KR101885773B1 - Apparatus and method for waking device from power save mode - Google Patents

Abstract

Discloses a method and apparatus for waking up a device from a power save mode to an active mode. The present invention relates to a system and method for transmitting a magic packet to an external device operating in a power save mode that repeats a doze state and an awake state according to a predetermined period, And transmitting a magic packet through the predetermined channel when a response to the magic packet is not received from the external device and a predetermined period has not elapsed after transmitting the magic packet through the predetermined channel, , So that the device can be remotely woken up in Peer to Peer (P2P) communication.

Description

[0001] Apparatus and method for waking a device from a power saving mode [0002]

The present invention relates to a method and apparatus for waking up a device from a power save mode, and more particularly to a method and apparatus for remotely waking up a device in Peer to Peer (P2P) communication.

Recently, Wi-Fi P2P (or Wi-Fi Direct; WFD) standards have been defined in order to support connection between devices more conveniently than conventional Wi-Fi. In order to transmit audio / video data satisfying high quality and low delay The Wi-Fi Display standard is defined by the request. Since Wi-Fi P2P supports conventional Wi-Fi and other power saving functions, there is a demand for a technology to wake a Wi-Fi P2P device in a power saving mode remotely to an active mode.

The present invention provides a method and apparatus for remotely waking up a device in P2P communication.

According to another aspect of the present invention, there is provided a method of switching a second device from a power save mode to an active mode, Transmitting a magic packet to the second device operating in the power save mode repeating a doze state and an awake state to inform the second device to switch to the active mode through a predetermined channel; And when the response to the magic packet from the second device has not been received and the predetermined period has not elapsed after transmitting the magic packet through the predetermined channel, the magic packet is retransmitted through the predetermined channel .

Preferably, when a response to the magic packet is not received from the second device, and the predetermined period has elapsed since the first transmission of the magic packet through the predetermined channel, And transmitting the magic packet through the network.

Preferably, the predetermined time is longer than a period in which the second device is in the dosing state.

Preferably, the predetermined time is the same as the predetermined period.

Preferably, the predetermined period is a beacon interval.

Advantageously, the predetermined channel includes a channel used when the first device has recently communicated with the second device.

Advantageously, the predetermined channel includes a social channel.

Preferably, when a response to the magic packet is received from the second device, the method further comprises forming a peer to peer group with the second device.

Preferably, the step of forming the P2P group includes forming a P2P group with the second device using a credential stored in the first device.

Preferably, the first device is a peer to peer client, and the second device is a peer to peer group owner.

Preferably, the magic packet is a probe request frame. The magic packet includes a sixth bit or a sixth bit of a device capability bitmap field of a P2P capability subelement of the probe request frame. And a value of 7 bits is 1.

Preferably, the magic packet is a P2P public action frame, and the type value of the P2P public action frame is any one of 9 to 255. [

Preferably, the Magic packet is a P2P action frame, and the type value of the P2P action frame is any of 4 to 255. [

Preferably, the first device and the second device are Wi-Fi P2P devices.

According to another aspect of the present invention, there is provided a method of switching a second device from a power save mode to an active mode, Forming and synchronizing peer to peer groups; And switching to the active mode when the second device operating in the power save mode repeats a doze state and an awake state based on the synchronization, when the second device is in the awake state And transmitting the magic packet to the second device.

Preferably, one of the first device and the second device is a peer to peer client and the other is a peer to peer group owner, State, the P2P group owner transmits beacon to the P2P client.

Preferably, the first device is a P2P client and the second device is a P2P group owner.

Preferably, transmitting the magic packet includes transmitting the magic packet to the second device after receiving the beacon from the second device when the second device is in the awake state .

Advantageously, the step of transmitting the magic packet includes transmitting the magic packet in a client traffic window (CTWindow).

According to an aspect of the present invention, there is provided a method of switching a power saving mode to an active mode by communicating with a first device communicating with a first device, from the first device, a magic packet informing the user to switch to the active mode when the second device operating in the power saving mode repeats the awake state and the awake state, step; And switching to the active mode upon receipt of the magic packet.

Preferably, the step of receiving the magic packet includes receiving the magic packet in a state where the magic packet is not synchronized with the first device.

