AHN, Hee-Jung (103-802, Citykukdong Apt.Pungnap-dong, Songpa-gu, Seoul 138-040, KR)
BAE, Han-Up (122-304, Olympic Seonsuchon Apt.Bangi-dong, Songpa-gu, Seoul 138-050, KR)
AHN, Hee-Jung (103-802, Citykukdong Apt.Pungnap-dong, Songpa-gu, Seoul 138-040, KR)
| Claims [1] A video chat service system for providing a video chat service between mobile stations in a communication network, the system comprising: a mobile switching center for receiving and routing a video call; and a video chat intermediate means for intermediating a video chat by receiving the routed call from the mobile switching center, forming a video communication channel between a calling mobile station and a called mobile station, and activating a chat program of each mobile station by transmitting, to each mobile station, a chat program invoke message instructing operation of the chat program. [2] The video chat service system according to claim 1, wherein the video chat intermediate means blocks a receive/transmit voice of each mobile station by transmitting a receive/transmit voice blocking message to each mobile station. [3] The video chat service system according to claim 1, wherein, in the case that a feature code for a video chat service is included in a call originating from the calling mobile station, the mobile switching center routes the originating call to the video chat intermediate means. [4] The video chat service system according to claim 1, wherein the video chat intermediate means includes: a storage means for storing a set of keywords and contents corresponding to each keyword in the set of keywords; a text recognition means for recognizing a specific keyword in a chat message; and an image combination means for extracting a content corresponding to the specific keyword recognized by the text recognition means from the storage means and combining the extracted content with a user's image. [5] The video chat service system according to claim 4, wherein the storage means separately stores a set of common keywords and common contents that are available to all users, and a set of private keywords and private contents that are individually set by each user. [6] The video chat service system according to claim 5, wherein the image combination means extracts a content to be combined with a user's image primarily by using the set of private keywords and the private contents, and secondarily by using the set of common keywords and the common contents. [7] The video chat service system according to claim 4, further comprising: a voice recognition means for recognizing a specific keyword in the voice transmitted between the calling mobile station and the called mobile station, wherein the voice recognition means extracts a content corresponding to the specific keyword recognized by the voice recognition means from the storage means and combines the extracted content with a user's image. [8] The video chat service system according to claim 1, wherein the video chat intermediate means recognizes a string starting with a special character in a chat message and processes an additional service corresponding to the recognized string. [9] A video chat service method for providing a video chat service between mobile stations in a communication network, the method comprising: forming a video communication channel between a calling mobile station and a called mobile station; activating a chat program of each mobile station by transmitting, to each mobile station, a chat program invoke message instructing operation of the chat program; and intermediating a chat message and a video communication between the calling mobile station and the called mobile station. [10] The video chat service method according to claim 9, further comprising: blocking a receive/transmit voice of each mobile station by transmitting a receive/transmit voice blocking message to each mobile station. [11] The video chat service method according to claim 9, further comprising: before activating the chat program, checking if a feature code for a video chat service is included in a call originating from the calling mobile station. [12] The video chat service method according to claim 9, further comprising: recognizing a specific keyword in a chat message; and combining a user's image with a content corresponding to the recognized specific keyword and transmitting the combined image to an opponent user. [13] The video chat service method according to claim 9, further comprising: recognizing a specific keyword in the voice transmitted between the calling mobile station and the called mobile station; and combining a user's image with a content corresponding to the recognized specific keyword and transmitting the combined image to an opponent user. [14] The video chat service method according to claim 9, further comprising: recognizing a string starting with a special character in a chat message; and processing an additional service corresponding to the recognized string. |
SYSTEM AND METHOD FOR PROVIDING VIDEO CHAT
SERVICE
Technical Field
[1] The present invention relates to a video chat service system and method for providing a video chat service in a mobile communication network. Background Art
[2] With development of mobile communication technologies, while moving, users can use a voice communication service using their mobile stations regardless of where they are located. The advances in mobile communication technologies makes it possible to provide a video communication service capable of face-to-face conversation, that goes beyond the voice communication service.
[3] To use the video communication service, users should orient the cameras of their mobile stations towards their faces. And, the users should put their mobile stations at a predetermined distance from themselves to see opponent users' images displayed on their mobile stations. Inevitably, the users should increase the volume of the opponent users' voices outputted from speakers of their mobile stations.
