Patent Publication Number: US-2012047236-A1

Title: Method and apparatus for file transfer

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. §119 from Korean Patent Application Nos. 10-2010-0081465 filed on Aug. 23, 2010 and 10-2011-0079092 filed on Aug. 9, 2011, the entire contents of which applications are hereby incorporated by reference. 
     BACKGROUND 
     Embodiments of the present inventive concept relate to a method for file transfer, and more particularly, to a file transfer method which may transfer files, by using a router, stored in an external storage device connected to the router to a user or a third party and apparatuses performing the method. 
     As a multi-media era is accelerated and contents are getting to be in a large capacity, demands for various kinds of contents and large amounts of information sharing have expanded. Currently a community service provided by a current internet portal has limited capacity to upload files because of an enormous cost of server. Accordingly, users had to use Web hard services to share large amounts of the information. The web hard service may secure a storage space large enough to upload the large amounts of information the users have requested; however, the users have to pay an amount in proportion to the capacity they requested. 
     SUMMARY OF THE DISCLOSURE 
     The present general inventive concept provides a file transfer method, by using a router, transferring files stored in an external storage device connected to the router to a user or a third party and apparatuses performing the method. 
     Another general inventive concept provides a file transfer method, in which a web server collects a variable IP address of a router in real time and renews itself with the most up to date connection information, so users can transmit and receive files to and from the router and apparatuses performing the method. 
     An embodiment of the present invention is directed to a router, including a connection module enabling data communication with an external storage device; and a file transfer module, transferring or receiving at least one of files between the external storage device and the electronic device, by using the connection module according to a file request signal of an electronic device. 
     According to embodiments, the file transfer module transfers connection information to a web server, every time a certain time passes, the external storage device is connected to the router, the IP address of the router changes, or the router turns on. Here, the connection information is an ID, a password and an IP address of the file transfer module. The file transfer module determines if the connection information is valid in response to a connection request signal output from the electronic device by using the connection information. 
     An embodiment of the present invention is directed to a web server, including a connection information reception module receiving connection information transferred from a router; a data base storing the connection information; and a connection information transfer module transferring, the connection information stored in the data base to a first electronic device in response to a connection information request signal of the first electronic device. Here, the connection information is an ID, a password and an IP address of the router. 
     According to embodiments, the web server further includes a user information reception module receiving an ID and password of the first electronic device and an ID and password of the router from the first electronic device connected to the web page which the web server provides; and a mapping table generation module generating a mapping table by mapping the ID and password of the first electronic device received from the user information reception module with the connection information received from the router. 
     According to embodiments, the web server further includes a transfer control module controlling at least one of files stored in an external storage device connected to the router to be transmitted to a second electronic device and controlling at least one of files to be received from a second electronic device and to be stored in an external storage device connected to the router in response to the transfer control request signal received from the first electronic device; and a file link module receiving the location and name of a file stored in the external storage device in response to the transfer control signal output from the transfer control module and linking the location and name of the file with the ID and password of the second electronic device connected to the web page which the web server provides. 
     An embodiment of the present invention is directed to a file transfer system, including a router connecting to an external storage device and communicating (by transmitting or receiving) at least one of files stored in the external storage device; a first electronic device for communicating the router with a file; and a web server. The web server includes a connection information reception module receiving connection information transferred from the router; a data base storing connection information received from the connection information reception module; and a connection information transfer module transferring connection information stored in the data base to the first electronic device in response to the connection information request signal of the first electronic device. Here, the connection information is an ID, a password and an IP address of the router. 
     An embodiment of the present invention is directed to a web server, including a user information reception module receiving an ID and a password of a first electronic device and an ID and a password of the router from the first electronic device connected to a web page which the web server provides; and a mapping table generation module generating a mapping table by mapping an ID and password of the first electronic device received from the user information reception module with the connection information received from the router. 
     An embodiment of the present invention is directed to a web server including a transfer control module controlling at least one of files, stored in an external storage device connected to the router to be transferred to a second electronic device and controlling at least one of files to be received from a second electronic device and to be stored in an external storage device connected to the router in response to a transfer control request signal received from the first electronic device; and a file link module receiving the location and name of a file stored in the external storage device in response to the transfer control signal output from the transfer control module and linking the location and name of the file with the ID and password of the second electronic device connected to the web page which the web server provides. 
