Patent Publication Number: US-2021181700-A1

Title: Electronic apparatus and control method thereof

Description:
CROSS-REFERENCE TO RELATED THE APPLICATION 
     This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2019-0167581 filed on Dec. 16, 2019 in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety. 
     BACKGROUND 
     Field 
     The disclosure relates to an electronic apparatus and a control method thereof under an Internet-of-things (IoT) system provided for controlling operations of a plurality of electronic apparatuses as connected to an access point (AP) and a server, and more particularly to an electronic apparatus and a control method thereof under the system when a new electronic apparatus is additionally used in the system. 
     Description of Related Art 
     To compute and process predetermined information in accordance with certain processes, an electronic apparatus may include a central processing unit (CPU), a chipset, a memory, and the like electronic components for the computation. Such an electronic apparatus may be variously classified in accordance with what information will be processed and what it is used for. For example, the electronic apparatus may be classified into an information processing apparatus such as a personal computer (PC), a server or the like for processing general information; an image processing apparatus for processing image data; an audio apparatus for audio process; home appliances for miscellaneous household chores; etc. The image processing apparatus may be embodied as a display apparatus that displays an image based on processed image data on its own display panel. Further, the electronic apparatus may be classified into a stationary type installed in one place, and a mobile type portable by a user according to use methods. 
     When a household is taken as an example, the household may own a plurality of miscellaneous electronic apparatuses such as a television (TV), a refrigerator, a washing machine, a mobile apparatus, etc. Like this, the electronic apparatus is closely grafted onto life of general users. With higher demands of users and corresponding development in performance of electronic apparatuses, a plurality of electronic apparatuses may not only operate independently of each other but also operate as interconnected with each other. Such an interconnection may be based on communication between the plurality of electronic apparatuses. In particular, a wireless communication method is applied to the communication in consideration of a mobile apparatus. However, when security is taken into account, wireless communication between the plurality of electronic apparatuses may be at risk. Therefore, it may be preferable in terms of security that a plurality of electronic apparatuses be registered to a unit network system to which a preset security protocol is applied to have communication connection. 
     Such a unit network may be capable of creating an IoT environment like a household&#39;s home network. However, it will get in trouble if a user can control operations of a TV or household appliances, control temperature of a boiler, release a door lock, turn on a light or carry out the like operations through an unauthorized unspecified mobile apparatus. In other words, the foregoing operations should be permitted to only the mobile apparatus registered to the server that manages the unit network, but not permitted to an unregistered mobile apparatus. Therefore, to use an electronic apparatus such as a mobile apparatus, etc. purchased by a user on the unit network, the user needs to go through a process of registering the purchased electronic apparatus to the server that manages the unit network. 
     SUMMARY 
     Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments. 
     In accordance with an aspect of the disclosure, an electronic apparatus includes at least one interface; and at least one processor configured to: register a first user account with a first server configured to provide a first service, through the at least one interface, identify a second server corresponding to an external apparatus connectable through the at least one interface, wherein the second server is configured to provide a second service different from the first service, register the first user account with the second server through the at least one interface to link the first user account to a second user account corresponding to the second service, and perform a linkage service operation based on the first service and the second service, using the first user account and the second user account. 
     The at least one processor may be further configured to: detect the external apparatus through the at least one interface, determine whether the first user account has been registered with the second server, and based on determining that the first user account is not registered with the second server, register the first user account with the second server. 
     The at least one processor may be further configured to: identify the external apparatus based on information about the external apparatus received from the external apparatus through the at least one interface. 
     The information about the external apparatus may include information about a manufacturer of the external apparatus, and the at least one processor may be further configured to identify the external apparatus based on the information about the manufacturer of the external apparatus. 
     The information about the external apparatus may further include a network address of the external apparatus, and the at least one processor may be further configured to identify the external apparatus based on the network address of the external apparatus and a network address table provided according to the manufacturer of the external apparatus. 
     The at least one processor may be further configured to: receive information about the second server from the external apparatus through the at least one interface, and identify the second server based on the received information about the second server. 
     The linkage service operation may include controlling the external apparatus. 
     The at least one processor may be further configured to perform the linkage service operation based on a control signal received from the external apparatus. 
     The linkage service operation may include controlling a second external apparatus connected to the second server through the external apparatus. 
     The at least one processor may be further configured to register the second user account with the second server through the at least one interface, based on a determination that the second user account obtained from the external apparatus has not been registered to the second server. 
     In accordance with an aspect of the disclosure, a method of controlling an electronic apparatus, includes registering a first user account with a first server configured to provide a first service; identifying a second server corresponding to a connectable external apparatus, wherein the second server is configured to provide a second service different from the first service; registering the first user account with the second server to link the first user account to a second user account corresponding to the second service; and performing a linkage service operation based on the first service and the second service, using the first user account and the second user account. 
     The method may further include: detecting the external apparatus; determining whether the first user account has been registered with the second server; and based on determining that the first user account is not registered with the second server, registering the first user account with the second server. 
     The method may further include: identifying the external apparatus based on information about the external apparatus received from the external apparatus. 
     The information about the external apparatus may include information about a manufacturer of the external apparatus, and the external apparatus may be identified based on the information about the manufacturer of the external apparatus. 
     The information about the external apparatus may further include a network address of the external apparatus, and the external apparatus may be identified based on the network address of the external apparatus and a network address table provided according to the manufacturer of the external apparatus. 