[4] As a result, people around the users may be damaged by the opponent users' loud voices during their video communication. Besides, private conversations are directly exposed to people around the users, and thus the users' privacy is not protected. To solve these problems, earphones may be used. However, the users should carry earphones with themselves all the time. If the users do not carry earphones with themselves, they suffer said problems.
[5] Recently, a video chat service is suggested to overcome the drawbacks of the video communication service. The video chat service enables users to have a text-based chat, not a voice -based chat, during video communication. However, to use the video chat service, users should press a special menu or key for the video chat service. As functions of mobile stations become more complicated, it is more difficult to use the video chat service, in particular for users who are not familiar to the functions of mobile stations.
[6] Furthermore, the video chat service follows the principle of a wired internet-based video chat service. That is, video communication and chat are operated separately. The image of video communication and the text of chat are transmitted independently. Thus, the typical video chat service is nothing but a video communication service, in which a voice-based conversation is replaced by a text-based conversation during video communication. Disclosure of Invention
Technical Problem
[7] It is an object of the present invention to solve the problems, and therefore, the present invention provides a video chat service system and method that allows for users to conveniently use a video chat service without input of a special key for the video chat service.
[8] And, the present invention provides a video chat service system and method, in which video communication and chat are linked to reflect a chat message on video communication in real time. Technical Solution
[9] To achieve the objects of the present invention, according to an aspect of the present invention, a video chat service system for providing a video chat service between mobile stations in a communication network, comprises a mobile switching center for receiving and routing a video call; and a video chat intermediate means for intermediating a video chat by receiving the routed call from the mobile switching center, forming a video communication channel between a calling mobile station and a called mobile station, and activating a chat program of each mobile station by transmitting a chat program invoke message to each mobile station.
[10] To achieve the objects of the present invention, according to another aspect of the present invention, a video chat service method for providing a video chat service between mobile stations in a communication network, comprises the steps of forming a video communication channel between a calling mobile station and a called mobile station; activating a chat program of each mobile station by transmitting a chat program invoke message to each mobile station; and intermediating a chat message and a video communication between the calling mobile station and the called mobile station.
Advantageous Effects
[11] The present invention provides a convenient use of a video chat service through an automatic mode conversion, whereby mobile stations are automatically converted into a chat mode when a video communication between subscribers starts. And, the present invention allows a video communication with a peculiar image by recognizing a specific keyword in a chat message during video communication and combining a content corresponding to the recognized specific keyword with an image of video communication in real time. Brief Description of Drawings
[12] FIG. 1 is a view illustrating a network configuration of a video chat service system according to an embodiment of the present invention. [13] FIG. 2 is a block diagram of a video chat intermediate system of FIG. 1.
[14] FIG. 3 is a flowchart of a video chat service method according to an embodiment of the present invention.
[15] FIG.4 is a view illustrating screens of a calling mobile station and a called mobile station that are in a video chat service according to an embodiment of the present invention. Mode for the Invention
[16] These objects, features and advantages of the present invention will become apparent with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed sufficiently in the following description to enable an ordinary person skilled in the art to easily practice the technical spirit of the present invention. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the present invention in detail. Hereinafter, the preferred embodiments of the present invention are described in detail with reference to the accompanying drawings.
[17] FIG. 1 is a view illustrating a network configuration of a video chat service system according to an embodiment of the present invention.
[18] As shown in FIG. 1, the video chat service system according to an embodiment of the present invention includes mobile stations 110 and 120, a radio access network (RAN) 130, a mobile switching center (MSC) 140, a home location register (HLR) 150 and a video chat intermediate system 160.
[19] The mobile stations 110 and 120 are terminals for providing voice/video communication to users who are moving. The mobile stations 110 and 120 have cameras embedded therein for video communication. The mobile stations 110 and 120 transmit a user's image taken by the cameras to an opponent user, and receive and display the opponent user's image thereon.
[20] The mobile stations 110 and 120 have chat programs therein for supporting a text- based chat. During video communication, the chat program displays a chat window on a mobile station, transmits a user's chat message to an opponent user, and displays a chat message received from the opponent user on the mobile station. The mobile stations 110 and 120 activate the chat program in response to an H.245 invoke message received from the video chat intermediate system 160. And, when the mobile stations 110 and 120 receive a receive/transmit voice blocking message from the video chat intermediate system 160, the mobile stations 110 and 120 do not output the opponent user's voice during video communication.
