze) the announcement
flag (SI information), the system on a chip with a high power
consumption needs to be activated in DVB-EWS existing method;
however, in the L1-pre signaling transmission method, the
system on a chip does not need to be activated to monitor the
15 emergency warning flag placed in the reserved bit of L1-pre
signaling and this reduces the power consumption.
[0061]
With this, since the receiver basically needs to
demodulate the P1 symbol to demodulate the P2 symbol, the
20 demodulation unit can monitor (analyze) the emergency warning
flag placed in the reserved bit of L1-pre signaling included
in the P2 symbol when the P1 and P2 symbols composing the T2
frame are received, and operate in a mode to be in a sleep
state (a low power consumption mode) when symbols of other
25 data are received. Then, when the emergency warning flag
placed in the reserved bit of the L1-pre signaling included
in the P2 symbol indicates that emergency warning information
is being transmitted (for example, when "0" changes to "1"),
the receiver activates the system on a chip and acquires and
30 outputs the emergency warning information transmitted from
the transmitter.
18
[0062]
Further, in Fig. 5, when the DVB-EWS existing method
(Fig. 1) is employed, the receiver cannot monitor (analyze)
the announcement flag (SI information) without activating the
system on a chip (SoC), the processing speed 5 to complete the
analysis takes a certain period of time such as several seconds,
for example.
[0063]
On the other hand, when the L1-pre signaling transmission
10 method (Figs. 2 and 3) is employed, in the receiver, since
the demodulation unit monitors (analyzes) the emergency
warning flag without activating the system on a chip, an
analysis process in the system on a chip is not necessary and
a monitoring result of the emergency warning flag can be
15 obtained before the system on a chip section. Thus, when the
L1-pre signaling transmission method is employed, compared
to the case that the DVB-EWS existing method is employed, the
process related to the emergency warning information can be
promptly executed.
20 [0064]
Here, in the L1-pre signaling transmission method, when
the emergency warning flag placed in the reserved bit of the
L1-pre signaling changes from "0" to "1" for example, the
receiver recognizes that the emergency warning information
25 is being transmitted and acquires the emergency warning
information by activating the system on a chip, and accordingly
the emergency warning flag (emergency warning notification
information) can serve as a so-called boot trigger.
[0065]
30 (Transmission of emergency warning information)
Here, in the receiver, the demodulation unit monitors
19
the emergency warning flag placed in the reserved bit of the
L1-pre signaling and, when the emergency warning flag changes
from "0" to "1" for example, the system on a chip is activated
and emergency warning information transmitted from the
transmitter is acquired and outputted. The 5 emergency warning
information can be transmitted by, for example, one of a method
using service information (SI) information, a method using
an auxiliary stream, and a method using a particular physical
layer pipe (PLP).
10 [0066]
(A) Method using SI information
In the method using the SI information, similarly to
the Emergency Warning System (DVB-EWS) according to the DVB
standard of Fig. 1, the emergency warning information is
15 transmitted using SI information.
[0067]
(B) Method using auxiliary stream
In the method using an auxiliary stream, the emergency
warning information as bit data is transmitted by an auxiliary
20 stream. In Fig. 6, symbols of auxiliary stream data included
in the T2 frame are illustrated in chronological order. In
the auxiliary stream, for example, a constant bit rate of about
hundreds bits is transmitted and information such as an area,
an epicenter, and the like can be informed by using the bit
25 data in a case of emergency warning information of earthquakes
and tsunami, for example. For example, in the receiver, by
executing a filtering process using information such as the
area, epicenter and the like transmitted as the auxiliary
stream, it is activated only when the information relates to
30 the place where the receiver is placed to acquire and output
emergency warning information transmitted from the
20
transmitter.
[0068]
Fig. 7 illustrates a part of information included in
the L1-post signaling. In Fig. 7, in a loop of the auxiliary
stream, AUX_STREAM_TYPE and AUX_PRIVATE_5 CONF are placed.
AUX_STREAM_TYPE is a 4-bit field that defines a type of the
auxiliary stream. AUX_PRIVATE_CONF is 28-bit field that
defines a modulation method, a code rate or the like of the
auxiliary stream.
10 [0069]
As illustrated in Fig. 8, when bits of "0000" are set
in AUX_STREAM_TYPE, it represents "TX-SIG," that is, an
auxiliary stream of transmitter signatures (TX-SIG). Further,
in AUX_STREAM_TYPE, bits other than the bits of "0000" all
15 represent "Reserved for future use", that is, reserved bits
for future extension. Here, in AUX_STREAM_TYPE, for example,
bits of "1111" are allocated to "Emergency signalling". With
this, it can be expressed that the emergency warning
information is being transmitted by the auxiliary stream.
20 [0070]
(C) Method using particular PLP
In the method using a particular PLP, emergency warning
information is transmitted using a PLP which is different from
the PLP for transmitting a stream of video and sound composing
25 content such as a program, for example. In this case, video
or sound can be included as the emergency warning information
and it becomes able to provide an Emergency Warning System
service.
[0071]
30 Here, the above described three methods are examples
and other methods may be employed. For example, a constant
21
bit data as emergency warning information may be transmitted
as a substitute for the information emergency warning flag
as the emergency warning notification.
[0072]
<3. 5 Second embodiment>
[0073]
A second embodiment explains a method for placing
emergency warning notification information that indicates
that emergency warning information is being transmitted in
10 P1 signaling to transmit (hereinafter, referred to as a "P1
signaling transmission method").