Preferably, the method further comprises forming a peer to peer group with the first device after switching to the active mode.

Preferably, the step of forming the P2P group includes forming a P2P group with the first device using a credential stored in the second device.

Preferably, the method further comprises: forming and synchronizing a peer-to-peer group with the first device, wherein the step of receiving the magic packet comprises: And receives the magic packet from the first device when in a wake state.

Preferably, the first device is a peer to peer client, and the second device is a peer to peer group owner.

Advantageously, the step of receiving the magic packet includes receiving the magic packet from the first device after transmitting the beacon to the first device when the second device is in the awake state .

According to an aspect of the present invention, there is provided an apparatus for switching a peer device from a power save mode to an active mode, a transmission unit for transmitting a magic packet notifying an external device operating in the power save mode that the doze state and the awake state are repeated to inform the external device of switching to the active mode through a predetermined channel; And a receiving unit for receiving a response to the magic packet from the external device, wherein the transmitting unit transmits the magic packet through the predetermined channel when a response to the magic packet is not received from the external device, The magic packet is retransmitted through the predetermined channel if a predetermined period has not elapsed after the magic packet is transmitted.

According to another aspect of the present invention, there is provided an apparatus for converting a peer device according to the present invention from a power save mode to an active mode, a synchronization unit for forming and synchronizing peer to peer groups; And means for, when the external device operating in the power save mode repeats a doze state and an awake state, notifying the switch to the active mode when the external device is in the awake state, And a transmitting unit for transmitting the magic packet to the external device.

According to an aspect of the present invention, there is provided an apparatus for switching from a power save mode to an active mode according to the present invention includes a doze state and an awake state, A receiving unit for receiving a magic packet informing that the device operating in the power saving mode repeats the active mode when the device is in the awake state; And a switching unit for switching to the active mode upon receipt of the magic packet.

According to an embodiment of the present invention, a probe request frame of a Wi-Fi peer-to-peer (P2P) standard includes a P2P capability sub-element of a probe request frame A power save mode in which the doze state and the awake state are repeated when the sixth bit or the seventh bit of the device capability bitmap field of the device capability bitmap field is 1, ) Informs the Wi-Fi P2P device operating in the active mode to switch to the active mode.

According to an embodiment of the present invention, a P2P public action frame of a Wi-Fi peer-to-peer (P2P) standard according to the present invention includes a type value of the P2P public action frame The Wi-Fi P2P device operating in a power save mode that repeats a doze state and an awake state is switched to an active mode And the like.

According to an embodiment of the present invention, a P2P action frame of a Wi-Fi peer-to-peer (P2P) P2P action frame according to the present invention is characterized in that the type value of the P2P action frame is 4 ~ 255, which indicates that the Wi-Fi P2P device operating in a power save mode that repeats the doze state and the awake state will switch to the active mode, .

The present invention includes a computer-readable recording medium storing a program for causing a computer to execute a method according to an embodiment of the present invention.

1 is a diagram illustrating a use case in which a P2P group owner communicates with a P2P client according to an embodiment of the present invention.
FIG. 2 is a diagram briefly illustrating a method by which a group owner wakes a client according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating a method of waking up a group owner by a client according to an embodiment of the present invention.
4 is a diagram illustrating an operation of a Wi-Fi P2P device in a power saving mode according to an embodiment of the present invention.
FIG. 5 is a flowchart illustrating a method for waking up a group owner in a state where a client according to an embodiment of the present invention does not form a P2P group.
6 is a flowchart illustrating a method of waking up a group owner in a state in which a client has a P2P group according to an embodiment of the present invention.
FIG. 7 shows a MAC frame format of IEEE 802.11.
FIG. 8 shows the definition of the device capability bitmap field of the Wi-Fi P2P.
FIG. 9 shows a type of P2P public action frame of Wi-Fi P2P.
FIG. 10 shows a type of P2P action frame of Wi-Fi P2P.
11 is a flowchart showing a flow of a method in which a first device according to an embodiment of the present invention switches a second device from a power saving mode to an active mode.
12 is a flowchart showing a flow of a method for a first device according to another embodiment of the present invention to switch a second device from a power saving mode to an active mode.
13 is a flowchart illustrating a method for a first device to switch a second device from a power saving mode to an active mode according to another embodiment of the present invention.
FIG. 14 is a flowchart showing a flow of a method of switching from a power saving mode to an active mode by a second device communicating with a first device according to an embodiment of the present invention.
15 is a diagram showing a configuration of an apparatus for switching an external device from a power saving mode to an active mode according to an embodiment of the present invention.
16 is a diagram showing a configuration of an apparatus for switching an external device from a power saving mode to an active mode according to another embodiment of the present invention.
17 is a diagram illustrating a configuration of an apparatus for switching from a power saving mode to an active mode according to an embodiment of the present invention.

