Image forming apparatus to support wi-fi direct and method of wi-fi direct connecting therein

CROSS-REFERENCE TO RELATED APPLICATIONS

0001This application claims priority under 35 U.S.C. §119 from Korean Patent Application No. 10-2012-0109261, filed on Sep. 28, 2012, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

00021. Field of the Invention

0003The present general inventive concept relates to an image forming apparatus to support Wi-Fi Direct, and more particularly, to an image forming apparatus to communicate with an external wireless device by supporting Wi-Fi Direct and a method of Wi-Fi Direct connecting.

00042. Description of the Related Art

0005Recently, peer-to-peer (P2P) communication by which wireless devices are directly connected without an additional wireless connecting apparatus is generalized and widely used. For example, Bluetooth enables such P2P communication. Although Bluetooth is limited to some extent in terms of transmission speed and transmission range, new versions of Bluetooth are continuously being developed to supplement the limitations.

0006In addition, Wi-Fi, which is a wireless local area network (LAN) standard based on IEEE 802.11 regulated by Wi-Fi Alliance, is basically a technology that allows using ultra-high speed internet by accessing an access point (AP) connected to a network infrastructure; however, Wi-Fi may serve the P2P communication by using an ad hoc mode. When using this ad-hoc mode, however, security is weakened, a transmission speed decreases, and an establishing method thereof is difficult to perform. Accordingly, Wi-Fi Alliance has suggested Wi-Fi Direct as a technique that makes P2P communication possible. Wi-Fi Direct allows P2P connection between wireless devices without using an AP, supports a transmission speed of a maximum of 250 Mbps, and performs security settings by using Wi-Fi protected access 2 (WPA2), in order to address problems of the ad-hoc function. In addition, Wi-Fi Direct supports a transmission range of a 200 m maximum, and thus, is considered as a substitute for P2P communication.

0007As described above, with the appearance of Wi-Fi Direct, use of P2P communication has increased more. However, P2P communication technology may need to be applied to image forming apparatuses, such as printers, scanners, fax machines, and multi-function printers. Accordingly, it is necessary to provide a technique for safely and easily using an image forming apparatus supporting P2P connection.

SUMMARY OF THE INVENTION

0008The present general inventive concept provides an image forming apparatus to support Wi-Fi Direct and a method of Wi-Fi Direct connecting.

0009The present general inventive concept also provides a computer-readable recording medium to contain computer-readable codes as a program to execute a method of Wi-Fi Direct connecting an image forming apparatus and a wireless device.

0010Additional features and utilities of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.

0011The foregoing and/or other features and utilities of the present general inventive concept may be achieved by providing an image forming apparatus to support Wi-Fi Direct, the apparatus including a wireless interface unit to receive a request for a Wi-Fi Direct connection from an external wireless device, a memory unit to store device information about wireless devices that were previously Wi-Fi Direct connected to the image forming apparatus, and a central processing unit to determine whether device information of the external wireless device that has requested the Wi-Fi Direct connection is stored in the memory unit, based on the stored device information, wherein when the external wireless device that has requested the Wi-Fi Direct connection is determined as corresponding to the stored device information, the central processing unit allows to establish a Wi-Fi Direct connection between the image forming apparatus and the external wireless device via the wireless interface unit.

0012The foregoing and/or other features and utilities of the present general inventive concept may also be achieved by providing an image forming apparatus to support Wi-Fi Direct, the apparatus including a print engine to conduct a printing operation, a memory unit to store device information about wireless devices that were previously Wi-Fi Direct connected to the image forming apparatus, a first wireless interface unit to connect to an access point (AP) of a network infrastructure, a second wireless interface unit to receive a request for Wi-Fi Direct connection from an external wireless device, a central processing unit to determine whether device information of the external wireless device that has requested Wi-Fi Direct connection is stored in the memory unit, based on the stored device information, a soft AP unit to allow the image forming apparatus to act as an AP when a Wi-Fi Direct connection is established, and a Dynamic Host Configuration Protocol (DHCP) server unit to allocate an IP address to a wireless device that is Wi-Fi Direct connected to the image forming apparatus, wherein the central processing unit allows a Wi-Fi Direct connection to be established between the image forming apparatus and the external wireless device via the second wireless interface unit if the external wireless device that has requested the Wi-Fi Direct connection is determined as corresponding to the stored device information.

0013The foregoing and/or other features and utilities of the present general inventive concept may also be achieved by providing a method of Wi-Fi Direct connecting in an image forming apparatus, the method including receiving a request for Wi-Fi Direct connection from an external wireless device, determining whether device information of the external wireless device that has requested the Wi-Fi Direct connection is stored, based on device information about wireless devices that were previously Wi-Fi Direct connected to the image forming apparatus which is stored in advance, and allowing to establish a Wi-Fi Direct connection if the external wireless device that has requested the Wi-Fi Direct connection is determined as corresponding to the stored device information.

0014The foregoing and/or other features and utilities of the present general inventive concept may be achieved by providing a computer-readable recording medium having embodied thereon a program to execute the method described above and below.

0015The foregoing and/or other features and utilities of the present general inventive concept may also be achieved by providing an image forming apparatus to support a Wi-Fi Direct, including a wireless interface unit to receive a request for a current Wi-Fi Direct connection from an external wireless device, and a central processing unit to determine whether there was a previous Wi-Fi Direct connection with the external wireless device, and to establish the current Wi-Fi Direct connection with the external wireless device according to the determination, to receive one of a command and data according to the established current Wi-Fi Direct connection, and to perform a printing operation using a print engine according to the received one of the command and data.

0016The central processing unit may establish the current Wi-Fi Direct connection without a user input of one of a push button and a pin code.

0017The central processing unit may compare previous information obtained through the previous Wi-Fi Direct connection with information on the current Wi-Fi Direct connection to determine that the external wireless device previously had the previous Wi-Fi Direct connection with the wireless interface unit.

0018The information may be at least one of a MAC address, an IP address, and an DHCP client identifier.

BRIEF DESCRIPTION OF THE DRAWINGS

0019These and/or other features and utilities of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

0020<figref idref="DRAWINGS">FIG. 1</figref> illustrates wireless local area network (WLAN) devices that support Wi-Fi Direct and are wirelessly connected to one another to form a wireless network and a legacy WLAN device;

0021<figref idref="DRAWINGS">FIG. 2</figref> is a view illustrating an operation of wireless connection between Wi-Fi Direct devices;

0022<figref idref="DRAWINGS">FIG. 3</figref> illustrates a list of Wi-Fi Direct devices after performing device discovery in a Wi-Fi Direct device according to an embodiment of the present general inventive concept;

0023<figref idref="DRAWINGS">FIG. 4</figref> is a detailed view illustrating an operation of group formation during a connecting operation between Wi-Fi Direct devices;

0024<figref idref="DRAWINGS">FIG. 5</figref> illustrates a display screen to execute Wi-Fi Protected Setup (WPS);

0025<figref idref="DRAWINGS">FIG. 6</figref> illustrates Wi-Fi Direct devices that are concurrently connected;

0026<figref idref="DRAWINGS">FIG. 7</figref> is a block diagram illustrating a hardware structure of an image forming apparatus supporting Wi-Fi Direct according to an embodiment of the present general inventive concept;

0027<figref idref="DRAWINGS">FIG. 8</figref> is a block diagram illustrating a software structure of an image forming apparatus supporting Wi-Fi Direct according to an embodiment of the present general inventive concept;

0028<figref idref="DRAWINGS">FIG. 9</figref> is a block diagram illustrating a hardware structure of an image forming apparatus supporting Wi-Fi Direct, according to an embodiment of the present general inventive concept;

0029<figref idref="DRAWINGS">FIG. 10</figref> illustrates a list of device information displayed by using a user interface unit or an embedded web server (EWS) according to an embodiment of the present general inventive concept;

