COMPACT GRAPHICAL INTERACTIVE BROADCAST INFORMATION SYSTEM

Abstract: A method and apparatus allows an information provider to broadcast a graphical interactive information system application to a user even using a low-bandwidth transport such as the VBI. A compact protocol encapsulates graphical information using definitions of graphical objects and resources. A scripting and command language is also highly compact. A reception component receives the compact protocol and displays and operates a complete graphical interactive information system application.

Description: COMPACT GRAPHICAL INTERACTIVE BROADCAST INFORMATION SYSTEM. Related Applications The subject matter of this application is related to the subject matter of the following applications: application serial number AAAA, entitled, "METHOD AND APPARATUS FOR DETERMINING BROADCASTER INFORMATION" , and application serial number BBBB , entitled "METHOD AND APPARATUS FOR ROUTING CONFIDENTIAL INFORMATION", each of the above applications filed by Brian P. Dougherty and Eric E. Del Sesto on April 25, 1995, having the same assignee as die present invention and incorporated herein by reference in tiieir entirety. Field of Invention The present invention relates to broadcast and receiving systems, and more specifically, to interactive broadcast and receiving systems. Background of Invention Interactive information systems allow an information provider to broadcast information to a user, and in some cases allow a user to send a response to a response collector. The user may receive die information on a wide variety of devices, such as a pager, cellular telephone, personal digital assistant or a television. An interactive information system on which the user receives d e information using a television is called an interactive television system. An interactive television system can enhance the television viewing experience. An interactive television system allows an information provider to broadcast information to users for viewing on tiieir television systems, and defines how the user is allowed to control die time, order, type of information displayed, or odier aspects. An interactive television system may allow the user to send to a response collector responses to die information received, or new information. Some interactive television systems provide a textual user interface, displaying formatted textual information to die user. However unlike graphical interactive information systems, text- based systems do not allow die information provider to control and present a wide variety of graphical information and formatting mat are commonly used widi graphical user interfaces. A graphical interactive information system uses a graphical user interface to display a variety of graphical information and allows die user to control the operation of the system based upon die graphical display. Text-based systems are more difficult to use and limit the appeal of d e interactive television system in much die same way diat text-based computer operating systems limited the appeal of computer systems prior to the introduction of graphical user interfaces. One such attempt (Lappington, U.S. Pat. No.5,343,239) inserts textual data in a binary format into unused lines in the Vertical Blanking Interval, or VBI, of the conventional television transmission for decoding by a set-top device and transmission to, and display on, a handheld remote control device. The VBI is a portion of the television picture which is broadcast, but not typically seen by die television viewer, and readily allows for insertion of data, such as closed captioning text. However, die limited data capacity of the VBI has tiius far prevented die use of graphical user interfaces, because the VBI does not have the data capacity required to send the large amount of data to date required for a graphical user interface. For example, Lappington does not disclose a graphical user interface. One interactive television system (Fascenda et al., U.S. Pat. No. 4,592,546) does not use the VBI at all, instead sending information to the user via an FM subcarrier channel. Such a system has die drawback of requiring a large initial user investment in equipment required to receive the information. Additionally, Fascenda does not suggest the transmission of graphical user interface information. To circumvent die limited capacity of the available data transport mechanisms, a functionally-limited graphical-like interactive television system has been developed (Young, U.S. Pat. No. 5,353,121). Young suggests a system which allows an information provider to send a sequence of text over die VBI to a set of predefined overlays. The result appears to be a more graphical display than Lappington, because boxes surround each section of die text. Aldiough Young does not disclose how the size of the box is determined, which party controls the size of the box, or how die box is displayed on the screen, nevertheless, the mere control of the widtii of a box surrounding text, widiout more, is not a graphical user interface of the type set forth in the illustrated embodiments of d e present invention. In addition, Young does not allow die information provider to design new overlays, and thus is limited to die overlays which have been predefined. This restriction limits die type and format of die data which can be displayed to data fitting into one of die predefined overlays existing in the user-device used to render die display. None of diese devices allows an information provider to broadcast a true graphical user interface to an interactive information system. Nor do these devices solve me additional problems inherent in die reception and display of a graphical user interface. One inherent problem is me reluctance of many users to significantly invest in separate reception or display equipment required to display and operate a graphical interactive information system. For example, many potential users of a graphical interactive television system will not pay e cost of receiving d e graphical interactive information over an FM channel because of die cost of the additional tuner equipment required by such an approach. Conventional set top cable television decoder boxes can provide a desirable reception platform for interactive television systems because tiiey are relatively cheap, contain much of d e necessary interface and reception equipment, and are accepted in most homes. However, die use of such devices would be acceptable if only inexpensive, compact modifications were required to display and operate a graphical interactive information system. Anod er problem is die lack of standards among reception and display equipment vendors. For example, conventional set-top cable decoder boxes might be used as a platform as described above. However, a variety of set-top equipment exists yielding a variety of capabilities. Each vendor promotes a system mat will use the vendor's equipment capabilities to e fullest extent possible. Vendors typically would not accept a system which was designed only for die most basic equipment, nor would tiiey likely accept a system which only operated wid the most feature-rich equipment. Another problem is the requirement for interactive television systems diat such a system work rapidly enough to operate in conjunction widi existing broadcast television shows. For example, graphical interactive television system applications which operate in conjunction with existing television game show programs must be transmitted to display die graphical user interface quickly. Furthermore, there must be a mechanism to make modifications to die user interface quickly, to allow large amounts of information to be updated rapidly. Sμmmary Q lnven iQn A mediod and apparatus allows an information provider to send a graphical interactive information system application to a reception component for presenting die graphical interactive information system to, and allowing its operation by, the user. The information provider provides a description of die layout and die information to be displayed, and one or more definitions, commands or scripts which compactly describe one or more graphical images to be displayed, and may describe die relationships between one or more of the graphical images, are encoded in a broadcast signal. The definitions, commands and scripts are compact, requiring relatively low bandwidth. A reception