     An embodiment of the present invention is directed to a file transfer method, including (A) receiving, by a web server, connection information including an ID, a password and IP address of an electronic device from a router; (B) transferring, by the web server, according to a mapping table in response to a connection information request signal output from an electronic device, connection information received from the router to the electronic device; (C) transferring, by the electronic device, a connection request signal to the router by using the connection information; (D) determining, by the router, if the connection information is valid according to the connection request signal; (E) transferring, by the electronic device, a file transfer request signal requesting transfer (by uploading or downloading) of at least one of files stored in an external storage device connected to the router, to the router when the router and the electronic device are connected to each other due to the connection information determined as valid; and (F) storing, by the router, a file transferred from an electronic device to the external storing device if the file transfer request signal request is upload, and transferring at least one of files stored in the external storage device, by fetching, to the electronic device, if the file transfer request signal is download. 
     Another example embodiment of the present invention is directed to a file transfer method, including (A) receiving, by the web server, a transfer control request signal including an ID and password of a second electronic device connected to a web page which the web server provides from the first electronic device so as to transfer, by the router, least one of files stored in an external storage device connected to the router, to a second electronic device by the request of the first electronic device; (B) transferring, by the web server, the transfer control signal request to the router and receiving a connection information including the location and name of the file stored in the external storage device from the router; (C) storing, by the web server, the link value by linking the location and name of the received file with the ID and password of the second electronic device; (D) transferring, by the web server, the location and name of the file including a router connection address in response to the file transfer request signal of the second electronic device connected by the link value to the second electronic device. 
     In one general aspect, a web server provides users with files transmitting and receiving service from and to a router so that the users can transmit and receive files stored in an external storage device connected to the router. 
     In another aspect, a web server provides users linked to a web server with accurate connection information of a router, after collecting real time variable IP address of a router, so that success rate of a file transfer can increase. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other aspects of the exemplary embodiments will become apparent from the following descriptions of the embodiments with reference to the accompanying drawings in which: 
         FIG. 1  shows a schematic block diagram of a file transfer system according to an example embodiment of the present invention; 
         FIG. 2  shows a schematic block diagram of a router illustrated in  FIG. 1 ; 
         FIG. 3  shows a schematic block diagram of a web server illustrated in  FIG. 1 ; 
         FIG. 4  shows a data flow of the file transfer system illustrated in  FIG. 1 ; 
         FIG. 5  shows a schematic block diagram of a file transfer system according to another example embodiment of the present invention; 
         FIG. 6  shows a schematic block diagram of a web server illustrated in  FIG. 5 ; 
         FIG. 7  shows a schematic block diagram of the file transfer system illustrated in  FIG. 5 ; and 
         FIG. 8  shows a schematic block diagram of a file transfer system according to still another example embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     Reference 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 by referring to the figures. 
     For the purposes of promoting an understanding of the principles of the inventive concept, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the inventive concept is thereby intended, such alterations and further modifications in the illustrated inventive concept, and such further applications of the principles of the inventive concept as illustrated therein being contemplated as would normally occur to one skilled in the art to which the inventive concept relates. 
     The use of the terms “first”, “second”, and the like does not imply any particular order, but they are included to identify individual elements. Moreover, the use of the terms first, second, etc. does not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. 
     If any component is mentioned as being “connected” to or “contacting” another component, the component may be directly connected to or directly contact another component, but it should be understood that any further component can be present between them. Meanwhile, if it is mentioned that any component is “directly connected to” or “directly contacts” another component, it should be understood that any further component is not present between them. Other expressions relating to relationships among components, for example “between”, “just between”, “directly adjacent to”, or the like should be interpreted in the same way. 
     The terminology used herein is for the purpose of describing just the particular embodiments and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising”, or “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof. 
     Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. 
       FIG. 1  shows a schematic block diagram of a file transfer system  10  according to an example embodiment of the present invention. Referring to  FIG. 1 , a file transfer system  10  includes an external storage device  20 , a router  30 , a web server  50  and an electronic device  60 . 
     An external storage device  20  is a device for storing data such as multi-media contents. The external storage device  20  is additionally separated from a device consuming a high power such as a computer. For example the external storage device  20  may be one of a USB flash drive, compact flash (CF), a multi-media card (MMC), a xD-picture card, a Secure digital (SD) memory card, a memory stick, an external solid state drive (SSD), and an external hard disk drive (HDD). The data is stored in various types of files. The external storage device  20  is connected to a router  30 . 
       FIG. 2  is a schematic block diagram of a router  30  illustrated in  FIG. 1 . Referring to  FIGS. 1 and 2 , the router  30  includes a connection module  31 , a file transfer module  33 , an IP address assignment module  35 , and a client connection module  37 . 
