[DESCRIPTION]
[Title]
INFORMATION PROCESSING DEVICE AND INFORMATION PROCESSING
METHOD
[Technical Field]
[OOOl]
The present technology relates to an information
processing device. More particularly, the present
technology relates to an information processing device
and an information processing method for exchanging
information by use of wireless communication.
[Background Art]
--
[0002]
There exist wireless communication technologies for
exchanging information by use of wireless communication.
For example, the standards regarding wireless local area
networks (LANs) recommended by the Institute of
Electrical and Electronic Engineers (IEEE) 802.11 are
coming into widespread use. Also proposed is wireless
fidelity (Wi-Fi) Direct (Wi-Fi peer-to-peer (P2P)
Specification), a standard for allowing multiple wireless
devices to directly exchange data therebetween on a P2P
basis without the intervention of routers.
[0003]
The Wi-Fi Direct standard defines a notice of absence
(NoA) as the protocol for enabling a wireless device
acting as a wireless base unit called a group owner (GO)
to enter sleep mode. Specifically, the standard allows
the GO to set sleep mode by notifying its clients
beforehand of a sleep start time, a sleep duration, and
other settings using a beacon, for example.
[0004]
As a typical technology regarding the NoA, a portable
terminal that enters suspend mode using the NoA has been
proposed (e.g., see PTL 1) .
[Citation List]
[Patent Literature]
[00051
[PTL 11
JP 2013-106348 A
[Summary]
[Technical Problem]
[00061
According to the above-mentioned existing technology, if
all devices connected to the GO are, Wi-Fi Direct
compatible devices, the GO sets sleep mode (suspend mode)
by notifying its clients of the sleep start time, sleep
duration, and other settings.
[00071
However, there may be cases where the GO is connected
with Wi-Fi Direct incompatible devices. If the GO is
connected with a Wi-Fi Direct incompatible device, the
Wi-Fi Direct incompatible device is incapable of
determining whether or not the GO is in sleep mode.
Conceivably, the Wi-Fi Direct incompatible device may
transmit data to the GO that is in sleep mode. In such a
case, communication is not conducted properly between the
Wi-Fi Direct incompatible device and the GO in sleep mode.
It is important that sleep mode (suspend mode) be set
appropriately even if the GO is connected with Wi-Fi
Direct incompatible devices.
[00081
The present technologyhasbeen developed in view of the
above circumstances. An object of the present technology
is to set the modes on power consumption in a suitable
manner.
[Solution to Problem]
[0009]
The present technology has been devised in order to solve
the above-mentioned problem. According to a first aspect
of the present technology, there are provided an
information processing device, an information processing
method for use therewith, and a program for causing a
computer to execute the information processing method.
The information processing device includes a control
section configured such that when the information
processing device in a first mode transitions to a second
mode in which the information processing device consumes
power differently than in the first mode, the control
section performs control to transmit at least one frame
including information notifying a first device compatible
with the second mode that the information processing
device is to transition to the second mode, the frame
further including information causing a second device
incompatible with the second mode to suppress
transmission. This technology provides an effect such
that when the own device transitions to the second mode,
-- --
a frame is transmitted which includes information for
notifying the first device compatible with the second
mode that the own device will transition to the second
mode, and information for causing the second device
incompatible with the second mode to suppress
transmission.
[OOlO]
According to the first aspect of the present technology,
on the basis of a determining rule, the control section
may postpone a scheduled time of transmitting the frame
before transmitting the frame. This provides the effect
of postponing the scheduled time of transmitting the
[ OOll]
Also according to the first aspect of the present
technology, the control section may notify the first
device and the second device of a scheduled time of
transmitting the frame before transmitting the frame.
This provides the effect of notifying the first device
and the second device of the scheduled time of
transmitting the frame before transmitting the frame.
[0012]
Also according to the first aspect of the present
technology, the control section may transmit the
scheduled time using a broadcast frame. This provides the
-- -- -
effect of transmitting the scheduled time using the
broadcast f rarne.
[0013]
Also according to the first aspect of the present
technology, the control section may base the determining
rule on information relating to the frame transmitted to
the information processing device. This provides the
effect of basing the determining rule on information
relating to the frame transmitted to the own device.
100141
Also according to the first aspect of the present
technology, the control section may stop transmission of
the frame on the basis of a determining rule. This
provides the effect of stopping transmission of the frame
on the basis of the determining rule.
[0015]
Also according to the first aspect of the present
technology, the control section may base the determining
rule on the receipt from an upper layer of data destined
for another information processing device connected with
the information processing device by a scheduled time of
transmitting the frame. This provides the effect of
basing the determining rule on the receipt from an upper
layer of data destined for another information processing
device connected with the own device by the scheduled
--
time-oftransmitting the frame.
[0016]
Also according to the first aspect of the present
technology, the control section may base the determining
rule on the receipt of another frame destined for the
information processing device by a scheduled time of
transmitting the frame. This provides the effect of
basing the determining rule on the receipt of another
frame destined for the own device by the scheduled time
of transmitting the frame.
[0017]
Also according to the first aspect of the present
technology, the control section may transmit as part of
the frame a first frame causing the first device and the
second device to suppress transmission. This provides the
effect of transmitting the first frame causing the first
device and the second device to suppress transmission.
[0018]
Also according to the first aspect of the present
technology, the control section may transmit as part of
the frame a second frame of which the information is not
recognized by the second device. This provides the effect
of transmitting the second frame of which the information
is not recognized by the second device.
[0019]
-
Also according to the first aspect of the present
technology, the control section may insert into the frame
an identifier identifying the information processing
device and duration information specifying duration in
which the information processing device is to transition
to the second mode before transmitting the frame. This
provides the effect of inserting into the frame the
identifier for identifying the own device and the
duration information for specifying the duration of the
transition to the second mode before transmitting the
frame .