     The method may further include: receiving information about the second server from the external apparatus, and identifying the second server based on the received information about the second server. 
     The method may further include the linkage service operation may include controlling the external apparatus. 
     The method may further include performing the linkage service operation based on a control signal from the external apparatus. 
     The linkage service operation may include controlling a second external apparatus connected to the second server through the external apparatus. 
     The method may further include registering the second user account with the second server, based on a determination that the second user account obtained from the external apparatus has not been registered to the second server. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features, and advantages of certain embodiments of the present disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  illustrates a system connected to a plurality of servers, according to an embodiment; 
         FIG. 2  is a block diagram of an electronic apparatus, according to an embodiment; 
         FIG. 3  is a flowchart showing an example in which an electronic apparatus registers a first user account to a second server so as to link the first user account with a second user account, according to an embodiment; 
         FIG. 4  illustrates an example in which an electronic apparatus detects an external apparatus, according to an embodiment; 
         FIG. 5  illustrates an example in which a first server and a second server store registration information, according to an embodiment; 
         FIG. 6  illustrates a an example in which a second server manages user accounts when the second server is liked to a first server, according to an embodiment; 
         FIG. 7  is a flowchart showing a process that an electronic apparatus registered to a first server registers a newly detected external apparatus to a second server, according to an embodiment; 
         FIG. 8  illustrates an example in which an external apparatus registered to a second server controls an electronic apparatus registered to a first server, according to an embodiment; 
         FIG. 9  illustrates an example in which an electronic apparatus registered to a first server controls an external apparatus registered to a second server, according to an embodiment; and 
         FIG. 10  illustrates an example in which a second server manages user accounts when the second server is linked to a first server, according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Below, embodiments will be described in detail with reference to accompanying drawings. Further, the embodiments described with reference to the accompanying drawings are not exclusive to each other unless otherwise mentioned, and a plurality of embodiments may be selectively combined within one apparatus. The combination of these plural embodiments may be discretionally selected and applied by a person having an ordinary skill in the art. 
     In the description of the embodiments, an ordinal number used in terms such as a first element, a second element, etc. is employed for describing variety of elements, and the terms are used for distinguishing between one element and another element. Therefore, the meanings of the elements are not limited by the terms, and the terms are also used just for explaining the corresponding embodiment without limiting the disclosure. 
     Further, a term “at least one” among a plurality of elements in the disclosure represents not only all the elements but also each one of the elements, which excludes the other elements or all combinations of the elements. 
       FIG. 1  illustrates a system connected to a plurality of servers. 
     As shown in  FIG. 1 , a plurality of electronic apparatuses  110 ,  120 ,  130  and  140  are connected to communicate with each other through a network, and establish an Internet-of-things (IoT) environment. There are no limits to the kinds of electronic apparatuses  110 ,  120 ,  130  and  140 , and the electronic apparatuses  110 ,  120 ,  130  and  140  may for example include a stationary display apparatus such as a television (TV), a monitor, a digital signage, a digital whiteboard, an electronic frame, etc.; an image processing apparatus such as a set-top box, an optical media player, etc.; an information processing apparatus such as a computer; a mobile apparatus such as a smartphone, a tablet computer, etc.; a wearable device, etc. 
     At least some among the plurality of electronic apparatuses  110 ,  120 ,  130  and  140  may be connected to a network. For example, each of the electronic apparatuses  110 ,  120 ,  130  and  140  can be connected to the network by Wi-Fi through an access point (AP)  103  connected to a gateway or router. According to system environments, some among the plurality of electronic apparatuses  110 ,  120 ,  130  and  140  may be connected to the network by a wired communication method, and they in this case may be connected to the gateway or router by a wire without the AP  103 . 
     The electronic apparatuses  110 ,  120 ,  130  and  140  are registered with a user account to servers  101  and  102 . Each of the electronic apparatuses  110 ,  120 ,  130  and  140  is logged in with the user account to the servers  101  and  102 , and thus permitted to control operations of the other electronic apparatuses  110 ,  120 ,  130  and  140 . There may be a plurality of servers  101  and  102 . This embodiment shows two servers  101  and  102 , i.e. a first server  101  and the second server  102 , but three or more servers may be provided. 
     The servers  101  and  102  individually provide services, and manage user accounts to provide the corresponding services. As one of methods of managing the user account, the servers  101  and  102  store the user accounts and information about registration of one or more electronic apparatuses  110 ,  120 ,  130  and  140  that are linked to the corresponding user account. By retrieving the stored information about the registration, each of the servers  101  and  102  can identify the connected electronic apparatuses  110 ,  120 ,  130  and  140 , the user account linked to the corresponding electronic apparatuses  110 ,  120 ,  130  and  140 , and other electronic apparatuses  110 ,  120 ,  130  and  140  linked to the corresponding user account. 
     The electronic apparatuses  110 ,  120 ,  130  and  140  may be connected to the first server  101  or the second server  102  through the network. However, for a linked operation among the electronic apparatuses  110 ,  120 ,  130  and  140  under the IoT environment, each of the electronic apparatuses  110 ,  120 ,  130  and  140  needs to be connected to other electronic apparatuses  110 ,  120 ,  130  and  140  while being logged in the servers  101  and  102  to which it is registered. The linked operation between two of the electronic apparatuses  110 ,  120 ,  130  and  140  includes a case where two of the electronic apparatuses  110 ,  120 ,  130  and  140  are registered to one server  101  or  102 , and a case where they are respectively registered to different servers  101  and  102 . 