The above objects, features and advantages will become more apparent from the following detailed description in conjunction with the accompanying drawings. It is to be understood that the following description and drawings are not to be interpreted as limiting the scope of the invention and that various detailed descriptions are provided to provide a thorough understanding of the present invention and are the basis of the claims, And is a basis for teaching the owner how to make and / or use the present invention.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention of the user, the operator, or the custom. Therefore, the definition should be based on the contents throughout this specification. Also, when an element is referred to as "comprising ", it means that it can include other elements as well, without departing from the other elements unless specifically stated otherwise. For convenience of explanation, the apparatus and method are described together when necessary.

In the drawings, elements having substantially the same functional configuration are denoted by the same reference numerals and signs as possible, and redundant description is omitted, if necessary. It should be noted that components can be quoted in advance. In addition, the size of each component in the drawings may be exaggerated for clarity of explanation.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a use case in which a P2P group owner (GO) 110 communicates with a P2P client 120 (Client) according to an embodiment of the present invention. The P2P group owner or the group owner 110 in the Wi-Fi P2P plays a similar role as the AP (Access Point) in the conventional Wi-Fi, and the P2P client or the client 120 in the Wi- It plays a similar role as a station (STA) in Wi-Fi.

A Wi-Fi P2P device includes a host and a network interface card (NIC), where the host and the NIC are on a single board or connected by a slot or cable. When in the power saving state, the host is in the power-on state while the power is connected but the NIC is in the power-off state. Here, the switched-off state means Standby, Sleep, Hibernation, or Soft Off. The NIC awakes from sleep mode to active mode, causing the host to come out of a hibernation or other switch off state. Thus, strictly speaking, the NIC of a Wi-Fi P2P device acts as a group owner or client, but for convenience, the Wi-Fi P2P device itself is also referred to as a group owner or client.

In the conventional Wi-Fi, it was necessary to have a separate AP in addition to the stations. However, since more and more mobile devices are used, all devices can be group owners in Wi-Fi P2P. Accordingly, Wi-Fi P2P supports the power saving function of the group owner that was not supported by the conventional Wi-Fi.

Conventional Wake on WLAN (WoWL) is a technology limited to contents defined in the conventional Wi-Fi. That is, the station must operate in Infrastructure Mode and be connected to an AP that supports WPA2 Authentication. Also, the AP must be on at all times. That is, the power saving mode of the AP is not supported. Therefore, there is a limitation in awaking the Wi-Fi P2P client 120 using the WoWL technology. WoWL also only defines when the AP wakes up the station and does not consider the station waking up the AP. Therefore, there is also a limit to wake up Wi-Fi P2P group owners (110) from sleep mode using WoWL technology.

FIG. 2 is a view schematically showing how a group owner 110 awakens a client 120 according to an embodiment of the present invention. The group owner 110 awakes the client 120 from the power saving mode to the active mode by sending a specific packet called Magic Packet to the client 120 operating in the power saving mode.

FIG. 3 is a diagram briefly illustrating a method by which a client 120 awakens a group owner 110 according to an embodiment of the present invention. The client 120 wakes up the group owner 110 from the power saving mode to the active mode by sending a magic packet to the group owner 110 operating in the power saving mode.

4 is a diagram illustrating an operation of a Wi-Fi P2P device in a power saving mode according to an embodiment of the present invention. A Wi-Fi P2P device operating in power-saving mode repeats the awake state and doze state with a beacon interval. When the group owner 110 and the client 120 form a peer to peer group and are synchronized, each device knows when the partner device is in the awake state, The device does not know when the external device is in the awake state. The present invention provides a method of waking up an external device not only when a group owner 110 and a client 120 form a P2P group, but also when a P2P group is not formed. However, it is assumed that both devices have already stored a credential by forming a persistent group.