[21] A feature code for a video chat service may be used in the present invention. When users want to use a video chat service, the users input a feature code (for example, *12) and a called party's phone number into the mobile stations 110 and 120 and press a video communication button. However, the feature code may be not used. The video chat function may be provided to only subscribers who have subscribed a video chat service.
[22] The radio access network 130 includes a NodeB and a radio network controller
(RNC), and supports access of the mobile stations 110 and 120 to a mobile communication network. The NodeB executes radio signal transmitting/receiving, radio channel encoding/decoding, signal intensity and quality measurement, baseband signal processing, radio resource management and self-maintenance and so on, by control of the radio network controller. The radio network controller executes functions for assignment/release of radio channel to/from the mobile stations 110 and 120, transmission power control of the mobile stations 110 and 120 and the NodeB, determining soft handoff/hard handoff between cells, transcoding, vocoding, operation and maintenance of NodeB, and so on.
[23] The mobile switching center 140 provides an interface between the radio access network 130 and the core network, and controls voice/video communication, data transmitting/receiving and various additional services. The mobile switching center 140 also provides a connection with another external network. In the present invention, when the mobile switching center 140 receives a video call originating from the mobile stations 110 and 120, the mobile switching center 140 inquires the home location register 150 of a called party's location information, and processes the originating call after receiving the called party's location information.
[24] And, when the mobile switching center 140 receives an initial address message
(IAM) for processing of the originating call, the mobile switching center 140 transmits a call setup message to the called mobile stations 110 and 120, and after receiving an answer message from the called mobile stations 110 and 120, transmits the answer message to the calling mobile stations 110 and 120 that have transmitted the initial address message.
[25] The home location register 150 stores and manages subscriber profiles, subscriber location information, additional service information and so on. When the home location register 150 receives a called party's location information request, the home location register 150 transmits a called party's location information in response to the request based on a subscriber profile and an additional service information of a caller.
[26] In the present invention, the home location register 150 may register video chat service information in subscriber profiles of mobile communication subscribers and manage the video chat service information. When the home location register 150 receives a called party's location information request, the home location register 150 checks whether or not a caller has subscribed a video chat service based on the stored subscriber profiles using an identification number of the caller. If the caller has subscribed a video chat service, the home location register 150 transmits, to the mobile switching center 140, a called party's location information including a routing information toward the video chat intermediate system 160 in response to the request.
[27] Alternatively, the home location register 150 may store and manage a feature code for a video chat service. If a feature code for a video chat service is included in a called party's location information request received from the mobile switching center 140, the home location register 150 transmits, to the mobile switching center 140, a called party's location information including a routing information toward the video chat intermediate system 160 in response to the request.
[28] The video chat intermediate system 160 intermediates a video communication and provides a chat service between a calling mobile station and a called mobile station. In this embodiment, a typical video communication is not made via the video chat intermediate system 160, and a video communication for video chat is made via the video chat intermediate system 160. When the video chat intermediate system 160 receives an initial address message (IAM) from the mobile switching center 140, the video chat intermediate system 160 transmits a call setup message to the called mobile station, so that a video communication is made between the calling mobile station and the called mobile station.
[29] When a video communication starts between the calling mobile station and the called mobile station via the video chat intermediate system 160, the video chat intermediate system 160 transmits chat program invoke messages to the calling mobile station and the called mobile station to activate a chat program of each mobile station. The video chat intermediate system 160 transmits, to the opponent user's mobile station, a chat message received through the chat program. And, the video chat intermediate system 160 transmits each receive/transmit voice blocking message to the calling mobile station and the called mobile station not to output the opponent user's voice during video communication.
[30] When the video chat intermediate system 160 receives the chat message through the chat program, the video chat intermediate system 160 recognizes a specific keyword in the chat message, searches for a content corresponding to the recognized specific keyword therein, such as an emoticon, a flash, a moving image, an advertisement and so on, combines the content with an image of video communication, and transmits the combined image to the opponent user. If at least two keywords to be recognized are included in the chat message or received simultaneously in a short time, the video chat intermediate system 160 combines a content corresponding to a keyword, which was recognized or received earlier, with an image. And, when the video chat intermediate system 160 transmits a voice during video communication, the video chat intermediate system 160 may recognize a specific keyword in the voice, searches for a content corresponding to the recognized specific keyword therein, such as an emoticon, a flash so on, combines the content with an image of video communication, and transmits the combined image to the opponent user.
