KR20110073239A - Method and apparatus for service discovery in wifi direct network - Google Patents

Abstract

PURPOSE: A service searching method and device thereof are provided to enable devices to search a usable service in a WFD network at a stage before connecting two layers. CONSTITUTION: A frame maker(1810) generates a service discovery request frame for searching a service which supports a second WFD device of a WFD(WiFi Direct) network. The frame forwarding unit(1820) transmits a service search request frame to a second WFD device. A frame receiver(1830) receives a service probe response frame by responding to service search request frame from the second WFD device.

Description

Method and apparatus for service discovery in WiFi direct network {Method and apparatus for service discovery in WiFi direct network}

The present invention relates to a service discovery method and apparatus thereof in a WiFi Direct (hereinafter referred to as WFD) network, and more particularly, to a two-layer association using a two-layer Wi-Fi Protected Setup (IE) Information Element (IE). The present invention relates to a method and apparatus for service discovery in a WFD network, wherein devices in the WFD network search for services available to each other.

The WFD network is a network that allows peer-to-peer connections with each other without WiFi devices participating in home networks, office networks, and hotspot networks, and has been proposed by the WiFi Alliance.

Devices in the WFD network should be able to search each other's capability information and the like. For the discovery of device and supported service capability information, three or more layers of discovery protocols of the OSI 7 layer have been conventionally used. Protocols of three or more layers include UPnP (Universal Plug and Play), Simple Service Discovery Protocol (SSDP), Zero Configuration Networking (ZeroConf), and DNS Service Discovery (DNS-SD).

However, a process of determining a service that a device can support using a protocol of three or more layers is started after a two-layer connection is preset to the corresponding device. After that, if it is determined that the device does not satisfy the service requirement of the user, the device needs to disconnect the layer 2 connection already established and reset the layer 2 connection to another device to search for a service that can be supported by another device.

Thus, given that small portable devices have low battery capacity, services that can be supported by the device at the Layer 2 Pre-Association Stage for improved energy efficiency and user experience. A new way to navigate is required.

An object of the present invention is to use devices in a Wi-Fi Direct (WFD) network in a Layer 2 Pre-Association Stage (WPD) using a Layer 2 Wi-Fi Protected Setup (IE) Information Element (IE). The present invention provides a method and apparatus for searching for a service in a WiFi Direct network that searches for possible services, and provides a computer-readable recording medium having recorded thereon a program for executing the method.

According to an embodiment of the present invention, a service discovery method of a first WFD device in a WFD network may include a service discovery request frame for discovering a service supported by a second WFD device of a WFD network. Generating; Sending the service discovery request frame to the second WFD device; And receiving a service search response frame from the second WFD device in response to the service search request frame; The service discovery request frame and the service discovery response frame are generated using a Wi-Fi Protected Setup (WPS) Information Element (IE).

According to an embodiment of the present invention, the WPS IE includes a WPS Attribue ID and a Sub-Attrib ID; The WPS attribute identifier includes a value identifying that it includes vendor extension data; The attachment identifier includes a value identifying a service supported by the second WFD device.

According to an embodiment of the present invention, the attachment identifier identifies at least one of system information, device capability information, display capability information, video profile information, audio profile information, transmission capability information, and 3D (Dimensional) capability information.

According to an embodiment of the present invention, the WPS IE in the service discovery response frame includes sub-elements for a service supported by the second WFD device.

According to an embodiment of the present invention, the sub-element for the service supported by the second WFD device includes system information, device capability information, display capability information, video profile information, audio profile information, transmission capability information, and 3D (Dimensional) capability. At least one of the information.

According to an embodiment of the present invention, the step of transmitting the service discovery request frame to the second WFD device may include transmitting the service discovery request frame to the second WFD device in a unicast manner or in a broadcast manner using a Probe Request frame. Send to.

According to an embodiment of the present invention, the method may further include selectively setting a layer 2 secure connection to the second WFD device based on the service information supported by the second WFD device included in the service discovery response frame. .

According to an embodiment of the present invention, the first WFD device and the second WFD device are WiFi Display Certified devices.

In addition, according to an embodiment of the present invention, the service discovery method of the second WFD device in the WFD network includes a service discovery request frame for searching for a service supported by the second WFD device of the WiFi Direct (WFD) network; Receiving from; Generating a service discovery response frame, which is a response frame to the service discovery request frame; And sending the service search response frame to the first WFD device; The service discovery request frame and the service discovery response frame are generated using a Wi-Fi Protected Setup (WPS) Information Element (IE).