component decodes the definitions, commands or scripts and generates die images for display on a display device such as a television. Thus, decoding provides a relatively large amount of graphical information from d e compact definitions, commands and scripts, allowing a even presently available low bandwidth broadcast media, such as die VBI, to be used to carry complete graphical interactive information system applications for display to, and operation by, a user. Even low bandwidth broadcast media can be used to carry complete graphical interactive information system applications for display and operation rapidly enough to allow a graphical interactive information system application integrated with die content of a conventional broadcast program or advertisement to be broadcast simultaneously widi die program or advertisement. Because special high-bandwidtii media are not required, existing inexpensive user equipment may be inexpensively modified and used to display and operate graphical interactive information system applications. Because of d e compact size of die information broadcast, the information may be stored in die reception component after reception on compact, inexpensive storage devices, helping to maintain die low cost of die user equipment. The reception component can adapt the image based upon die capabilities of die reception component, die display device, or botii, allowing reception and display on a wide variety of user equipment. Because die command decoder that adapts the image is aware of its own capabilities, adaptation information need not be broadcast, maintaining die small size of the information broadcast. Because the image is generated and adapted by die reception component, die description of die image is platform-independent, freeing die information provider of the necessity of formatting information differently for each type of reception component. The image or sequence of images may be displayed in response to commands from the user in a manner defined by the information provider. Certain user commands may be transmitted from the user to a response collector. A Brief Description of the Drawings Figure 1 is an illustration of a conventional television screen displaying a conventional television program with a graphical interactive information system application displayed according to one embodiment of the present invention. Figure 2A is a block schematic diagram of a provider component apparatus according to one embodiment of die present invention. Figure 2B is a block schematic diagram of a reception component apparatus according to one embodiment of die present invention. Figure 2C is a block schematic diagram of a provider component apparatus according to an alternate embodiment of the present invention. Figure 2D is a block diagram of developers and information providers according to one embodiment of die present invention. Figure 3 is a block schematic diagram of user equipment according to one embodiment of the present invention. Figure 4 is a flowchart illustrating a method of one embodiment of the present invention. Figure 5 is a block diagram representing a format of an application header record according to one embodiment of die present invention. Figure 6 is a block diagram representing a format of a form definition record according to one embodiment of die present invention. Figure 7A is an illustration of a conventional television display with a form according to one embodiment of die present invention. Figure 7B is a block diagram representing a format of a form object definition record according to one embodiment of the present invention. Figure 8 is a block diagram representing a format of a button object definition record according to one embodiment of the present invention. Figure 9 is a block diagram representing a format of a text object definition record according to one embodiment of the present invention. Figure 10 is a block diagram representing a format of a bitmap object definition record according to one embodiment of die present invention. Figure 11 is a block diagram representing a format of a list object definition record according to one embodiment of the present invention. Figure 12 is a block diagram representing a format of a timer object definition record according to one embodiment of the present invention. Figure 13 is a block diagram representing a format of a picture object definition record according to one embodiment of the present invention. Figure 14A is a block diagram representing a format of a resource definition record according to one embodiment of the present invention. Figure 14B is a block diagram representing a format of a text resource according to one embodiment of die present invention. Figure 14C is a block diagram representing a format of a bitmap resource according to one embodiment of die present invention. Figure 14D is a block diagram representing a format of a picture resource according to one embodiment of the present invention. Figure 14E is a block diagram representing a format of a picture resource element according to one embodiment of the present invention. Figure 14F is a block diagram representing a format of a resource list according to one embodiment of die present invention. Figure 14G is a block diagram representing a format of a resource list element according to one embodiment of die present invention. Figure 15 is a block diagram representing a format of an update record according to one embodiment of the present invention. Figure 16 is a block diagram representing a format of an interactive icon definition record according to one embodiment of die present invention. Figure 17A is a block diagram representing a format of a script execute record according to one embodiment of the present invention. Figure 17B is a block diagram representing a format of a script resource according to one embodiment of die present invention. Figure 18A is a flowchart illustrating a method of broadcasting a broadcaster information table according to die present invention. Figure 18B is a flowchart illustrating a method of Receiving a broadcaster information table according to die present invention. Figure 18C is a flowchart illustrating a mediod of using a broadcaster information table according to die present invention. Figure 19 is a flowchart illustrating a method of drawing a form on a display according to die present invention. Figure 20 is a flowchart illustrating a mediod of drawing an object on a display according to die present invention. Figure 21 is a flowchart illustrating a method of drawing a resource on a display according to die present invention. Figure 22 is a block diagram representing a format of a response record according to one embodiment of die present invention. Figure 23 is a block schematic diagram illustrating a response network according to one embodiment of die present invention. Figure 24 is a flowchart illustrating a method of allowing a user to use an unsecure communication line to send confidential information to an order processor according to the present invention. Detailed Description of a Preferred Embodiment I. Example. Referring now to Figure 1, a sample graphical interactive television system application display is shown. A display screen 110 of a conventional television 112 displays a conventional television show which contains a politician 114 giving a speech. A graphical interactive information system application form 116 having a border 130 is displayed by the graphical interactive television system on die screen 110 of die television 112. The form 116 may contain text descriptions 126, 128 and pictures or icons 120, 122 corresponding to buttons 118, 124 to allow the user to make a selection by pressing a numeric key using a conventional television remote control device. When the user indicates a selection by pressing a remote control key corresponding to a button 118, 124, a new form may be displayed containing additional information relating to die indicated selection. In one embodiment, one or more selections may cause the graphical interactive television system to send response information to a response collector which may or may not be the information provider. For example, button 118 can allow die user to make a $25 campaign contribution to the candidate 114. If during the broadcast program a second candidate follows the first candidate 114, an identical