[0074]
(T2 frame)
Fig. 9 is a diagram illustrating a format of a T2 frame.
15 [0075]
The T2 frame of Fig. 9 is formed similarly to the T2
frame of Fig. 2; however, in the P1 signaling transmission
method, emergency warning notification information is placed
in a reserved bit of P1 signaling included in a P1 symbol.
20 Here, in the P1 signaling, a transmission type and basic
transmission parameters are included.
[0076]
More specifically, the P1 signaling (P1) includes S1,
S2 and the like as parameters. S1 and S2 indicate in which
25 of single input single output (SISO) or multiple input, single
output (MISO) P2 is to be transmitted, and a fast frourier
transform (FFT) size or the like when FFT calculation of P2
is executed.
[0077]
30 (1) Defining particular bit sequence in reserved bits in S2
field
22
[0078]
Fig. 10 is a diagram illustrating a detailed
configuration of an S1 field. In Fig. 10, the S1 field is
composed of three bits.
5 [0079]
In the S1 field, when bits of "000" are set, it is indicated
that "T2_SISO," which is a preamble signal, is a T2-base
preamble signal and SISO is employed as the P2 transmission
method. Further, when bits of "001" are set, it is indicated
10 that "T2_MISO," which is a preamble signal, is a T2-base
preamble signal and MISO is employed as the P2 transmission
method.
[0080]
Further, in the S1 field, when bits of "010" are set,
15 it is indicated that "Non_T2," which is a preamble signal,
is not a T2 preamble signal. Here, when the bits are set as
"010" in the S1 field, the S2 field indicates information
different from the FFT size or the like of the case that bits
of "000," "001," "011," or "100" is set.
20 [0081]
In other words, as illustrated in Fig. 11, when the bits
of "000" are set in the S2 field 1, it is indicated that it
is "Undefined FEF part," which is a preamble signal of an
undefined future extension frame (FEF), and has structure
25 different from the T2 frame.
[0082]
Further, in the S2 field 1, the bits from "001" to "111"
all indicate "Reserved for future use," that is, reserved bits
for future extension. Among these reserved bits, any
30 particular bit sequence is allocated to emergency warning
notification information that indicates that emergency
23
warning information is being transmitted.
[0083]
Referring back to Fig. 10, when the bits of "011" are
set in the S1 field, it indicates "T2_LITE_SISO," which is
that the preamble signal is a preamble signal 5 of T2_LITE and
that SISO is employed as the P2 transmission method. Further,
when the bits of "100" are set, it indicates "T2_LITE_MISO,"
which is that the preamble signal is a preamble signal of T2_LITE
and that MISO is employed as the P2 transmission method.
10 [0084]
Here, in the S1 field, the bits of "101," "110," or "111"
all indicate "Reserved for future use," that is, reserved bits
for future extension.
[0085]
15 As described above, in the P1 signaling transmission
method, since a particular bit sequence (emergency warning
notification information) indicating that the emergency
warning information is being transmitted is placed in the
reserved bits of the S2 field of the P1 signaling, the receiver
20 monitors the bit sequence set in the S2 field and, when a
particular bit sequence (for example, "001," "111," or the
like) is detected, the emergency warning information
transmitted from the transmitter can be acquired and output.
[0086]
25 (2) Defining particular bit sequence in reserved bits of S1
field
[0087]
Fig. 12 is a diagram illustrating a detailed
configuration of an S1 field. In Fig. 12, information set
30 in the S1 field is similar to the information set in the S1
field of Fig. 10. Here, in the S1 field of Fig. 12, one of
24
particular bit sequences (special bit sequence) among the
reserved bits of "101," "110," or "111" is allocated to
emergency warning notification information that indicates
that the emergency warning information is being transmitted.
5 [0088]
In this case, since the particular bit sequence
(emergency warning notification information) indicating that
the emergency warning information is being transmitted is
allocated to the reserved bits in the S1 field, as illustrated
10 in Fig. 13, the particular bit sequence indicating that the
emergency warning information is being transmitted is not
allocated to the reserved bit of the S2 field.
[0089]
Here, as illustrated in Fig. 14, to the reserved bits
15 of the S1 field, a new parameter is to be allocated according
to the digital video broadcasting-next generation handheld
(DVB-NGH) standard. In the S1 field of Fig. 14, "NGH_SISO"
is allocated to the bits of "101," "NGH_MISO" is allocated
to the bits of "110," and "ESC" is allocated to the bits of
20 "111," respectively.
[0090]
As described above, in the P1 signaling transmission
method, since the particular bit sequence (emergency warning
notification information) indicating that the emergency
25 warning information is being transmitted is placed in the
reserved bits of the S1 field of the P1 signaling, the receiver
can monitor the bit sequence set in the S1 field and, when
the particular bit sequence (for example, "101," "111," or
the like) is detected, the emergency warning information can
30 be acquired and output.
[0091]
25
(Comparison between DVB-EWS existing method and P1 signaling
transmission method)
Next, with reference to Fig. 15, power consumption and
processing speed in the DVB-EWS existing method and P1
signaling transmission method 5 are compared.
[0092]
Regarding power consumption of the receiver, when the
P1 signaling transmission method (Fig. 9 to 13) is employed,
the P1 symbol composing the T2 frame is demodulated and the
10 bit sequence set in the reserved bits of the P1 signaling
included in the P1 symbol can be monitored (analyzed). In
other words, in this case, since the bit sequence is monitored
in the demodulation unit which is a section before the system
on a chip (SoC), similarly to the above described L1-pre
15 signaling transmission method, only the power to activate the
tuner and demodulation unit is consumed and the high power
consuming system on a chip does not need to be activated.