[31] Alternatively, the video chat intermediate system 160 does not combine a content corresponding to the recognized specific keyword with an image of video communication, but may substitute the content for the image, i.e., transmit the content to the opponent user in place of the image. For example, the video chat intermediate system 160 substitutes a content corresponding to the recognized specific keyword for a caller's image and transmits the content to a called mobile station so that the content is displayed on the called mobile station.
[32] And, if a string starting with a special character is included in a chat message received through a chat program, the video chat intermediate system 160 recognizes and process the string having the special character as an instruction. For example, if a chat message of '©substitute image' is received, the video chat intermediate system 160 recognizes a string having '@', i.e., 'substitute image' as an instruction, requests a substitute image to a substitute image service server, and transmits the substitute image to the opponent user instead of an actual image of the user. Alternatively, the video chat intermediate system 160 may directly store and manage substitute images, and transmit a substitute image to the opponent user upon the user's request, instead of an actual image of the user. In this case, it is obvious that the substitute image is combined with a content corresponding to a specific keyword, such as an emoticon or the like, and transmitted to the opponent user.
[33] A string starting with a special character included in a chat message received through a chat program is recognized and processed as an instruction by the following reason; in a typical video communication, when users want to use an additional service during video communication, the users should press a key for the additional service. However, the key input is recognized as a chat message input during video communication, and a desired additional service is not available. However, in the present invention, if a special character or a string starting with a special character is inputted into a chat window during video communication, the special character or the string starting with a special character is not recognized and processed as a chat message due to the special character, but as an instruction to request a predetermined additional service.
[34] The video chat intermediate system 160 may register and manage common contents that are available to all of video chat service subscribers and private contents that are set individually by each video chat service subscriber. At this time, the common contents may include advertisement contents. The video chat intermediate system 160 recognizes a specific keyword in a chat message received through a chat program during video communication, and searches for a content corresponding to the specific keyword, such as an emoticon, a flash and so on, in the common contents or the private contents. Voice is recognized in the same way.
[35] FIG. 2 is a block diagram of the video chat intermediate system 160 of FIG. 1.
[36] As shown in FIG. 2, the video chat intermediate system 160 includes a gateway 210, an application server 220, a database server 230, a text recognition engine 240, a voice recognition engine 250 and an image combination server 260.
[37] The gateway 210 is linked with the mobile switching center 140 of the mobile communication network, and responsible for receiving/transmitting a signal from/to the mobile communication network. The gateway 20 receives a signal from the mobile communication network and transmits the signal to the application server 220.
[38] The application server 220 is a call processing means, and intermediates a video communication between the mobile stations 110 and 120. When the application server 220 receives an initial address message (IAM) related to call setup from a caller's mobile switching center through the gateway 210, the application server 220 transmits the initial address message to a called party's mobile switching center through the gateway 210. In this way, the application server 220 intermediates a video communication between the calling mobile station and the called mobile station. Accordingly, a video communication is made between the calling mobile station and the called mobile station via the application server 220.
[39] And, after a video communication starts between the calling mobile station and the called mobile station, the application server 220 transmits chat program invoke messages to the calling mobile station and the called mobile station at the same time to activate a chat program of each mobile station. After then, the application server 220 receives and transmits a chat message. And, the application server 220 transmits each receive/transmit voice blocking message to the calling mobile station and the called mobile station not to output an opponent user's voice through each mobile station.
[40] Further, the application server 220 recognizes a string starting with a special character in the chat message, and requests an additional service to a related system according to the special character.
[41] The database server 230 stores and manages specific keywords and contents corresponding to the specific keywords. The database server 230 registers and manages a set of common keywords that are applicable to all of video chat service subscribers and common contents (for example, emoticons, flashes, advertisements and so on) corresponding to the common keywords, and a set of private keywords that were set individually by each video chat service subscriber and private contents corresponding to the private keywords.
[42] The text recognition engine 240 recognizes a specific keyword in the chat message between video chat users. The text recognition engine 240 extracts the specific keyword from the chat message with reference to the set of keywords recorded in the database server 230. If at least two keywords to be recognized are included in the chat message, the text recognition engine 240 combines a content corresponding to a keyword, which was recognized earlier, with an image. And, if specific keywords to be recognized are simultaneously transmitted in a short time, the text recognition engine 240 combines a content corresponding to a keyword, which was recognized or transmitted earlier, with an image.