0030<figref idref="DRAWINGS">FIG. 11</figref> illustrates an operation of Wi-Fi Direct connection of an image forming apparatus to support Wi-Fi Direct according to an embodiment of the present general inventive concept;

0031<figref idref="DRAWINGS">FIG. 12</figref> is a detailed flowchart of an operation of Wi-Fi Direct connection of an image forming apparatus to support Wi-Fi Direct, according to an embodiment of the present general inventive concept;

0032<figref idref="DRAWINGS">FIG. 13</figref> illustrates an operation of Wi-Fi Direct connection of an image forming apparatus to support Wi-Fi Direct, according to an embodiment of the present general inventive concept;

0033<figref idref="DRAWINGS">FIG. 14</figref> illustrates an operation of Wi-Fi Direct connection of an image forming apparatus to support Wi-Fi Direct, according to an embodiment of the present general inventive concept; and

0034<figref idref="DRAWINGS">FIG. 15</figref> is a flowchart illustrating a method of Wi-Fi Direct connecting in an image forming apparatus to support Wi-Fi Direct according to an embodiment of the present general inventive concept.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

0035Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present general inventive concept while referring to the figures. For clarity of description of the features of the embodiments of the present invention, details that are well-known to one of ordinary skill in the art will be omitted. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

0036Hereinafter, a multi-function printer (MFP) that supports Wi-Fi Direct will be described as an example of an image forming apparatus supporting a peer-to-peer (P2P) connection. However, the present general inventive concept is not limited thereto. It is possible that it can be applied to a printer, a scanner, a fax machine, etc., to perform a printing and/or scanning operation.

0037Before describing embodiments of the present general inventive concept, basic connections and operations of an MFP that supports Wi-Fi Direct will be described with reference to accompanying drawings.

0038<figref idref="DRAWINGS">FIG. 1</figref> illustrates wireless local area network (WLAN) devices that are wirelessly connected to one another to form a wireless network and a legacy WLAN device. Referring to <figref idref="DRAWINGS">FIG. 1</figref>, an MFP <b>110</b> supports Wi-Fi Direct and is wirelessly connected to a smart phone <b>120</b> supporting the Wi-Fi Direct, a laptop computer <b>130</b> supporting the Wi-Fi Direct, and a legacy WLAN laptop computer <b>140</b>. The legacy WLAN laptop computer <b>140</b> refers to a laptop computer, to which conventional WLAN technology is applied and which does not support the Wi-Fi Direct. Here, “supporting the Wi-Fi Direct” is referred to as “having components to communicate with a wireless device using the Wi-Fi Direct.”

0039WLAN devices may support Wi-Fi Direct, hereinafter referred to as Wi-Fi Direct devices, and may be P2P connected, unlike other conventional Wi-Fi supporting devices. In detail, according to the conventional Wi-Fi technology, to form a WLAN, a Wi-Fi device may be wirelessly connected to a router connected to a network infrastructure that is already established, that is, an access point (AP). Here, Wi-Fi devices that are wirelessly connected may be regarded as acting as a station. However, according to the Wi-Fi Direct, one of the Wi-Fi Direct devices that are to form a wireless network functions as an AP, and the rest of Wi-Fi Direct devices are wirelessly connected to the Wi-Fi Direct device functioning as an AP and function as stations. Accordingly, a wireless network between Wi-Fi Direct devices may be formed without an AP connected to a network infrastructure. In addition, once a wireless network is formed between Wi-Fi Direct devices, legacy WLAN devices, such as Wi-Fi devices, may recognize the Wi-Fi Direct device functioning as an AP, and may function as stations to be wirelessly connect thereto.

0040Referring to <figref idref="DRAWINGS">FIG. 1</figref>, the Wi-Fi Direct MFP <b>110</b>, the Wi-Fi Direct smart phone <b>120</b>, and the Wi-Fi Direct laptop computer <b>130</b>, which are Wi-Fi Direct devices, form a wireless network without an AP connected to a network infrastructure. As devices supporting Wi-Fi Direct are wirelessly connected to one another without an AP connected to a network infrastructure, a P2P group may be formed. Here, the Wi-Fi Direct MFP <b>110</b> functions as an AP, and a device that functions as an AP among the Wi-Fi Direct devices is referred to as a group owner (GO) of a P2P group. The Wi-Fi Direct smart phone <b>120</b> and the Wi-Fi Direct laptop computer <b>130</b> are wirelessly connected to the Wi-Fi Direct MFP <b>110</b>, which is a GO, and function as stations that are referred to as clients. The legacy WLAN laptop computer <b>140</b>, which does not support Wi-Fi Direct, recognizes the Wi-Fi Direct MFP <b>110</b>, which is a GO, as an AP, so as to wirelessly connect to a wireless network that the Wi-Fi Direct devices have formed.

0041While the Wi-Fi Direct MFP <b>110</b> is illustrated as a GO among the Wi-Fi Direct devices in <figref idref="DRAWINGS">FIG. 1</figref>, according to another embodiment, other Wi-Fi Direct devices, for example, one of the Wi-Fi Direct smart phone <b>120</b> and the Wi-Fi Direct laptop computer <b>130</b>, may be a GO, and the Wi-Fi Direct MFP <b>110</b> may be a client or a station to allow wireless connection. Which Wi-Fi Direct device is going to be a GO is determined in an operation of Wi-Fi Direct connection through negotiation between them, as described below in detail. A Wi-Fi Direct device may become a GO by itself before being connected without negotiation, and such a Wi-Fi Direct device is referred to as an autonomous group owner (AGO). Also, a wireless network that is formed around an AGO is referred to as an autonomous P2P group. When an autonomous P2P group is formed, a legacy WLAN device may recognize the AGO as an AP of a network infrastructure and connect thereto.

0042Although <figref idref="DRAWINGS">FIG. 1</figref> illustrates a P2P group that is formed by Wi-Fi Direct devices without an AP connected to a network infrastructure, if there is an AP connected to a network infrastructure, Wi-Fi Direct devices may also connect to the AP and may function as stations.

0043Hereinafter, an operation of wireless connection between Wi-Fi Direct devices and characteristics of Wi-Fi Direct will be described in detail. For easy understanding, an MFP supporting Wi-Fi Direct (hereinafter, a Wi-Fi Direct MFP) will be described as an example. However, the scope of the present invention is not limited thereto, and examples of Wi-Fi Direct devices may include any devices such as a printer, a scanner, or a fax machine that supports Wi-Fi Direct. Also, while Wi-Fi Direct is described as an example of P2P communication, other P2P communication methods such as Bluetooth or Zigbee may also be regarded as being included in the embodiments of the present invention within an applicable range.

0044<figref idref="DRAWINGS">FIG. 2</figref> is a view illustrating an operation of wireless connection between Wi-Fi Direct devices. <figref idref="DRAWINGS">FIG. 2</figref> illustrates a Wi-Fi direct connection between a Wi-Fi Direct MFP <b>210</b> and a Wi-Fi Direct laptop computer <b>220</b>, for example. The Wi-Fi Direct connection includes a device discovery, a group formation, and a secure connection. Referring to <figref idref="DRAWINGS">FIG. 2</figref>, the Wi-Fi Direct MFP <b>210</b>, which is one of the Wi-Fi Direct devices, receives a request <b>201</b> for the device discovery, and searches whether there is a near Wi-Fi Direct device in operation <b>202</b>. The request for the device discovery may be received via a user interface unit of the Wi-Fi Direct MFP <b>210</b>, for example, via a user interface unit implemented on a display, such as a liquid crystal display (LCD), included in the Wi-Fi Direct MFP <b>210</b>. After the Wi-Fi Direct MFP <b>210</b> performs the device discovery, if a near Wi-Fi Direct device is found, the Wi-Fi Direct MFP <b>210</b> shows a device found through the device discovery to a user on the display, and receives a connection request <b>203</b> from the user. The connection request <b>203</b> may also be received by pressing a button or by touching a touch panel via the display of the Wi-Fi Direct MFP <b>210</b>, and if a plurality of Wi-Fi Direct devices are found, the Wi-Fi Direct MFP <b>210</b> may show them as a list on the display and the user may select one of them and request a connection thereto.