FIG. 5 is a flowchart illustrating a method of waking a group owner 110 in a state in which a client 120 according to an embodiment of the present invention does not form a P2P group. For convenience of explanation, it is assumed that the client 120 is a Blu-ray Disc (BD) player as a source device and the group owner 110 is a TV as a sink device. It should be noted that the method for waking up the group owner 110 is mainly described for the sake of convenience of explanation. However, the method described below can also be applied to the group owner 110 waking up the client 120. FIG.

 The group owner 110 of the persistent group periodically awakes to transmit a beacon while operating in the power save mode (510).

When a client 120 is triggered by user input or the like, for example, when a user wants to view a BD, the client 120 transmits a magic packet to the group owner 110 through a predetermined channel. At this time, since the client 120 does not know when the group owner 110 is in the awake state, the client 120 repeatedly transmits the magic packet until a response to the magic packet is received from the group owner 110. [ The intervals at which the magic packet is repeatedly transmitted are made sufficiently shorter than the period in which the group owner 110 is in the awake state. If the group owner 110 is using the same channel as the client 120, the magic packet is received within one cycle, i.e., a beacon interval. Accordingly, when the response to the magic packet is not received, the client 120 repeatedly transmits the magic packet for at least the beacon interval through one channel.

If the client 120 has not received a response from the group owner 110 until one period has passed, the client 120 changes the transmission channel to another channel 530 and repeatedly transmits the magic packet 520 ). If the client 120 does not receive a response from the group owner 110 until one more period passes, steps 530 and 520 are repeated in which the transmission channel is changed and the magic packet is repeatedly transmitted.

In one embodiment, client 120 may preferentially use the channel that communicated with group owner 110 recently. If the group owner 110 is using an existing channel, magic packets are received within one cycle, i.e., a beacon interval.

In another embodiment, the client 120 may preferentially use a Social Channel. The social channels are channels 1, 6, and 11 in the 2.4 GHz band. If the group owner 110 is using a social channel, the magic packet is received within three cycles, that is, three times the beacon interval.

In another embodiment, the client 120 may first use the channel that communicated with the group owner 110 recently, and then use the social channel. In this case, if the group owner 110 uses the existing channel or the social channel, the magic packet is received within four cycles.

If the client 120 knows the period in which the group owner 110 is in the doze state, the client 120 may repeatedly transmit the magic packet over a channel for a time longer than the doze period. Therefore, the client 120 can shorten the time for searching for the group owner 110 by changing the channel at a period of time that is slightly longer than the dose period.

Upon receiving the magic packet from the client 120, the group owner 110 switches to the active state 540 and transmits a response to the magic packet to the client 120 to notify success or failure of the magic packet.

When the client 120 receives a success response as a response to the magic packet from the group owner 110, the client 120 forms a P2P group with the group owner 110 to exchange data (560). That is, the client 120 proceeds to the invitation phase of the Wi-Fi P2P and exchanges invitation request and response messages to form a persistent P2P group in the determined channel. Both devices know what the WPA authentication will be through the shared credentials after the roles of the group owner 110 and the client 120 are determined in the existing persistent group. Thus, without going through WPS negotiation, the client 120 accesses the group owner 110 through Authentication and Association request and response. It then performs a 4-way handshake, a WPA negotiation. Security setup is performed through WPA negotiation. After the connection is established in the second layer between the two devices, data transmission in the application layer is started and the image of the BD player is output to the TV.

FIG. 6 is a flowchart illustrating a method of waking a group owner 110 in a state where a client 120 according to an embodiment of the present invention is formed with a P2P group. The method described below may also be applied to the case where the group owner 110 wakes up the client 120. The method for waking up the group owner 110 is not limited to the method described above.

The client 120 and the group owner 110 are currently synchronized because they belong to the same group. The group owner 110 transmits a beacon after transitioning from a doze state to an awake state, and performs a task of synchronizing or giving information about the group to a group member or a new client of the group owner (610). Therefore, the BD player as the client 120 that is synchronized knows the time when the beacon is transmitted, that is, the time when the group owner 110 becomes the awake state. When triggered by the user's input, the client 120 receives 610 the magic packet in the CTWindow of the group owner 110 after receiving the beacon transmitted by the group owner 110 in the next awake state.