[0093]
In other words, in the DVB-EWS existing method (Fig.
20 1), the high power consuming system on a chip needs to be
activated to monitor the announcement flag (SI information);
however, in the P1 signaling transmission method, the system
on a chip does not need to be activated to monitor the bit
sequence set in the S1 field or S2 field and the power consumption
25 can be suppressed.
[0094]
With this, as illustrated in Fig. 15, the receiver can
monitor (analyze) the bit sequence set, by the demodulation
unit, in the reserved bits of the P1 signaling only when
30 receiving the P1 symbol composing the T2 frame, and operates
in a mode in a sleep state (a low power consumption mode) when
26
receiving other P2 and data symbols. Then, when a particular
bit sequence (for example, "101," "111," or the like) is
detected as the bit sequence in the reserved bit of the P1
signaling of the P1 symbol, the receiver activates the system
on a chip so that the emergency warning information 5 transmitted
from the transmitter is acquired and output.
[0095]
Further, when the P1 signaling transmission method (Fig.
9 to 13) is employed, in the receiver, since the demodulation
10 unit monitors (analyzes) the bit sequence without activating
the system on a chip, an analyzing process in the system on
a chip is not needed and a particular bit sequence monitoring
result can be obtained in a stage prior to the system on a
chip. Thus, when the P1 signaling transmission method is
15 employed, the process related to the emergency warning
information can be done promptly, compared to the case that
the DVB-EWS existing method (Fig. 1) is employed. Here, in
the P1 signaling transmission method, since the P2 symbol is
not needed to be demodulated to demodulate the P1 symbol, the
20 power consumption can be suppressed and the processing speed
is further improved, compared to the L1-pre signaling
transmission method in which both of the P1 and P2 symbols
needed to be demodulated.
[0096]
25 Here, in the P1 signaling transmission method, when a
particular bit sequence is set in the reserved bits of the
P1 signaling, since the receiver recognizes that the emergency
warning information is being transmitted and the system on
a chip is activated to acquire emergency warning information,
30 the particular bit sequence (emergency warning notification
information) can serve as so-called boot trigger information.
27
[0097]
(Transmission of emergency warning information)
Here, in the receiver, the demodulation unit monitors
the bit sequence placed in the reserved bits of the P1 signaling
and, when a particular bit sequence is detected, 5 the system
on a chip is activated and the emergency warning information
transmitted from the transmitter is acquired and output.
Similarly to the L1-pre signaling transmission method, the
emergency warning information can be transmitted by one of
10 (A) method using SI information, (B) method using auxiliary
stream, and (C) method using particular PLP, for example.
[0098]
Here, as illustrated in Fig. 16, when a stream of video
and sound of a normal program is transmitted, P1 of the T2
15 frame and data are repeatedly transmitted; however, in a case
that (C) method using particular PLP is employed, when the
emergency warning notification information in which P1 (P1
signaling) is placed, since the data can be placed thereafter,
the flexibility of data design of the transmission frames can
20 be improved.
[0099]
<4. System configuration>
[0100]
(Configuration example of emergency warning information
25 transmission system)
Fig. 17 is a diagram illustrating an example of a
configuration of an emergency warning information
transmission system to which the present technology is applied.
Here, the system represents an assembly of a plurality of
30 components (devices or the like).
[0101]
28
An emergency warning information transmission system
1 is composed of an information provision device 10, a
transmission device 20, and a reception device 30.
[0102]
The information provision device 5 10 is managed by
Meteorological Agency or other government agencies for example,
generates emergency warning information to notify an
occurrence of various emergency situations such as natural
disasters like earthquakes or tsunami caused by earthquakes,
10 typhoons or heavy rains, stormy winds, tornados, floods,
wildfire, and provides the information to the transmission
device 20. Here, the information provision device 10 and the
transmission device 20 are connected via an arbitrary
communication path such as the Internet, a dedicated line,
15 or the like.
[0103]
The transmission device 20 corresponds to the above
described transmitter and is managed by a broadcasting station
that provides terrestrial digital broadcast service, for
20 example. The transmission device 20 transmits content such
as a program using digital broadcast signals. Further, when
emergency warning information is provided from the information
provision device 10, the transmission device 20 transmits by
including emergency warning information and emergency warning
25 notification information in digital broadcast signals.
[0104]
The reception device 30 corresponds to the above
described receiver, is composed of a television, a set-top
box, or the like for example, and is placed at individual homes
30 or the like. The reception device 30 receives digital
broadcast signals transmitted from the transmission device
29
20 and outputs video or sound of content of a program or the
like.
[0105]
Further, when emergency warning notification
information included in the digital 5 broadcast signals
indicates that the emergency warning information is being
transmitted, the reception device 30 acquires the emergency
warning information included in the digital broadcast signals
to output a warning sound or displays a warning message on
10 a screen for example. With this, a warning alert can be
instantly notified to a user.
[0106]
Here, in the emergency warning information transmission
system 1 of Fig. 17, the transmission device 20 is made to
15 receive provision of emergency warning information from the
information provision device 10 which is managed by a
government agency; however, the transmission device 20 may
acquire emergency warning information from an information
source other than the information provision device 10.