     For example, a linked operation between the electronic apparatus  120 , which may be for example a mobile apparatus, and the electronic apparatus  130 , which may be for example an image processing apparatus registered to the same second server  102  may be taken into account. The electronic apparatus  120  logs in to the second server  102  with the user account. The second server  102  identifies many apparatuses such as the electronic apparatus  130  linked to the user account logged in by the electronic apparatus  120 . The second server  102  permits a control signal to be transmitted to the electronic apparatus  130 , when it is identified that the control signal sent from the electronic apparatus  120  is targeted at or destined for the image processing apparatus  130  and the electronic apparatus  130  is linked to the user account. Thus, the electronic apparatus  130  receives the control signal from the electronic apparatus  120  via the second server  102 , and performs an operation corresponding to the received control signal. 
     Meanwhile, a linked operation between the electronic apparatus  110 , which may be for example a TV, registered to the first server  101  and the electronic apparatus  120  registered to the second server  102  may be taken into account. The electronic apparatus  110  logs in to the first server  101  with a predetermined first user account. The first server  101  identifies that the electronic apparatus  120 , i.e. the target of the control signal sent from the electronic apparatus  110  is linked to (or linked to) a second user account corresponding to the first user account, and transmits the control signal to the second server  102  that manages the second user account. 
     When it is identified that the target of the control signal transmitted from the first server  101  is the electronic apparatus  120  linked to the second user account, the second server  102  permits the control signal to be transmitted to the electronic apparatus  120 . Thus, the electronic apparatus  120  receives the control signal transmitted from the electronic apparatus  110  via the first server  101  and the second server  102 , and performs an operation corresponding to the received control signal. 
     As above, the plurality of electronic apparatuses  110 ,  120 ,  130  and  140  may operate as linked to one another while being registered to the servers  101  and  102 . 
     Meanwhile, at an initial point in time when the first server  101  registers the electronic apparatus  110  with the first user account and the second server  102  registers the electronic apparatus  120  with the second user account, the first user account and the second user account are not linked yet. Therefore, the electronic apparatus  110  may operate to link the first user account and the second user account together in the first server  101  or the second server  102  in response to a predetermined event. For example, this event may occur when the electronic apparatus  110  detects the electronic apparatus  120 . In this regard, operations of the electronic apparatus  110  will be described later. 
     Below, elements of an electronic apparatus will be described. 
     As shown in  FIG. 2 , an electronic apparatus  200  includes many hardware elements needed for operations. The elements included in the electronic apparatus  200  are not limited to only the following examples, but may include additional elements or exclude some elements as necessary when the electronic apparatus  200  is embodied. An external apparatus  205  basically includes hardware similar to that of the electronic apparatus  200  in this embodiment or a typical electronic apparatus, and thus detailed descriptions thereof will be omitted. 
     The electronic apparatus  200  may include an interface  210 . The interface  210  includes an interface circuit through which the electronic apparatus  200  performs communication with various kinds of external apparatuses such as the external apparatus  205  and the servers  201  and  202  and transmits and receives data. 
     The interface  210  may include one or more wired interface  211  for wired communication. The wired interface  211  includes a connector or port to which a cable of previously defined transmission standards is connected. For example, the wired interface  211  includes a port connecting with a terrestrial or satellite antenna to receive a broadcast signal or connecting with a cable for cable broadcasting. Further, the wired interface  211  include ports to which cables of various wired transmission standards such as high definition multimedia interface (HDMI), DisplayPort (DP), digital video interactive (DVI), component, composite, S-video, thunderbolt, and the like to connect with various image processing apparatuses. Further, the wired interface  211  includes a port of universal serial bus (USB) standards to connect with a USB device. Further, the wired interface  211  includes an optical port to which an optical cable is connected. Further, the wired interface  211  includes an audio input port to which an external microphone is connected, and an audio output port to which a headset, an earphone, a loudspeaker etc. is connected. Further, the wired interface  211  includes an Ethernet port connected to a gateway, a router, a hub, etc. for connection with the WAN. 
     The interface  210  may include one or more wireless interface  212  for wireless communication. The wireless interface  212  includes an interactive communication circuit including at least one of elements such as a communication module, a communication chip, etc. corresponding to various kinds of wireless communication protocols. For example, the wireless interface  212  includes a Wi-Fi communication chip for wireless communication with the AP based on Wi-Fi; a communication chip for wireless communication based on Bluetooth, Zigbee, Z-Wave, WirelessHD, wireless gigabits (WiGig), near field communication (NFC), etc.; an infrared (IR) module for IR communication; a mobile communication chip for mobile communication with a mobile device; etc. 
     The electronic apparatus  200  may include the display  220 . The display  220  includes a display panel capable of displaying an image on a screen thereof. The display panel may have a light receiving structure like a liquid crystal display (LCD) type, or a self-emissive structure like an organic light emitting diode (OLED) type. The display  220  may include an additional element according to the structures of the display panel. For example, when the display panel is of the LCD type, the display  220  includes an LCD panel, a backlight unit for illuminating the LCD panel, and a panel driving substrate for driving liquid crystal of the LCD panel. 