[0020]
Also according to the first aspect of the present
technology, the control section may insert the identifier
and the duration information into at least either a
physical layer (PHY) header or a media access control
(MAC) header of the frame before transmitting the frame.
This provides the effect of inserting the identifier and
the duration information into at least either the PHY
header or the MAC header of the frame before transmitting
the frame.
[0021]
Also according to the first aspect of the present
technology, the control section may set a destination of
the frame for the information processing device. This
- - --
provides the effect of setting the destination of the
frame for the own device.
[0022]
Also according to the first aspect of the present
technology, as a waiting duration before transmitting the
frame, the control section may set a duration guaranteed
to be shorter than the duration in which each of the
first device and the second device waits for transmission.
This provides the effect of setting a duration guaranteed
to be shorter than the duration in which each of the
first device and the second device waits for transmission,
as the waiting duration before transmitting the frame.
LO0231
According to a second aspect of the present technology,
there are provided an information processing device, an
information processing method for use therewith, and a
program causing a computer to execute the information
processing method. The information processing device
includes a communication section configured to receive a
frame transmitted by another information processing
device in a first mode notifying that the other
information processing device is to transition to a
second mode in which the other information processing
device consumes power differently than in the first mode,
the frame including information enabling the other
--a information processing device to notify a first device
compatible with the second mode that the other
information processing device is to transition to the
second mode, the frame further including information
causing a second device incompatible with the second mode
to suppress transmission. The information processing
device further includes a control section configured to
perform control regarding the transmission ,of the own
device on the basis of the information included in the
frame. This provides an effect such that upon receipt of
the frame including diverse information, the transmission
of the own device is controlled on the basis of the
information included in the frame.
[00241
According to the second aspect of the present technology,
the control section may determine whether the frame is
for notifying that the other information processing
device is to transition to the second mode on the basis
of whether or not a source address and a destination
address included in the frame coincide with each other.
This provides the effect of determining whether the frame
is for notifying that the other information processing
device will transition to the second mode on the basis of
whether or not the source address and the destination
address included in the frame coincide with each other.
- -
I00251
Also according to the second aspect of the present
technology, the control section may set a duration in
which the own device is to transition to the second mode
on the basis of a duration included in the frame as the
duration in which the other information processing device
is to transition to the second mode. This provides the
effect of setting the duration in which the own device
will transition to the second mode on the basis of the
duration included in the frame as the duration in which
the other information processing device will transition
to the second mode.
[00261
Also according to the second aspect of the present
technology, if there is a frame to be transmitted to the
other information processing device and if a waiting
duration required before transmitting the frame is longer
than a duration at the end of which the other information
processing device is to exit the second mode, the control
section may perform processing of transmitting the frame.
This provides the effect of performing the processing of
transmitting the frame if there is a Frame to be
transmitted to the other information processing device
and if a waiting duration required before transmitting
the frame is longer than the duration in which the other
-.
information processing device will transition to the
second mode.
[0027]
Also according to the second aspect of the present
technology, if there is a frame to be transmitted and if
the frame is destined for an entity other than the other
information processing device, the control section may
perform processing of transmitting-the frame. This
provides the effect of performing the processing of
transmitting the frame if there is a frame to be
transmitted and if the frame is destined for an entity
other than the other information processing device.
[Advantageous Effect of Invention]
[0028]
The present technology provides the advantage of suitably
setting the modes on power consumption. This and other
advantages outlined above, however, are not limitative of
the technology. The present technology also offers other
advantages that will be apparent in the disclosure that
follows.
[Brief Description of Drawings]
[0029]
[FIG. 1 1
FIG. 1 is a schematic view showing a typical system
configuration of a communication system 10 in a first
~~ -~~~p embodiment of the present technology.
[FIG. 21
FIG. 2 is a block diagram showing a typical functional
structure of an information processing device 100 in the
first embodiment of the present technology.
[FIG. 31
FIG. 3 is a sequence chart showing typical communication
processes between devices making up the communication
system 10 in the first embodiment of the present
technology.
[FIG. 41
FIG. 4 is a schematic view showing a typical structure of
power save information transmitted by the information
processing device 100 in the first embodiment of the
present technology.
[ F I G . 51
F I G . 5 is a schematic view showing a typical structure of
a Sleep frame transmitted by the information processing
device 100 in the first embodiment of the present
technology.
[ F I G . 61
F I G . 6 is a schematic view showing a typical structure of
a legacy signal field (L-SIG) included in the Sleep frame
transmitted by the information processing device 100 in
the first embodiment of the present technology.
- -
[ F I G _ 7 I
F I G . 7 is a schematic view showing another typical
structure of the Sleep frame transmitted by the
information processing device 100 in the first embodiment
of the present technology.
[ F I G . 81
F I G . 8 is a schematic view showing another typical
structure of the Sleep frame transmitted by the
information processing device 100 in the first embodiment
of the present technology.
[ F I G . 91
F I G . 9 is a schematic view showing another typical
structure of the Sleep frame transmitted by the
information processing device 100 in the first embodiment
of the present technology.
[ F I G . 101
F I G . 10 is a schematic view showing another typical
structure of the Sleep frame transmitted by the
information processing device 100 in the first embodiment
of the present technology.
[ F I G . 111
F I G . 11 is a schematic view showing another typical
structure of the Sleep frame transmitted by the
information processing device 100 in the first embodiment
of the present technology.
- .-
[ F I G . 121
F I G . 12 is a schematic view showing another typical
structure of the Sleep frame transmitted by the
information processing device 100 in the first embodiment
of the present technology.
[ F I G . 131
F I G . 13 is a schematic view showing another typical
structure of the Sleep frame transmitted by the
information processing device 100 in the first embodiment
of the present technology.