20 Further, the information provision device 10 does not always
have to be managed by a government agency and may be managed
by a private organization or a broadcasting station itself.
[0107]
Further, in the emergency warning information
25 transmission system 1 of Fig. 17, only one transmission device
20 is illustrated; however, a plurality of transmission devices
20 are provided in each broadcasting station in actual.
Further, in Fig. 17, only one reception device 30 is
illustrated; however, a plurality of reception devices 30 are
30 provided in actual.
[0108]
30
(Configuration example of transmission device)
Fig. 18 is a diagram illustrating an example of a
configuration of the transmission device 20 of Fig. 17.
[0109]
In Fig. 18, the transmission device 5 20 includes an
emergency warning information acquisition unit 211, an
emergency warning information processing unit 212, a content
acquisition unit 213, a content processing unit 214, a
signaling generation unit 215, a signaling processing unit
10 216, a transmission frame generation unit 217, and a broadcast
signal transmission unit 218.
[0110]
When emergency warning information is provided from the
information provision device 10 via an arbitrary communication
15 path, the emergency warning information is acquired by the
emergency warning information acquisition unit 211 and
provided to the emergency warning information processing unit
212. The emergency warning information provided from the
emergency warning information acquisition unit 211 is
20 processed by the emergency warning information processing unit
212 and supplied to the transmission frame generation unit
217.
[0111]
Here, in the emergency warning information processing
25 unit 212, a filtering process for removing unnecessary
information (for example, information which is not related
to the broadcasting area) or a file format converting process
or the like is performed on the emergency warning information,
for example.
30 [0112]
The content acquisition unit 213 acquires content of
31
a program or the like and provides the contents to the content
processing unit 214. The content processing unit 214
processes the contents supplied from the content acquisition
unit 213 and provides the contents to the transmission frame
generation 5 unit 217.
[0113]
Here, as the content, for example, corresponding
contents according to a broadcasting time period from a storage
area of already recorded contents, or live contents from a
10 studio or on location is acquired. Further, in the content
processing unit 214, encoding or format type conversion
processing or the like on the contents, for example are
executed.
[0114]
15 The signaling generation unit 215 generates signaling
and supplies the signaling to signaling processing unit 216.
The signaling processing unit 216 processes signaling from
the signaling generation unit 215 and supplies the signaling
to the transmission frame generation unit 217.
20 [0115]
Here, as the signaling, for example, P1 signalling, L1
pre-signalling, and L1 post-signalling according to the DVB-T2
standard are generated. Further, when emergency warning
information is provided from the information provision device
25 10 via any communication path, the signaling processing unit
216 includes emergency warning notification information
indicating that emergency warning information is being
transmitted to the P1 signaling or L1-pre signaling.
[0116]
30 More specifically, when the above described L1-pre
signaling transmission method (Figs. 2 and 3) is employed,
32
since a 1-bit emergency warning flag indicating that emergency
warning information is being transmitted is allocated to a
reserved bit of the L1-pre signaling, the emergency warning
flag is made to be "1." Further, when the above described
P1 signaling transmission method (Fig. 9 to 5 13) is employed,
since a particular bit sequence indicating that emergency
warning information is being transmitted is allocated to the
reserved bit of the S1 field or S2 field of the P1 signaling,
the particular bit sequence is made to be set.
10 [0117]
When emergency warning information is not provided from
the information provision device 10, a transmission frame such
as a T2 frame according to the DVB-T2 standard is generated
by the transmission frame generation unit 217 on the basis
15 of contents data from the content processing unit 214 and
signaling data from the signaling processing unit 216 and
supplied to the broadcast signal transmission unit 218.
[0118]
Further, when the emergency warning information has been
20 provided from the information provision device 10, a
transmission frame such as a T2 frame according to the DVB-T2
standard by the transmission frame generation unit 217 on the
basis of the emergency warning information from the emergency
warning information processing unit 212, contents data from
25 the content processing unit 214, and signaling data from the
signaling processing unit 216 and supplied to the broadcast
signal transmission unit 218.
[0119]
Here, in this case, in the P1 signaling or the L1-pre
30 signaling, emergency warning notification information
indicating that the emergency warning information is being
33
transmitted is included. Further, as described above, the
emergency warning information can be transmitted by, for
example, any one of (A) method using SI information, (B) method
using auxiliary stream, and (C) method using particular PLP.
5 [0120]
The broadcast signal transmission unit 218 executes,
for example, coding, digital modulation such as orthogonal
frequency division multiplexing (OFDM), upconversion to a
radio frequency (RF) band (frequency channel allocated to the
10 broadcasting station), or power amplification on the
transmission frame from the transmission frame generation unit
217 and transmits the frame as a digital broadcast signal via
an antenna 219.
[0121]
15 Here, in the transmission device 20 of Fig. 18, it is
not required to provide all the function blocks physically
in a single device, and at least a part of the function blocks
may be provided as a device which is physically independent
from other function blocks. For example, the emergency
20 warning information processing unit 212 may be provided in
a server in the Internet.
[0122]
(Configuration example of reception device)
Fig. 19 is a diagram illustrating an example of the
25 reception device 30 of Fig. 17.
[0123]
In Fig. 19, the reception device 30 is composed of a
tuner 312, a demodulation unit 313, a control unit 314, a display
unit 315, and a speaker 316.