0045Upon receiving the connection request <b>203</b>, the group formation is conducted between Wi-Fi Direct devices that are to be connected in operation <b>204</b>. Group formation refers to determining which Wi-Fi Direct devices are to be connected to one another, and which of the Wi-Fi Direct devices is going to be a GO or a client. Which Wi-Fi Direct device is going to be a GO is determined through negotiation between the Wi-Fi Direct devices, as described below with reference to <figref idref="DRAWINGS">FIG. 4</figref> in detail.

0046When groups are formed, devices of each group need secure connections, a technique for which is Wi-Fi Protected Setup (WPS). WPS refers to a function of easily establishing a secure connection between Wi-Fi supporting devices. Examples of WPS include a personal identification number (PIN) method and a push button configuration (PBC) method. In the PIN method, a previously set PIN code is input to establish a secure connection. In the PBC method, a WPS button included in a Wi-Fi Direct device is pressed to establish a secure connection.

0047The PCB method will be described below. A user may request secure connection by pressing a WPS button included in the Wi-Fi Direct MFP <b>210</b> in operation <b>205</b>. Then, secure connection may be established by pressing a WPS button included in the Wi-Fi Direct laptop computer <b>220</b> or a WPS button implemented on an application program for Wi-Fi Direct connection of the Wi-Fi Direct laptop computer <b>220</b> within a predetermined period of time, for example, within 120 seconds. The WPS button implemented on an application program for the Wi-Fi Direct connection of the Wi-Fi Direct laptop computer <b>220</b> means an object that is displayed on a display of the Wi-Fi Direct laptop computer <b>220</b> according to an application program for the Wi-Fi Direct connection. A detailed example of the WPS button is indicated by reference numeral <b>510</b> of <figref idref="DRAWINGS">FIG. 5</figref> which will be described below. A user may request the secure connection by clicking a WPS button displayed on a display of the Wi-Fi Direct laptop computer <b>220</b> by using a mouse or the like. When the WPS button is pressed to request secure connection, one of the Wi-Fi Direct devices that is designated as a GO in the group formation operation transmits security information to devices that are designated as clients in operation <b>206</b>. As secure connection is established by encoding the security information according to the Wi-Fi Protected Access 2 (WPA2)-Pre-Shared Key (PSK) authorization method according to Wi-Fi Direct, security performance is much higher than conventional methods, such as a Wired Equivalent Privacy (WEP) method or a Wi-Fi Protected Access (WAP) method.

0048When conducting WPS, a Wi-Fi Direct device that is a client is connected to a Wi-Fi Direct device that is a GO in operation <b>207</b>, and the Wi-Fi Direct device that is a GO uses a Dynamic Host Configuration Protocol (DHCP) server to automatically allocate an Internet protocol (IP) address to Wi-Fi Direct devices in operation <b>208</b> to thereby complete P2P connection between Wi-Fi Direct devices.

0049As described above, in the operation of wireless connection of Wi-Fi Direct devices, in the Wi-Fi Direct MFP <b>210</b>, operation <b>205</b> of pressing a WPS button according to the PBC method or the PIN method is necessary. When the Wi-Fi Direct MFP <b>210</b> is used at homes or in offices, the same wireless devices of a user (e.g., the Wi-Fi Direct smart phone <b>120</b>, the Wi-Fi Direct laptop computer <b>130</b>, and the legacy WLAN laptop computer <b>140</b>) may attempt the Wi-Fi Direct connection to the Wi-Fi Direct MFP <b>210</b>. Accordingly, in the wireless connection operation between Wi-Fi Direct devices of the Wi-Fi Direct MFP <b>210</b>, it may be necessary to perform the operation <b>205</b> of pressing a WPS button according to the PBC method or the PIN method.

0050In order to provide convenience to the user, an operation of wireless connection between Wi-Fi Direct devices according to the embodiment of the present general inventive concept may be performed to omit the operation <b>205</b> of pressing a WPS button formed on wireless devices to be successfully connected via Wi-Fi Direct. This will be described in more detail with respect to a wireless connection operation between Wi-Fi Direct devices with reference to <figref idref="DRAWINGS">FIGS. 9 through 15</figref>. Hereinafter, a Wi-Fi Direct technology is described for better understanding of the embodiment of the present general inventive concept.

0051Although a basic operation of connecting Wi-Fi Direct devices has been described above, each connecting operation and characteristics of Wi-Fi Direct will be described in detail with reference to the drawings hereinafter.

0052<figref idref="DRAWINGS">FIG. 3</figref> illustrates a list of found Wi-Fi Direct devices after performing a device discovery in a Wi-Fi Direct device according to an embodiment of the present general inventive concept. When the Wi-Fi Direct device conducts the device discovery, device information, such as a type of a device and a service set identifier (SSID), is exchanged via a probe request and a probe response that are WLAN packets transmitted between them, and the device that conducts the device discovery displays the collected information. As illustrated in <figref idref="DRAWINGS">FIG. 3</figref>, an SSID <b>310</b> and a device type <b>320</b> of Wi-Fi Direct devices that are found to be near are represented as text or icons. Here, all of the found devices may be displayed on the list; however, the devices may be filtered according to device types so that a list including only desired types of devices may be displayed. According to the Wi-Fi Direct technology, the device types are classified and defined according categories or user preferences. The categories may be computers, input devices, printers, scanners, fax machines, copy machines, and cameras, and each category is divided into sub-categories. For example, a computer is classified into sub-categories of a personal computer (PC), a server, and a laptop computer, and the like.

0053<figref idref="DRAWINGS">FIG. 4</figref> is a detailed view illustrating an operation of a group formation during a connecting operation between Wi-Fi Direct devices. Group formation may be referred to as deciding which Wi-Fi Direct devices are to be connected to one another to form a network, which device is to be a GO, and which device is going to be a client. For example, when a Wi-Fi Direct MFP <b>410</b> conducts the device discovery, and a laptop computer <b>420</b> is selected among the found Wi-Fi Direct devices to attempt the connection, the Wi-Fi Direct MFP <b>410</b> sends a GO negotiation request to the laptop computer <b>420</b> in operation <b>401</b>. The laptop computer <b>420</b> that has received a GO negotiation request compares one or more intent values of the laptop computer <b>420</b> and those of the Wi-Fi Direct MFP <b>410</b>. When the intent value of the Wi-Fi Direct MFP <b>410</b> is greater than that of the laptop computer <b>420</b>, the laptop computer <b>420</b> designates the Wi-Fi Direct MFP <b>410</b> as a GO. When the intent value of the Wi-Fi Direct MFP <b>410</b> is not greater than that of the laptop computer <b>420</b>, the laptop computer <b>420</b> designates itself as a GO. Here, the intent value refers to a value representing a degree of task intent in each device, and is determined by a manufacturer or design preference or a user preference. Devices to which power is supplied all the time as a main power source, like an MFP, may have a relatively high intent value. As described above, after determining which device is going to be a GO by comparing the intent values, the laptop computer <b>420</b> sends the corresponding result to the Wi-Fi Direct MFP <b>410</b> as a response to the GO negotiation in operation <b>402</b>. The Wi-Fi Direct MFP <b>410</b> that receives the determination result transmits an acknowledgement to the laptop computer <b>420</b> in operation <b>403</b> in order to confirm the receipt of the negotiation to thereby complete the group formation. When the group formation is completed, the Wi-Fi Direct device, which is the GO, manages security information and SSIDs of the other Wi-Fi Direct devices included in the group.