Upon receiving the magic packet, the group owner 110 switches to the active mode (630) and transmits a response to the magic packet to the client (640). This ensures that the two devices in the persistent group are ready to transmit image data. Thereafter, data transmission is performed in the third layer (650).

The magic packet according to an embodiment of the present invention conforms to IEEE 802.11 and Wi-Fi P2P. The magic packet includes the contents of a command for changing the value of the power management field, which is a subfield of the frame control field of the device receiving the magic packet, from 1 to 0 regardless of the form . That is, the magic packet includes a request to exit the sleep mode and prepare to receive the image data. The MAC frame format of IEEE 802.11 is shown in Fig.

In one embodiment, the Magic Packet is a Probe Request frame, and the Magic Packet is a Probe Request frame. The magic packet includes a Device Capability Bitmap field of the P2P Capability subelement, which is one of the sub- To the < / RTI > The definition of the Device Capability Bitmap field of the Wi-Fi P2P is shown in Fig. If the sixth bit or 7 bit value of the Device Capability Bitmap field is 1, a magic packet can be represented.

In another embodiment, the magic packet may be implemented as a P2P public action frame, which is added to the Reserved of the type of the P2P public action frame. FIG. 9 shows the Type of the P2P public action frame of the Wi-Fi P2P. If the type value of the P2P public action frame is any one of 9 to 255, a magic packet can be represented.

In another embodiment, the magic packet may be implemented as a P2P action frame, adding to the Reserved of the type of the P2P action frame. FIG. 10 shows the type of the P2P action frame of the Wi-Fi P2P. If the type value of the P2P action frame is any of 4 to 255, it may indicate a magic packet.

11 is a flowchart showing a flow of a method in which a first device according to an embodiment of the present invention switches a second device from a power saving mode to an active mode. Referring to FIG. 11, a method in which a first device according to an exemplary embodiment of the present invention switches a second device from a power saving mode to an active mode includes transmitting, to a second device operating in a power saving mode, And transmitting a magic packet through the predetermined channel when the predetermined period has not elapsed since the response to the magic packet was not received from the second device and the magic packet was transmitted through the predetermined channel And retransmitting the magic packet (step 1120).

12 is a flowchart showing a flow of a method for a first device according to another embodiment of the present invention to switch a second device from a power saving mode to an active mode. The method shown in FIG. 12 is similar to the method shown in FIG. 11 except that a response to the magic packet is not received from the second device, the magic packet is first transmitted through the predetermined channel, The method further includes a step 1210 of transmitting a magic packet through a channel different from the predetermined channel by changing a transmission channel.

13 is a flowchart illustrating a method for a first device to switch a second device from a power saving mode to an active mode according to another embodiment of the present invention. 13, the first device according to another embodiment of the present invention may switch the second device from the power saving mode to the active mode by forming and synchronizing a P2P group with a second device (step 1310) And transmitting (1320), based on the synchronization, the magic packet to the second device when the second device operating in the power save mode is in the awake state.

FIG. 14 is a flowchart showing a flow of a method of switching from a power saving mode to an active mode by a second device communicating with a first device according to an embodiment of the present invention. Referring to FIG. 14, a method for switching a second device communicating with a first device from a power saving mode to an active mode according to an embodiment of the present invention includes: when a second device operating in a power saving mode is in an awake state A step 1410 of receiving a magic packet from a first device, and a step 1420 of switching to an active mode upon receipt of a magic packet.

FIG. 15 is a diagram illustrating a configuration of a device 1500 for switching a peer device from a power saving mode to an active mode according to an embodiment of the present invention. Referring to FIG. 15, a device 1500 for switching an external device from a power saving mode to an active mode according to an embodiment of the present invention transmits a magic packet to a target device operating in a power saving mode via a predetermined channel And a receiving unit 1520 that receives a response to the magic packet from the external device. The transmitting unit 1510 receives the response to the magic packet from the external device, If the predetermined period has not elapsed after transmitting the magic packet through the predetermined channel, the magic packet is retransmitted through the predetermined channel.