     A module of the present invention may mean a functional or structural combination of hardware for performing a technical concept according to embodiments of the present invention and software for driving the hardware. For example, the module may mean a logical or functional unit of a predetermined program code or a hardware resource for performing the program code. It may not always mean a physically connected program code or a kind of hardware. 
     A connection module  31  enables a data communication between the external storage device  20  and the router  30 . That is, when the external storage device  20  is physically connected to the router  30 , the connection module  31  may transfer files stored in the external storage device  20  to the router  30  or transfer files transferred from the router  30  to the external storage device  20 . 
     A file transfer module  33  transfers one of files stored in the external storage device  20  to an electronic device  60  by using a connection module  31  according to a download file transfer request signal of the electronic device  60 . Also, a file transfer module  33  receives a file from an electronic device  60  according to an upload file transfer request signal and by using a connection module  31  stores the file to an external storage device  20 . That is, the router  30  performs a role of a file transfer protocol (FTP) server by including the file transfer module  33 . 
     An IP address assignment module  35  receives a dynamic IP through an external network, and converts a received dynamic IP into a plurality of imaginary dynamic IPs. A client connection module  37  enables communication between a plurality of clients  40 - 1 ,  40 - 2 , . . . ,  40 -N or communication between each of the plurality of clients  40 - 1 ,  40 - 2 , . . . ,  40 -N and the external network according to the plurality of imaginary dynamic IPs. The external network means a wide area network (WAN), and each of the plurality of clients  40 - 1 ,  40 - 2 , . . . ,  40 -N means an electronic device such as a computer or a laptop computer. 
     Each of the plurality of clients  40 - 1 ,  40 - 2 , . . . ,  40 -N may receive files stored in the external storage device  20  by using the client connection module  37  and the connection module  31  or transfer its files to the external storage device  20 . Each of the plurality of clients  40 - 1 ,  40 - 2 , . . . ,  40 -N may communicate with the router  30  by wired network or by wireless network. A web server  50  provides a web page including a user interface for transferring a file to a user using an electronic device  60 . 
       FIG. 3  shows a schematic block diagram of a web server  50  illustrated in  FIG. 1 . Referring to  FIG. 1  or  3 , the web server  50  includes a connection information reception module  51 , a data base  53 , a connection information transfer module  55 , a user information reception module  57 , and a mapping table generation module  59 . 
     The connection information reception module  51  receives connection information from the file transfer module  33  of the router  30 . The connection information includes an ID, a password and a dynamic IP address of the router  30 . Here, the connection information reception module  51  receives a variably allocated IP address of the router  30  and therefore, the web server  50  can retain up to date IP address of a router. 
     The data base  53  stores connection information received from the connection information reception module  51 . According to embodiments, the data base  53  may be embodied in an additional data base server. The connection information transfer module  55  transfers connection information stored in the data base  53  to the electronic device  60  in response to a connection information request signal of the electronic device  60 . Here, the connection information transfer module  55  provides the electronic device  60  with the connection information that can directly access the router  30 . 
     The user information reception module  57  receives an ID and password of an electronic device  60  connected to a web page provided by a web server  50 , and an ID and a password of the router  30 . The web server  50  provides a user interface so that a user using the electronic device  60  can transfer a file, and by using the web page, the ID and password of the electronic device  60  and the ID and password of the router  30  can be received from the user. Here, the ID and password of the electronic device  60  refers to the ID and password of a user using an electronic device  60  connected to a web page which the web server  50  provides (for example: log in ID/password). 
     A mapping table generation module  59  generates a mapping table by mapping an ID and password of an electronic device  60  received from the user information reception module  57  with the connection information including an ID, password and IP address of the router  30  received from the router  30  and stores a generated mapping table in the data base  53 . Referring to  FIG. 1 , the electronic device  60  includes a file transfer request module  61 . 
     The electronic device  60  may request a transfer of files stored in the external storage device  20  connected to the router  30  by using the file transfer request module  61 . For example, the electronic device  60 , as a terminal capable of internet communications, may be one of a computer, a smart phone, a laptop computer, a cellular phone, a tablet PC, a MP3 player, a smart TV and a navigation device. The electronic device  60  operates as a file transfer protocol (FTP) client by including the file transfer request module  61 . 
     Hereinafter, an operation performed by the electronic device  60  should be understood as an operation performed by the file transfer request module  61  if there is no special explanation. 