[ F I G . 141
F I G . 1 4 is a flowchart showing a typical procedure for
sleep-related processing performed by the information
processing device 100 in the first embodiment of the
present technology.
[FIG. 151
FIG. 15 is a flowchart showing another typical procedure
for the sleep-related processing performed by the
information processing device 100 in the first embodiment
of the present technology.
[FIG. 161
FIG. 16 is a flowchart showing another typical procedure
for the sleep-related processing performed by the
information processing device 100 in the first embodiment
of the present technology.
- .-
[FIG. 171
FIG. 17 is a flowchart showing a typical procedure for
processing of Sleep frame reception performed by an
information processing device 200 in the first embodiment
of the present technology.
[FIG. 181
FIG. 18 is a flowchart showing a typical procedure for
processing performed by the information processing device
200 in the first embodiment of the present technology
when the master station is in sleep mode.
[FIG. 191
FIG. 19 is a flowchart showing a typical procedure for
processing of transmission suppression performed by an
information processing device 201 in the first embodiment
of the present technology.
[ F I G . 203
F I G . 20 is a sequence chart showing typical communication
processes between devices making up the communication
system 10 in a second embodiment of the present
technology.
[ F I G . 2 1 1
F I G . 21 is a schematic view showing a typical structure
of a first Sleep frame transmitted by the information
processing device 100 in the second embodiment of the
present technology.
- --
[ F I G . 2 2 1
F I G . 22 is a schematic view showing a typical structure
of a second Sleep frame transmitted by the information
processing device 100 in the second embodiment of the
present technology.
[ F I G . 2 3 1
F I G . 23 is a schematic view showing another typical
structure of the second Sleep frame transmitted by the
information processing device 100 in the second
embodiment of the present technology.
[ F I G . 2 4 1
F I G . 2 4 is a schematic view showing another typical
structure of the second Sleep frame transmitted by the
information processing device 100 in the second
embodiment of the present technology.
[FIG. 251
FIG. 25 is a flow chart showing a typical procedure for
processing of Sleep frame reception performed by the
information processing device 200 in the second
embodiment of the present technology.
[FIG. 261
FIG. 26 is a block diagram showing a typical schematic
structure of a smartphone.
[FIG. 271
FIG. 27 is a block diagram showing a typical schematic
structure of a car navigation device.
-
[FIG. 281
FIG. 28 is a block diagram showing a typical schematic
structure of a wireless access point.
[Description of Embodiments]
[0030]
Described below are the modes for carrying out the
present technology (called the embodiments hereunder).
The description will be given under the following
headings :
1. First Embodiment (an example in which a Sleep frame is
transmitted immediately before the master station enters
sleep mode)
2. Second Embodiment (an example in which two kinds of
frames are transmitted as the Sleep frame)
3. Applications
[0031]
1. First Embodiment
(Typical configuration of the communication system)
FIG. 1 is a schematic view showing a typical system
configuration of a communication system 10 in a first
embodiment of the present technology.
[0032]
The communication system 10 is made up of an information
processing device (master station) 100 and information
--
processinid~vices (slave stations) 200 and 201. In the
ensuing description, the notations of the master station
and slave stations may be abbreviated as needed. In FIG.
1, the devices connected with each other are shown linked
by dotted lines.
[0033]
The information processing device 100 is an information
processing device (wireless communication .device) serving
as the hub of a wireless network. The information
processing device 100 may be connected in wired or
wireless fashion with an external network (e.g., the
Internet). The information processing device 100 may be a
fixed or mobile information processing device having a
wireless communication function. For example, the fixed
information processing device is an information
processing device such as an access point or a base
station in a wireless LAN system. The mobile information
processing device may be an information processing device
such as a smartphone, a mobile phone, or a tablet.
[0034]
For example, the information processing devices 200 and
201 are each a mobile information processing device
(wireless communication device) having a wireless
communication function.
[0035]
- .-
Theinformation processing devices lQ0, 200, and 201 each
have a communication function compatible with the IEEE
802.11 wireless LAN standards, for example. The wireless
LAN complies with Wi-Fi, Wi-Fi Direct, or Wi-Fi CERTIFIED
Miracast (technical specification name: Wi-Fi Display),
for example. The wireless LAN may alternatively comply
with some other suitable communication system for
wireless communication.
LOO361
The information processing device 100 functions as the
master station (base unit), and the information
processing devices 200 and 201 each function as a slave
station (extension unit). The information processing
device 100 also functions as an access point under which
the information processing devices 200 and 201 operate.
That is, FIG. 1 shows an example in which there is one
wireless master station (information processing device
100) with which two wireless slave stations (information
processing devices 200 and 201) are connected. This,
however, is not limitative of the system configuration of
the embodiments according to the present technology.
Although FIG. 1 illustrates a communication system
constituted by one wireless master station and two
wireless slave stations, the number of master stations
and that of slave stations are not limited thereby. For
--
example, the present technology may be applied to a
communication system including two or more wireless
master stations (information processing devices). This
technology may also be applied to a communication system
including three or more wireless slave stations
(information processing devices) .
100371
One of two information processing devices communicating
with each other may be a master station and the other a
slave station. Alternatively, two interconnected
information processing devices may be two slave stations
communicating directly with each other.
[0038]
The information processing devices 100 and 200 each
include a specific function (i.e., a function for
supporting sleep mode). On the other hand, the
information processing device 201 has no such specific
function. The information processing devices devoid of
the specific function are referred to as legacy devices.
The specific function will be discussed hereunder in
conjunction with each of the embodiments of the present
technology. The legacy device may be defined as an
information processing device having a communication
function complying with the wireless LAN standards of
IEEE 802.11a, IEEE 802.11g, IEEE 802.11n, or IEEE
--
802.11ac, for example.