form 116 may be displayed related to information or a response collector different from that relating to die first candidate 114. Graphical interactive information is communicated to the user by broadcasting graphical interactive information system applications. A graphical interactive information system application is a set of definitions, commands, scripts and data which may be used to produce a graphical user interface, determine how a user may control die graphical interactive information system application and external devices and control and define response information. Graphical interactive applications may be broadcast to correspond to odier information broadcast, such as in die example of Figure 1 above. When die graphical interactive application is broadcast to correspond to a broadcast program, it is called a program application. When die graphical interactive application is broadcast to correspond to an advertisement, it is called an advertisement application. A graphical interactive application may be broadcast which does not relate to a broadcast program or advertisement, and such an application is called a graphical virtual interactive channel. For example, widi a graphical interactive television system, a program listing guide or weatiier information may be broadcast independentiy of the odier broadcast programs. Because of die flexibility of the system, any form of information may be broadcast. II, Hardware. Referring now to Figures 2 A and 2B, two components, a provider component 206 and a reception component 234, are used to implement a graphical interactive information system in accordance widi die present invention. The provider component 206 allows die generation and broadcast of die graphical interactive information system application, and the reception component 234 allows for die reception, decoding, control and display of the graphical interactive information system application. The present invention allows die provider component 206 to define die display and control of a graphical interactive information system application to be displayed on the reception component 234 without requiring the high bandwidth normally associated widi interactive information systems which display a graphical user interface. The provider component 206 compresses the graphical interactive information system applications by isolating only die information needed to allow the reception component 234 to produce the graphical user interface and by encapsulating the remainder of the application. Because of this graphical application compression and encapsulation, high bandwidth is not required to broadcast die application. The graphical interactive information system application is broadcast to die reception component 234, which is able to reproduce a complete graphical interactive information application from the small amount of information it receives from the provider component 206 plus its own resident intelligence. A. Provider Component. The provider component 206 inserts and broadcasts graphical interactive information system applications onto a broadcast signal. In one embodiment, a conventional broadcast signal is provided by signal provider 208. In one embodiment, signal provider 208 is a program generator. In anodier embodiment, signal provider 208 is a video signal source from a live feed. In another embodiment, signal provider 208 is a video signal from a video storage device, such as a video tape recorder. The provider component 206 also contains a graphical interactive compact protocol generator and formatter 210. A graphical interactive compact protocol generator and formatter 210 is used by an information provider to generate die interactive information system information to be broadcast. In one embodiment, die graphical interactive compact protocol generator and formatter 210 is a conventional 486 personal computer system widi a stored program for operation as described below. The graphical interactive compact protocol generator and formatter 210 generates die compact protocol, described below, in response to commands provided to it by an information provider. In one embodiment, the information provider types in die compact protocol bytes which will represent die graphical user interface as described below. In anodier embodiment, a visual interface is used to allow a form designer to design forms and immediately see how tiiey will appear. The graphical interactive compact protocol generator and formatter 210 translates and formats die form appearing on the computer screen of the graphical interactive compact protocol generator and formatter 210 into the compact protocol described below. In anodier embodiment, die graphical interactive compact protocol generator and formatter 210 receives assignment of attribute commands such as forml .border.color = red, and generates the proper compact protocol commands as described below. A compact protocol inserter 212 inserts the compact protocol from the compact protocol generator 210 into the broadcast medium. The broadcast medium is the frequency spectrum used to carry die compact protocol. In one embodiment, the graphical interactive information system is a graphical interactive television system, the broadcast medium is a standard North American television signal according to NTSC standards, and the vertical blanking interval, or VBI, is used as a transport to broadcast the compact protocol. A transport is the specific portion of die broadcast medium which will carry die compact protocol. In one embodiment, conventional methods are employed to insert data into the VBI of a conventional broadcast from a broadcast device. The North American Broadcast Teletext Standard EIA-506, OSI layers 1-4, defines the metiiods and protocols for sending data in one or more lines of die VBI. In one embodiment, die conventional TDS-3 Data Delivery System, available commercially from Norpak of Katana, Ontario, Canada acts as a compact protocol inserter 212 by receiving an RS-232 serial bit stream, buffering the bit stream, and inserting the bits over one or more lines of the VBI. In one embodiment, error checking or error correcting codes such as Hamming codes are inserted with the data. In one embodiment, the compact protocol inserter 212 translates die data into a Hamming code, and in anodier embodiment, the compact protocol generator 210 produces Hamming coded data or adds a parity bit. The compact protocol inserter 212 is coupled to a transmitter 214 which broadcasts die compact protocol described below. In one embodiment, the transmitter 214 is a conventional television broadcast transmitter which receives and broadcasts the signal from conventional VBI inserter 212 which includes die conventional broadcast program and advertisement output signal from program generator 208, and the compact protocol from compact protocol generator and formatter 210. In this fashion, graphical interactive television information may be broadcast on die same frequency widi a related television program. In another embodiment, die transmitter 214 is a conventional cable system head-end amplifier. In another embodiment, die signal provider 208 does not output a television program, and the compact protocol is broadcast without a television program. In anodier embodiment, die transmitter 214 is a conventional cellular telephone transmitter. In anodier embodiment, transmitter 214 is a conventional pager transmitter. These embodiments allow interactive information systems to be used independently of a conventional broadcast such as a television broadcast if desired, allowing die user to access die information from a cellular telephone or cellular equipped personal digital assistant, or even a pager. A graphical interactive television system need not use die VBI to broadcast a compact protocol for use with a television program, as a wide variety of other transports are available. Some of diese transports broadcast die compact protocol separately from die television program, yet retain die ability to coordinate die graphical interactive information with a television program. In tiiis case, transmitter 214 does not broadcast the television program, instead allowing anodier transmitter to broadcast die program. This allows transmitter 214 to broadcast the compact protocol on any type of frequency. In one embodiment, the transmitter 214 is a conventional out-of-band transmitter