30 [0124]
The tuner 312 executes synchronization on components
34
of a predetermined frequency channel from a digital broadcast
signal received from the antenna 311. The demodulation unit
313 executes a demodulation process of a digital broadcast
signal which is synchronized by the tuner 312. Regarding the
demodulation process, the demodulation process 5 is executed
on the transmission frame such as a T2 frame according to the
DVB-T2 standard, which is received as a digital broadcast
signal.
[0125]
10 The control unit 314 executes a decoding process such
as decoding on a signal from the demodulation unit 313 and
displays a video of content such as a program obtained as the
result on the display unit 315 and outputs sound from the speaker
316. Here, the control unit 314 is composed of a system on
15 a chip (SoC).
[0126]
Here, the demodulation unit 313 monitors emergency
warning notification information included in the reserved bit
of the P1 signaling or L1-pre signaling and determines whether
20 or not the emergency warning notification information
indicates that emergency warning information is being
transmitted.
[0127]
More specifically, when the above described L1-pre
25 signaling transmission method (Figs. 2 and 3) is employed,
since a 1-bit emergency warning flag indicting that emergency
warning information is being transmitted is allocated to the
reserved bit of the L1-pre signaling, it is monitored whether
the emergency warning flag is "1." Further, when the above
30 described P1 signaling transmission method (Fig. 9 to 13) is
employed, since a particular bit sequence indicating that
35
emergency warning information is being transmitted is
allocated to the reserved bits of the S1 field or S2 field
of the P1 signaling, it is monitored whether the particular
bit sequence is set.
5 [0128]
When the emergency warning notification information
indicates that the emergency warning information is being
transmitted as a result of the emergency warning notification
information monitoring by the demodulation unit 313, the
10 control unit 314 acquires the emergency warning information
to, for example, output the warning sound from the speaker
316 or displays a warning message on the display unit 315.
With this, a warning alert can be instantly informed to the
user.
15 [0129]
Here, in the reception device 30, since the demodulation
unit 313 monitors the emergency warning notification
information, the control unit 314 as a system on a chip does
not need to be activated. Then, when the emergency warning
20 notification information indicates that the emergency warning
information is being transmitted as a result of the emergency
warning notification information monitoring result by the
demodulation unit 313, the control unit 314 as a system on
a chip is activated and acquires the emergency warning
25 information.
[0130]
Thus, when the L1-pre signaling transmission method
(Figs. 2 and 3) or the P1 signaling transmission method (Fig.
9 to 13) is employed, as explained with reference to Figs.
30 4, 5, and 15, the process related to the emergency alert
information can be executed more promptly at a low power
36
consumption, compared to the DVB-EWS existing method (Fig.
1).
[0131]
Further, since the emergency warning information is
transmitted, for example, by any one of (5 A) method using SI
information, (B) method using auxiliary stream, or (C) method
using particular PLP, the receiver is to receive the emergency
warning information transmitted by any one of the methods.
[0132]
10 Here, regarding the reception device 30 of Fig. 19, a
configuration in which the display unit 315 and speaker 316
are internally installed has been explained; however, the
display unit 315 and speaker 316 may be externally provided.
[0133]
15 <5. Process flows in each device>
[0134]
Next, with reference to a flowchart of Fig. 20 and 21,
a flow of process executed in each device composing the
emergency warning information transmission system 1 of Fig.
20 17 will be explained.
[0135]
(Emergency warning information transmission process)
Firstly, with reference to the flowchart of Fig. 20,
a flow of an emergency warning information transmission process
25 executed by the transmission device 20 of Fig. 17 will be
explained.
[0136]
In step S211, it is determined whether or not emergency
warning information is provided from the information provision
30 device 10 via any communication path. In step S211, when it
is determined that the emergency warning information has been
37
provided from the information provision device 10, the process
proceeds to step S212.
[0137]
In step S212, the emergency warning information provided
from the information provision device 10 5 is acquired by the
emergency warning information acquisition unit 211 and
supplied to the emergency warning information processing unit
212. In step S213, the emergency warning information supplied
from the emergency warning information acquisition unit 211
10 is processed by the emergency warning information processing
unit 212 and supplied to the transmission frame generation
unit 217.
[0138]
When the process in step S213 is finished, the process
15 proceeds to step S214. Here, in step S211, when it is
determined that the emergency warning information is not
provided from the information provision device 10, the
processes in steps S212 and S213 are skipped and the process
proceeds to step S214.
20 [0139]
In step S214, contents such as a program are acquired
by the content acquisition unit 213 and supplied to the content
processing unit 214. In step S215, the contents supplied from
the content acquisition unit 213 is processed by the content
25 processing unit 214 and supplied to the transmission frame
generation unit 217.
[0140]
In step S216, signaling is generated by the signaling
generation unit 215 and supplied to the signaling processing
30 unit 216. In step S217, the signaling from the signaling
generation unit 215 is processed by the signaling processing
38
unit 216 and supplied to the transmission frame generation
unit 217.
[0141]
Here, in step S211, when it is determined that emergency
warning information is provided from the information 5 provision
device 10 and the emergency warning information is acquired
and processed (steps S212 and S213), emergency warning
notification information indicating that the emergency
warning information is being transmitted is included in P1
10 signaling or L1-pre signaling.
[0142]
More specifically, when the above described L1-pre
signaling transmission method (Figs. 2 and 3) is employed,
emergency warning flag allocated to the reserved bit of the
15 L1-pre signaling is made to "1." Further, when the above
described P1 signaling transmission method (Fig. 9 to 13) is
employed, a particular bit sequence allocated to the reserved
bits of the S1 field or S2 field of the P1 signaling is set.