[00391
As described above, the information processing device 201
is a slave station operating as a legacy device. The
information processing device 200 is a slave station that
is not a legacy device.
[0040]
Mobile wireless devices such as mobile phones are driven
by battery. That means the technology and scheme to save
power are important for these devices. For example, power
is consumed when radio signals are transmitted and
received. Thus in order to minimize power consumption,
each mobile wireless device when not required to
communicate may transition to suspend mode in which a
wireless system is driven with a minimum of power with no
radio signal transmitted or received.
[0041]
For example, IEEE 802.11, a typical wireless LAN standard,
defines a protocol under which a wireless extension unit,
before entering suspend mode (sleep mode) for a certain
duration, transmits to its wireless base unit a frame
notifying that the extension unit will transition to
suspend mode.
[0042]
Recent years have witnessed the appearance of wireless
mobile devices (e. g., ~xt-access point (AP) ) playing the
role of a wireless base unit. This gives importance to a
wireless system enabling the wireless base unit to save
power efficiently.
[0043]
For example, as described above, the Wi-Fi Direct
standard defines the NoA as the protocol according to
which the wireless device acting as the wireless base
unit (GO) enters sleep mode. The NoA, however, is not
backward compatible.
[0044]
For example, if the GO is connected with a Wi-Fi Direct
incompatible device (legacy device) for example, that
device cannot determine whether or not the GO is in sleep
mode. Thus the Wi-Fi Direct incompatible device may
conceivably send data to the GP in sleep mode. In such a
case, communication is not carried out correctly between
the Wi-Fi Direct incompatible device and the GO in sleep
mode.
[O0451
As described above, if the GO is connected with a Wi-Fi
Direct incompatible device, the NoA scheme may not let
the wireless base unit save power appropriately.
LOO461
The embodiment of the present technology provides an
-- - --
example in which the wireless base unit transmits a Sleep
frame just before entering sleep mode. That is, the
master station under IEEE 802.11ax transmits the Sleep
frame at the time of setting suspend mode (power save
mode). The Sleep frame at least includes a notification
of the sleep duration of the own device and information
for causing legacy devices to suppress transmission.
roo471
The Sleep frame thus transmitted gives a wireless
extension unit capable of recognizing the Sleep frame (a
device compatible with this method (e.g., IEEE 802.11ax
compatible device)) the notification that the base unit
will enter sleep mode (e.g., for a sleep duration). On
the other hand, the Sleep frame causes a wireless
extension unit incapable of recognizing the Sleep frame
(a legacy device incompatible with this method) to
suppress transmission. For example, transmission
suppression may be set using the network allocation
vector (NAV) .
100481
It is also possible to set properly the format of the
Sleep frame for enabling the base unit to save power.
[00491
With the embodiment of the present technology, when sleep
mode is set for the master station, the setting is
- --
assumed to mean not only the state in which the master
station is in sleep mode but also the state where the
master station performs various (e.g., limited) processes.
That is, in the sleep duration, the master station does
not need to transition to suspend mode by turning off its
wireless power supply. For example, in the sleep duration,
the master station may perform suck processes as scanning
other channels to check an ambient wireless environment
and communicating with another master station or slave
stations being connected (including P2P connections). If
the normal state is regarded as a first mode, sleep mode
may be considered to be a second mode in which power is
consumed differently from the first mode. The mention of
sleep mode includes the meaning of suspend mode or power
save mode. The normal state of the master station is an
example of the first mode stated in the appended claims.
Sleep mode is an example of the second mode stated in the
appended claims.
[0050]
(Typical structure of the information processing device
(master station))
FIG. 2 is a block diagram showing a typical functional
structure of the information processing device 100 in the
first embodiment of the present technology. The
functional structure (regarding wireless communication)
-
of the information processing devices 200 and 201 is
substantially the same as that of the information
processing device 100 and thus will not be discussed
further .
[00511
The information processing device 100 includes a data
processing section 110, a communication section 120, an
antenna 130, a storage section 140, and a control section
150. Whereas FIG. 2 shows an example in which the
information processing device 100 includes one wireless
interface portion 122 paired with the antenna 130, the
information processing device may include two or more
wireless interface portions paired with the antenna each.
[0052 ]
The data processing section 110 processes various data
under the control of the control section 150. For example,
at the time of transmitting data input from an upper
layer, the data processing section 110 generates a packet
for wireless transmission by performing such processes as
adding a header and an error-detecting code to the data.
The data processing section 110 supplies the packet thus
generated to the communication section 120. At the time
of receiving data input from the communication section
120, the data processing section 110 may perform
processes such as analyzing the header, detecting any
-- - --
packet error, and reordering packets, and supply the
processed data to an upper protocol layer of the data
processing section 110.
[00531
The communication section 120 includes a signal
processing portion 121, a wireless interface portion 122,
and a channel estimation portion 123.
[00541
The signal processing portion 121 performs various
signal-related processes under the control of the control
section 150. For example, at the time of transmission,
the signal processing portion 121 performs such signalrelated
processes as encoding, interleaving, modulation,
and signal spatial separation if necessary on the data
input from the data processing section 110 under a coding
and modulating scheme established by the control section
150. The signal processing portion 121 supplies each
wireless interface portion 122 with a transmitted symbol
stream obtained by the signal processing.
LO0551
At the time of reception, the signal processing portion
121 may demultiplex as needed a received symbol, stream
input from the wireless interface portion 122 and reverse
the processes performed upon transmission. The signal
processing portion 121 supplies the data processing
-- - section 110 with the received symbol stream thus
processed.