[43] The voice recognition engine 250 recognizes a specific keyword in the voice between video chat users. The voice recognition engine 250 extracts the specific keyword from the voice with reference to the set of keywords recorded in the database server 230.
[44] The image combination server 260 extracts, from the database server 230, a content corresponding to the specific keyword recognized by the text recognition engine 240 or the voice recognition engine 250. And, the image combination server 260 combines the extracted content with an image of a user who has transmitted the corresponding specific keyword. The combined image is transmitted to and displayed on an opponent user's mobile station. That is, the image combination server 260 recognizes a specific keyword included in a chat message, extract a content corresponding to the recognized specific keyword, combines the extracted content with an opponent user's image that is displayed on each user's mobile station during video communication, and transmits the combined image together with the chat message.
[45] Alternatively, the image combination server 260 extracts, from the database server
230, a content corresponding to the specific keyword recognized by the text recognition engine 240 or the voice recognition engine 250. And, the image combination server 260 does not combine the extracted content with an image of a user who has transmitted the specific keyword, but substitutes the extracted content for an image of the user who has transmitted the specific keyword. The extracted content is displayed on an opponent user's mobile station in place of the user's image.
[46] Hereinafter, description is made based on the mobile station 110 of FIG. 1 as a calling mobile station and the mobile station 120 of FIG. 1 as a called mobile station.
[47] FIG. 3 is a flowchart of a video chat service method according to an embodiment of the present invention.
[48] Referring to FIG. 3, a caller attempts to make a video communication by inputting a called party's phone number into the calling mobile station 110 and pressing a send button. Subsequently, an originating call containing the called party's phone number is transmitted to the caller's mobile switching center 140 (S301).
[49] The caller's mobile switching center 140 receives the originating call from the calling mobile station 110, and transmits a called party's location information inquiry message to the home location register 150 for call setup. When the caller's mobile switching center 140 receives a called party's location information answer message from the home location register 150, the caller's mobile switching center 140 checks a called party's location information (S303). The home location register 150 transmits, to the caller's mobile switching center 140, the called party's location information answer message including a routing information toward the video chat intermediate system 160 based on video chat service subscription information included in a subscriber profile of the caller.
[50] Alternatively, a caller attempts to make a video communication by inputting a called party's phone number and a feature code for a video chat service into the calling mobile station 110, and pressing a video communication button. In this case, the caller's mobile switching center 140 requests interpretation of the feature code to the home location register 150. When the home location register 150 interprets the feature code and recognizes as a feature code for a video chat service, the home location register 150 transmits a routing information toward the video chat intermediate system 160 to the caller's mobile switching center 140.
[51] Preferably, the home location register 150 requests a routing number to the video chat intermediate system 160 that provides a service of the present invention, and after receiving the routing number, transmits the called party's location information answer message including the routing number to the caller's mobile switching center 140.
[52] After the caller's mobile switching center 140 checks the called party's location information, the caller's mobile switching center 140 transmits an initial address message (IAM) to the video chat intermediate system 160 (S305).
[53] After the video chat intermediate system 160 receives the initial address message, the video chat intermediate system 160 checks the called party's location information using the called party's phone number included in the initial address message and transmits the initial address message to the called party's mobile switching center 140 (S307). The video chat intermediate system 160 checks the called party's location information in the same way that the caller's mobile switching center generally checks the called party's location information. That is, the video chat intermediate system 160 checks the called party's location information from the home location register using the called party's phone number.
[54] After the called party's mobile switching center 140 receives the initial address message from the video chat intermediate system 160, the called party's mobile switching center 140 transmits a call setup message to the called mobile station 120 (S309). Subsequently, the video chat intermediate system 160 receives a connect message from the called mobile station 120 upon the called party's hook off (i.e., pressing a send button). Description of a general call setup step, such as paging, transmitting an alert message to the called mobile station 120, transmitting an address complete message to the video chat intermediate system 160 and so on, is omitted herein.
[55] After the called party's mobile switching center 140 receives the connect message from the called mobile station 120, the called party's mobile switching center 140 transmits an answer message (ANM) to the video chat intermediate system 160 (S313). The video chat intermediate system 160 transmits the answer message to the caller's mobile switching center 140 (S315). In this way, a bearer channel is formed between the calling mobile station 110 and the called mobile station 120 via the video chat intermediate system 160.