According to an embodiment of the present invention, transmitting the service discovery response frame to the first WFD device transmits the service discovery response frame to the first WFD device in a unicast manner using a probe response frame.

In addition, according to an embodiment of the present invention includes a computer-readable recording medium on which a program for performing the method is recorded.

In addition, according to an embodiment of the present invention, in the WFD network, the first WFD device generates a service discovery request frame for searching for a service supported by the second WFD device of the WFD network. A frame generator; A frame transmitter which transmits the service discovery request frame to the second WFD device; And a frame receiving unit receiving a service search response frame from the second WFD device in response to the service search request frame; The service discovery request frame and the service discovery response frame are generated using a Wi-Fi Protected Setup (WPS) Information Element (IE).

In addition, according to an embodiment of the present invention, in the WFD network, the second WFD device receives a service discovery request frame for searching for a service supported by the second WFD device of the WFD (WiFi Direct) network from the first WFD device. Receiving unit; A frame generation unit generating a service discovery response frame which is a response frame to the service discovery request frame; And a frame transmitter for transmitting the service search response frame to the first WFD device; The service discovery request frame and the service discovery response frame are generated using a Wi-Fi Protected Setup (WPS) Information Element (IE).

1 illustrates a WiFi Direct (WFD) network according to an embodiment of the present invention.
2 is a flowchart illustrating a service discovery request process of a first WFD device in a WFD network according to an embodiment of the present invention.
3 is a flowchart illustrating a service discovery response process of a second WFD device in a WFD network according to an embodiment of the present invention.
4 illustrates a Wi-Fi Protected Setup (WPS) Information Element (IE) according to an embodiment of the present invention.
5 illustrates a service search request TLV of a service search request frame according to an embodiment of the present invention.
6 illustrates a service search response TLV of a service search response frame according to an embodiment of the present invention.
7 illustrates a sub-attrib ID value and its meaning according to an embodiment of the present invention.
8 illustrates information included in a system information sub element according to an embodiment of the present invention.
9 illustrates information included in a device capability sub element according to an embodiment of the present invention.
FIG. 10 illustrates information included in a display capability sub element according to an embodiment of the present invention.
11 illustrates information included in a video profile sub element according to an embodiment of the present invention.
12 illustrates information included in an audio profile subelement according to an embodiment of the present invention.
FIG. 13 illustrates information included in a transport capability sub element according to an embodiment of the present invention.
FIG. 14 illustrates information included in a 3D capability subelement according to an embodiment of the present invention.
15 illustrates status code values of the 3D capability subelements in accordance with an embodiment of the present invention.
16 illustrates an exemplary service search request frame according to an embodiment of the present invention.
17 illustrates an exemplary service search response frame according to an embodiment of the present invention.
18 is a block diagram illustrating a first WFD device structure according to an embodiment of the present invention.
19 is a block diagram illustrating a second WFD device structure according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements, and the size of each element in the drawings may be exaggerated for clarity.

1 illustrates a WiFi Direct (WFD) network according to an embodiment of the present invention.

The WFD network 100 may include at least one WiFi device including a first WFD device 110 and a second WFD device 120. WFD devices include devices that support WiFi, such as display devices, printers, digital cameras, projectors, and mobile phones. The WFD device includes a WiFi Display Certified device.

WFD devices in a WFD network may connect directly to each other without using a wireless local area network (WLAN) access point (AP). To this end, the WFD device implements a new firmware protocol.

In the example shown, the first WFD device 110 is a mobile phone and the second WFD device 120 is a display device. The first WFD device 110 and the second WFD device 120 may configure a WFD network by establishing a direct peer-to-peer connection with each other.

2 is a flowchart illustrating a service discovery request process of a first WFD device in a WFD network according to an embodiment of the present invention.

In the WFD network according to an embodiment of the present invention, the WFD devices search for services that the WFD device can support in the Layer 2 Pre-Association Stage.

In operation 220, the first WFD device generates a service discovery request frame for searching for a service supported by the second WFD device of the WFD network.

In step 230, the first WFD device sends a service discovery request frame to the second WFD device.

In operation 240, the first WFD device receives a service discovery response frame from the second WFD device in response to the service discovery request frame.

The service discovery request frame and the service discovery response frame according to an embodiment of the present invention are generated by using a Wi-Fi Protected Setup (WPS) Information Element (IE). The WPS IE is described in detail below with reference to FIG.