     The electronic apparatus  200  may include a user input unit  230 . The user input unit  230  includes a circuit related to various input interfaces to be controlled by a user to thereby receive a user input. The user input unit  230  may be variously configured according to the kinds of electronic apparatus  200 , and may for example include a mechanical or electronic button of the electronic apparatus  200 , a touch pad, a sensor, a camera, and a touch screen installed in the display  220 , a remote controller separated from the main body of the electronic apparatus  200 , etc. 
     The electronic apparatus  200  may include a storage unit  240 . The storage unit  240  is configured to store digitalized data. The storage unit  240  includes a nonvolatile storage in which data is retained regardless of whether power is supplied or not, and a volatile memory in which data loaded to be processed by a processor  250  is retained only when power is supplied. The storage includes a flash memory, a hard disc driver (HDD), a solid-state drive (SSD), a read only memory (ROM), etc., and the memory includes a buffer, a random-access memory (RAM), etc. The storage unit  240  in this embodiment may for example be configured to store a user account of the electronic apparatus  200 , a manufacturer or a brand of the electronic apparatus  200 , apparatus information, etc. 
     The electronic apparatus  200  may include the processor  250 . The processor  250  includes one or more hardware processors achieved by a central processing unit (CPU), a chipset, a buffer, a circuit, etc. which are mounted on a printed circuit board (PCB). Alternatively, the processor  250  may be designed as a system on chip (SoC). The processor  250  includes modules corresponding to various processes of a demultiplexer, a decoder, a scaler, an audio digital signal processor (DSP), an amplifier, etc. Here, some or all of such modules may be achieved by the SoC. For example, a demultiplexer, a decoder, a scaler, and the like module related to an image process may be achieved as an image processing SoC, and an audio DSP may be achieved as a chipset separated from the SoC. 
     The processor  250  may perform registration to a first server  201  with a first user account previously stored in the storage unit  240  or input through the user input unit  230 . In this case, the processor  250  can receive a predetermined service provided by the first server  201  by logging in to the first server  201  with the first user account. 
     Meanwhile, the processor  250  in this embodiment may identify a second server  202 , to which a second user account of the external apparatus  205  is registered, when the external apparatus  205  is newly detected through the interface  210 , and register the first user account to the second server  202  so that the first user account can be linked to the second user account. With this, the processor  250  performs a linked operation between the electronic apparatus  200  and the external apparatus  205 . 
     Below, it will be described that the first user account registered to the first server  201  is registered to the second server  202  by the electronic apparatus  200 . 
       FIG. 3  is a flowchart showing that an electronic apparatus registers a first user account to a second server so as to link the first user account with a second user account. 
     As shown in  FIG. 3 , the following operations are performed or controlled by the processor of the electronic apparatus. 
     At operation  310  the electronic apparatus is registered to a first server with a first user account. Thus, the electronic apparatus can receive a first service from the first server by logging in to the first server with the first user account. 
     At operation  320  the electronic apparatus detects an external apparatus. The external apparatus refers to an apparatus registered to a second server different from the first server. Here, the electronic apparatus identifies the external apparatus based on information about the external apparatus received from the external apparatus. For example, the electronic apparatus may obtain information about the manufacturer of the external apparatus from the information about the external apparatus. Alternatively, the electronic apparatus may store a table of a manufacturer corresponding to a network address such as a media access control (MAC) address, and retrieve the manufacturer corresponding to the network address obtained from the information about the external apparatus from the table. In this way, the electronic apparatus can identify a model name, a manufacture, a brand, etc. of the external apparatus. 
     At operation  330  the electronic apparatus identifies the second server to which the external apparatus has been registered. For example, the electronic apparatus may identify that the external apparatus has been registered to the second server, based on the information received from the external apparatus. 
     At operation  340  the electronic apparatus obtains a second user account of the external apparatus. 
     At operation  350  the electronic apparatus registers the first user account to the second server so that the first user account can be linked to the second user account. In other words, the first user account registered to the first server and the second user account registered to the second server are linked together by the electronic apparatus. Here, the electronic apparatus identifies whether the first user account has already been registered to the second server, and then registers the first user account to the second server when it is identified that the first user account has not been registered to the second server yet. 
     At operation  360  the electronic apparatus may use the first user account and the second user account to perform a linkage service operation based on a first service provided by the first server and a second service provided by a second server. 
     Thus, when the external apparatus registered to the second server is detected, the electronic apparatus enables the first server and the second server to be interlinked with each other, thereby performing a linked operation with the external apparatus. 
     Meanwhile, this embodiment shows that the second external apparatus detected by the electronic apparatus has already been registered to the second server. However, it may also be taken into account that the detected second external apparatus has not been registered to the second server. In this case, the electronic apparatus may perform a process of registering the external apparatus to the second server with the second user account, on behalf of the external apparatus. A process of registering the first user account to be linked with the second user account may be performed after the foregoing process. 
     Meanwhile, the processor of the electronic apparatus may perform at least a part of data analysis, data process and result information generation based on at least one of machine learning, neural network, deep learning algorithms as a rule-based or artificial intelligence (AI) algorithm in order to perform operations of registering the electronic apparatus to the first server with the first user account, identifying the second server to which the external apparatus has been registered in response to detection of a new external apparatus in the IoT environment, and enabling a linked operation with the external apparatus by registering the first user account to the second server so that the first user account can be linked with the second user account of the external apparatus. 