[56] Next, the calling mobile station 110 attempts a codec negotiation, i.e., H.245 negotiation for a video communication with the called mobile station 120 (S317). After the codec negotiation completes, a video communication starts between the calling mobile station 110 and the called mobile station 120 (S319). The caller's image taken by the calling mobile station 110 is transmitted to and displayed on the called mobile station 120 in real time, and the called party's image taken by the called mobile station 120 is transmitted to and displayed on the caller's mobile station 110 in real time. In this way, a face-to-face communication is made between the caller and the called party.
[57] After a video communication starts between the calling mobile station 110 and the called mobile station 120, the video chat intermediate system 160 transmits each chat program invoke message to the calling mobile station 110 and the called mobile station 120 to activate a chat program of each mobile station (S321, S322). And, the video chat intermediate system 160 transmits a receive/transmit voice blocking message to each mobile station. Thus, the calling mobile station 110 and the called mobile station 120 do not output an opponent user's voice due to the receive/transmit voice blocking message.
[58] The calling mobile station 110 and the called mobile station 120 activate the chat programs in response to the chat program invoke message received from the video chat intermediate system 160. Preferably, a chat window created by the chat program is displayed at a lower portion on each screen of the calling mobile station 110 and the called mobile station 120. The caller and the called party can have a chat with each other through the chat windows while seeing the opponent user' image displayed on each mobile station.
[59] For example, a caller inputs a chat message, which is to be transmitted to the called mobile station 120, into a chat window displayed on the calling mobile station 110. The chat message is converted into an H.245 message and transmitted to the video chat intermediate system 160 (S325). After the video chat intermediate system 160 receives the chat message, the video chat intermediate system 160 recognizes a specific keyword in the chat message (S327). As mentioned above, the video chat intermediate system 160 has a set of common keywords that are applicable to all of video chat service subscribers and common contents corresponding to the common keywords, such as emoticons or the like, and a set of private keywords that are set individually by each of video chat service subscriber and private contents corresponding to the private keywords. The video chat intermediate system 160 recognizes a specific keyword in the chat message with reference to the set of common keywords or the set of private keywords. In the case that the present invention is applied to advertisement, only the common keywords and the common contents are used.
[60] The video chat intermediate system 160 extracts a content corresponding to the recognized specific keyword, such as an emoticon or the like (S329). The video chat intermediate system 160 extracts the corresponding content from the common contents or the private contents. Preferably, content extraction from the private contents has priority.
[61] The video chat intermediate system 160 combines the extracted content with the caller's image to be transmitted to the called mobile station 120 (S331). The video chat intermediate system 160 transmits the combined image to the called mobile station 120 (S333). At the same time, the video chat intermediate system 160 transmits the caller's chat message to the called mobile station 120. Thus, the chat message transmitted by the caller, and the combined image, in which the caller's image is combined with a content corresponding to a specific keyword included in the chat message, are displayed on the called mobile station 120.
[62] Alternatively, the video chat intermediate system 160 may substitute the extracted content for the caller's image to be transmitted to the called mobile station 120, and transmit the extracted content to the called mobile station 120. The extracted content is displayed on the called mobile station 120 in place of the caller's image.
[63] Although FIG. 3 shows the video chat intermediate system 160 recognizes a specific keyword in a chat message, combines an image of video communication with a content corresponding to the recognized specific keyword and transmits the combined image to an opponent user, the video chat intermediate system 160 may recognize a specific keyword in the voice received during video communication, search for a content corresponding to the recognized specific keyword, combine the content with an image of video communication, and transmit the combined image to an opponent user.
[64] In this embodiment, the caller is a general video chat service subscriber. The caller's mobile switching center charges a video communication fee to the caller. The caller's mobile switching center charges a video communication fee from the point of time of receiving an answer message (ANM) from the called party's mobile switching center. The mobile communication service may be provided at a post-paid charge rate as mentioned above. Alternatively, the mobile communication service may be provided at a pre-paid charge rate. According to the pre-paid charge rate, the caller can use a communication service as much as his/her pre-paid offerings. If the caller consumes the pre-paid offerings, the caller cannot the communication service any more. The pre-paid charge service is provided through an intelligent network system.