According to an embodiment of the present invention, after determining the service information supported by the second WFD device included in the service discovery response frame, selectively secures the second layer with the second WFD device only if the device satisfies the user's requirements. You can establish a connection. Therefore, according to an embodiment of the present invention, a device satisfying a user's requirement among a plurality of WFD devices may be selected in a pre-layer 2 connection step.

Therefore, according to an embodiment of the present invention, by searching for a service that the WFD device can support in the pre-layer 2 connection step, it is possible to avoid a repetitive layer 2 connection establishment process in order to search for a device supporting a service desired by the user. It can reduce consumption and improve the user experience.

According to an embodiment of the present invention, for the service discovery of the WFD device, it is possible to minimize the cost and implementation complexity of the service discovery in the pre-layer 2 connection stage by minimizing the exchanged frame format and the transmission and reception procedure. It can support easy connection establishment between WFD devices in WFD network.

3 is a flowchart illustrating a service discovery response process of a second WFD device in a WFD network according to an embodiment of the present invention.

In step 320, the second WFD device receives a service discovery request frame from the first WFD device.

In operation 330, the second WFD device generates a service discovery response frame, which is a response frame to the service discovery request frame.

In step 340, the second WFD device sends a service search response frame to the first WFD device.

4 illustrates a Wi-Fi Protected Setup (WPS) Information Element (IE) according to an embodiment of the present invention.

Wi-Fi Protected Setup (WPS) has been proposed by the WiFi Alliance as a standard for easy and secure installation of wireless home networks. The purpose of WPS is to simplify the process of connecting home devices to wireless networks and to protect home networks from external attacks.

The WPS defines an 802.11 WPS Information Element (IE), as shown, and the WPS IE is included in a beacon, a Probe Request frame, and a Probe Response frame in the WFD network and transmitted.

According to an embodiment of the present invention, the WPS IE may be used to packetize the service discovery request frame and the service discovery response frame which are respectively transmitted and received for service discovery of the WFD device. That is, the service search request frame refers to a probe request frame including a WPS IE including a data field for a service search request. In addition, the service discovery response frame refers to a probe response frame including a WPS IE including a data field for a service discovery response.

The first WFD device that wants to search for a service of the second WFD device may transmit the service discovery request frame to the second WFD device in a unicast method or a broadcast method using a Probe Request frame.

After receiving the service discovery request frame, the second WFD device may transmit the service discovery response frame to the first WFD device in a unicast manner using a probe response frame in response thereto.

In the illustrated example, the WPS IE includes "Element ID", "Length", "Organizationally Unique Identifier" (OUI), and "Data" fields (or data fields). Each size of the "Element ID", "Length", and "OUI" fields is 1, 1, and 4 octets. The size of the "Data" field is a variable size, ranging from at least 1 octet to at most 251 octets.

In the present embodiment, the value of "Element ID" is "221", the value of "OUI" is "0x0050F204", and when the size of the "Data" field is N, "Length" has a value of "4 + N". Detailed definitions of the "Element ID", "Length", "OUI", and "Data" fields of the WPS IE follow the WPS standard, and thus a detailed description thereof is omitted here.

5 illustrates a service search request TLV of a service search request frame according to an embodiment of the present invention.

The data field of the service discovery request frame includes a service discovery request TLV described in a type length value (TLV) format.

The service discovery request TLV contains the fields "WPS Attrib ID", "Length", "OUI", "Sub-Category ID", "Transaction ID" and "Sub-Attrib ID", each of which in turn is 1, 2 , 4, 1, 1 and 1 octets in size.

The "WPS Attrib ID" (or WPS Attribute Identifier) field contains the identifier of the WPS attribute, and the "Length" field contains the length value of the service search request TLV. The "OUI" field contains the identifier assigned to the agency, and the "Sub-Category ID" field contains the revision identification number of the WFD standard. The "Transaction ID" field includes an identifier for associating a service discovery request frame with a service discovery response frame, and the "Sub-Attrib ID" (or an appendage identifier) field includes an identifier for identifying a service supported by the WFD device. .

According to this embodiment, the "WPS Attrib ID" field has a value of "0x1049" as a value for identifying vendor extension data, the "Length" field is "7", and the "OUI" field identifies a WFA authority. Has a value of "0x506F9A", and the "Sub-Category ID" field is a current revision identification number of the WFD standard and has a value of "0x01".

The "Transaction ID" field is set to any non-zero value when the service search request frame is generated.