16 is a diagram showing a configuration of a device 1600 for switching an external device from a power saving mode to an active mode according to another embodiment of the present invention. 16, a device 1600 for switching an external device from a power saving mode to an active mode according to another embodiment of the present invention includes a synchronization unit 1610 for forming and synchronizing P2P groups with an external device, And a transmitting unit 1620 that transmits the magic packet to the external device when the external device operating in the power saving mode is in the awake state based on the external device.

17 is a diagram showing a configuration of a device 1700 for switching from a power saving mode to an active mode according to an embodiment of the present invention. 17, a device 1700 for switching from a power saving mode to an active mode according to an embodiment of the present invention receives magic packets when the device 1700 operating in a power saving mode is in an awake state And a switching unit 1720 for switching to the active mode according to the reception of the magic packet.

The present invention can also be embodied as computer-readable codes on a computer-readable recording medium. The computer-readable recording medium includes all storage media such as a magnetic storage medium and an optical reading medium. It is also possible to record the data format of the message used in the present invention on a recording medium.

The present invention has been described in detail with reference to the preferred embodiments shown in the drawings. These embodiments are to be considered as illustrative rather than limiting, and should be considered in an illustrative rather than a restrictive sense. Although specific terms are used herein, they are used for the purpose of describing the concept of the present invention only and are not used to limit the scope of the present invention described in the claims or the claims. Therefore, those skilled in the art will appreciate that various modifications, substitutions, and alterations can be made hereto without departing from the spirit and scope of the present invention as defined by the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims and their equivalents. . It is to be understood that such equivalents include all components that are invented in order to perform the same function irrespective of the currently known equivalents as well as the equivalents to be developed in the future.

Claims (33)