0054When the group formation is completed, a secure connection is established between the Wi-Fi Direct devices included in the group through WPS. <figref idref="DRAWINGS">FIG. 5</figref> illustrates a display screen <b>500</b> for executing WPS. The display screen <b>500</b> illustrated in <figref idref="DRAWINGS">FIG. 5</figref> may be displayed on a user interface unit of a display of a Wi-Fi Direct MFP. Referring to <figref idref="DRAWINGS">FIG. 5</figref>, the user may select a WPS button <b>510</b> or a PIN code <b>520</b> to execute WPS. When executing WPS via the WPS button <b>510</b>, the WPS button <b>510</b> of the Wi-Fi Direct MFP is pressed. When the WPS buttons of devices to be connected are pressed within a predetermined period of time, the security information is automatically exchanged between the devices such that a secure connection is established. Here, when the Wi-Fi Direct device that is the GO provides the security information, the Wi-Fi Direct devices that are the clients receive the security information. Also, the secure connection is established by encoding the security information using a WPA2-PSK authorization method, and thus, high security may be achieved.

0055However, as described above, an input of the WPS button <b>510</b> of <figref idref="DRAWINGS">FIG. 5</figref> may be unnecessary if the Wi-Fi Direct connection is repeatedly attempted by the same wireless devices, to which the user has previously connected before the Wi-Fi Direct connection is attempted, in the same Wi-Fi Direct environment like the home or office. Accordingly, an operation of the wireless connection between Wi-Fi Direct devices according to the embodiment of the present general inventive concept may be omitted in <figref idref="DRAWINGS">FIG. 5</figref> with respect to the Wi-Fi Direct devices according to the embodiment of the present general inventive concept. This will be described below in detail with respect to an operation of a wireless connection between Wi-Fi Direct devices with reference to <figref idref="DRAWINGS">FIGS. 9 through 15</figref> below.

0056A Wi-Fi Direct device may be connected to a network infrastructure and then may be connected to another Wi-Fi Direct device through P2P connection at the same time, and this is called concurrent connection. <figref idref="DRAWINGS">FIG. 6</figref> illustrates Wi-Fi Direct devices that are concurrently connected. Referring to <figref idref="DRAWINGS">FIG. 6</figref>, a Wi-Fi Direct MFP <b>620</b> is connected to a smart phone <b>610</b>, which is another Wi-Fi Direct device, through P2P connection, and is connected to an AP <b>630</b> of a network infrastructure at the same time. The Wi-Fi Direct MFP <b>620</b> is connected to the smart phone <b>610</b> through P2P connection, and thus may directly transmit or receive printing data or the like from the smart phone <b>610</b>, and may directly transmit or receive printing data from the network infrastructure via the AP <b>630</b> at the same time.

0057When Wi-Fi Direct devices are concurrently connected as illustrated in <figref idref="DRAWINGS">FIG. 6</figref>, or when a Wi-Fi Direct device is connected using wires to a network infrastructure and also connected to another Wi-Fi Direct device through P2P connection at the same time, different IP addresses and MAC addresses may be used for each connection, that is, for connection to the network infrastructure and connection to the other Wi-Fi Direct device. This is referred to as multihoming. This multihoming allows the Wi-Fi Direct device to support different services according to respective interfaces that are concurrently connected. For example, services of all functions of an MFP may be provided via an interface connected to the network infrastructure but only services partial functions of the MFP may be provided via an interface that is connected to another Wi-Fi Direct device.

0058<figref idref="DRAWINGS">FIG. 7</figref> is a block diagram illustrating a hardware structure of an image forming apparatus supporting a Wi-Fi Direct according to an embodiment of the present general inventive concept. Referring to <figref idref="DRAWINGS">FIG. 7</figref>, the image forming apparatus supporting Wi-Fi Direct may include a WLAN interface unit <b>710</b>, an Ethernet interface unit <b>720</b>, a central processing unit (CPU) <b>730</b>, a memory unit <b>740</b>, a user interface unit <b>750</b>, a scanner unit <b>760</b>, a fax unit <b>770</b>, and a print engine <b>780</b>. The memory unit <b>740</b> may include a random access memory (RAM) <b>742</b> and a read only memory (ROM) <b>744</b>. If the image forming apparatus supports only WLAN, the Ethernet interface unit <b>720</b> may not be included. Also, if the image forming apparatus is a printer, the scanner unit <b>760</b> and the fax unit <b>770</b> may not be included.

0059The WLAN interface unit <b>710</b> refers to hardware performing the IEEE 802.11 b/g/n function, and may communicate with a main board, on which the CPU <b>730</b> is mounted, of an image forming apparatus via a universal serial bus (USB). The WLAN interface unit <b>710</b> may have electrical and mechanical components to support the Wi-Fi Direct such that the image forming apparatus can be used as Wi-Fi Direct device to communicate with an external Wi-Fi Direct wireless device and to perform an image forming operation using at least one of the scanner unit <b>760</b>, the fax unit <b>770</b>, and the print engine <b>780</b> according to data or command received through the Wi-Fi-Direct communication. The Ethernet interface unit <b>720</b> refers to hardware that performs wired Ethernet communication according to IEEE 802.3. The CPU <b>730</b> controls overall operations of the image forming apparatus, and the memory unit <b>740</b> stores information for controlling the MFP and print data to be read when it is necessary. The user interface unit <b>750</b> functions as a medium for the user to identify information of the image forming apparatus and to input a command to the image forming apparatus. The user interface unit <b>750</b> may be configured in various ways according to a design or user preference. For example, the user interface unit <b>750</b> may be simply configured as two or four lines on a display, such as an LCD or a light-emitting diode (LED) display, or may be implemented as a graphic user interface (GUI) so as to represent various graphics. The scanner unit <b>760</b>, the fax unit <b>770</b>, and the print engine <b>780</b> are hardware for performing functions of a scanner, a fax machine, and a printer.

0060<figref idref="DRAWINGS">FIG. 8</figref> is a block diagram illustrating a software structure of an image forming apparatus supporting a Wi-Fi Direct according to an embodiment of the present general inventive concept. The software structure of the image forming apparatus supporting the Wi-Fi Direct will be briefly described below with reference to <figref idref="DRAWINGS">FIG. 8</figref>.

0061A WLAN dongle firmware <b>801</b> is firmware for WLAN connection, which may be stored in WLAN dongle hardware or may be transmitted from a main board of an image forming apparatus to the WLAN dongle hardware when booting the image forming apparatus. A bus driver <b>802</b> and a serial ATA (STA) host driver <b>803</b> are each a low level bus driver for communication with WLAN hardware. A WLAN control channel <b>804</b> and a WLAN data channel <b>805</b> refer to channels for communicating with WLAN firmware. A Wi-Fi Direct module <b>807</b> is a module that conducts Wi-Fi Direct connection and provides an operating command to the WLAN firmware. An IEEE 802.11u generic advertisement service (GAS) module <b>808</b> performs functions according to IEEE 802.11u GAS, and a WPS module <b>810</b> performs a WPS function. A soft AP module <b>811</b> is a software module that helps an image forming apparatus to act as an AR A transmission control protocol (TCP)/IP <b>813</b> is a standard protocol for network transmission. A Wi-Fi Direct connection manager <b>812</b> is a module for controlling Wi-Fi Direct connection. A Wi-Fi Direct user interface <b>815</b> allows the user to conduct settings related to Wi-Fi Direct, and may be included in an embedded web server (EWS) <b>814</b>. A DHCP server <b>816</b> automatically allocates an IP to a Wi-Fi Direct device that is connected as a client. A network application program <b>817</b> allows various application operations related to a network.

0062The Wi-Fi Direct technology described above has the following advantages.