If you want to search all services supported by the target WFD device, the data field of the service search request frame includes one service search request TLV, and the "Sub-Attrib ID" field of the service search request TLV is set to a value of "0". Is set.

If the target WFD device wants to search for one specific service, the data field of the service search request frame includes one service search request TLV, and the "Sub-Attrib ID" field of the service search request TLV is shown in FIG. 7. It is set to a predetermined service identification value corresponding to the specific service described in.

If the target WFD device wants to search for a plurality of specific services, the data field of the service search request frame includes a plurality of service search request TLVs, and the "Sub-Attrib ID" field of each service search request TLV is It is set to a predetermined service identification value corresponding to the specific service described in FIG.

The "Sub-Attrib ID" field will be described later in detail with reference to FIG. 7.

6 illustrates a service search response TLV of a service search response frame according to an embodiment of the present invention.

The data field of the service discovery response frame includes a service discovery response TLV described in a type length value (TLV) format.

The service discovery response TLV contains the fields "WPS Attrib ID", "Length", "OUI", "Sub-Category ID", "Transaction ID", "Sub-Attrib ID" and "Sub-Element" (or sub element) fields. Each field in turn has a size of 1, 2, 4, 1, 1, 1, and variable length octets.

The "Sub-Element" field includes information about a service supported by the WFD device. The meanings of the "WPS Attrib ID", "Length", "OUI", "Sub-Category ID", "Transaction ID", and "Sub-Attrib ID" fields have the same meaning as the corresponding fields of the service discovery request TLV. Therefore, a detailed description thereof will be omitted here.

According to this embodiment, the "WPS Attrib ID" field has a value of "0x1049" as a value for identifying that it contains vendor extension data, and the "OUI" field has a value of "0x506F9A" for identifying a WFA authority, and "Sub The -Category ID "field is the current revision identification number of the WFD standard and has a value of" 0x01 ". The "Length" field has a value of "7 + N" when the size of the "Sub-Element" field is N.

The "Transaction ID" field is set to a value included in the service search request frame to identify that the service search response frame is generated in response to the service search request frame.

If you want to search all services supported by the target WFD device, the data field of the service search request frame includes one service search request TLV, and the "Sub-Attrib ID" field of the service search request TLV is set to a value of "0". Is set. In this case, the data field of the service search response frame includes a plurality of service search response TLVs. The "Sub-Attrib ID" field of each service search response TLV includes a predetermined service identification value corresponding to the specific service, described in FIG. 7. The "Sub-Element" of each service search response TLV includes predetermined information corresponding to the specific service identified by "Sub-Attrib ID" described in Figs. 8 to 15, respectively.

If the target WFD device wants to search for one specific service, the data field of the service search request frame includes one service search request TLV, and the "Sub-Attrib ID" field of the service search request TLV is shown in FIG. 7. It is set to a predetermined value corresponding to the specific service described in. In this case, the data field of the service search response frame includes one service search response TLV. The "Sub-Attrib ID" field of the service search response TLV includes a predetermined service identification value corresponding to the specific service described in FIG. 7. The "Sub-Element" of the service search response TLV includes predetermined information corresponding to the specific service identified by "Sub-Attrib ID" described in Figs. 8 to 15, respectively.

If the target WFD device wants to search for a plurality of specific services, the data field of the service search request frame includes a plurality of service search request TLVs, and the "Sub-Attrib ID" field of each service search request TLV is It is set to a predetermined value corresponding to the specific service described in FIG. In this case, the data field of the service search response frame includes a plurality of service search response TLVs. The "Sub-Attrib ID" field of each service search response TLV includes a predetermined service identification value corresponding to the specific service, described in FIG. 7. The "Sub-Element" of each service search response TLV includes predetermined information corresponding to the specific service identified by "Sub-Attrib ID" described in Figs. 8 to 15, respectively.

7 illustrates a sub-attrib ID value and its meaning according to an embodiment of the present invention.

"Sub-Attrib ID" indicates various Capabilities that the WFD device supports. "Sub-Attrib ID" has a size of one octet. In this embodiment, values "0x00" through "0x07" are assigned to specific capabilities of the device, respectively, and values "0x08" through "0xff" are reserved.

When the value of "Sub-Attrib ID" is "0x00", this indicates all capability information supported by the device. If you want to search all services supported by the target WFD device, the data field of the service search request frame includes one service search request TLV, and the "Sub-Attrib ID" field of the service search request TLV is set to a value of "0". Is set.