which transmits the compact protocol on an unused portion of die television frequency spectrum. In another embodiment, the transmitter 214 is a conventional FM transmitter. Any form of broadcast, wire or cable transmitter may be used to broadcast die compact protocol. In one embodiment, the developer of an interactive information system application may be a different person or entity from the broadcaster who broadcasts die application. Referring now to Figures 2A and 2C, one embodiment of a provider component 266 is shown. Compact protocol generator and formatter 276 is similar to compact protocol generator and formatter 210. However, the compact protocol generator and formatter 276 is not a part of the provider component 266. Instead, anodier party known as the developer develops die graphical interactive information system applications on the compact protocol generator and formatter 276 and provides diem via diskette or modem or odier communication device to the information provider. The information provider loads the graphical interactive information system application from the developer into a graphical interactive information system application server 270. The graphical interactive information system application server 270 sends the graphical interactive information system application to the compact protocol inserter 272, which is similar to compact protocol inserter 212, and controls die operation of the compact protocol inserter 212 to allow, for example, die information proVider to control die transport , such as VBI line used to broadcast die graphical interactive information system application. In anodier embodiment, graphical interactive information system application server 270 also controls die frequency of the application broadcast. Transmitter 274 is similar to transmitter 214. This arrangement allows for multiple parties to contribute to die graphical interactive information system. Referring now to Figure 2A, 2B, and 2D, one embodiment of the providers of graphical interactive information is shown. Graphical interactive information system application developers 281, 282, 283, 284, 285 develop applications using compact protocol generators and formatters 276 for one or more broadcasters 286, 288, 290 who broadcast programs, graphical interactive information system applications using provider components 266, or botii, to users and cable operators 292, 294; who rebroadcast signals to users from broadcasters 286, 288, 290 and may provide additional applications or broadcaster information using provider components 206 or 266. B. Reception Component - Graphical Information System Application Display and Control. In one embodiment, die reception component 234 is contained in die user reception equipment similar to conventional user reception equipment. Referring now to Figure 3, one embodiment of die user reception equipment 308 is shown. Conventional television receiver 310 such as a Sony KV32V55 is coupled to a set-top decoder 312 which is coupled via cable 322 to antenna 316. In one embodiment, antenna 316 is replaced by a cable 324 containing a CATV transmission signal. The set-top decoder 312 is similar, but not identical, to a conventional set- top decoder, such as the Jerrold DPV7217/V5B available commercially from General Instrument Corporation of Hatboro, PA. The internal components of set-top decoder 312 according to die present invention are described below. Referring again to Figure 2B the reception component includes a tuner 216 to receive from input 219 and decode a broadcast signal containing the compact protocol. In one embodiment, tuner 216 is a conventional television broadcast tuner. In another embodiment, tuner 216 is a conventional CATV tuner. In another embodiment, tuner 216 is a conventional FM tuner. In anodier embodiment, tuner 216 is a conventional cellular telephone tuner. In another embodiment, tuner 216 is a conventional pager tuner. The reception component also includes a data extractor 218 coupled to die tuner 216 to extract the compact protocol from the decoded broadcast signal. In one embodiment, the data extractor 218 is a conventional VBI inband data extraction circuit, such as part number SAA5296 available from Philips Semiconductors of San Jose, CA. In another embodiment, the data extractor 218 is a conventional modem. Other conventional data extraction equipment and techniques may also be used. In one embodiment, data extractor 218 provides a serial bitstream containing the extracted compact protocol onto bus 232. Bus 232 is coupled to microprocessor 222 which stores via bus 232 die extracted compact protocol information into storage device 226 as instructed by a program stored in storage device 224, and described below. In one embodiment, microprocessor 222 is a conventional 68040 microprocessor available commercially from Motorola, Inc., of Schaumburg, 111., although any suitable microprocessor may be used. In one embodiment storage device 226 is a conventional addressable RAM memory array. In one embodiment, die microprocessor 222 uses die error code information from die extracted data to check or correct errors, terminating the application if errors are detected. The microprocessor 222 may decode the data from die error coded data by removing the error code prior to storage in storage device 226. In one embodiment, storage device 224 is a conventional addressable ROM. In another embodiment, storage device 224 is a conventional flash memory which is readable and writable, yet retains its contents when power is no longer available. Such an embodiment allows any software or data which is resident in the reception component to be modified or changed by broadcasting it using die capabilities of die present invention. For example, a new feature of die reception component could be implemented via broadcast, eliminating the need for the user to replace a part of or all of die reception component to implement die new feature. As described below, the microprocessor 222 uses the program stored in storage device 224 and die compact protocol information stored in storage device 226 to generate die graphical user interface display information, which is sent from die microprocessor 222 via bus 232 to a graphics display generator 228. In one embodiment, die graphics display generator 228 is a conventional VGA graphics adapter, such as model number ET4000 available from Tseng Labs of Newtown, PA, coupled to a conventional video genlock processor, such as model GSP500 available from Integrated Circuit Systems of Valley Forge, PA. The graphics display generator 228 is coupled to bus 232 to receive die graphical user interface generated by the graphical interactive information system. In one embodiment, graphics display generator 228 also receives the broadcast signal corresponding to a broadcast program via line 227 from tuner 216 to allow simultaneous display of the broadcast program and the graphical interactive information system application. In anodier embodiment, graphics display generator 228 receives a broadcast program signal via line 229 from optional additional tuner 252, and line 227 is not used. This two-tuner 216, 252 approach allows a graphical interactive information application to be displayed simultaneously with a broadcast program widiout requiring die application to be broadcast on die same frequency as die program. The display generator 228 is coupled to a display 230. In one embodiment, the display 230 is an LCD display. In another embodiment, the display 230 is a conventional television receiver and the remaining elements 235 of the reception component as later described herein are contained in a set-top decoder. In one embodiment, the microprocessor 222 is also coupled to a user input decoder 244 coupled to a user input receiver 250 to allow die user to communicate widi die microprocessor 222 in order to operate die graphical interactive information system. In one embodiment, die user input decoder 244 is a conventional infrared remote control decoder. The user input receiver is a conventional infrared receiver 250 dirough which the user may use a conventional handheld remote control device, such as remote control 330 of Figure 3. Remote control keys pressed by die user translate to coded infrared signals diat are received by infrared receiver 250, and are decoded by the user input decoder 244 and sent to die microprocessor 222 to allow