[0056]
The wireless interface portion 122 is an interface that
connects with another information processing device and
transmits and receives diverse information thereto and
therefrom. For example, at the time of transmitting data
input from the signal processing portion 121, the
wireless interface portion 122 subjects the data to
conversion to an analog signal, amplification, filtering,
and frequency up-conversion, before outputting the data
to the antenna 130. At the time of reception, the
wireless interface portion 122 typically reverses the
processes on the data input from the antenna 130, and
supplies the result of the processes to the signal
processing portion 121 and the channel estimation portion
123.
[0057]
The channel estimation portion 123 calculates complex
channel gain information relating to a propagation path
from a preamble part and a training signal part of the
input signal from the wireless interface portion 122. The
complex channel gain information thus calculated is sent
via the control section 150 to the signal processing
portion 121 for demodulation and stream demultiplexing.
[0058]
The storage section 140 serves as a work area for data
processing by the control section 150 and functions as a
storage medium that holds various data. For example, the
storage section 140 may be a storage medium as a
nonvolatile memory, a magnetic disk, an optical disk, or
a magneto-optical (MO) disk. The nonvolatile memory may
be an electrically erasable programmable read-only memory
(EEPROM) or an erasable programmable ROM (EPROM). The
magnetic disk may be a hard disk or some other suitable
disk-like magnetic material disk. The optical disk may be
a compact disc (CD), a digital versatile disc recordable
(DVD-R), or a Blu-ray Disc (BD) (registered trademark).
[0059]
The control section 150 controls various receiving and
transmitting operations of the data processing section
110 and the communication section 120. For example, the
control section 150 transfers information between
configured sections, sets communication parameters, and
enables the data processing section 110 to schedule
packets.
[0060]
For example, when the information processing device 100
transitions to sleep mode, the control section 150
performs control to transmit a Sleep frame to each slave
station. The Sleepframe includes trio kinds of
information: information for notifying a first device
(slave station) compatible with sleep mode that the
information processing device 100 will transition to
sleep mode, and information for causing a second device
(legacy device) incompatible with sleep mode to suppress
transmission.
[00611
Each slave station (information processing devices 200
and 201) may receive the above-mentioned frame sent by
the information processing device 100 notifying that it
will transition to sleep mode, for example. In such a
case, the own device having received the frame controls
its transmission on the basis of the information included
in the frame.
[0062]
(Examples of communication)
FIG. 3 is a sequence chart showing typical communication
processes between the devices making up the communication
system 10 in the first embodiment of the present
technology.
[00631
First, the control section 150 of the information
processing device 100 inserts power save information into
the frame (401). The control section 150 of the
- -
information processing device 100 then transmits by
broadcast the frame (broadcast frame) that includes the
power save information (402 to 404). For example, a
beacon frame may be transmitted as the broadcast frame.
The power save information will be discussed later in
detail with reference to FIG. 4.
[0064]
When the control section (equivalent to the control
section 150 in FIG. 2) of the information processing
device 200 receives the frame including the power save
information (403), the control section acquires the power
save information included in the received frame (405).
The control section of the information processing device
200 then records the acquired power save information
(405) to a storage section (equivalent to the storage
section 140 shown in FIG. 2).
[00651
When the control section (equivalent to the control
section 150 in FIG. 2) of the information processing
device 201 receives the frame including the power save
information (404), the control section performs reception
processing regarding the received frame.
[0066]
After the control section 150 of the information
processing device 100 transmits the frame including the
--
power sayinformation (402), the control section 150
performs sleep-related processing (406).
roo671
Thereafter, when a scheduled time of Sleep frame
transmission included in the transmitted power save
information is reached, the control section 150 of the
information processing device 100 transmits a Sleep frame
to the slave stations (407 to 409). Each of these
processes will be discussed later in detail with
reference to FIGS. 14 to 16. After transmitting the Sleep
frame to the slave stations (407), the control section
150 of the information processing device 100 sets sleep
100681
Upon receipt of the Sleep frame (408), the control
section of the information processing device 200 performs
Sleep frame reception processing (410). The Sleep frame
reception processing will be discussed later in detail
with reference to FIGS. 17 and 18.
[00691
Upon receipt of the Sleep frame (409), the control
section of the information processing device 201 performs
transmission suppression processing (411). The
transmission suppression processing will be discussed
later in detail with reference to FIG. 19.
[ o m - -
As described above, the information processing device 200
is a device that can recognize the Sleep frame
transmitted from the information processing device 100.
Upon receipt of the Sleep frame, the information
processing device 200 recognizes that the information
processing device 100 has transitioned to sleep mode.
[00711
The information processing device 201 is a Sleep frame
incompatible device that can receive the Sleep frame but
is unable to fully recognize it.
[0072]
(Example of power save information)
FIG. 4 is a schematic view showing a typical structure of
the power save information transmitted by the information
processing device 100 in the first embodiment of the
present technology.
[OD731
The power save information is typically made up of an
element identifier (ID) 301, a length 302, a sleep
duration 303, a scheduled time of Sleep frame
transmission 304, and a remaining time before Sleep frame
transmission 305. In FIG. 4, the fields accommodating the
information items are each topped by a value in octets.
Likewise, the fields (or some of them) in some of the
.-
subsequent drawings will be each topped by a value in
octets.
[0074]
FIG. 4 illustrates the power save information that
includes the sleep duration 300, the scheduled time of
Sleep frame transmission 304, and the remaining time
before Sleep frame transmission 305. Alternatively, power
save information may be used which includes at least one
of the items that are the sleep duration 303, the
scheduled time of Sleep frame transmission 304, and the
remaining time before Sleep frame transmission 305. One
or multiple items of the information are stored in a
power save information element when transmitted. For
example, the information items are stored in a beacon
frame when transmitted.
[0075]
The scheduled time of Sleep frame transmission 304 may
include information that uniquely determines a certain
point in time, a cyclical time relative to a given point
in time, or both.