[0143]
20 In step S218, when the emergency warning information
is provided from the information provision device 10 ("YES"
in step S211), in the transmission frame generation unit 217,
a transmission frame such as a T2 frame according to the DVB-T2
standard is generated on the basis of the emergency warning
25 information from the emergency warning information processing
unit 212, content data form the content processing unit 214,
and signaling data from the signaling processing unit 216,
and supplied to the broadcast signal transmission unit 218.
Here, in this case, in the P1 signaling or L1-pre signaling,
30 the emergency warning notification information indicating
that the emergency warning information is being transmitted
39
is included.
[0144]
Here, when emergency warning information is not provided
from the information provision device 10 ("NO" in step S211),
a transmission frame such as a T2 frame according 5 to the DVB-T2
standard is generated by the transmission frame generation
unit 217 on the basis of the content data from the content
processing unit 214 and signaling data from the signaling
processing unit 216, and supplied to the broadcast signal
10 transmission unit 218.
[0145]
In step S219, the broadcast signal transmission unit
218 executes a predetermined process on the transmission frame
from the transmission frame generation unit 217 and transmits
15 the transmission frame as a digital broadcast signal via the
antenna 219. When the process in step S219 is finished, the
emergency warning information transmission process of Fig.
20 ends.
[0146]
20 The emergency warning information transmission process
has been explained. In the emergency warning information
transmission process, when emergency warning information is
provided from the information provision device 10, emergency
warning notification information indicating that the
25 emergency warning information is being transmitted is included
in the P1 signaling or L1-pre signaling together with the
emergency warning information and is transmitted using digital
broadcast signals.
[0147]
30 (Emergency warning information reception process)
Next, with reference to the flowchart of Fig. 21, a flow
40
of an emergency warning information reception process executed
by the reception device 30 of Fig. 17 will be explained. Here,
it is assumed that the reception device 30 is in a sleep state
at the start timing of the emergency warning information
5 reception process.
[0148]
In step S311, the tuner 312 synchronizes components of
predetermined frequency channel with the digital broadcast
signal received by the antenna 311. In other words, the
10 reception device 30 receives the digital broadcast signal from
the transmission device 20.
[0149]
In step S312, the demodulation unit 313 executes a
demodulation process of the digital broadcast signal
15 synchronized by the tuner 312. In step S313, the demodulation
unit 313 determines whether the emergency warning notification
information included in the reserved bit of the P1 signaling
or L1-pre signaling indicates that the emergency warning
information is being transmitted on the basis of the result
20 of the demodulation process in step S312.
[0150]
More specifically, when the above described L1-pre
signaling transmission method (Figs. 2 and 3) is employed,
the emergency warning flag allocated to the reserved bit of
25 the L1-pre signaling is monitored and it is determined that
the emergency warning notification information indicates that
the emergency warning information is being transmitted when
the emergency warning flag is "1." Further, when the above
described P1 signaling transmission method (Fig. 9 to 13) is
30 employed, the bit sequence set in the reserved bits of the
S1 field or S2 field of the P1 signaling is monitored and it
41
is determined that the emergency warning notification
information indicates that the emergency warning information
is being transmitted when the particular bit sequence is set.
[0151]
In step S313, when it is determined 5 that the emergency
warning notification information indicates that the emergency
warning information is being transmitted, the process proceeds
to step S314. In step S314, the control unit 314 as the system
on a chip is activated and the control unit 314 acquires and
10 outputs the emergency warning information. For example, the
control unit 314 controls to output a warning sound from the
speaker 316 and displays a warning message on the display unit
315 on the basis of the emergency warning information. With
this, a warning alert can be instantly informed to the user.
15 [0152]
Here, in step S313, when it is determined that the
emergency warning notification information does not indicate
that the emergency warning information is being transmitted,
the process of step S314 is skipped. When the process of step
20 S314 is finished or skipped, the emergency warning information
reception process of Fig. 21 ends.
[0153]
In the above, the emergency warning information
reception process has been explained. In the emergency
25 warning information reception process, when the emergency
warning information is transmitted from the transmission
device 20, since the emergency warning notification
information included in the reserved bit of the P1 signaling
or L1-pre signaling indicates that the emergency warning
30 information is being transmitted, the emergency warning
information is acquired and output according to the result
42
of monitoring the emergency warning notification information.
[0154]
<6. Computer configuration>
[0155]
The above described series of processes 5 may be executed
by hardware or may be executed by software. When the series
of processes are executed by software, a program that composes
the software is installed in the computer. Fig. 22 is a diagram
illustrating a configuration example of hardware of the
10 computer that executes the above described series of processes
with a program.
[0156]
In the computer 900, a central processing unit (CPU)
901, a read only memory (ROM) 902, and a random access memory
15 (RAM) 903 are connected to one another by a bus 904. To the
bus 904, an input/output interface 905 is further connected.
To the input/output interface 905, an input unit 906, an output
unit 907, a recording unit 908, a communication unit 909, and
a drive 910 are connected.
20 [0157]
The input unit 906 is composed of a keyboard, a mouse,
a microphone, or the like. The output unit 907 is composed
of a display, a speaker, or the like. The recording unit 908
is composed of hard disk, a non-volatile memory, or the like.
25 The communication unit 909 is composed of a network interface
or the like. The drive 910 drives a removable medium 911 such
as a magnetic disk, an optical disk, a magnetic optical disk,
a semiconductor memory, and the like.