0063The Wi-Fi Direct device is connectable to other devices anywhere and anytime, and thus, has maximum mobility and portability. If a new Wi-Fi Direct device is added, the Wi-Fi Direct device may be immediately connected to the new Wi-Fi Direct device and used. In addition, it may be identified whether there is an available device or service before establishing the connection to other devices, and thus, the Wi-Fi direct devices may be conveniently used. In addition, the connection may be performed simply and stably by a simple operation, for example, pressing a WPS button, and the connection may be performed with high security functions by using the WPA2 technology.

0064Also, Wi-Fi Direct technology may provide various functions that may not be provided by a conventional WLAN technology.

0065For example, a device discovery function whereby near Wi-Fi Direct devices may be found according to device types; a service discovery function corresponding to services provided by near Wi-Fi Direct devices may be found; a power management function that allows an efficient use of electrical power; a concurrent connection function that may form a P2P connection between the Wi-Fi Direct devices while connecting to an existing network infrastructure; a function of separating a security domain between the network infrastructure connection and the Wi-Fi Direct connection; and a cross-connection function which allows sharing of an internet connection may be provided by the Wi-Fi Direct technology.

0066Also, as the Wi-Fi Direct technology is based on IEEE 802.11, the Wi-Fi Direct devices are compatible with conventional legacy WLAN devices.

0067Hereinafter, a method of Wi-Fi Direct connecting in an image forming apparatus supporting a Wi-Fi Direct according to an embodiment of the present general inventive concept will be described in detail with reference to <figref idref="DRAWINGS">FIGS. 9 through 15</figref>.

0068<figref idref="DRAWINGS">FIG. 9</figref> is a block diagram illustrating an image forming apparatus <b>900</b> supporting a Wi-Fi Direct, according to an embodiment of the present general inventive concept.

0069Since the hardware structure of the image forming apparatus has been explained above with reference to <figref idref="DRAWINGS">FIG. 7</figref>, detail descriptions thereof will be omitted.

0070<figref idref="DRAWINGS">FIG. 9</figref> illustrates hardware components included in the image forming apparatus <b>900</b> to support the Wi-Fi Direct without illustrating all the hardware components of the image forming apparatus illustrated in <figref idref="DRAWINGS">FIG. 7</figref>.

0071A WLAN interface unit <b>910</b> receives a request for a Wi-Fi Direct connection from an external wireless device <b>940</b>, for example, the Wi-Fi Direct smart phone <b>120</b>, the Wi-Fi Direct laptop computer <b>130</b>, or the legacy WLAN laptop computer <b>140</b> of <figref idref="DRAWINGS">FIG. 1</figref>. The operation of the request for the Wi-Fi direct connection as above may be performed during a device discovery described above with reference to <figref idref="DRAWINGS">FIG. 2</figref>.

0072The image forming apparatus <b>900</b> supporting the Wi-Fi Direct receives a request for a device discovery from a user and searches whether there is a wireless device <b>940</b> that supports the Wi-Fi Direct. The request for the device discovery may be received via a user interface unit of the image forming apparatus <b>900</b>. If the external wireless device <b>940</b> supporting the Wi-Fi Direct is found to be near as a result of the device discovery by the image forming apparatus <b>900</b>, the image forming apparatus <b>900</b> generates, outputs, or displays the external wireless device <b>940</b> to a user via the user interface unit, and receives from the user a selection of the external wireless device <b>940</b> that the user wants to connect. Thereafter, the WLAN interface unit <b>910</b> receives a request for the Wi-Fi Direct connection from the external wireless device <b>940</b> selected by the user.

0073A memory unit <b>920</b> stores device information regarding wireless devices that were previously connected to the image forming apparatus <b>900</b> through the Wi-Fi Direct connection. The device information that is stored as stated above has been stored in advance before receiving a request for the Wi-Fi Direct connection from the WLAN interface unit <b>910</b>. Here, the device information includes at least one of a MAC address and a DHCP client identifier of wireless devices that were previously Wi-Fi Direct connected to the image forming apparatus <b>900</b>.

0074When allocation of an IP address via a DHCP server in an operation of establishing a connection to the wireless devices which had previously successfully performed the Wi-Fi Direct connection to the image forming apparatus <b>900</b> is completed, the image forming apparatus <b>900</b> receives the MAC address and the DHCP client identifier, for which the IP address is allocated. Here, the memory unit <b>920</b> stores the device information, such as the MAC address and the DHCP client identifier of wireless devices, which were previously successful in Wi-Fi Direct connection, in order to determine whether the external wireless device <b>940</b>, which is attempting the Wi-Fi Direct connection to the image forming apparatus <b>900</b> at the present moment, is one that was previously connected.

0075The MAC address of the external wireless device <b>940</b> includes both a device address, which is used before the Wi-Fi Direct connection, and an interface address, which is used after the Wi-Fi Direct connection, and the memory unit <b>920</b> may store them individually. The DHCP client identifier of the external wireless device <b>940</b> is data included in a DHCP request data packet received by the image forming apparatus <b>900</b> during the allocation of an IP address via the DHCP server, and is coded data, for example.

0076A CPU <b>930</b> determines whether the device information of the external wireless device <b>940</b>, which has requested the Wi-Fi Direct connection, is stored in the memory unit <b>920</b> or not, based on the device information stored in the memory unit <b>920</b>. When the external wireless device <b>940</b> is determined as corresponding to the device information that is stored in the memory unit <b>920</b> in advance, the CPU <b>930</b> performs an operation of establishing a Wi-Fi Direct connection between the image forming apparatus <b>900</b> and the external wireless device <b>940</b> via the WLAN interface unit <b>910</b>.

0077In detail, the CPU <b>930</b> compares the MAC address of the external wireless device <b>940</b> that has requested Wi-Fi Direct connection and the MAC address stored in the memory unit <b>920</b>. Furthermore, the CPU <b>930</b> compares a DHCP client identifier of the external wireless device <b>940</b> that is received via the DHCP server with the DHCP client identifier stored in the memory unit <b>920</b>.

0078An operation of pressing a WPS button according to a PBC method or a PIN method may be required during the wireless connection process between the Wi-Fi Direct devices. However, this may be inconvenient to a user if the same user attempts the Wi-Fi Direct connection in the same Wi-Fi Direct environment.

0079According to the embodiment of the present general inventive concept, it is possible to omit the operation of pressing a WPS button since the device information about wireless devices which were previously Wi-Fi Direct connected to the image forming apparatus <b>900</b> is stored in the memory unit <b>920</b>. The CPU <b>930</b> determines whether the external wireless device <b>940</b>, which has requested the Wi-Fi Direct connection, is a wireless device that was previously connected in the Wi-Fi Direct connection.

0080If the CPU <b>930</b> determines that the device information of the external wireless device <b>940</b> corresponds to the device information stored in the memory unit <b>920</b>, the image forming apparatus <b>900</b> automatically establishes a Wi-Fi Direct connection without any input by a user to select or approve the Wi-Fi Direct connection via a user interface unit. Accordingly, when the user attempts the Wi-Fi Direct connection to the image forming apparatus <b>900</b> by using the external wireless device <b>940</b> which was previously Wi-Fi Direct connected, the user may perform the Wi-Fi Direct connection without a button press according to the PBC method and the PIN method of WPS.

0081The above-described function of allowing the Wi-Fi Direct devices to establish a Wi-Fi Direct connection without an input regarding approval of the Wi-Fi Direct connection may be established or cancelled directly by the user via the user interface unit included in the image forming apparatus <b>900</b> or an EWS.

0082Furthermore, a list of device information stored in the memory unit <b>920</b> may be directly managed by the user via the user interface unit included in the image forming apparatus <b>900</b> or an EWS. That is, a manager or a user of the image forming apparatus <b>900</b> may view a list of device information displayed via the user interface unit of the EWS, remove information from the list of the device information or add information to the list of the device information. Also, the manager or user of the image forming apparatus <b>900</b> may set to provide an easy reconnection function, which may not require a user selection, for example, an operation of pressing a WPS button, only to one or more particular ones of the wireless devices included in the list of the device information displayed via the user interface unit or the EWS. However, the easy reconnection function may not be applied to the rest of the wireless devices which can be connected through a user selection, for example, the operation of pressing a WPS button. The manager or user of the image forming apparatus <b>900</b> may obtain history information as to how often wireless devices corresponding to respective device information were Wi-Fi Direct connected to the image forming apparatus <b>900</b>. The history information may include a connection frequency, a connection period, or etc., to correspond to characteristics of the previous connection.