[0076]
In the manner described above, before transmitting the
Sleep frame, the control section 150 of the information
processing device 100 notifies each slave station of the
scheduled time of Sleep frame transmission. In this case,
-. ~.-
the control section 150 may transmit the scheduled time
using a broadcast frame.
[0077]
(Typical frame formats of the Sleep frame)
The Sleep frame is a frame for notifying the slave
stations except legacy devices of the duration in which
the master station will transition to sleep mode while
causing the.legacy devices to suppress transmission as
long as the master station is in sleep mode. This
requires a frame format that not only the slave stations
except legacy devices fully interpret but also the legacy
devices enable to interpret the Sleep frame to a certain
extent. Such a Sleep frame may come in diverse forms.
Some typical Sleep frame formats are described below.
[00781
(Example of using the HE PPDU format frame)
FIG. 5 is a schematic view showing a typical structure of
the Sleep frame transmitted by the information processing
device 100 in the first embodiment of the present
technology. FIG. 5 shows an example of using a high
frequency (HE) physical layer convergence procedure
(PLCP) protocol data unit (PPDU) format frame as the
Sleep frame.
[0079]
FIG. 6 is a schematic view showing a typical structure of
an L-SIG included in the Sleep frame transmitted by the
information processing device 100 in the first embodiment
of the present technology. The L-SIG in FIG. 6
corresponds to an L-STG 313 shown in FIG. 5, for example.
[00801
The HE PPDU format frame is fully interpreted only by the
slave stations except legacy devices (i.e., by the
information processing device 200). In this frame, only a
legacy short training field (L-STF) 311 through the L-SIG
313 are interpreted by the legacy devices (i.e., by the
information processing device 201).
[00811
In the first embodiment of the present technology, a
legacy data rate (L - DATARATE) value and a legacy length
(L - LENGTH) value are set in the L-SIG 313. That is, the
L - DATARATE value is set in a RATE field 651 and the
L - LENGTH value in a LENGTH field 652, as shown in FIG. 6
In this manner, by use of the L - DATARATE and L - LENGTH
values in the L - SIG 313, the master station (information
processing device 100) can notify the slave stations of
the duration in which the master station (information
processing device 100) will transition to sleep mode. For
example, the L - DATARATE and L - LENGTH values to be
included in the frame are such as to permit the
calculation of the duration in which the master station
-
(information processing device 100) will transition to
sleep mode by use of the following equation 1:
Sleep Duration = (L - LENGTH/L - DATARATE) . . . Equation 1
[0082]
Under IEEE 802.11, a wireless device that has received a
frame cannot transmit anything while performing
calculations on the basis of the L - DATARATE and L - LENGTH
values. For example, the legacy device (information
processing device 201) that has received the HE PPDU
format frame cannot interpret the frame as the Sleep
frame. However, the legacy device (information processing
device 201) having received the frame may set
transmission suppression in such a manner that
transmission will not take place for the duration
calculated on the basis of the L - DATARATE and L - LENGTH
values.
[0083]
The master station (information processing device 100)
inserts the identifier of the Sleep frame into a Frame
Control field 318 in the MAC header. Thus the identifier
enables the slave station (information processing device
200)capable of fully interpreting the HE PPDU frame to
recognize that the received frame is the Sleep frame.
[0084]
The master station (information processing device 100)
- -- --
may also insert into a Duration field 319 the sleep
duration in which the master station (information
processing device 100) will transition to sleep mode.
[0085]
(Example of using the Management frame)
A Management frame format may be used as the Sleep frame.
In this case, the master station (information processing
device 100) transmits the Management frame using a legacy
PPDU format. This enables not only the slave stations
except legacy devices (i.e., information processing
device 200) but also the legacy devices (information
processing device 201) to fully interpret the frame.
[0086]
FIG. 7 is a schematic view showing another typical
structure of the Sleep frame transmitted by the
information processing device 100 in the first embodiment
of the present technology. FIG. 7 shows an example in
which the Management frame is used as the Sleep frame.
LOO871
Generally, a destination address is set in an Address 1
field (333), a source address is set in an Address 2
field (334), and the address of the master station
(information processing device 100) with which the own
device is connected is set in an Address 3 field (335).
[00881
--
In thefirst embodiment of the present technology,
however, the address of the orin device (i. e., master
station address) is inserted into all of the Address 1
field (333), the Address 2 field (334), and the Address 3
field (335) of the Management frame. This enables the
slave stations except legacy devices (information
processing device 200) to recognize that the Management
frame is the Sleep frame.
[0089]
The legacy devices (information processing device 201)
not cognizant of that rule cannot determine whether or
not the Management frame is the Sleep frame.
[00901
Alternatively, the master station (information processing
device 100) may insert the Sleep frame identifier into a
Frame Body field 337 instead of using the Address 1 field
(333), the Address 2 field (334), and the Address 3 field
(335) for notification purposes.
[0091]
In the first embodiment of the present technology, the
duration in which the master station (information
processing device 100) will transition to sleep mode is
set in a Duration field 332 in the Management frame
Because the duration value (Duration field 332) in this
case is a value placed in the MAC header, backward
compatibility is guaranteed. This enables the legacy
devices not cognizant of the Sleep frame to interpret the
Duration field 332.
[0092]
Also under IEEE 802.11, a wireless device that has
received a frame cannot transmit anything for the
duration whose value is set in the Duration value
(Duration field 332) of the frame. Thus the legacy device
having received the Management frame can be set to
suppress transmission only for the duration placed in the
Duration field 332 without having to interpret the frame
as the Sleep frame.
[00931
(Example of setting the Sleep frame identifier in the MAC
header)
Described below is an example in which the Sleep frame
identifier is set in the MAC header.
[0094]
FIGS. 8 and 9 are schematic views showing other typical
structures of the Sleep frame transmitted by the
information processing device 100 in the first embodiment
of the present technology. FIG. 8 shows an example in
which the Sleep frame identifier is set in a Frame
Control field for transmission using the Management frame.