When the value of "Sub-Attrib ID" is "0x01", this indicates information corresponding to the system level of the device. Information corresponding to the system level of the device will be described later in detail with reference to FIG. 8.

 When the value of "Sub-Attrib ID" is "0x02", this indicates device capability information. The capability information of the device will be described later in detail with reference to FIG. 9.

 When the value of "Sub-Attrib ID" is "0x03", it indicates display capability information. The display capability information will be described later in detail with reference to FIG. 10.

When the value of "Sub-Attrib ID" is "0x04", it indicates video profile information of the device. The video profile information will be described later in detail with reference to FIG. 11.

When the value of "Sub-Attrib ID" is "0x05", this indicates audio profile information of the device. Audio profile information will be described later in detail with reference to FIG. 12.

When the value of "Sub-Attrib ID" is "0x06", it indicates transmission capability information of the device. Transmission capability information will be described later in detail with reference to FIG.

When the value of "Sub-Attrib ID" is "0x07", it indicates 3D (Dimensional) capability information of the device. The 3D capability information will be described later in detail with reference to FIG. 14.

If the target WFD device wants to search for one specific service, the data field of the service search request frame includes one service search request TLV, and the "Sub-Attrib ID" field of the service search request TLV is shown. It is set to a predetermined value corresponding to the specific service as shown. In this case, the data field of the service search response frame includes one service search response TLV. The "Sub-Attrib ID" field of the service search response TLV includes a predetermined service identification value included in the service search request TLV.

8 illustrates information included in a system information sub element according to an embodiment of the present invention.

According to one embodiment of the present invention, the system information sub-element includes at least one of a manufacturing code, a product code, a date of manufacture, a serial number, a serial number specification, and a product name.

The manufacturing code is a four byte ASCII code, and the product code is a product code assigned by the manufacturer and has a size of two bytes. The serial number is 4 bytes in size. The serial number specification is 16 bytes in size and describes the serial number description in ASCII code. The product name is 16 bytes in size and describes the product name in ASCII code.

9 illustrates information included in a device capability sub element according to an embodiment of the present invention.

According to an embodiment of the present invention, the device capability sub-element includes a bit for setting whether it is a video transmission source, a bit for setting whether it is a video reception source, a bit for setting whether it is an audio transmission source, and setting whether it is an audio reception source or not. Bits, bits to set whether AV synchronization information is provided, bits to set audio delay control, bits to set connection availability, bits to set HDCP support, bits to set CEC support, and maximum number of video transmission streams At least one of 8 bits for setting the number, 8 bits for setting the maximum number of audio transmission streams, 8 bits for setting the maximum number of video receiving streams, and 8 bits for setting the maximum number of audio receiving streams.

FIG. 10 illustrates information included in a display capability sub element according to an embodiment of the present invention.

According to an embodiment of the present invention, the display capability sub-element may include a feature, an RGB color depth, a YCbCr 444 color depth, a YCbCr 442 color depth, a horizontal size, and a vertical screen size ( Vertical Size).

Support features include bits to enable pivot support, bits to enable support for "YCbCr 4: 4: 4", bits to enable support for "YCbCr 4: 4: 2", and support for "underscan". Contains the bit to set.

RGB color depth is a bit to set whether or not to support RGB with 24-bit color per pixel, a bit to set whether to support RGB with 30-bit color per pixel, a bit to set whether to support RGB with 36-bit color per pixel and 48 bits per pixel Contains bits that set whether or not RGB is supported as a color.

YCbCr 444 color depth is a bit to set whether or not to support YCbCr at 24 bits per pixel, a bit to set whether to support YCbCr to 30 bits per pixel, a bit to set whether to support YCbCr to 36 bits per pixel, and 48 per pixel Includes bits that set whether or not to support YCbCr as the bit color.

The YCbCr 442 color depth is the bit that sets YCbCr support with 16-bit color per pixel, the bit that sets YCbCr support with 24-bit color per pixel, the bit that sets YCbCr support with 30-bit color per pixel, and the pixel per pixel. Includes bits that set whether or not to support YCbCr in 36-bit color.

The horizontal screen size has a horizontal screen size value in millimeters (mm).

The vertical screen size has a vertical screen size value in millimeters (mm).

11 illustrates information included in a video profile sub element according to an embodiment of the present invention.

According to an embodiment of the present invention, the video profile subelement describes codec profile information including at least one of a baseline profile and an extension profile.