[0158]
30 In the computer 900 composed as described above, a program
stored in the ROM 902 or recording unit 908 is loaded in the
43
RAM 903 by the CPU 901, via the input/output interface 905
and bus 904, and executed so that the above described series
of processes are executed.
[0159]
The program that the computer 900 5 (CPU 901) executes
can be recorded and provided in the removable medium 911 such
as a packaged medium for example. Further, the program can
be provided via a wired or wireless transmission medium such
as a local area network, the Internet, digital satellite
10 broadcasting, or the like.
[0160]
In the computer 900, the program can be installed to
the recording unit 908 by attaching the removable medium 911
to the drive 910 via the input/output interface 905. Further,
15 the program can be received by the communication unit 909 via
a wired or wireless transmission medium and installed to the
recording unit 908. Other programs can be stored in the ROM
902 or recording unit 908 in advance.
[0161]
20 Here, according to this specification, the process that
the computer executes according to the program does not always
have to be executed in chronological order according to the
order described in the flowchart. In other words, the process
that the computer executes according to the program includes
25 processes that are executed in parallel or individually (for
example, parallel processing or a process by an object).
Further, the program may be processed by a single computer
(processor) or may be processed by a plurality of computers
in a distributed manner.
30 [0162]
Here, the embodiments of the present technology are not
44
limited to the above described embodiments and various changes
may be applied within the scope of the present technology.
[0163]
Further, the present technology may have the following
5 configuration.
[0164]
(1)
A transmission device including:
an emergency warning information acquisition unit
10 configured to acquire emergency warning information;
a content acquisition unit configured to acquire a
content;
a transmission frame generation unit configured to
generate a transmission frame that includes emergency warning
15 notification information indicating that the emergency
warning information is being transmitted in P1 signaling or
L1-pre signaling, as a transmission frame, according to the
digital video broadcasting-terrestrial 2 (DVB-T2) standard,
composed of a first preamble signal of the P1 signaling, a
20 second preamble signal of the L1-pre signaling, and the content
data; and
a transmission unit configured to transmit the
transmission frame as a digital broadcast signal.
(2)
25 The transmission device according to (1), wherein, when
included in the L1-pre signaling, the emergency warning
notification information is placed in a reserved bit of the
L1-pre signaling.
(3)
30 The transmission device according to (2),
wherein
45
the emergency warning notification information is a
1-bit emergency warning flag, and
the emergency warning information is transmitted using
service information (SI) information, an auxiliary stream,
or a particular physical layer pipe (PLP) 5 which are defined
in the DVB-T2 standard.
(4)
The transmission device according to (1), wherein, when
included in the P1 signaling, the emergency warning
10 notification information is placed in a reserved bit of the
P1 signaling.
(5)
The transmission device according to (4),
wherein
15 the emergency warning notification information is a
particular bit sequence, and
the emergency warning information is transmitted using
SI information, an auxiliary stream, or a particular PLP which
are defined in the DVB-T2 standard.
20 (6)
The transmission device according to any of (1) to (5),
further including a signaling generation unit configured to
generate the P1 signaling and the L1-pre signaling.
(7)
25 A transmission method of a transmission device,
the transmission device executing steps of:
acquiring emergency warning information;
acquiring content;
generating a transmission frame that includes emergency
30 warning notification information indicating that the
emergency warning information is being transmitted in P1
46
signaling or L1-pre signaling as a transmission frame,
according to the DVB-T2 standard, composed of a first preamble
signal including the P1 signaling, a second preamble signal
including the L1-pre signaling, and content data; and
transmitting the transmission 5 frame as a digital
broadcast signal.
(8)
A reception device including:
a reception unit configured to receive, as a digital
10 broadcast signal, a transmission frame, according to DVB-T2
standard, composed of a first preamble signal including P1
signaling, a second preamble signal including L1-pre signaling,
and content data; and
a demodulation unit configured to demodulate the first
15 preamble signal, or the first preamble signal and the second
preamble signal and monitor emergency warning notification
information indicating that emergency warning information is
being transmitted in the P1 signaling included in the first
preamble signal or the L1-pre signaling included in the second
20 preamble signal.
(9)
The reception device according to (8), wherein when
including in the L1-pre signaling, the emergency warning
notification information is placed in a reserved bit of the
25 L1-pre signaling.
(10)
The reception device according to (9),
wherein
the emergency warning notification information is a
30 1-bit emergency warning flag, and
the emergency warning information is transmitted using
47
SI information, an auxiliary stream, or a particular PLP which
are defined by the DVB-T2 standard,
further including
a control unit configured to be activated when the
emergency warning notification information 5 indicates that the
emergency warning information is being transmitted, and
acquire the emergency warning information transmitted using
the SI information, the auxiliary stream, or the particular
PLP.
10 (11)
The reception device according to (8), wherein, when
included in the P1 signaling, the emergency warning
notification information is placed in a reserved bit of the
P1 signaling.
15 (12)
The reception device according to (11), wherein
the emergency warning notification information is a
particular bit sequence, and
the emergency warning information is transmitted using
20 SI information, an auxiliary stream, or a particular PLP, which
are defined in the DVB-T2 standard,
further including
a control unit configured to be activated when the
emergency warning notification information indicates that the
25 emergency warning information is being transmitted, and
acquire the emergency warning information transmitted using
the SI information, the auxiliary stream, or the particular
PLP.