     For example, the processor of the electronic apparatus may function as a learner and a recognizer. The learner may perform a function of generating the learned neural network, and the recognizer may perform a function of recognizing (or inferring, predicting, estimating and identifying) the data based on the learned neural network. The learner may generate or update the neural network. The learner may obtain learning data to generate the neural network. For example, the learner may obtain the learning data from the storage unit of the electronic apparatus or from the outside. The learning data may be data used for learning the neural network, and the data subjected to the foregoing operations may be used as the learning data to teach the neural network. 
     Before teaching the neural network based on the learning data, the learner may perform a preprocessing operation with regard to the obtained learning data or select data to be used in learning among a plurality of pieces of the learning data. For example, the learner may process the learning data to have a preset format, apply filtering to the learning data, or process the learning data to be suitable for the learning by adding/removing noise to/from the learning data. The learner may use the preprocessed learning data for generating the neural network which is set to perform the operations. 
     The learned neural network may include a plurality of neural networks (or layers). The nodes of the plurality of neural networks have weights, and the plurality of neural networks may be connected to one another so that an output value of a certain neural network can be used as an input value of another neural network. As an example of the neural network, there are a convolutional neural network (CNN), a deep neural network (DNN), a recurrent neural network (RNN), a restricted Boltzmann machine (RBM), a deep belief network (DBN), a bidirectional recurrent deep neural network (BRDNN) and deep Q-networks. 
     Meanwhile, the recognizer may obtain target data to carry out the foregoing operations. The target data may be obtained from the storage unit of the electronic apparatus or from the outside. The target data may be data targeted to be recognized by the neural network. Before applying the target data to the learned neural network, the recognizer may perform a preprocessing operation with respect to the obtained target data, or select data to be used in recognition among a plurality of pieces of target data. For example, the recognizer may process the target data to have a preset format, apply filtering to the target data, or process the target data into data suitable for recognition by adding/removing noise. The recognizer may obtain an output value output from the neural network by applying the preprocessed target data to the neural network. Further, the recognizer may obtain a stochastic value or a reliability value together with the output value. 
     Below, a method by which the electronic apparatus detects the external apparatus will be described. 
       FIG. 4  illustrates that an electronic apparatus detects an external apparatus. 
     As shown in  FIG. 4 , when an electronic apparatus  410  includes a wireless interface supporting Bluetooth (BT), Bluetooth low energy (BLE), or the like direct wireless communication, the electronic apparatus  410  may periodically broadcast a discovery signal such as a beacon signal. The discovery signal broadcasted by the electronic apparatus  410  is given to be detectable by various apparatuses placed within a preset distance range from the electronic apparatus  410 . The discovery signal may include predetermined information about the electronic apparatus  410 . The predetermined information may for example include identification information of the electronic apparatus  410 , wireless communication standards supported by the electronic apparatus  410 , etc. 
     When the discovery signal is based on the wireless communication standards supported by both the electronic apparatus  410  and an external apparatus  420 , the external apparatus  420  can receive and recognize such a broadcasted discovery signal. The external apparatus  420  may transmit a response signal corresponding to the received discovery signal to the electronic apparatus  410 , and performs a pairing process based on the wireless communication standards, thereby being paired with the electronic apparatus  410  for the wired communication. 
     The electronic apparatus  410  receives a response signal of the external apparatus  420  to the broadcasted discovery signal through the wireless interface, and thus identifies that the external apparatus  420  is detected ( 430 ). The response signal from the external apparatus  420  may for example include various pieces of information about the external apparatus  420 , such as the apparatus information, brand, manufacturer, network-address information, etc. of the external apparatus  420 . The electronic apparatus  410  can identify a server, to which the external apparatus  420  will be registered, based on such information from the external apparatus  420 . 
     Alternatively, the electronic apparatus  410  may detect various signals generated in the external apparatus  420 . The external apparatus  420  may for example generate a control signal for controlling other apparatuses, a communication signal to be transmitted to other apparatuses, or a discovery signal used by the external apparatus  420  for scanning other apparatuses. When the external apparatus  420  transmits such a signal by one of various methods such as broadcasting, etc., the electronic apparatus  410  can detect the corresponding signal. 
     Such a signal may include predetermined information about the external apparatus  420 . Thus, the electronic apparatus  410  receives the signal from the external apparatus  420  through the wireless interface, and identifies that the external apparatus  420  is detected ( 440 ). Such a signal from the external apparatus  420  may be generated in the external apparatus  420  regardless of the electronic apparatus  410  (i.e. regardless of operations of the electronic apparatus  410 , or without targeting the electronic apparatus  410 ), but the electronic apparatus  410  can recognize that the external apparatus  420  is detected based on information included in the corresponding signal. 
     Like this, the electronic apparatus  410  may detect the external apparatus  420  through the wireless interface. Alternatively, the electronic apparatus  410  may detect wired connection of the external apparatus  420  through a wired interface. For example, when a user connects a cable connecting with the external apparatus  420  to the wired interface of the electronic apparatus  410 , the electronic apparatus  410  may detect the connection of the external apparatus  420  through the cable. 
     Below, a method by which an electronic apparatus and an external apparatus are registered to a server will be described. 
       FIG. 5  illustrates that a first server and a second server store registration information. 