       FIG. 4  shows a data flow of a file transfer system  10  of a file received from the router  30  to the electronic device  60  illustrated in  FIG. 1 . Referring to  FIGS. 1 to 4 , the web server  50  receives an ID and password of a user using an electronic device  60  connected to a web page which the web server  50  provides and an ID and a password of the router  30  (S 10 ). Here, the user sets up an ID and password in advance along with a ID and password of the router used to transfer files. For users, using a plurality of routers  30 , the user will need to set up an ID and password for each distinct router  30 . The user may also set inherent user ID and password for every individual router  30 . 
     Afterwards, the web server  50  generates a mapping table by mapping the received ID and password of an electronic device  60  with the received connection information including an ID, password and IP address of the router  30  respectively (S 20 ). The web server  50  refers to the mapping table and provides corresponding router information to the user logging in, and then a particular router is selected by the user to receive requests to remit/receive a file. During the time the web server  50  is running, the web server  50  receives connection information from the router  30  (S 30 ). Here, the connection information is an ID, a password, dynamic IP address of a router  30 . The router  30  performs a role of a file transfer protocol (FTP) server by including the file transfer module  33 . Accordingly, an ID, a password, and a dynamic IP address of the router  30  corresponds to an ID, a password, and a dynamic IP address of the file transfer module  33 . 
     Additionally, the web server  50  receives connection information from a router  30  every time a certain time passes, an external storage device  20  is connected to a router  30 , an IP address of a router changes, or a router  30  turns on. Therefore, because the web server  50  receives in real time the ever-changing IP address of a router  30  periodically or by event, the up to date IP address of a router  30  can always be saved. So, when the IP address of a router  30  becomes a variable, the web sever  50  provides, in regard to the file remit/receive request being requested by the electronic device  60 , provides an accurate connection information based on the IP address of a router  30  that has been stored in real time. After the above steps (S 10 -S 30 ), the user can request the above-mentioned file transfer (upload/download) after logging in to the web server  50 . 
     A user of the electronic device  60  connects to a web page provided by a web server  50  and performs a file transfer request module  61  of an electronic device  60 . Also, the user, by using an electronic device  60 , transfers connection information request signal requesting connection information that can connect to a router  30  to a web server  50  (S 40 ). The operation (e.g. log in) of connecting to the web page above is a user inputting his/her own ID and password to the web page. 
     Here, the user does not need to know each and every IP address of the router  30 . That is, the web server  50  transfers connection information including a dynamic IP address of the router  30  by referencing mapping table to the file transfer request module  61  of the electronic device  60  in response to the connection information request signal, so the user only needs to know his/her ID and password. 
     The web server  50  transfers the connection information to the electronic device  60  by referencing the mapping table in response to a connection information request signal output from the electronic device  60  when the connection request signal of the user is received (S 50 ). 
     When the connection information is received, the electronic device  60  transfers a connection request signal to the router  30  by using the connection information received for data communication with the router  30  (S 60 ). The connection request signal includes the connection information. 
     When a connection occurs due to the connection information, the router  30  determines if the connection information is valid in response to the connection request signal transferred from the electronic device  60  (S 70 ). In other words, the router  30  compares the connection information with ID, password and dynamic IP of the router  30  received from the electronic device  60  and determines whether the connection request is received from a person with a just right. If the request is determined as valid, the router  30  transmits the connection success signal to the electronic device  60  (S 80 ). 
     The electronic device  60  selects at least one of files stored in the external storage device  20  connected to the router  30  and transmits a file transfer request signal to the router  30  (S 90 ). Naturally, the electronic device  60  may select some of all the files stored in the external storage device  20 . 
     When a file transfer request is made, the router  30  can transfer a file to the electronic device  60 , by fetching, a selected file in response to a file transfer request signal received from the electronic device  60  (S 110 ). 
     Meanwhile, the embodiments explain that the electronic device  60  downloads a file from the external storage device, but it is self-evident that the electronic device  60  may transfer a file to the external storage device  20  connected to the router  30 . 
       FIG. 5  shows a schematic block diagram of a file transfer system  10 ′ according to another example embodiment of the present invention. Referring to  FIG. 5 , a file transfer system  10 ′ includes an external storage device  20 , a router  30 , a web server  50 , and a plurality of electronic devices  62 ,  64 , . . . ,  66 . An external storage device  20  and a router  30  have the same drawing numeral, operation and function as the external storage device  20  and the router  30  of  FIG. 1 , so that explanation thereof is omitted. 