(13)
30 A reception method of a reception device,
the reception device executing steps of:
48
receiving, as a digital broadcast signal, a transmission
frame, according to DVB-T2 standard, composed of a first
preamble signal including P1 signaling, a second preamble
signal including L1-pre signaling, and content data; and
demodulating the first preamble signal, 5 or the first
preamble signal and the second preamble signal, and monitoring
emergency warning notification information indicating that
emergency warning information is being transmitted in the P1
signaling included in the first preamble signal or the L1-pre
10 signaling included in the second preamble signal.
REFERENCE SIGNS LIST
[0165]
1 Emergency warning information transmission system
15 10 Information provision device
20 Transmission device
30 Reception device
211 Emergency warning information acquisition unit
212 Emergency warning information processing unit
20 213 Content acquisition unit
214 Content processing unit
215 Signaling generation unit
216 Signaling processing unit
217 Transmission frame generation unit
25 218 Broadcast signal transmission unit
312 Tuner
313 Demodulation unit
314 Control unit
315 Display unit
30 316 Speaker
900 Computer
49
901 CPU
50
CLAIMS
1. A transmission device comprising:
an emergency warning information acquisition unit
configured to acquire emergency warning 5 information;
a content acquisition unit configured to acquire a
content;
a transmission frame generation unit configured to
generate a transmission frame that includes emergency warning
10 notification information indicating that the emergency
warning information is being transmitted in P1 signaling or
L1-pre signaling, as a transmission frame, according to the
digital video broadcasting-terrestrial 2 (DVB-T2) standard,
composed of a first preamble signal of the P1 signaling, a
15 second preamble signal of the L1-pre signaling, and the content
data; and
a transmission unit configured to transmit the
transmission frame as a digital broadcast signal.
20 2. The transmission device according to claim 1, wherein,
when included in the L1-pre signaling, the emergency warning
notification information is placed in a reserved bit of the
L1-pre signaling.
25 3. The transmission device according to claim 2,
wherein
the emergency warning notification information is a
1-bit emergency warning flag, and
the emergency warning information is transmitted using
30 service information (SI) information, an auxiliary stream,
or a particular physical layer pipe (PLP) which are defined
51
in the DVB-T2 standard.
4. The transmission device according to claim 1, wherein,
when included in the P1 signaling, the emergency warning
notification information is placed in a reserved 5 bit of the
P1 signaling.
5. The transmission device according to claim 4,
wherein
10 the emergency warning notification information is a
particular bit sequence, and
the emergency warning information is transmitted using
SI information, an auxiliary stream, or a particular PLP which
are defined in the DVB-T2 standard.
15
6. The transmission device according to claim 1, further
comprising a signaling generation unit configured to generate
the P1 signaling and the L1-pre signaling.
20 7. A transmission method of a transmission device,
the transmission device executing steps of:
acquiring emergency warning information;
acquiring content;
generating a transmission frame that includes emergency
25 warning notification information indicating that the
emergency warning information is being transmitted in P1
signaling or L1-pre signaling as a transmission frame,
according to the DVB-T2 standard, composed of a first preamble
signal including the P1 signaling, a second preamble signal
30 including the L1-pre signaling, and content data; and
transmitting the transmission frame as a digital
52
broadcast signal.
8. A reception device comprising:
a reception unit configured to receive, as a digital
broadcast signal, a transmission frame, according 5 to DVB-T2
standard, composed of a first preamble signal including P1
signaling, a second preamble signal including L1-pre signaling,
and content data; and
a demodulation unit configured to demodulate the first
10 preamble signal, or the first preamble signal and the second
preamble signal and monitor emergency warning notification
information indicating that emergency warning information is
being transmitted in the P1 signaling included in the first
preamble signal or the L1-pre signaling included in the second
15 preamble signal.
9. The reception device according to claim 8, wherein when
including in the L1-pre signaling, the emergency warning
notification information is placed in a reserved bit of the
20 L1-pre signaling.
10. The reception device according to claim 9,
wherein
the emergency warning notification information is a
25 1-bit emergency warning flag, and
the emergency warning information is transmitted using
SI information, an auxiliary stream, or a particular PLP which
are defined by the DVB-T2 standard,
further comprising
30 a control unit configured to be activated when the
emergency warning notification information indicates that the
53
emergency warning information is being transmitted, and
acquire the emergency warning information transmitted using
the SI information, the auxiliary stream, or the particular
PLP.
5
11. The reception device according to claim 8, wherein, when
included in the P1 signaling, the emergency warning
notification information is placed in a reserved bit of the
P1 signaling.
10
12. The reception device according to claim 11, wherein
the emergency warning notification information is a
particular bit sequence, and
the emergency warning information is transmitted using
15 SI information, an auxiliary stream, or a particular PLP, which
are defined in the DVB-T2 standard,
further comprising
a control unit configured to be activated when the
emergency warning notification information indicates that the
20 emergency warning information is being transmitted, and
acquire the emergency warning information transmitted using
the SI information, the auxiliary stream, or the particular
PLP.
25 13. A reception method of a reception device,
the reception device executing steps of:
receiving, as a digital broadcast signal, a transmission
frame, according to DVB-T2 standard, composed of a first
preamble signal including P1 signaling, a second preamble
30 signal including L1-pre signaling, and content data; and
demodulating the first preamble signal, or the first
54
preamble signal and the second preamble signal, and monitoring
emergency warning notification information indicating that
emergency warning information is being transmitted in the P1
signaling included in the first preamble signal or the L1-pre
signaling included in the second 5 preamble signal.