[65] In the case that the caller is a prepaid subscriber, a video call originating from the calling mobile station 110 is transmitted to the called mobile station 120 via the intelligent network system. The intelligent network system provides a video communication within the pre-paid offerings of the caller. Accordingly, a video call of the caller who uses a video chat service is transmitted to the called mobile station 120 via the intelligent network system and the video chat intermediate system 160, and the intelligent network system charges the user for the video communication. As mentioned above, the video chat intermediate system 160 transmits each chat program invoke messages to the calling mobile station 110 and the called mobile station 120, recognizes a specific keyword in a chat message received through a chat program, searches for a content corresponding to the recognized specific keyword, combines the content with an image of video communication, and transmits the combined image to an opponent user.
[66] FIG. 4 is a view illustrating each screen of a calling mobile station and a called mobile station that are in a video chat service according to an embodiment of the present invention.
[67] As described above with reference to FIGs. 1 to 3, when a video communication starts between the calling mobile station and the called mobile station, the video chat intermediate system 160 transmits each chat program invoke messages to the calling mobile station and the called mobile station to activate a chat program of each mobile station. As shown in FIGs. 4(a) and 4(d), a user's image, an opponent user's image and chat windows 401 and 403 are activated and displayed on the screens of the calling mobile station and the called mobile station. FIG. 4(a) shows an example of the screen of the calling mobile station, and FIG. 4(d) shows an example of the screen of the called mobile station. As shown in FIG. 4(a), the called party's image (A image) received from the called mobile station in real time is displayed on the screen of the calling mobile station at a larger size than the caller's image (B image). On the contrary, as shown in FIG. 4(d), the caller's image (B image) received from the calling mobile station in real time is displayed on the screen of the called mobile station at a larger size than the called party's image (A image). However, the present invention is not limited in this regard. The user's image may be displayed on the screen at the same size as the opponent user's image. [68] As shown in FIG. 4(a), when the chat windows 401 and 403 are activated, the caller inputs, into the chat window 401, a chat message that will be transmitted to the opponent user. In FIG. 4(a), the caller inputs "Honey, I love you-". The chat message is transmitted to the video chat intermediate system 160. After the video chat intermediate system 160 receives the chat message, the video chat intermediate system 160 recognizes a specific keyword in the chat message. In FIG. 4(a), the video chat intermediate system 160 recognizes a keyword 'love', and extracts a heart-shaped emoticon corresponding to the keyword 'love'. As shown in FIG. (4c), the video chat intermediate system 160 combines the extracted heart-shaped emoticon with the caller's image (B image), and transmits the combined image to the called mobile station. As shown in FIG. (4d), the caller's real-time image and the heart-shaped emoticon 405 are displayed on the called mobile station.
[69] In summary, a video communication service provides an advantage of a face-to-face communication over a voice communication service. However, disadvantageously, the voice output through a speaker of a mobile station makes noise and damages the surrounding people. If a user lowers the volume of the voice, the user cannot hear the voice. To solve the problem, the present invention enable users to have a text-based chat during video communication, so that the users can use a video communication even in the space where silence should be kept.
[70] And, the present invention provides an interesting chat service beyond a monotonous chat service during video communication. According to the present invention, when a user has a chat with an opponent user during video communication, an image to be transmitted to the opponent user and a content corresponding to a specific keyword included in the user's chat message, such as an emoticon, a flash or the like are displayed on the opponent user's mobile station in combination.
[71] Various features of the present invention are herein described, but they are by way of illustration only, not for the purpose of limiting the scope of the invention. And, certain features may be used singularly or in combination with other features in one embodiment or at least two embodiments.
[72] Although the drawings illustrate the exemplary steps of the method performed in a predetermined sequence, the present invention is not limited in this regard. For example, the steps may not be performed in the predetermined sequence or in a consecutive manner. All of the steps may not be necessary to obtain desired results. Multitasking or parallel processing may be advantageous to perform the steps of the method. Furthermore, although the preferred embodiment shows individual components of the system, the present invention is not limited in this regard. The components of the system may be incorporated into a single software product or into multiple software products as one package. [73] The method of the present invention may be stored in a storage medium (CD-ROM,
RAM, ROM, floppy disc, hard disc, optical disc and so on) as a computer-readable program, which is apparent to an ordinary person skilled in the art, and its detailed description is herein omitted.
[74] As such, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the scope of the invention will become apparent to those skilled in the art from this detailed description.