die user to communicate widi the interactive television system. In one embodiment, die microprocessor 222 responds to certain remote control keys decoded when tiiey relate to choices displayed by the user component 234, but not to odier remote control keys, to allow die operation of functions unrelated to die graphical interactive information system application simultaneously widi die operation of die graphical interactive information system application using die same user input device. In another embodiment, die user input receiver 250 is a conventional personal digital assistant keypad device and the user input decoder 244 is a conventional keypad decoder. In anodier embodiment, die user input receiver 250 is a conventional cellular telephone keypad device and die user input decoder 244 is the keypad decoder. In another embodiment, die user input receiver 250 is a conventional pager switching device and the user input decoder 244 is a conventional switching device decoder. C. Reception Component - External Device Control. In one embodiment, microprocessor 222 is coupled to a conventional infrared command encoder 256 which accepts an infrared command input and encodes a signal for a conventional infrared emitter 258 to allow the interactive information system to control external devices, such as a VCR. P. Reception Component - Return Channel. In one embodiment, certain user responses are sent to a response collector for processing. Referring momentarily to Figure 1, button 118 allows a user to make a selection which will send a $25 campaign contribution to the candidate 114. Referring again to Figure 2B data line driver 246 accepts data from microprocessor 222 and sends it to communications port 248 to allow die microprocessor to send user responses and other information described below to a response collector who may process the responses. In one embodiment, the data line driver 246 is a conventional modem and communications port 248 is a conventional telephone jack, which allows die reception component 234 to send user responses to a response collector having a receiving modem connected to a conventional telephone line. In another embodiment, the data line driver 246 is a conventional DTMF tone dialer. In another embodiment, the data line driver 246 is a conventional controller for a system of addressable CATV set-top converters such as the ACC-4000 addressable controller available from General Instrument Coφoration of Hatboro, PA, used to provide conventional pay-per-view services. In this embodiment, communications port 248 is coupled to receive die cable TV coax line 219 which is coupled to the tuner 216. E. Reception Component Tuner Control. In one embodiment, microprocessor 222 is coupled to tuner 216 and optional tuner 252 to allow the microprocessor 222 to communicate widi and control the tuned frequency of the tuners 216, 252. This capability can provide such services as channel selection via the interactive information system. One such use of the service would be to allow a user to change channels from a program guide. The user's selection would automatically change the tuned frequency of the tuners 216, 252 to die desired channel. In one embodiment, tuners 216, 252 contain a broadcaster information table, described below, in a storage device 217, 253 of the tuner 216, 252 identifying the broadcaster corresponding to each tunable channel. This allows die reception component to determine, for example, which channel number corresponds to die Cable News Network, which may be necessary because different cable systems carry Cable News Network on different channels. Storage devices 217, 253 are coupled to die microprocessor 222 to allow the microprocessor 222 to determine which tuner channel number corresponds to a particular station. In one embodiment, die storage devices 217, 253 are ROMs, installed at the time of manufacture with the channel guide burned in. In another embodiment, storage devices 217, 253 are flash memory to allow die channel guide to be received and extracted from a broadcast signal like the compact protocol as described above, to allow microprocessor 222 to store die broadcaster information table in storage devices 217, 253. In anodier embodiment, die broadcaster information table is broadcast as a part of die compact protocol described below, die broadcaster information table is stored in storage device 226, and storage devices 217, 253 are not used. m. Compact Protocol. The compact protocol is used to broadcast a compact set of information and commands from die information provider to the user in an efficient manner, allowing the use of low bandwidtii transports such as die VBI. Referring now to Figure 4, one embodiment of a method of sending and operating a graphical interactive information system using die compact protocol is shown. In one embodiment, an application header record is encoded and broadcast to initiate the process and describe the information which follows 410412. The application header record and the information will define a graphical interactive information system application. One or more desired graphical descriptions such as object or resource definition records and optional scripts or commands, each described below, are encoded and broadcast in any order 416, 418. In one embodiment, die application header record is received and decoded 414 prior to die encoding of definitions, scripts and commands 416, although odier embodiments encode, broadcast, receive store and decode the application header record, definitions, scripts and commands in one unit. In one embodiment, no particular order of die steps described above is required as long as the application header definition is broadcast before die broadcast of any definition, script or command in die application. The information broadcast is received and decoded and used by die reception component to display die graphical information and to allow die user to interact with the information broadcast and perform die functions described herein 420, 422. Some or all of the information broadcast may be stored at any time 420. In one embodiment, a graphical interactive information system application is broadcast again and again, allowing a user to tune to a program at any time yet receive die entire graphical interactive information system application. Any desired updates as described below may be encoded and sent 424 and received and decoded 426. If there are additional definitions or updates of resources or objects, tiiey may be sent until the application is complete 428, 430. In one embodiment, a termination command described below is broadcast to stop the operation of the application 430. As described below, a new application may be sent while an original application is in operation or transmission, for example, to allow a new advertisement application to interrupt an original program application, which resumes operation upon termination of die advertisement application. In one embodiment, die new application is also broadcast and operated using the mediod described above and shown in Figure 4. A suspend application command is sent by die new or original application in order to suspend die operation of die existing application, and a resume application command may be sent by either application to terminate die new application and resume die operation of the original application. In anodier embodiment, the new application must send a termination command in order to terminate itself, as a resume application command would only suspend die new application and resume the original application. Because descriptions of standard graphical objects are transmitted in place of many of die bitmaps or odier high-bandwidth display components which would otherwise be required, several advantages are realized. First, a low-bandwidth transport such as the VBI is adequate to allow the display of complex graphics. Second, the system is device-independent. The information provider simply describes the effect desired and each reception component reproduces it as best it can. An effect or image for which display is not allowed or not possible on die reception component can be ignored by that reception component, but displayed on odier reception components. A. Application Header Record. In one embodiment, an application begins witii an application header record to identify die information as die start of an interactive