     As shown in  FIG. 5 , a first server  510  and a second server  520  manages user accounts and many electronic apparatuses. For example, the first server  510  stores first registration information  530  which includes a first user account and identification information about a first electronic apparatus  550  and a second electronic apparatus  560  under the first user account. Further, the second server  520  stores second registration information  540  which includes a second user account and identification information about a first external apparatus  570  and a second external apparatus  580  under the second user account. In this embodiment, terms of the electronic apparatus and the external apparatus are just given for convenience to distinguish between the plurality of apparatuses. Further, the first user account refers to an account to used for registration to the first server  510 , and the second user account refers to an account to be used for registration to the second server  520 . 
     When the first server  510  receives a registration request using the first user account from the first electronic apparatus  550  or the second electronic apparatus  560 , the first server  510  registers the identification information of the first electronic apparatus  550  or the second electronic apparatus  560  under the first user account, thereby generating or updating the first registration information  530 . On the sample principle, when the second server  520  receives a registration request using the second user account from the first external apparatus  570  or the second external apparatus  580 , the second server  520  registers the identification information of the first external apparatus  570  or the second external apparatus  580  under the second user account, thereby generating or updating the second registration information  540 . 
     In this state, a linked operation between the apparatuses registered to the same server will be described. For example, it will be assumed that the first electronic apparatus  550  and the second electronic apparatus  560  have been registered with the same first user account to the first server  510 , and the first electronic apparatus  550  and the second electronic apparatus  560  are being logged in to the first server  510  with the first user account. When the first electronic apparatus  550  transmits a control signal for controlling the second electronic apparatus  560  to the first server  510 , the first server  510  identifies that the corresponding control signal is transmitted from the first electronic apparatus  550  logged in with the first user account, and the corresponding control signal is targeted at the second electronic apparatus  560 . When it is identified that the first registration information  530  shows the second electronic apparatus  560  has been registered under the same first user account, the first server  510  permits the control signal to be transmitted to the second electronic apparatus  560  so that the second electronic apparatus  560  can operate based on the control signal. When it is identified that the second electronic apparatus  560  has not been registered under the first user account, the first server  510  prohibits the control signal from being transmitted. 
     Like this, the linked operation using the first server  510 , which may be for example a registration server, or  620  is possible between the first electronic apparatus  550  and the second electronic apparatus  560  registered to the same first server  510 , or between the first external apparatus  570  and the second external apparatus  580  registered to the same second server  520 . On the other hand, for a linked operation between the apparatuses registered to the different servers  510  and  620  (for example, between the first electronic apparatus  550  and the first external apparatus  570  or between the first electronic apparatus  550  and the second external apparatus  580 ), the first server  510  or the second server  520  need to take both the first registration information  530  and the second registration information  540  into account. Below, such an embodiment will be described. 
       FIG. 6  illustrates a principle that a second server manages user accounts when the second server is liked to a first server. 
     As shown in  FIG. 6 , a first server  610  stores first registration information  630  prepared for managing a first user account, and a second server  620  stores second registration information  640  prepared for managing a second user account. An electronic apparatus  660  may use the first user account to receive a first service from the first server  610 , and an external apparatus  670  may use a second user account to receive a second service from the second server  620 . These are the same as described in the foregoing embodiments. 
     When the electronic apparatus  660  detects the external apparatus  670 , the electronic apparatus  660  identifies the second server  620  to which the external apparatus  670  is registered with the second user account, and performs a process for registering the first user account to the second server  620  so that the first user account can be linked to the second user account. In this case, the second registration information  640  of the second server  620  is provided to manage both the second user account and the first user account corresponding to (i.e. linked to) the second user account. Further, the second registration information  640  may additionally include identification information of apparatuses linked to the user accounts, for example, the identification information of the external apparatus  670  linked to the second user account, and the identification information of the electronic apparatus  660  linked to the first user account. 
     Based on the second registration information  640 , the second server  620  may offer a service linked to the first server  610 . For example, it will be assumed that the external apparatus  670  transmits a control signal to the electronic apparatus  660  to thereby control operations of the electronic apparatus  660 . The external apparatus  670  logs in with the second user account to the second server  620 , and transmits the control signal targeted at the electronic apparatus  660  to the second server  620 . When the electronic apparatus  660  targeted by the control signal does not belong to the second user account, the second server  620  identifies whether the electronic apparatus  660  belongs to the first user account linked to the second user account. When it is identified that the electronic apparatus  660  targeted by the control signal belongs to neither the second user account nor the first user account, the second server  620  prohibits the transmission of the control signal. On the other hand, when it is identified that the electronic apparatus  660  targeted by the control signal belongs to the first user account, the second server  620  manages the first user account and transmits the control signal to the first server  610  to which the electronic apparatus  660  is connected. 
     When it is identified that the control signal received from the second server  620  is targeted at the electronic apparatus  660  logged in with the first user account, the first server  610  transmits the control signal to the electronic apparatus  660 . Thus, a linked operation between the electronic apparatus  660  and the external apparatus  670  respectively registered to the different servers  610  and  620 . 
     Meanwhile, when the electronic apparatus detects the external apparatus, the external apparatus may not be registered to any server. In this case, the electronic apparatus may identify the second server designated to register the external apparatus, and register the external apparatus to the identified second server. Below, it will be described that the electronic apparatus registered to the first server registers a newly detected external apparatus to the second server. 
       FIG. 7  is a flowchart showing a process that an electronic apparatus registered to a first server registers a newly detected external apparatus to a second server. 