0083<figref idref="DRAWINGS">FIG. 10</figref> illustrates a list of the device information displayed by using a user interface unit or EWS. Referring to <figref idref="DRAWINGS">FIG. 10</figref>, the displayed list of device information shows a list of wireless devices which were previously successful in the Wi-Fi Direct connection to the image forming apparatus <b>900</b> and which are stored in the memory unit <b>920</b>. As described above, the device information includes the MAC address and the DHCP client identifier of the wireless devices. In addition, the list of the device information may also display history information as to how often each of wireless devices was Wi-Fi Direct connected to the image forming apparatus <b>900</b>.

0084The manager or the user of the image forming apparatus <b>900</b> may view information, remove information from, or add information to the list of the device information via a screen illustrated in <figref idref="DRAWINGS">FIG. 10</figref>. Also, although not illustrated in <figref idref="DRAWINGS">FIG. 10</figref>, the manager or user of the image forming apparatus <b>900</b> may set up to provide an easy reconnection function, which may not require a user selection or further process, for example, the operation of pressing a WPS button, only to one or more particular ones of the wireless devices from the list of device information displayed via the user interface unit or the EWS. However, the user may set up the easy reconnection function not to be applied to the rest of the wireless devices.

0085<figref idref="DRAWINGS">FIG. 11</figref> illustrates an operation of a Wi-Fi Direct connection of an image forming apparatus supporting Wi-Fi Direct according to an embodiment of the present general inventive concept. Referring to <figref idref="DRAWINGS">FIG. 11</figref>, the operation of the Wi-Fi Direct connection according to the embodiment of the present general inventive concept is performed in the image forming apparatus <b>900</b> of <figref idref="DRAWINGS">FIG. 9</figref>. Since the descriptions above about general Wi-Fi Direct technology described with reference to <figref idref="DRAWINGS">FIG. 8</figref> and the description with reference to <figref idref="DRAWINGS">FIG. 9</figref> may also be applied to the operation of the Wi-Fi Direct connection of <figref idref="DRAWINGS">FIG. 11</figref> according to the embodiment of the present general inventive concept, detail descriptions thereof will be omitted.

0086In operation <b>1101</b>, an image forming apparatus <b>1110</b> functions as an AGO and may form a network by itself, and transmits one or more beacon packets corresponding to a request for a connection periodically and wirelessly and is on a standby state so that one or more wireless devices disposed adjacent to the image forming apparatus <b>1110</b> may be able to attempt the Wi-Fi Direct connection. When a user performs a device discovery of the Wi-Fi Direct devices in a wireless device <b>1120</b>, the wireless device <b>1120</b> wirelessly transmits a probe request packet to the image forming apparatus <b>1110</b>. The image forming apparatus <b>1110</b> that has received the probe request packet of the wireless device <b>1120</b> responds to the wireless device <b>1120</b> by transmitting a probe response packet to the wireless device <b>1120</b>. A WLAN interface unit of the image forming apparatus <b>1110</b> receives a provision discovery request packet, which is a request for the Wi-Fi Direct connection, from the wireless device <b>1120</b>. Here, upon receiving the request for the Wi-Fi Direct connection from the wireless device <b>1120</b>, an LED included in the image forming apparatus <b>1110</b> may blink to inform the user that a request for the connection has been received from the wireless device <b>1120</b>.

0087In operation <b>1102</b>, the wireless device <b>1120</b> displays the image forming apparatus <b>1110</b> that supports the Wi-Fi Direct to the user, and receives a selection of the image forming apparatus <b>1110</b> from the user.

0088In operation <b>1103</b>, when the selection of the image forming apparatus <b>1110</b> is input via the wireless device <b>1120</b>, the image forming apparatus <b>1110</b> performs group information with the wireless device <b>1120</b> which is to be Wi-Fi Direct connected.

0089In operation <b>1104</b>, the image forming apparatus <b>1110</b>, for example, the CPU of the image forming apparatus <b>1110</b>, determines whether device information (for example, MAC address) of the wireless device <b>1120</b>, which has requested the Wi-Fi Direct connection, is stored in a memory unit, based on the device information (MAC address) stored in the memory unit.

0090If the device information (MAC address) of the wireless device <b>1120</b> is determined as corresponding to the device information (MAC address) stored in the memory unit, the image forming apparatus <b>1110</b> automatically attempts to establish a Wi-Fi Direct connection without any input by the user regarding approval of the Wi-Fi Direct connection via the user interface unit. Here, the image forming apparatus <b>1110</b> transmits a response for the Wi-Fi Direct connection (provision discovery response packet) to the wireless device <b>1120</b>. Accordingly, if the user again attempts the Wi-Fi Direct connection to the image forming apparatus <b>1110</b>, by using the same wireless device <b>1120</b> which was previously Wi-Fi Direct connected before the current connection attempt, the user may set the Wi-Fi Direct connection without a user input, for example, an input of a WPS button.

0091In operation <b>1105</b>, when the group is formed, the image forming apparatus <b>1110</b> and the wireless device <b>1120</b> belonging to the group may set WPS or Wi-Fi Simple Configuration (WSC) to perform a secure connection with each other. Here, when the Wi-Fi Direct connecting is performed, the secure connection may be performed by encoding using a WPA2-PSK authorization method.

0092In operation <b>1106</b>, when the secure connection is completed, the wireless device <b>1120</b>, which is a client, is connected to the image forming apparatus <b>1110</b>, which is an AGO.

0093In operation <b>1107</b>, the image forming apparatus <b>1110</b>, for example, a DHCP server of the mage forming apparatus <b>1110</b>, allocates an IP address to the wireless device <b>1120</b>, which is a client, to thereby complete the Wi-Fi Direct connection between the image forming apparatus <b>1110</b> and the wireless device <b>1120</b>.

0094<figref idref="DRAWINGS">FIG. 12</figref> is a detailed flowchart illustrating an operation of a Wi-Fi Direct connection of an image forming apparatus supporting a Wi-Fi Direct, according to an embodiment of the present general inventive concept. Referring to <figref idref="DRAWINGS">FIG. 12</figref>, the operation of the Wi-Fi Direct connection according to the embodiment of the present general inventive concept may be sequentially performed. Since descriptions above about the general Wi-Fi Direct technology with reference to <figref idref="DRAWINGS">FIGS. 1 through 8</figref> and with reference to <figref idref="DRAWINGS">FIGS. 9 through 11</figref> may also be applied to the Wi-Fi Direct connection of <figref idref="DRAWINGS">FIG. 12</figref> according to the embodiment of the present general inventive concept, detail descriptions thereof will be omitted below.

0095In operation <b>1201</b>, the image forming apparatus <b>900</b> may function as an AGO and form a network by itself, and transmit one or more beacon packets periodically and wirelessly and be on a standby state so that one or more wireless devices disposed to be able to communicate with the image forming apparatus <b>900</b> may attempt the Wi-Fi Direct connection.

0096In operation <b>1202</b>, the WLAN interface unit <b>910</b> of the image forming apparatus <b>900</b> receives a provision discovery request packet for the WI-Fi Direct connection from the external wireless device <b>940</b>.

0097In operation <b>1203</b>, the image forming apparatus <b>900</b>, for example, the CPU <b>930</b> of the image forming apparatus <b>900</b>, determines whether the device information (MAC address) of the external wireless device <b>940</b>, which has requested the current Wi-Fi Direct connection, is stored in the memory unit <b>920</b>, based on the device information (MAC address) stored in the memory unit <b>920</b>.