The baseline profile includes bits for setting level 1 support and bits for setting level 2 support.

The extension profile includes bits for setting level 1 support and bits for setting level 2 support.

12 illustrates information included in an audio profile subelement according to an embodiment of the present invention.

According to an embodiment of the present invention, the audio profile sub-element has 48KHz stereo and bit rate for supporting 16-bit LPCM at 1536Kbps, low complexity (LC) profile, 2 channel and Advanced Audio Coding at 128Kbps data rate. ) Bit to set whether to support Dolby Digital 5.1 at data rate of 576Kbps, Bit to set whether to support DTS (Digital Theater System) 5.1 at data rate of 768Kbps, 48KHz stereo, 6 channels and 4608Kbps to data rate Bits to set 16 bit LPCM support, Bits to set Dolby Digital Plus support at data rate up to 1.7 Mbps, Bits to set Dolby TrueHD support at data rate up to 18 Mbps and DTS HD master to Data rates up to 25.4 Mbps It includes at least one of the bits for setting whether or not support.

FIG. 13 illustrates information included in a transport capability sub element according to an embodiment of the present invention.

According to an embodiment of the present invention, the transmission capability sub element describes transmission capability information including at least one of transmission capability information for error feedback and transmission capability information for receiving a user input.

The transmission capability information for error feedback includes bits for setting whether to support Real-time Transport Protocol (RTP) / Audio Video Profile (AVP), bits for setting whether to support RTP / Audio-Visual Profile with Feedback (AVPF), and currently set Bits for setting the number of RTP sessions and bits for setting the maximum number of RTP sessions that can be supported.

Transmission capability information for receiving user input includes bits that set ASCII input characters, bits that set single / multiple pointing input values, function code input value set bits, and IB (In Band) User Input Back Channel (UIBC) support. It includes at least one of a bit for setting the bit, a bit for setting whether to support OOB (Out Of Band) UIBC using RTP and a bit for setting whether to support OOB (Out Of Band) UIBC using Zigbee.

FIG. 14 illustrates information included in a 3D capability subelement according to an embodiment of the present invention.

According to an embodiment of the present invention, the 3D capability sub-element includes bits for setting a status code, frame packing support setting bit, field packing support setting bit, line alternative support setting bit, and "Full Side by Side" support. Whether to set bit, whether to support "Half Side by Side" bit, whether to support "L + depth" bit, whether to support "L + depth + Gfx + G-depth" bit or whether to support "Frame Sequential" bit At least one.

15 illustrates status code values of the 3D capability subelements in accordance with an embodiment of the present invention.

The status code includes at least one of 3D support setting bits and 3D partial support setting bits.

16 illustrates an exemplary service search request frame according to an embodiment of the present invention.

The service search request frame refers to a probe request frame including a WPS IE including a data field for a service search request.

In the illustrated example, the WPS IE includes "Element ID", "Length", "Organizationally Unique Identifier" (OUI), and "Data" fields (or data fields). Each size of the "Element ID", "Length", and "OUI" fields is 1, 1, and 4 octets. The size of the "Data" field is a variable size, ranging from at least 1 octet to at most 251 octets.

In the illustrated example, the "Element ID" value is "221", the "OUI" value is "0x0050F204", and the "Length" has a "4 + N" value when the size of the "Data" field is N.

The data field of the service discovery request frame includes a service discovery request TLV described in a type length value (TLV) format.

The service discovery request TLV contains the fields "WPS Attrib ID", "Length", "OUI", "Sub-Category ID", "Transaction ID" and "Sub-Attrib ID", each of which in turn is 1, 2 , 4, 1, 1 and 1 octets in size.

In the example shown, the "WPS Attrib ID" field has a value of "0x1049" as a value that identifies vendor extension data, the "Length" field is "7", and the "OUI" field identifies a WFA authority. 0x506F9A ", and the" Sub-Category ID "field is the current revision identification number of the WFD standard and has a value of" 0x01 ".

The "Transaction ID" field is set to any value other than 0 when the service search request frame is generated, and has a value of "0x01" in the illustrated example.

In the example shown, the "Sub-Attrib ID" field has a value "0x01", which means that it requests system information of the target WFD device.

17 illustrates an exemplary service search response frame according to an embodiment of the present invention.

The service discovery response frame refers to a probe response frame including a WPS IE including a data field for a service discovery response.