A method for a first device to switch a second device from a power save mode to an active mode,
The second device operating in the power save mode repeats a doze state and an awake state according to a predetermined period, ;
When a response to the magic packet is not received from the second device and a predetermined period has not elapsed after transmitting the magic packet through the predetermined channel, the magic packet is retransmitted through the predetermined channel step; And
When a response to the magic packet is not received from the second device and a predetermined period elapses after the first transmission of the magic packet through the predetermined channel, ≪ / RTI > delete The method according to claim 1,
Wherein the predetermined period of time is longer than a period in which the second device is in the dosed state. The method according to claim 1,
Wherein the predetermined period is the same as the predetermined period. The method according to claim 1,
Wherein the predetermined period is a beacon interval. The method according to claim 1,
Wherein the predetermined channel includes a channel used by the first device when it has recently communicated with the second device. The method according to claim 1,
Wherein the predetermined channel comprises a social channel. The method according to claim 1,
Further comprising forming a peer to peer group with the second device when a response to the magic packet is received from the second device. 9. The method of claim 8,
The step of forming the P2P group comprises:
And forming a P2P group with the second device using a credential stored in the first device. The method according to claim 1,
Wherein the first device is a peer to peer client and the second device is a peer to peer group owner. The method according to claim 1,
The magic packet is a probe request frame,
Wherein the value of the sixth or seventh bit of the Device Capability Bitmap field of the P2P capability subelement of the probe request frame is one. The method according to claim 1,
The Magic packet is a P2P public action frame (P2P public action frame)
And the type value of the P2P public action frame is any one of 9 to 255. [ The method according to claim 1,
The Magic packet is a P2P action frame,
Wherein the type value of the P2P action frame is any one of 4 to 255. < RTI ID = 0.0 > 26. < / RTI > The method according to claim 1,
Wherein the first device and the second device are Wi-Fi P2P devices. A method for a first device to switch a second device from a power save mode to an active mode,
Forming and synchronizing peer to peer groups with the second device; And
Wherein the beacon is received from the second device when the second device operating in the power save mode repeats a doze state and an awake state based on the synchronization, ;
And transmitting to the second device a magic packet informing to switch to the active mode after receiving the beacon. 16. The method of claim 15,
Wherein one of the first device and the second device is a peer to peer client and the other is a peer to peer group owner,
And when the second device is in the awake state, the P2P group owner sends a beacon to the P2P client. 16. The method of claim 15,
Wherein the first device is a P2P client and the second device is a P2P group owner. delete 18. The method of claim 17,
Wherein the step of transmitting the magic packet comprises:
And transmitting the magic packet in a Client Traffic Window (CTWindow). CLAIMS What is claimed is: 1. A method for a second device communicating with a first device to transition from a power save mode to an active mode,
In a state in which the second device operating in the power saving mode repeats a doze state and an awake state is in the awake state and is not synchronized with the first device, Receiving a magic packet from the first device, And
And switching to the active mode upon receipt of the magic packet. delete 21. The method of claim 20,
Further comprising: forming a peer-to-peer group with the first device after switching to the active mode. 23. The method of claim 22,
The step of forming the P2P group comprises:
And forming a P2P group with the first device using a credential stored in the second device. 21. The method of claim 20,
Further comprising: forming and synchronizing peer to peer groups with the first device,
Wherein the receiving the magic packet comprises:
And when the second device is in the awake state, receiving the magic packet from the first device based on the synchronization. 21. The method of claim 20,
Wherein the first device is a peer to peer client and the second device is a peer to peer group owner. 26. The method of claim 25,
Wherein the receiving the magic packet comprises:
And receiving the magic packet from the first device after transmitting the beacon to the first device when the second device is in the awake state. An apparatus for switching a peer device from a power save mode to an active mode,
Transmitting a magic packet notifying an external device operating in the power saving mode that a doze state and an awake state are repeated according to a predetermined cycle to switch to the active mode through a predetermined channel ; And
And a receiving unit for receiving a response to the magic packet from the external device,
The transmitter may further comprise:
When the response to the magic packet is not received from the external device and the magic packet is transmitted through the predetermined channel and the predetermined period has not elapsed, the magic packet is retransmitted through the predetermined channel, When a response to the magic packet is not received from the external device and a predetermined period has elapsed since the first transmission of the magic packet through the predetermined channel, the magic packet is transmitted through a channel different from the predetermined channel And transmits the data. An apparatus for switching a peer device from a power save mode to an active mode,
A synchronization unit for forming and synchronizing peer to peer groups with the external device; And
When the external device operating in the power save mode repeats a doze state and an awake state based on the synchronization, receives a beacon from the external device when the external device is in the awake state And a transmitting unit for transmitting a magic packet to the external device to inform that the active mode is to be switched. A device for switching from a power save mode to an active mode,
Wherein the device is in the awake state in which the device operating in the power save mode that repeats a doze state and an awake state is switched to the active mode in a state in which the device is not in synchronization with an external device to be communicated A receiving unit for receiving a magic packet from the external device; And
And a switching unit for switching to the active mode upon receipt of the magic packet. 1. An apparatus including a probe request frame of a Wi-Fi peer-to-peer (P2P) standard,
A synchronization unit for establishing synchronization with a Wi-Fi P2P device;
A receiving unit for receiving a beacon from the Wi-Fi P2P device; And
If the value of the sixth bit or the seventh bit of the device capability bitmap field of the P2P capability subelement after receiving the beacon is 1, the doze state and the awake Wherein the Wi-Fi P2P device operating in a power save mode that repeats a awake state informs the Wi-Fi P2P device to switch to an active mode. An apparatus comprising a P2P public action frame of Wi-Fi peer to peer specification,
A synchronization unit for establishing synchronization with a Wi-Fi P2P device;
A receiving unit for receiving a beacon from the Wi-Fi P2P device; And
A power saving mode in which a doze state and an awake state are repeated when the type value of the P2P public action frame is any of 9 to 255 after receiving the beacon; The P2P public action frame indicating that the Wi-Fi P2P device operating in the active mode is to be switched to an active mode. 1. An apparatus comprising a peer to peer (P2P) action frame of Wi-Fi P2P (P2P)
A synchronization unit for establishing synchronization with a Wi-Fi P2P device;
A receiving unit for receiving a beacon from the Wi-Fi P2P device; And
A power saving mode in which a doze state and an awake state are repeated when the type value of the P2P action frame is any of 4 to 255 after receiving the beacon, And the P2P action frame informing the Wi-Fi P2P device operating as an active mode to switch to an active mode. A computer-readable recording medium storing a program for causing a computer to execute the method according to any one of claims 1, 3 to 17, 19 to 20, and 22 to 26.

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