0098When the external wireless device <b>940</b> is determined as an external wireless device corresponding to the device information that is stored in the memory unit <b>920</b>, the method proceeds to operation <b>1204</b>, in which the Wi-Fi Direct connection is automatically attempted without an input of a user regarding approval of the Wi-Fi Direct connection via the user interface unit. That is, establishment of the Wi-Fi Direct connection is automatically attempted without a user input, for example, an input of a WPS button by a user. Here, the image forming apparatus <b>900</b> transmits a provision discovery response packet for the Wi-Fi Direct connection to the external wireless device <b>940</b>. However, if the device information of the external wireless device <b>940</b> (for example, MAC address) is determined as a wireless device not corresponding to the device information (MAC address) stored in the memory unit <b>920</b>, the image forming apparatus <b>900</b> may end a connection with the external wireless device <b>940</b>.

0099In operation <b>1204</b>, as a part of provisioning, the image forming apparatus <b>900</b>, which is an AGO, functions as an AP so as to operate as an internal registrar, and the external wireless device <b>940</b> operates as an enrollee, thereby performing a Wi-Fi simple configuration (WSC) exchange.

0100In operation <b>1205</b>, when the provisioning is completed, the external wireless device <b>940</b> transmits an authentication/association request packet to the image forming apparatus <b>900</b>, and the image forming apparatus <b>900</b> transmits an authentication/association response packet as a response thereto, and then a 4-way handshake operation is performed to complete the wireless connection operation.

0101In operation <b>1206</b>, the image forming apparatus <b>900</b>, particularly, a DHCP server, allocates an IP address to the external wireless device <b>940</b>, which is a client, to thereby complete Wi-Fi Direct connection between the image forming apparatus <b>900</b> and the external wireless device <b>940</b>.

0102The image forming apparatus <b>900</b> according to the embodiment of <figref idref="DRAWINGS">FIGS. 11 and 12</figref>, for example, the CPU <b>930</b> of the image forming apparatus <b>900</b>, conducts the determination by using only the MAC address of the external wireless device <b>940</b> and the MAC address stored in the memory unit <b>920</b>. However, it is possible that the image forming apparatus <b>900</b> of <figref idref="DRAWINGS">FIGS. 13 and 14</figref> according to an embodiment of the present general inventive concept, for example, the CPU <b>930</b> of the image forming apparatus <b>900</b>, conducts the determination by using both the MAC address and the DHCP client identifier. Using the DHCP identifier in addition to the MAC address in the determination prevents an automatic connection of an ill-intended user to the image forming apparatus <b>900</b> by stealing the same MAC address as that of the wireless device which was previously connected. Packets according to the DHCP are transmitted or received while being coded, and thus, a value of a client identifier in a DHCP packet obtained from a wireless device that was previously connected cannot be used by an ill-intended user. Hereinafter, the determination by using both the MAC address and the DHCP client identifier will be described.

0103<figref idref="DRAWINGS">FIG. 13</figref> illustrates an operation of a Wi-Fi Direct connection of an image forming apparatus supporting a Wi-Fi Direct, according to an embodiment of the present general inventive concept. Referring to <figref idref="DRAWINGS">FIG. 13</figref>, the operation of the Wi-Fi Direct connection according to the current embodiment may be performed in order in the image forming apparatus <b>900</b>, and includes operations illustrated in <figref idref="DRAWINGS">FIGS. 11 and 12</figref>. Since descriptions above about the general Wi-Fi Direct technology described with reference to <figref idref="DRAWINGS">FIGS. 1 through 8</figref> and the description with reference to <figref idref="DRAWINGS">FIGS. 9 through 12</figref> may be also applied to the Wi-Fi Direct connection of <figref idref="DRAWINGS">FIG. 13</figref> according to the embodiment of the present general inventive concept, detail descriptions thereof will be omitted below.

0104In operation <b>1301</b>, an image forming apparatus <b>1310</b> operates as an AGO to form a single wireless network by itself, and wirelessly and periodically transmits a beacon packet and is on a standby state so that one or more external wireless devices may attempt the Wi-Fi Direct connection with the image forming apparatus <b>1310</b>. When a user performs a device discovery regarding Wi-Fi Direct devices in a wireless device <b>1320</b>, the wireless device <b>1320</b> wirelessly transmits a probe request packet. The image forming apparatus <b>1310</b> transmits a probe response packet to the wireless device <b>1320</b> upon receiving the probe request packet from the wireless device <b>1320</b>. A WLAN interface unit of the image forming apparatus <b>1310</b> receives a provision discovery request packet for the Wi-Fi Direct connection from the wireless device <b>1320</b>.

0105In operation <b>1302</b>, the wireless device <b>1320</b> displays to the user the found image forming apparatus <b>1310</b> that supports a Wi-Fi function, and receives a selection of the image forming apparatus <b>1310</b>.

0106In operation <b>1303</b>, when the selection of the image forming apparatus <b>1310</b> is input via the wireless device <b>1320</b>, the image forming apparatus <b>1310</b> performs a group formation with respect to the wireless device <b>1320</b> that is to be Wi-Fi Direct connected.

0107In operation <b>1304</b>, the image forming apparatus <b>1310</b>, for example, a CPU of the image forming apparatus <b>1310</b>, determines whether device information (for example, MAC address) of the wireless device <b>1310</b>, which has requested Wi-Fi Direct connection, is stored in a memory unit, based on device information (MAC address) stored in the memory unit.

0108If the device information (MAC address) of the wireless device <b>1310</b> is determined as a wireless device corresponding to the device information (MAC address) stored in the memory unit, the image forming apparatus <b>1310</b> automatically attempts to establish a Wi-Fi Direct connection without any input by the user regarding approval of the Wi-Fi Direct connection via the user interface unit. Here, the image forming apparatus <b>1310</b> transmits a response for the Wi-Fi Direct connection (provision discovery response packet) to the wireless device <b>1320</b>. Accordingly, if the user again attempts the Wi-Fi Direct connection to the image forming apparatus <b>1110</b> by using the same wireless device <b>1320</b>, which was previously Wi-Fi Direct connected before the currently attempting connection, the user may set an option on the Wi-Fi Direct connection, for example, an connection option without a user input, for example, an input of a WPS button.

0109In operation <b>1305</b>, when the group is formed, the image forming apparatus <b>1310</b> and the wireless device <b>1320</b> belonging to the group may set a WPS or WSC to perform a secure connection with each other. Here, when Wi-Fi Direct connecting, the secure connection may be performed by encoding using the WPA2-PSK authorization method.

0110In operation <b>1306</b>, when the secure connection is completed, the wireless device <b>1320</b>, which is a client, is connected to the image forming apparatus <b>1310</b>, which is an AGO.

0111In operation <b>1307</b>, the image forming apparatus <b>1310</b> receives a DHCP request packet from the wireless device <b>1320</b>. Here, encoded information about the device information of the wireless device <b>1320</b> is included in the DHCP request packet.

0112In operation <b>1308</b>, the image forming apparatus <b>1310</b>, for example, the CPU of the image forming apparatus <b>1310</b>, determines whether the device information (for example, DHCP client identifier) of the wireless device <b>1320</b>, which has requested Wi-Fi Direct connection, is included in the memory unit <b>1320</b> based on the device information (DHCP client identifier) stored in the memory unit.

0113In operation <b>1309</b>, when the device information (DHCP client identifier) of the wireless device <b>1320</b> is determined as a wireless device corresponding to the device information (DHCP client identifier) stored in the memory unit, a DHCP server of the image forming apparatus <b>1310</b> allocates an IP address to the wireless device <b>1320</b>, which is a client to thereby complete the Wi-Fi Direct connection between the image forming apparatus <b>1310</b> and the wireless device <b>1320</b>.