FIG. 9 shows an example in which the Sleep frame
--
identifier is set in a Frame Body field for transmission
using the Management frame. That is, FIG. 8 gives an
example in which the Frame Body field is not provided,
and FIG. 9 gives an example in which a Frame Body field
621 is disposed.
[0095]
As shown in FIGS. 8 and 9, the identifier indicative of
the Management frame is set in Type fields 602 and 612 in
Frame Control fields 601 and 611, respectively. The
identifier (bit value) and its meanings are shown in
Tables 604, 605, 614, and 615.
[0096]
As shown in FIG. 8, when the Sleep frame identifier is
set in the Frame Control field, the identifier indicative
of the Management frame is placed into a Subtype field
603. The identifier (bit value) and its meanings are
shown in Tables 606 and 607.
[0097]
As shor.~n in FIG. 9, when the Sleep frame identifier is
set in the Frame Body field, the identifier indicative of
an Action no Acknowledge (Ack) frame is placed into a
Subtype field 613. The identifier (bit value) and its
meanings are shown in Tables 616 and 617. The identifier
indicative of the Sleep frame is set in a Category field
622 in the Frame Body field 621. The identifier (code)
-- -
and its meanings are shown in Tables 625 and 626. The
master station identifier is set in a basic service set
identifier (BSSID) field 623, and information relating to
the sleep duration is placed in a Sleep Duration field
624.
roo981
(Example of using the Control frame)
A Control frame may alternatively be used as the Sleep
frame. In this case, the master station (information
processing device 100) transmits the Control frame using
the legacy PPDU format. This enables not only the slave
stations except legacy devices (information processing
device 200) but also the legacy devices (information
processing device 201) to fully interpret the frame.
I00991
FIG. 10 is a schematic view showing another typical
structure of the Sleep frame transmitted by the
information processing device 100 in the first embodiment
of the present technology. FIG. 10 shows an example in
which the Control frame is used as the Sleep frame.
[OlOO]
In the first embodiment of the present technology, the
address of the master station (information processing
device 100) is set in both a return address (RA) field
343 and a BSSID transmitting station address (TA) field
-
344.
[OlOl]
The duration in which the master station (information
processing device 100) will transition to sleep mode is
set in a Duration field 342.
[01021
Alternatively, the master station (information processing
device 100) may set the Sleep frame identifier in a Frame
Control field 341 in the Control frame. This enables the
slave stations capable of fully interpreting the Control
frame to determine that this frame is the Sleep frame.
[0103]
(Example of setting the Sleep frame identifier in the MAC
header)
Described below is an example in which the Sleep frame
identifier is set in the MAC header.
[0104]
FIG. 11 is a schematic view showing another typical
structure of the Sleep frame transmitted by the
information processing device 100 in the first embodiment
of the present technology. FIG. 11 shows an example in
which the Sleep frame identifier is set in a Frame
Control field for transmission using the Control frame.
[01051
As shown in FIG. 11, the identifier indicative of the
- -- -- -
Control frame is set in a Type field 632 in a Frame
Control field 632. This identifier (bit value) and its
meanings are shown in Tables 634 and 635. The identifier
indicative of the Sleep frame is set in a Subtype field
633. This identifier (bit value) and its meanings are
shown in Tables 636 and 637.
[0106]
FIGS. 8 , 9, and 11 have shown examples in which the
Management frame or the Control frame is used as the
Sleep frame. This scheme can also be applied to the case
where the HE PPDU format frame (shown in FIG. 5) is used.
[01071
(Example of using a null data packet (NDP) frame)
An NDP frame may also be used as the Sleep frame. In this
case, the NDP frame is a frame that has only the PHY
header and is devoid of a payload.
[0108]
FIG. 12 is a schematic view showing another typical
structure of the Sleep frame transmitted by the
information processing device 100 in the first embodiment
of the present technology. FIG. 12 shows an example in
which the NDP frame is used as the Sleep frame.
[0109]
An L-SIG 353 is a field that guarantees backward
compatibility. That means the L-SIG 353 holds information
-
that can be interpreted by both the slave stations except
legacy devices (i.e., information processing device 200)
and the legacy devices (information processing device
201). In the first embodiment of the present technology,
the L - LENGTH and L-DATARATE values are set in the L-SIG
353. The structure of the L-SIG 353 is the same as that
shown in FIG. 6.
[0110]
A high-efficiency signal field A (HE-SIG-A) 354 through a
high-efficiency signal field B (HE-SIG-B) 357 hold
information that can only be interpreted by the slave
stations except legacy devices (i.e., by the information
processing device 200) .
[0111]
In the first embodiment of the present technology, the
identifier of the master station (information processing
device 100) is set in at least either the HE-SIG-A 354 or
the HE-SIG-B 357. This allov~s any other wireless device
disconnected from the master station (information
processing device 100) to ignore the NDP frame.
[0112]
Also in the first embodiment of the present technology,
the identifier indicating that the NDP frame is the Sleep
frame (i.e., Sleep frame identifier) is set in at least
either the HE-SIG-A 354 or the HE-SIG-B 357. This enables
t E l a v e stations except legacy devices (information
processing device 200) to recognize that the NDP frame is
the Sleep frame.
[0113]
The legacy devices (e.g., information processing device
201) incapable of interpreting the HE-SIG-A 354 and
subsequent fields cannot determine whether or not the NDP
frame is the Sleep frame.
roll41
(Example of setting the Sleep frame identifier in the PHY
header)
Described below is an example in which the Sleep frame
identifier is set in the PHY header.