application. In one embodiment, if application information is received widiout an application header, die application may be stored, but may not run. Referring now to Figure 5, one embodiment of an application header record 508 is shown. Byte 510 identifies die data as an application header record 508, by having a value equal to 1. Byte 512 describes the application type. Byte 512 having a value equal to 0 signifies a program application such as that described above for use widi the politician's speech. Byte 512 equal to 1 signifies an advertisement application. Byte 512 may have a value equal to 2, signifying a virtual interactive channel. Byte 512 may have odier values, indicating odier forms of applications. Referring now to Figures 2A, 2B and 5, bytes 514, 515 contain the version and revision number, respectively, of the protocol used to communicate between die provider component 206 and die reception component 234 as described below. The receipt of version and revision numbers by a reception component 234 allows die reception component 234 to respond to protocols which are generated by different versions or revisions of die protocol generator 210. In one embodiment, the reception component 234 disregards a protocol which specifies a version number of which die reception component 234 is unaware or incompatible. Referring again to Figure 5, long word 516 is an application identifier, a unique identifier which identifies die application. This information may be sent to a response collector to identify die information provider and application which generated die response. In one embodiment, a long word is four bytes in length, altiiough odier lengths may also be used. Bytes 518, 522, and word 520 assist die microprocessor in its memory management function described below by identifying many of die memory requirements in advance. In one embodiment, a word is two bytes in length, altiiough other lengths may also be used. Byte 518 contains die number of forms in die application, byte 522 identifies die total number of script resources, and word 520 identifies the total number of text, bitmap and picture resources defined by die application. These terms and tiieir operation are described below. In one embodiment, bytes of all records are broadcast in die order shown in the Figures 5, 6, 7B, 8, 9, 10, 11, 12, 13, 14A, 14B, 14C, 14D, 14E, 15, 16, 17A, 17B and 22. B. Graphical Object Definitions. The compact protocol allows the broadcast of graphical interactive information by die use of a set of graphical object definitions. Graphical object definitions describe characteristics of graphical objects, such as size of the object, color of the object, location on die display, and odier characteristics of die graphical object. Graphical objects include the form object, buttons on die form, bitmaps, pictures, lists, as well as non-graphical objects such as timers. In one embodiment, a text object contains descriptive information such as font and color about a text string, as well as the location of die text string, but does not contain die text string itself. Text strings are resources, and are separate from a text object which describes diem. 1. Form Definition Record. Each application may contain one or more forms. A form is a collection of objects which are defined as a single unit by die information provider using a form definition record. Objects in a form which are capable of being displayed are displayed togetiier. Referring now to Figure 6, one embodiment of a form definition record 608 is shown. Byte 610 has a value of 2 to identify the record as die start of a form definition. Word 611 is die size, in bytes, of die form definition record. Byte 612 is an identifier assigned by the information provider to identify die form defined by die form definition record 608. In one embodiment, a second form having die same form number as one already defined in an application is ignored. Block 614 contains one or more object definitions for die form as described below. Referring now to Figures 2B and 6, in one embodiment, after microprocessor 222 receives a form definition record 608, die microprocessor 222 under control of a program stored in storage device 224 allocates an area of the storage device 226 for the form, die objects on the form, resources required by the form and application control information to allow die user to interact with die form. Microprocessor 222 generates and stores several tables in storage device 226 as described below. 3. Object Definitions. Several standard objects may be defined using compact object definitions, which allow die user to specify die look of graphical objects by transmitting an object identifier as the first byte of die object, and only a few parameters. a. Form Objects. One type of object is a form object. A form object defines a rectangular region of die screen and the appearance of die region. The information provider defines form objects using a form object definition record. Referring now to Figure 7A, one embodiment of a form object 700 having a border 706 and an interior 702 is shown displayed on a screen 703 of a conventional television set 704. The form object may be transparent, in which case die other objects in the form appear to float over die display. If die display is a television screen, and die application is not a graphical interactive virtual channel, a transparent form object can cause die other objects in the form to appear to float over the broadcast picture. Otherwise, the form object covers all or a part of the broadcast picture and the objects may cover all, a part, or none of the form. Referring now to Figures 7A and 7B, one embodiment of a form object definition record 708 is shown. Byte 710 identifies die object as a form by having a value of 000001 in the least significant six bits. Bytes 712, 714, 716, 718 contain die position of die left side, top, right side and bottom of the form 700, respectively, relative to the center 701 of the screen 703 using a coarse coordinate system. A coarse coordinate system is a representation of a unit of width and height. In one embodiment, the unit of widtii and height is selected to allow representation of die entire width or height of the display in a single byte of 256 unique numbers. In one embodiment, die display is a North American television signal television screen according to NTSC standards having a widtii of 160 color clock widths, each color clock widtii being die width covered by die electron beam in 280 nanoseconds, and a height of 400 interlaced scan lines. In one embodiment, coarse coordinate units equal one color clock in width and two scan lines in height. In one embodiment, die center 701 of the screen 703 is represented as coarse coordinates 128, 128. Byte 719 contains a description code for the style of the border 706 of form 700. In one embodiment, valid description codes are 0 for no border, 1 for a thin line border, 2 for a tiiick line border, 3 for a gothic style border, and 4 for a border having a "wavy" appearance, though other embodiments could use other codes or styles. Byte 720 contains a color code for die color of die border 706. Byte 721 contains a color code for the color of die interior 702 of die form 700. Byte 722 and word 724 are used to locate the script, described below, for die form. Byte 722 is an index into a script handle table for the location of die first byte of a script resource containing die script to execute. A script handle table is a table of pointers to die script resources for die application. A script resource is a block of memory which may contain numerous scripts. In one embodiment, a script resource may not exceed 64K bytes in size. Word 724 contains die offset from die first memory location of die script resource to die initialization script. If the most significant bit of byte 710 is set, block 730 contains optional hint information regarding die appearance of the form, such as textured appearance or transition effects such as fade in and fade out. Hints for one embodiment are listed in Appendix A. If die capabilities of die user's interactive system cannot accommodate die appearance or effects indicated by the hints, the interactive system may ignore die information or display it as closely as possible. If the most significant bit of byte 710 is cleared, block 730 contains no bytes and is not used. b t BvttQn Qbjgcts. Anodier object