0114<figref idref="DRAWINGS">FIG. 14</figref> illustrates an operation of a Wi-Fi Direct connection of an image forming apparatus supporting a Wi-Fi Direct, according to an embodiment of the present general inventive concept. Referring to <figref idref="DRAWINGS">FIG. 14</figref>, a method of performing the Wi-Fi Direct connection according to the embodiment may time-sequentially performed in the image forming apparatus <b>900</b> of <figref idref="DRAWINGS">FIG. 9</figref>, and thus, the method of <figref idref="DRAWINGS">FIG. 14</figref> includes operations illustrated in <figref idref="DRAWINGS">FIGS. 11 and 12</figref>. Since descriptions above about the general Wi-Fi Direct technology with reference to <figref idref="DRAWINGS">FIGS. 1 through 8</figref> and with reference to <figref idref="DRAWINGS">FIGS. 9 through 13</figref> may be also applied to the Wi-Fi Direct connection of <figref idref="DRAWINGS">FIG. 14</figref> according to the embodiment of the present general inventive concept, detail descriptions thereof will be omitted below.

0115In operation <b>1401</b>, the image forming apparatus <b>900</b> operates as an AGO to form a single wireless network by itself, and is on a standby state so that near wireless devices may attempts the Wi-Fi Direct connection.

0116In operation <b>1402</b>, the WLAN interface unit <b>910</b> of the image forming apparatus <b>900</b> receives a provision discovery request packet for the Wi-Fi Direct connection, from the external wireless device <b>940</b>.

0117In operation <b>1403</b>, the image forming apparatus <b>900</b>, for example, the CPU <b>930</b> of the image forming apparatus <b>900</b>, determines whether the device information (for example, MAC address) of the external wireless device <b>940</b>, which has requested the Wi-Fi Direct connection, is included in the memory unit <b>920</b> based on the device information (MAC address) stored in the memory unit <b>920</b>.

0118When the external wireless device <b>940</b> is determined as a wireless device corresponding to the device information that is stored in the memory unit <b>920</b>, the operation proceeds to operation <b>1404</b>, in which the Wi-Fi Direct connection is automatically attempted without an input of a user regarding approval of the Wi-Fi Direct connection via the user interface unit. That is, establishment of Wi-Fi Direct connection is automatically attempted without a user input, for example, an input of a WPS button of the user. Here, the image forming apparatus <b>900</b> transmits a provision discovery response packet for the Wi-Fi Direct connection to the external wireless device <b>940</b>. However, if the device information of the external wireless device <b>940</b> (MAC address) is determined as a wireless device not corresponding to the device information (MAC address) stored in the memory unit <b>920</b>, the image forming apparatus <b>900</b> may terminate a connection to the external wireless device <b>940</b>.

0119In operation <b>1404</b>, as a part of provisioning, the image forming apparatus <b>900</b>, which is an AGO, functions as an AP so as to operate as an internal registrar, and the external wireless device <b>940</b> operates as an enrollee, thereby performing a WSC exchange.

0120In operation <b>1405</b>, when the provisioning is completed, the external wireless device <b>940</b> transmits an authentication/association request packet to the image forming apparatus <b>900</b>, and the image forming apparatus <b>900</b> responds by transmitting an authentication/association response, and then a 4-way handshake operation is performed to thereby complete the wireless connection operation.

0121In operation <b>1406</b>, the image forming apparatus <b>900</b> receives a request for an IP address that is to be used from the external wireless device <b>940</b> via a DHCP.

0122In operation <b>1407</b>, the image forming apparatus <b>900</b>, for example, the CPU <b>930</b> of the image forming apparatus <b>900</b>, determines whether the device information (DHCP client identifier) of the external wireless device <b>940</b>, which has requested the current Wi-Fi Direct connection, is included in the memory unit <b>920</b> based on the device information (DHCP client identifier) stored in the memory unit <b>920</b>. That is, the CPU <b>930</b> determines the MAC address in operation <b>1403</b> in advance, and further determines the DHCP client identifier in operation <b>1407</b>.

0123If the device information (DHCP client identifier) of the external wireless device <b>940</b> is determined as corresponding to the device information (DHCP client identifier) of the memory unit <b>920</b>, the method proceeds to operation <b>1408</b>. However, if the device information (DHCP client identifier) of the external wireless device <b>940</b> is determined as a wireless device not corresponding to the device information (DHCP client identifier) included in the memory unit <b>920</b>, a connection to the external wireless device <b>940</b> may end.

0124In operation <b>1408</b>, the image forming apparatus <b>900</b>, for example, a DHCP server of the image forming apparatus <b>900</b>, allocates an IP address to the external wireless device <b>940</b>, which is a client, thereby completing the Wi-Fi Direct connection between the image forming apparatus <b>900</b> and the external wireless device <b>940</b>.

0125<figref idref="DRAWINGS">FIG. 15</figref> is a flowchart illustrating a method of performing a Wi-Fi Direct connection in an image forming apparatus supporting a Wi-Fi Direct according to an embodiment of the present general inventive concept. The method of <figref idref="DRAWINGS">FIG. 15</figref> includes operations illustrated in <figref idref="DRAWINGS">FIGS. 11 through 14</figref>.

0126In operation <b>1501</b>, the WLAN interface unit <b>910</b> receives a request for Wi-Fi Direct connection from the external wireless device <b>940</b>.

0127In operation <b>1502</b>, the CPU <b>930</b> determines whether the device information of the external wireless device <b>940</b>, which has requested the Wi-Fi Direct connection, is stored, based on device information that is stored in advance in the memory unit <b>920</b> and corresponds to a wireless device which was previously Wi-Fi Direct connected to the image forming apparatus <b>900</b>.

0128In operation <b>1503</b>, if the external wireless device <b>940</b> that has requested the current Wi-Fi Direct connection is determined as a wireless device corresponding to the device information stored in the memory unit <b>920</b>, the CPU <b>930</b> allows to establish a Wi-Fi Direct connection between the image forming apparatus <b>900</b> and the external wireless device <b>940</b>.

0129In the image forming apparatus <b>900</b> supporting the Wi-Fi Direct and the method of performing the Wi-Fi Direct connection of the image forming apparatus <b>900</b> supporting Wi-Fi Direct according to an embodiment of the present general inventive concept, device information of wireless devices that were previously connected is stored, and when the same wireless devices attempts the Wi-Fi Direct connection, the stored device information is used to quickly establish a connection without a user input, for example, an input of a WPS button. Therefore, when the same wireless devices that were previously connected attempt the Wi-Fi Direct connection, the connection can be easily performed without inconvenience of pressing the WPS button of the image forming apparatus <b>900</b> each time.

0130As described above, when the Wi-Fi Direct connection is performed in an image forming apparatus supporting the Wi-Fi Direct, by determining whether a wireless device which is currently attempting the Wi-Fi Direct connection has been previously connected to the Wi-Fi Direct or not, the Wi-Fi Direct connection may be established without inputting a user input, for example, a WPS button to thereby provide inconvenience to the user by excluding an operation of pressing or selecting a WPS button every time. Also, Wi-Fi Direct devices may be connected quickly and easily in an image forming apparatus that supports the Wi-Fi Direct.

0131The present general inventive concept can also be embodied as computer-readable codes on a computer-readable medium. The computer-readable medium can include a computer-readable recording medium and a computer-readable transmission medium. The computer-readable recording medium is any data storage device that can store data as a program which can be thereafter read by a computer system. Examples of the computer-readable recording medium include read-only memory (ROM), random-access memory (RAM), CD-ROMs, magnetic tapes, floppy disks, and optical data storage devices. 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. The computer-readable transmission medium can transmit carrier waves or signals (e.g., wired or wireless data transmission through the Internet). Also, functional programs, codes, and code segments to accomplish the present general inventive concept can be easily construed by programmers skilled in the art to which the present general inventive concept pertains.

0132Although a few embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.