The WPS IE includes "Element ID", "Length", "Organizationally Unique Identifier" and "Data" fields (or data fields). In the illustrated example, the "Element ID" value is "221", the "OUI" value is "0x0050F204", and the "Length" has a "4 + N" value when the size of the "Data" field is N.

The data field of the service discovery response frame includes a service discovery request TLV described in a type length value (TLV) format.

The service discovery response TLV contains the fields "WPS Attrib ID", "Length", "OUI", "Sub-Category ID", "Transaction ID", "Sub-Attrib ID" and "Sub-Element" (or sub element) fields. Each field in turn has a size of 1, 2, 4, 1, 1, 1, and variable length octets. The meanings of the "WPS Attrib ID", "Length", "OUI", "Sub-Category ID", "Transaction ID", and "Sub-Attrib ID" fields have the same meaning as the corresponding fields of the service discovery request TLV. Therefore, a detailed description thereof will be omitted here.

The "Length" field has a value of "7 + N" when the size of the "Sub-Element" field is N.

In the illustrated example, the "Transaction ID" field is set to "0x01" which is a value included in the service search request frame to identify the service search response frame generated in response to the service search request frame.

In the example shown, the "Sub-Element" field contains system information, identified by the "Sub-Attrib ID" of the service search request frame. According to one embodiment of the present invention, the system information sub-element includes at least one of a manufacturing code, a product code, a date of manufacture, a serial number, a serial number specification, and a product name.

18 is a block diagram illustrating a first WFD device structure according to an embodiment of the present invention.

The first WFD device 1800 includes a frame generator 1810, a frame transmitter 1820, and a frame receiver 1830. The first WFD device 1800 discovers a service that WFD devices can support in another WFD device (eg, the second WFD device 1900) in a Layer 2 Pre-Association Stage in the WFD network.

The frame generation unit 1810 generates a service discovery request frame for searching for a service supported by the second WFD device of the WFD network. The service search request frame is generated using the WPS IE. The WPS IE includes a WPS Attribue ID and a Sub-Attrib ID. The WPS attribute identifier includes a value that identifies vendor extension data, and the attachment identifier includes a value that identifies a service supported by the second WFD device.

The appendage identifier identifies at least one of system information, device capability information, display capability information, video profile information, audio profile information, transmission capability information, and 3D (Dimensional) capability information.

The frame transmitter 1820 transmits the service discovery request frame to the second WFD device. The frame transmitter 1820 transmits the service discovery request frame to the second WFD device in a unicast method or a broadcast method using a Probe Request frame.

The frame receiving unit 1830 receives the service search response frame from the second WFD device in response to the service search request frame.

In addition, the first WFD device 1800 may further include a connection setting unit (not shown). The connection setting unit optionally sets a layer 2 secure connection to the second WFD device based on the service information supported by the second WFD device included in the service discovery response frame.

The first WFD device and the second WFD device may be WiFi Display Certified devices.

19 is a block diagram illustrating a second WFD device structure according to an embodiment of the present invention.

The second WFD device 1900 includes a frame receiver 1910, a frame generator 1920, and a frame transmitter 1930.

The frame receiver 1910 receives a service discovery request frame from the first WFD device.

The frame generator 1920 generates a service search response frame that is a response frame to the service search request frame. The service search response frame is generated using the WPS IE. The WPS IE includes a WPS Attribue ID and a Sub-Attrib ID.

The WPS attribute identifier includes a value that identifies vendor extension data, and the attachment identifier includes a value that identifies a service supported by the second WFD device.

The appendage identifier identifies at least one of system information, device capability information, display capability information, video profile information, audio profile information, transmission capability information, and 3D (Dimensional) capability information.

The WPS IE in the service search response frame includes sub-elements for the service supported by the second WFD device. The sub element for the service supported by the second WFD device includes at least one of system information, device capability information, display capability information, video profile information, audio profile information, transmission capability information, and 3D (Dimensional) capability information.

The frame transmitter 1930 transmits the service discovery response frame to the first WFD device. The frame transmitter 1930 transmits the service discovery response frame to the first WFD device in a unicast manner using a probe response frame.

Although the preferred embodiment of the present invention has been described in detail above, the scope of the present invention is not limited thereto, and various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the appended claims.

For example, a first WFD device 1800 and a second WFD device 1900 according to an exemplary embodiment of the present invention may be a bus coupled to units of respective devices as shown in FIGS. 18 and 19, respectively. At least one processor coupled to the bus for storing instructions, received or generated messages, the at least one processor coupled to the bus for performing instructions as described above. It may include a memory coupled to.