     As shown in  FIG. 7 , the following operations are performed or controlled by the processor of the electronic apparatus. 
     At operation  710  the electronic apparatus is registered to the first server with a first user account. 
     At operation  720  the electronic apparatus detects the external apparatus. 
     At operation  730  the electronic apparatus identifies the external apparatus based on information about the external apparatus received from the external apparatus. For example, the electronic apparatus may obtain information about the manufacturer of the external apparatus from the information about the external apparatus. Alternatively, the electronic apparatus may store a table of a manufacturer corresponding to a network address such as a MAC address, and retrieve the manufacturer corresponding to the network address obtained from the information about the external apparatus from the table. In this way, the electronic apparatus can identify a model name, a manufacture, a brand, etc. of the external apparatus. 
     At operation  740  the electronic apparatus obtains a second user account from the information about the external apparatus received from the external apparatus. The second user account may be involved in the information about the external apparatus, or may be transmitted as separate information from the external apparatus to the electronic apparatus. 
     At operation  750  the electronic apparatus identifies the second server designated to register the identified external apparatus. For example, the electronic apparatus may identify the second server by receiving information for designating the second server from the external apparatus. Alternatively, when the manufacturer of the external apparatus is identified, the electronic apparatus may retrieve the second server corresponding to the identified manufacturer from a previously stored list or a database (DB). 
     At operation  760  the electronic apparatus registers the external apparatus to the second server with the second user account. 
     At operation  770  the electronic apparatus identifies whether the first user account has been registered to the second server. When it is identified that the first user account has been registered to the second server, the first user account and the second user account have already been linked with each other in the second server, and therefore the electronic apparatus does not perform an additional operation. 
     On the other hand, when it is identified that the first user account has not been registered to the second server, at operation  780  the electronic apparatus registers the unregistered first user account to the second server, thereby making the first user account be linked with the second user account. 
     Meanwhile, unlike the foregoing embodiment, the electronic apparatus may identify that the detected external apparatus is designated to be registered to the first server. In this case, the electronic apparatus transmits network information for connecting with the first server to the external apparatus. Thus, the external apparatus connects with the first server based on the network information received from the electronic apparatus, and performs a registration process in the first server. For example, the network information includes an SSID of an AP and a password of the AP when the electronic apparatus is connected to the first server through the AP. Alternatively, the electronic apparatus may transmit information about the first user account to the external apparatus when requested by the external apparatus. In the future, the electronic apparatus uses the first user account to perform an operation together with the external apparatus based on a first service. Because the electronic apparatus and the external apparatus have been registered to the first server under the first user account, the electronic apparatus can perform a first service-based operation linked with the external apparatus through the first server. 
     Below, operations of when the external apparatus controls the electronic apparatus will be described in detail. 
       FIG. 8  illustrates that an external apparatus registered to a second server controls an electronic apparatus registered to a first server. 
     As shown in  FIG. 8 , at operation  810  an electronic apparatus  801  logs in to a first server  803  with a first user account. At operation  815  an external apparatus  802  logs in to a second server  804  with a second user account. The second server  804  stores linkage information between user accounts, i.e. registration information for designating linkage between the second user account and the first user account. 
     At operation  820  an event previously defined in the external apparatus  802  occurs. In response to the event, at operation  825  the external apparatus  802  transmits a control command for the electronic apparatus  801  to the second server  804 . The control command includes information about a target to which the corresponding control command will be transmitted. 
     At operation  830  the second server  804  identifies the target of the received control command, based on the first user account linked with the second user account. In other words, the second server  804  identifies that the control command is targeted at the electronic apparatus  801 , and the electronic apparatus  801  belongs to the first user account designated to be link to the second user account. At operation  835  the second server  804  transmits the control command to the first server  803  based on identification results. 
     At operation  840  the first server  803  identifies the target of the control command received from the second server  804 . At operation  845  the first server  803  transmits the control command to the electronic apparatus  801  based on identification results. Because the control command received in the first server  803  is targeted at the electronic apparatus  801  registered with the first user account, it is possible to identify the target in this process even though the first server  803  does not necessarily have the linkage information about the user account. 
     At operation  850  the electronic apparatus  801  performs an operation based on the control command received from the first server  803 . 
     Below, detailed operations of when the electronic apparatus controls the external apparatus will be described. 
       FIG. 9  illustrates that an electronic apparatus registered to a first server controls an external apparatus registered to a second server. 
     As shown in  FIG. 9 , at operation  910  a second server  904  provides linkage information of a user account to a first server  903 . Although an electronic apparatus  901  registers a first user account to the second server  904  so as to be linked to a second user account, the second server  904  may share the linkage information of the user account with the first server  903 . Thus, the first server  903  may link and manage the first user account and the second user account together like the second server  904 . 
     At operation  915  the electronic apparatus  901  logs in to the first server  903  with the first user account. At operation  920  an external apparatus  902  logs in to the second server  904  with the second user account. 
     At operation  925  an event previously defined in the electronic apparatus  901  occurs. In response to the event, at operation  930  the electronic apparatus  901  transmits the control command for the external apparatus  902  to the first server  903 . 
     At operation  935  the first server  903  identifies the target of the received control command, based on the second user account linked to the first user account. In other words, the first server  903  identifies that the control command is targeted at the external apparatus  902 , and the external apparatus  902  belongs to the second user account designated to be linked to the first user account. At operation  940  the first server  903  transmits the control command to the second server  904  based on identification results. 