is the button object. Referring now to Figure 1, buttons 118, 124 are selected by die user in order to interact with the graphical interactive information system. A button is defined by the information provider using a button object definition record. Referring now to Figure 8, one embodiment of a button object definition record 808 is shown. Byte 810 has a value of 2 to identify the definition as a button object. Bytes 811, 812, 813, 814 identify the positions of the left edge, top edge, right edge, and bottom edge of die button as a distance from die upper left hand corner of the form in coarse coordinate units. Word 816 contains a resource number corresponding to a text, bitmap or picture resource to use for die button. Numbers on the button are inserted automatically on this image based upon die location of die button on die form. Optional byte 817 contains text color information, and optional word 818 contains bits corresponding to die font, size and style of the text if die resource is a text resource, indicated by setting the second most significant bit in Byte 817. Resources are described below. In one embodiment, the text size measurement is in l/500dι of a display screen height. Byte 820 contains an index into the script handle table to die pointer for the script resource containing die script to execute when die user selects die button. Word 822 contains an offset from die start of die script resource to die script to be executed when the user selects die button. The most significant bit of byte 810 is set if hint information exists in block 828. A hint is a description of how an object can appear on certain systems capable of displaying such an appearance. Where the reception component is not capable of such a display, die hint may be ignored, or die reception component may provide an appearance matching die desired appearance as closely as possible. Numbers are assigned to buttons and displayed by the reception component, but diese assignments may be overridden using hints. Odier hints for one embodiment are listed in Appendix A. Optional block 828 contains one or more bytes of die hint data if die most significant bit of byte 810 is set, and block 828 contains no bytes otherwise, c. Text Objects. Text object descriptions are provided by the information provider to describe die location and appearance of text, but do not contain any of die actual text itself. The text itself is a resource, described below. Referring now to Figure 9, one embodiment of a text object definition record 908 is shown. Byte 910 contains an object type identifier having a value of 3 to indicate die object is a text object. Bytes 912, 914, 916, 918 describe the left edge, top edge, right edge and bottom edge, respectively, in coarse coordinate units from the upper left corner of die form object, of a box into which die text resource may be placed by die reception component. Byte 920 contains a code for the color of die text. Byte 922 contains text alignment information. Word 924 contains die resource handle of the text string which die reception component is to display in die box. Word 926 defines the font, size and style to use to display the resource. The font makes up die first four bits, die size makes up the next six bits and die style makes up the remaining six bits of word 926. Block 932 contains optional hint flags, size and data similar to the hints described above and shown in Figure 8. d. Bitmap Objects. A bitmap object is used to display a bitmap resource, described below, on the form. An information provider defines a bitmap object using a bitmap object definition record. Referring now to Figure 10, one embodiment of a bitmap object definition record 1008 is shown. The least significant six bits of byte 1010 contain an object type identifier having a value of 4 to indicate the object is a bitmap object. Bytes 1012, 1014, 1016, 1018 define the left edge, top edge, right edge and bottom edge, respectively, in coarse coordinate units from the upper left corner of the form object, of a box into which the bitmap may be placed. Word 1022 contains a handle to the resource containing the bitmap. Block 1032 provides hints as described above and shown in Figure 8. e. ist Objects. A list object provides die user widi a list of options and allows for a selection of one or more options. An information provider defines a list object using a list object definition record. Referring now to Figure 11, one embodiment of a list object definition record 1108 is shown. The least significant six bits of byte 1110 contain an object type identifier having a value of 5 to indicate the object is a list object. Bytes 1111, 1112, 1113, 1114 define die left edge, top edge, right edge and bottom edge, respectively, in coarse coordinate units from the upper left corner of the form object, of a box into which die list may be displayed. If the second most significant bit of byte 1110 is set, dien word 1116 holds font, size and style information similar to word 926 of Figure 9 and Byte 1117 holds the color code of the list, odierwise word 1116 and byte 1117 are unused. Byte 1118 holds die number of entries in the list, and byte 1120 allows a default selection to be specified using the order of die entries in block 1122 beginning with entry 0. In one embodiment, the default selection is initially highlighted to indicate which entry will be selected by the user if die user selects a button marked "yes" as instructed by the scripting commands described below. Block 1122 contains one or more words containing die resource handle, described below, of the each entry in the list. Optional block 1128 provide optional hint data as described above and shown in Figure 8. In one embodiment, die reception component displays the resources along with a number it assigns to each resource to accommodate selection by die user, unless overridden by hints. In anodier embodiment, user responses, such as specific remote control keys, are assigned to move a cursor up or down the items in the list. f. Timer Objects. Timer objects allow the graphical interactive information system application to use timed events, such as a timed response to a question in a game. An information provider defines die timer object using a timer object definition record. Referring now to Figure 12, one embodiment of a timer object definition record 1208 is shown. The least significant six bits of byte 1210 contain an object type identifier having a value of 6 to indicate the object is a timer object. The second most significant bit of byte 1210 is a flag indicating if die timer operates one time, or restarts again after each period has elapsed. Word 1212 contains a value equal to the period of the timer in l/60ths of a second. Byte 1214 contains die script handle of die script resource containing die script to Execute at die end of die period indicated as described above. Word 1216 contains an offset from the start of die script resource specified as described above to the script to execute when the period has elapsed from the time die object is received or the last period ended, g. Picture Objects. A picture object allows an information provider to define a picture using a picture resource, which is a list of several bitmaps, text resources and drawing primitive functions, which can allow the picture resource definition to be more compact than an equivalent single bitmap resource. An information provider defines a picture object using a picture object definition record. Referring now to Figure 13, one embodiment of a picture object definition record 1308 is shown. Byte 1310 contains an object type identifier having a value of 7 to indicate die object is a picture object. Bytes 1312, 1314, 1316, 1318 define die left edge, top edge, right edge and bottom edge, respectively, in coarse coordinate units from die upper left corner of die form object, of a box into which the picture resource may be placed. Word 1322 contains die handle of a picture resource, described below, to display in die box. Block 1328 provide hints as described above and shown in Figure 8. C. Resource Definitions. Unlike object definitions which define die appearance of an object, resources represent data which can be displayed. The compact protocol also allows die information provider to define certain resources, such a bitmaps, to provide die pictures or icons 120, 122 shown in Figure 1. Text is also provided dirough die use of resources. Some resources are predefined, and others may be defined by die information provider. An information provider defines resources using resources definition records. Referring now to Figure 14A, one embodiment of a resource definition record 1408 is shown. Byte 1410 identifies the record as a resource definition record by having a value equal to 2. Word 1411 contains a value equal to the number of bytes in die resource definition record. Word 1412 is die resource handle of the resource. In one embodiment, four types of resources may be defined in block 1414, a text resource, a bitmap resource, a picture resource and a bitmap resource list. The stored program in the storage device of the reception component will interpret die resource and format it according to the capabilities of die reception component so diat it may be rendered as closely as possible to die definition. If necessary, the stored program may discard a resource definition data diat it cannot use, for example, because die resource has a higher resolution than die reception component is capable of rendering as described below. 