     Each of the plurality of electronic devices  62 ,  64 , . . . ,  66  includes each of file transfer request modules  63 ,  65 , . . . ,  67 . The plurality of electronic devices  62 ,  64 , . . . ,  66  have the same operation and function as the electronic device  60  of  FIG. 1 . The web server  50  allows a first electronic device  62  to select a file in the external storage device  20  connected to the router  30  and to transfer a selected file to a second electronic device  64 . According to embodiments, the web server  50  may enable the selected file to be transferred as a lump to a plurality of electronic devices  64 , . . . ,  67 . 
       FIG. 6  shows a schematic block diagram of a web server illustrated in  FIG. 5 . Referring to  FIGS. 5 and 6 , the web server  50  includes a connection information reception module  51 , a file link module  52 , a data base  53 , a transfer control module  54 , a connection information transfer module  55 , a user information reception module  57  and a mapping table generation module  59 . 
     A connection information reception module  51 , a data base  53 , a connection information transfer module  55 , a user information reception module  57  and a mapping table generation module  59  have the same drawing numeral, operation and function as the connection information reception module  51 , the data base  53 , the connection information transfer module  55 , the user information reception module  57  and the mapping table generation module  59 , so that explanation thereof is omitted. 
     The transfer control module  54  receives a control request signal from a first electronic device  62 . The transfer control request signal is a signal which controls the first electronic device  62  to select at least one of files stored in the external storage device  20  connected to the router  30 , and then controls the second electronic device  64  to access the router  30  and receive the file selected by the first electronic device  62 . 
     Here, the user (first user) using the first electronic device  62  is different from the user (second user) using a second electronic device  64 . Also, the control request signal includes an ID and password of a second electronic device that plans to connect to the web page provided by the web server  50 . That is, the first user registers in advance the ID and password of the second user to the web server  50  so that the second user will be permitted to receive a file. 
     A file link module  52  transfers a transfer control signal, which controls the second electronic device  64  to access to a file selected by the first electronic device  62 , to the router  30  in response to a transfer control request signal received from the transfer control module  54 . The router  30  receives the transfer control signal and stores the file information and ID and password of a second user. 
     The file link module  52  receives the name and location of a file the first user plans to remit to the second user from the router  30  and generates a router connection address that corresponds to the ID and password of the second user transferred from the first electronic device  62 . The file link module  52  stores the router connection address and a link value (link address to web server  50 ) that links to the router connection address to the data base  53 . 
     When the second electronic device  64  attempts to access the file selected by the first electronic device  62 , the transfer control module  54  receives the link value from the file link module  52  and determines whether the second electronic device  64  has an access right. 
     A connection information control module  55  transfers the newly updated router connection address stored in the data base in comparison with the link value in response to the connection information request signal received from the second electronic device  64  to the second electronic device  64 . When the second electronic device  64  receives the router connection address, it connects to the router  30  by using the received connection information and then receives the file selected by the first user. 
       FIG. 7  shows a data flow where a file transfers from the first user to the second user by using a router  30  system illustrated in the file transfer system  10 ′ of  FIG. 5 . 
     Referring to  FIGS. 5 to 7 , it is assumed that operations of S 10  to S 80  of  FIG. 4  are performed in a file transfer system of  FIG. 7  and the first electronic device  62  is connected to the router  30  by performing operations of S 10  to S 80  of  FIG. 4 . 
     The first electronic device  62  selects at least one of files stored in the external storage device  20  connected to the router  30  and transfers a transfer control request signal, which controls the second electronic device  64  to access to the router  30  so that the selected file can be transferred to the web server  50  (S 120 ). 
     Here, the transfer control request signal includes an ID and password of a second electronic device  64  that plans to connect to the web page provided by the web server  50 . According to embodiments, the first electronic device  62  may select some of all of files stored the external storage device  20 . 
     The web server  50  transfers a transfer control signal, which controls the second electronic device  64  to access the selected file, to the router  30  in response to the transfer control request signal (S 130 ). Accordingly, since the web server  50  registers that the second user will connect to the router  30  in advance, the second electronic device  64  may access the router  30  only for the file selected by the first electronic device  62  and receive the file selected by the first user. 
     The router  30  fetches a location and a name of the selected file in response to the transfer control signal (S 140 ), and transfers a location and a name of the selected file to the web server  50  (S 150 ). At this time, the web server  50  generates a router connection address by using the location and name of the received file and the ID and password of the second electronic device  64  received from the first electronic device  62 . Then, web server  50  stores the router connection address and a link value (link address to web server  50 ) that distinguishes the router connection address. 