     At operation  945  the second server  904  identifies the target of the control command received from the first server  903 . At operation  950  the second server  904  transmits the control command to the external apparatus  902  based on identification results. 
     At operation  955  the external apparatus  902  performs an operation based on the control command received from the second server  904 . 
     Meanwhile, the foregoing embodiments show the electronic apparatus registered to the first server with the first user account and the external apparatus registered to the second server with the second user account. However, when the external apparatus serves as a kind of hub, the external apparatus may connect with another external apparatus. Below, such an embodiment will be described. 
       FIG. 10  illustrates a principle that a second server manages user accounts when the second server is linked to a first server. 
     As shown in  FIG. 10 , a first server  1010  stores first registration information  1030  given to manage a first user account, and a second server  1020  stores second registration information  1040  given to manage a second user account. An electronic apparatus  1060  can use the first user account to receive a first service from the first server  1010 , and a first external apparatus  1070  can use the second user account to receive a second service from the second server  1020 . 
     In this embodiment, the first external apparatus  1070  connects with a second external apparatus  1080 , and the second external apparatus  1080  is provided to communicate with the second server  1020  through the first external apparatus  1070 . The second external apparatus  1080  may receive the service from the second server  1020  by using the second user account like the first external apparatus  1070 . 
     Like a case where the first external apparatus  1070  is registered to the second server  1020  with the second user account, the second external apparatus  1080  may also be registered to the second server  1020  with the second user account. 
     The second registration information  1040  is designated to allow the first user account to be linked with the second user account. This is the same as described in the foregoing embodiment. Further, according to the second registration information  1040 , the first external apparatus  1070  and the second external apparatus  1080  have been registered under the second user account, and therefore the second server  1020  can manage the second external apparatus  1080  like a case of the first external apparatus  1070 . However, the second external apparatus  1080  is connected to the first external apparatus  1070 , and thus a signal between the second server  1020  and the second external apparatus  1080  is transmitted via the first external apparatus  1070 . 
     A process that the second external apparatus  1080  transmits a control signal to the electronic apparatus  1060  is as follows. When a predetermined event occurs in the second external apparatus  1080 , the second external apparatus  1080  transmits the control signal to the first external apparatus  1070 . The first external apparatus  1070  transmits the received control signal to the second server  1020 . 
     The second server  1020  identifies that the control signal is targeted at the electronic apparatus  1060  under the first user account based on the second registration information  1040 . The second server  1020  transmits the control signal to the first server  1010 . 
     The first server  1010  identifies that the control signal is targeted at the electronic apparatus  1060 , and transmits the control signal to the electronic apparatus  1060 . Thus, the electronic apparatus  1060  can perform an operation based on the control signal from the second external apparatus  1080 . 
     The operations of the apparatus described in the foregoing embodiments may be performed by artificial intelligence provided in the corresponding apparatus. The artificial intelligence may be applied to various general systems by utilizing a machine learning algorithm. An artificial intelligence system refers to a computer system with intelligence of a human or being second to a human. In such a system, a machine, an apparatus or a system autonomously performs leaning and identifying and is improved in accuracy of recognition and identification based on accumulated experiences. The artificial intelligence is based on elementary technology by utilizing machine learning technology and algorithms based on an algorithm of autonomously classifying and learning features of input data, and copying perception, identification and the like functions of a human brain. 
     The elementary technology may for example include at least one of language comprehension technology for recognizing a language and a text of a human, visual understanding technology for recognizing a thing like a human sense of vision, inference and prediction technology for identifying information and logically making inference and prediction, knowledge representation technology for processing experience information of a human into knowledge data, and motion control technology for controlling a vehicle&#39;s automatic driving or a robot&#39;s motion. 
     Here, linguistic comprehension refers to technology of recognizing, applying and processing a human&#39;s language or text, and includes natural language processing, machine translation, conversation system, question and answer, voice recognition and synthesis, etc. 
     Inference and prediction refer to technology of identifying information and logically making prediction, and includes knowledge- and probability-based inference, optimized prediction, preference-based plan, recommendation, etc. 
     Knowledge representation refers to technology of automating a human&#39;s experience information into knowledge data, and includes knowledge building such as data creation and classification, knowledge management such as data utilization, etc. 
     The methods according to the foregoing embodiments may be achieved in the form of a program instruction that can be implemented in various computers, and recorded in a computer readable medium. Such a computer readable medium may include a program instruction, a data file, a data structure or the like, or combination thereof. For example, the computer readable medium may be stored in a nonvolatile storage unit such as universal serial bus (USB) memory, regardless of whether it is deletable or rewritable, for example, a RAM, a ROM, a flash memory, a memory chip, an integrated circuit (IC) or the like memory, or an optically or magnetically recordable or machine (e.g., a computer)-readable storage unit medium, for example, a compact disk (CD), a digital versatile disk (DVD), a magnetic disk, a magnetic tape or the like. It will be appreciated that a memory, which can be included in a mobile terminal, is an example of the machine-readable storage unit medium suitable for storing a program having instructions for realizing the embodiments. The program instruction recorded in this storage unit medium may be specially designed and configured according to the embodiments, or may be publicly known and available to those skilled in the art of computer software. Further, the computer program instruction may be implemented by a computer program product. 
     Although a few embodiments 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 scope as defined in the appended claims and their equivalents.