[0115]
FIG. 13 is a schematic view showing another typical
structure of the Sleep frame transmitted by the
information processing device 100 in the first embodiment
of the present technology. FIG. 13 shows an example in
which the Sleep frame identifier is set in a HE-SIG field
[01161
As shown in FIG. 13, the identifier indicative of the
Sleep frame is set in a Sleep Frame field 643. The master
station identifier is set in a basic service set (BSS)
Color field 641. Either a field 642 is used to hold the
duration value, or this field is omitted. For example, if
--
the NDP frame shown in FIG. 24 is used, then the field
642 is used to hold the duration value.
[0117]
(Typical operations of sleep-related processing (master
station) )
FIGS. 14 to 16 are flowcharts showing typical procedures
for sleep-related processing performed by the information
processing device 100 in the first,embodiment of the
present technology. The processes shown in FIGS. 14 to 16
correspond to the processes (406 and 407) indicated in
FIG. 3. The processing is described below, first with
reference to FIG. 14.
101181
The control section 150 of the information processing
device 100 first determines whether or not the scheduled
time of Sleep frame transmission (i.e., previously
announced sleep duration) is reached on the basis of the
power save information included in the frame transmitted
by broadcast (step S801). If the scheduled time of Sleep
frame transmission has yet to be reached (step S801), the
operation of the sleep-related processing is terminated.
[0119]
If it is determined that the scheduled time of Sleep
frame transmission is reached (step S801), the control
section 150 of the information processing device 100
- - determines whether or not sleep mode is possible (step
S802). The rules for determining whether or not sleep
mode is possible are explained below.

[CLAIMS]
[Claim 11
An information processing device comprising:
a control section configured such that when the
information processing device in a first mode transitions
to a second mode in which the information processing
device consumes power differently than in the first mode,
the control section performs control to transmit at least
one frame including information notifying a first device
compatible with the second mode that the information
processing device is to transition to the second mode,
the frame further including information causing a second
--
device incompatible with the second mode to suppress
transmission.
[Claim 21
The information processing device according to claim 1,
wherein, on the basis of a determining rule, the control
section postpones a scheduled time of transmitting the
frame before transmitting the frame.
[Claim 31
The information processing device according to claim 1,
wherein the control section notifies the first device and
the second device of a scheduled time of transmitting the
frame before transmitting the frame.
[Claim 41
The information processing device according to claim 2,
wherein the control section transmits the scheduled time
using a broadcast frame.
[Claim 51
The information processing device according to claim 2,
wherein the control section bases the determining rule on
information relating to the frame transmitted to the
information processing device.
[Claim 61
The information processing device according to claim 1,
wherein the control section stops transmission of the
frame on the basis of a determining rule.
--
[Claim 71 --
The information processing device according to claim 6,
wherein the control section bases the determining rule on
the receipt from an upper layer of data destined for
another information processing device connected with the
information processing device by a scheduled time of
transmitting the frame.
[Claim 81
The information processing device according to claim 6,
wherein the control section bases the determining rule on
the receipt of another frame destined for the information
processing device by a scheduled time of transmitting the
[Claim 91
The information processing device according to claim 1,
wherein the control section transmits as part of the
frame a first frame causing the first device and the
second device to suppress transmission.
[Claim 101
The information processing device according to claim 9,
wherein the control section transmits as part of the
frame a second frame of which the information is not
recognized by the second device.
[Claim 111
The information processing device according to claim 1,
whereiETh-e control section inserts into the-frame an
identifier identifying the information processing device
and duration information specifying duration in which the
information processing device is to transition to the
second mode before transmitting the frame.
[Claim 121
The information processing device according to claim 11,
wherein the control section inserts the identifier and
the duration information into at least either a physical
layer header or a media access control header of the
frame before transmitting the frame.
[Claim 131
The information processing device according to claim 1,
wherein the control section sets a destination of the
frame for the information processing device.
[Claim 141
The information processing device according to claim 1,
wherein, as a waiting duration before transmitting the
frame, the control section sets a duration guaranteed to
be shorter than the duration in which each of the first
device and the second device waits for transmission.
[Claim 151
An information processing device comprising:
a communication section configured to receive a frame
transmitted by another information processing device in a
fiEt mode notifying that the other iCfOrmation
processing device is to transition to a second mode in
which the other information processing device consumes
power differently than in the first mode, the frame
including information enabling the other information
processing device to notify a first device compatible
with the second mode that the other information
processing device is to transition to the second mode,
the frame further including information causing a second
device incompatible with the second mode to suppress
transmission; and
a control section configured to perform control regarding
the transmission of the own device on the basis of the
information included in the frame.
[Claim 161
The information processing device according to claim 15,
wherein the control section determines whether the frame
is for notifying that the other information processing
device is to transition to the second mode on the basis
of whether or not a source address and a destination
address included in the frame coincide with each other.
[Claim 171
The information processing device according to claim 15,
wherein the control section sets a duration in which the
own device is to transition to the second mode on the
basis of a duration included intheframe as the duration
in which the other information processing device is to
transition to the second mode.
[Claim 181
The information processing device according to claim 15,
wherein, if there is a frame to be transmitted to the
other information processing device and if a waiting
duration required before transmitting the frame is longer
than a duration at the end of which the other information
processing device is to exit the second mode, the control
section performs processing of transmitting the frame.
[Claim 191
The information processing device according to claim 15,
wherein, if there is a frame to be transmitted and if the
frame is destined for an entity other than the other
information processing device, the control section
performs processing of transmitting the frame.
[Claim 201
An information processing method comprising:
a procedure for use when an information processing device
in a first mode transitions to a second mode in which the
information processing device consumes power differently
than in the first mode, the procedure being used to
transmit at least one frame incl.uding information
notifying a first device compatible with the second mode
that the information p r o c e d~ev~ic e is to transitj-on
to the second mode, the frame further including
information causing a second deiiice incompatible with the
second mode to suppress transmission,