In addition, the system according to the present invention can be embodied as computer readable codes on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. The computer-readable recording medium may be a magnetic storage medium (for example, a ROM, a floppy disk, a hard disk, etc.), an optical reading medium (for example, a CD-ROM, a DVD, etc.), and a carrier wave (for example, the Internet). Storage medium). The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

Claims (18)

Generating a service discovery request frame for searching for a service supported by a second WFD device of a WFD network;
Sending the service discovery request frame to the second WFD device; And
Receiving a service search response frame from the second WFD device in response to the service search request frame;
The service discovery request frame and the service discovery response frame are generated using a Wi-Fi Protected Setup (WPS) Information Element (IE). The method of claim 1,
The WPS IE includes a WPS Attribue ID and a Sub-Attrib ID;
The WPS attribute identifier includes a value identifying that it includes vendor extension data;
The appendage identifier includes a value for identifying a service supported by the second WFD device. The method of claim 1, wherein the appendage identifier is
At least one of system information, device capability information, display capability information, video profile information, audio profile information, transmission capability information, and 3D (Dimensional) capability information, wherein the service discovery method of the first WFD device in the WFD network . The method of claim 1,
The WPS IE in the service discovery response frame includes a sub element for a service supported by the second WFD device. The method of claim 4, wherein the sub element for the service supported by the second WFD device is
A service discovery method of a first WFD device in a WFD network comprising at least one of system information, device capability information, display capability information, video profile information, audio profile information, transmission capability information, and 3D (Dimensional) capability information. . The method of claim 1, wherein transmitting the service discovery request frame to the second WFD device
And transmitting the service discovery request frame to the second WFD device in a unicast manner or in a broadcast manner using a Probe Request frame. The method of claim 1,
Selectively establishing a layer 2 secure connection to the second WFD device based on service information supported by the second WFD device included in the service discovery response frame. 1 Service discovery method of WFD device. The method of claim 1,
And the first WFD device and the second WFD device are WiFi Display Certified devices. Receiving a service discovery request frame for searching for a service supported by a second WFD device of a WFD network from the first WFD device;
Generating a service discovery response frame, which is a response frame to the service discovery request frame; And
Sending the service search response frame to the first WFD device;
The service discovery request frame and the service discovery response frame are generated using a Wi-Fi Protected Setup (WPS) Information Element (IE). The method of claim 9,
The WPS IE includes a WPS Attribue ID and a Sub-Attrib ID;
The WPS attribute identifier includes a value identifying that it includes vendor extension data;
The appendage identifier includes a value for identifying a service supported by the second WFD device. The method of claim 10, wherein the appendage identifier is
At least one of system information, device capability information, display capability information, video profile information, audio profile information, transmission capability information, and 3D (Dimensional) capability information, wherein the service discovery method of the second WFD device in the WFD network. . The method of claim 9,
The WPS IE in the service discovery response frame includes a sub element for a service supported by the second WFD device. The method of claim 12, wherein the sub-element for the service supported by the second WFD device
A service discovery method of a second WFD device in a WFD network, comprising at least one of system information, device capability information, display capability information, video profile information, audio profile information, transmission capability information, and 3D capability information. . 10. The method of claim 9, wherein transmitting the service discovery response frame to the first WFD device is
And transmitting the service discovery response frame to the first WFD device in a unicast manner using a probe response frame. The method of claim 9,
The first WFD device and the second WFD device is a WiFi display authentication device, characterized in that the service discovery method of the second WFD device in the WFD network. A frame generation unit generating a service discovery request frame for searching for a service supported by a second WFD device of a WFD network;
A frame transmitter which transmits the service discovery request frame to the second WFD device; And
A frame receiving unit receiving a service search response frame from the second WFD device in response to the service search request frame;
The first WFD device in the WFD network, wherein the service discovery request frame and the service discovery response frame are generated using a Wi-Fi Protected Setup (WPS) Information Element (IE). A frame receiving unit receiving a service discovery request frame for searching for a service supported by a second WFD device of a WFD network from the first WFD device;
A frame generation unit generating a service discovery response frame which is a response frame to the service discovery request frame; And
A frame transmitter for transmitting the service discovery response frame to the first WFD device;
The service discovery request frame and the service discovery response frame are generated using a Wi-Fi Protected Setup (WPS) Information Element (IE). A computer-readable recording medium having recorded thereon a program for performing the method according to any one of claims 1 to 15.

Images