     Here, when the link value is stored, the web server  50  or the first electronic device  62  notifies the link value to the second electronic device  64 . For example, the web server  50  notifies the second user the link value by using a program of a web server  50  by the request of the first user. Or, the first electronic device  62  can receive the link value from the web server  50  and then by using ways such as email, SMS, and SNS notify the second user the link value. 
     Afterwards, the second electronic device  64  connects to the web server and transfers a connection information request signal, which requests the connection information of the router  30  where the selected file is located, using the link value that has been notified to the second electronic device  64 , to the web server  50  (S 160 ). At this time, the connection information request operation refers to the act of the user clicking the link value that distinguishes the router connection address stored in the web server  50 . 
     The web server  50  determines if the connection information of the second user is valid in response to the connection information request signal received (S 170 ). The web server  50  determines the validity when the received link value including the ID and password of the second user coincides with the stored ID and password of the second user. 
     When the web server  50  determines the request of the second electronic device  64  to be right, the router connection address corresponding to the link value is transferred to the second electronic device  64  (S 180 ). 
     Here, every time the web server  50  receives the most up to date IP address from the router  30  in real time, then the router connection information renews to the received most up to date IP address. Therefore, the second user can connect to the router  30  by receiving router connection address that has been renewed to the most up to date IP address, even if by connecting to the web server  50  after the link value has been received and a fixed amount of time passes. For example, in the case the second user clicks on the link value a week after receiving the link value, the user can receive the file by using the router connection information reflecting the most up to date router IP address even if the address of the router  30  has been changed during the week. 
     The second electronic device  64  transfers a connection request signal to the router  30  by using the received router connection address (S 190 ). 
     The router  30  determines if the transferred connection request signal is valid (S 200 ) by comparing the connection information transferred from the second electronic device  64  and the connection information stored in the router  30 , and in the case it is valid, transfers a transfer success signal to the second electronic device  64  (S 210 ). Here, the router  30  determines the connection to be a success when the file information received from the second electronic device  64  and the ID and password of the second user coincides with stored information. Thus, the second electronic device  64  can access the router  30  by the selected file of the first electronic device  62 . 
     The second electronic device  64  transfers a file transfer request signal, which requests a transfer of a file selected by the first electronic device  62  to the second electronic device  64 , to the router  30  when the connection success signal is received (S 220 ). The router  30  fetches a requested file in the external storage device  20  connected to the router  30  (S 230 ) and transfers it to the second electronic device  64  (S 240 ). According to embodiments, the first electronic device  62  may enable not only the second electronic device  64  but also a plurality of electronic devices to receive a file selected by the first electronic device  62 . 
     The embodiments described a second electronic device  64  downloading files stored in the external storage device  20  by the request of the first electronic device  62 . To substitute the downloading components with the uploading components, it is self evident that the second electronic device  64  can upload a file to the external storage device  30  connected to the router  30  by the request of the first electronic device  62 . 
       FIG. 8  shows a schematic block diagram of a file transfer system according to still another example embodiment of the present invention. Referring to  FIG. 8 , a file transfer system  10 ″ includes a user server  41 , a web server  50  and an electronic device  60 . A web server  50  ad an electronic device  60  have the same drawing numeral, operation and function as the web server  50  and the electronic device  60  of  FIG. 1 , so that explanation thereof is omitted. 
     A user server  41  refers to a device providing a service to a plurality of clients  40 - 1 ,  40 - 2 , . . . ,  40 -N through a network. For example, the service refers to a file transfer or a content offer of a web page. The user server  41  includes modules of the router  30  illustrated in  FIG. 2 , an operation and a function of each module of  FIG. 2  may be applicable to the user server  41  as explained in  FIG. 2 . For example, the user server  41  may be embodied in a PC or a laptop computer. The user server  41  is connected to a plurality of clients  40 - 1 ,  40 - 2 , . . . ,  40 -N through a network. Here, the external storage device  20  may connect to user server  41  as a subsidiary device or substitute as a recording medium in a user server  41 . 
     The user server  41  may transfer or receive at least one of files with the electronic device  60  and include the same module as the file transfer module  33  of  FIG. 2 . According to embodiments, user server  41  transfers a dynamic IP address or a static IP address of the user server  41  to the web server  50  as connection information. 
     Although 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.