1. Text Resources. A text resource contains text data. Referring now to Figure 14B, one embodiment of a text resource 1428 is shown. Byte 1430 having a value equal to 1 identifies the resource as type text, and block 1432 contains a null terminated text string, such as ASCIIZ. 2. Bitmap Resources. A bitmap resource is used to hold bitmaps. Bitmaps are described in Kliewer, EGA/VGA Programmer's Reference Guide (2nd. ed., McGraw Hill 1990). Referring now to Figure 14C, one embodiment of a bitmap resource 1438 is shown. Byte 1440 having a value equal to 2 identifies the resource as type bitmap. In one embodiment, die resolution of the bitmap is higher man the coarse coordinate system, allowing the utilization of the full display resolution of die reception component. Bytes 1441, 1442, 1443, 1444 define four colors for use as described below. Word 1446 defines die widtii in pixels of die bitmap and word 1448 defines the height of the bitmap in pixels. Block 1450 contains one or more bytes of the bitmap data, each byte in block 1450 containing four pairs of bits, each pair representing one of the four colors defined above, of a pixel. Each pixel is drawn to the right of the pixel before until the pixel width 1446 is reached, at which point the next pixel is drawn at the left boundary of die next row and die process repeats until all die pixels are drawn. Any form of bitmap or similar format may be used. For example, bitmaps using a byte per pixel, where each byte represents die color of a pixel, may be used. In one embodiment, the bitmap data is compressed using such compression techniques as conventional run-lengtii encoding. 3. Picture Resources. Picture resources are used to hold zero or more graphical elements such as text strings, bitmaps, and primitive drawing functions, as well as relative position information. Referring now to Figure 14D, one embodiment of a picture resource 1458 is shown. Byte 1460 having a value equal to 32 identifies die resource as type picture. Word 1462 contains the number of bytes in the picture resource definition record. Block 1464 contains zero or more picture resource elements described below. Referring now to Figure 14E, one embodiment of a picture resource element is shown. The least significant six bits in byte 1470 indicate the type of the element. Element types include text or bitmap resources, as well as drawing functions such as ellipse, circle, horizontal line or vertical line. The type codes are listed for one embodiment are: text = 24, bitmap = 32, point drawing function = 1, horizontal line drawing function = 2, vertical line drawing function = 3, rectangle drawing function = 4, filled rectangle drawing function = 5, diagonal line drawing function = 6, ellipse drawing function = 7, circle drawing function = 8, and spline drawing function = 9. The most significant bit of byte 1470 indicates die last element in the picture resource, allowing multiple elements to be a part of a picture resource. Bytes 1472, 1474 contain die x and y coarse coordinate relative to the center of the screen of the upper left corner of the element, and bytes 1476, 1478 contain the x and y coarse coordinates relative to the center of the screen of die lower right corner of the element, except for the horizontal line drawing function, which does not contain byte 1478, the vertical line drawing function, which does not contain byte 1476, and die point drawing function and bitmaps which do not contain bytes 1476 or 1478 because in each case, the omitted byte or bytes are unnecessary. Byte 1480 contains the color code for die element, unless the element type is bitmap. Word 1482 contains a resource handle if die type is text or bitmap, otiierwise, word 1482 is unused. Block 1484 contains additional information if die type is text, similar to word 926 of Figure 9. 4τ Resource Lists Resource lists contain one or more bitmap resources. Referring now to Figure 14F, one embodiment of a resource list 1488 is shown. Byte 1490 contains a unique value to identify the resource as type resource list. Block 1492 contains one or more resource list elements. Referring now to Figure 14G, one embodiment of a resource list element 1498 is shown. Word 1497 contains an offset to die byte following die resource list element, or zero if resource list element 1498 is the last element in the list. Block 1499 contains a bitmap resource described above and shown in Figure 14C. P. Indexing Definitions. Referring now to Figure 2B, in one embodiment, microprocessor 222 performs several memory management functions. Microprocessor 222 maintains in storage device 226 a pointer to each form in an application using a form handle table. The form handle table contains a pointer to the first byte of each form object in die application. The objects in each form are stored as a linked list, with the form object pointing to the first object in die linked list. An object is located by using die form handle table to locate the form, and then traversing the linked list until the desired object is located. In one embodiment, objects may be referenced by type and position in the list. For example, button 3 is the third button found while traversing the list. In another embodiment, all objects are sequentially numbered in the list, and objects are referred to by this object number. The location of each resource is stored using a resource handle table in which each entry in die table contains a pointer to die resource. The resource is located by using a resource handle index to locate die pointer in the resource handle table, and using die pointer to locate die resource. Because several applications may be resident in the storage device 226 at one time, more man one set of die tables and lists described above may be maintained by microprocessor 222, allowing a program application to stay resident while an advertisement application is operating, so diat die program application need not be reloaded after die end of the advertisement when the program resumes. The program application or advertisement application may be suspended or terminated by an advertisement application. In one embodiment, more man one advertisement application may be resident in storage device 226 to allow a user to send a response to one advertisement application after the advertisement terminates, yet still receive the application for die following advertisement. In one embodiment, only the form or forms of die application related to die response will remain in storage device 226 after microprocessor 222 receives a second advertisement application. In one embodiment, a program application is allocated a larger percentage of memory than an advertisement application due to the longer running time of the program application. In one embodiment, a program application may occupy 75% of die available memory as described below, leaving 25% for one or more advertisement applications. A virtual interactive channel application may occupy 100% of the available application memory. In one embodiment, memory is allocated by limiting the number of available handles in the application's handle table based upon die type of application as described above. Although this embodiment does not strictly enforce die actual memory usage of the application, it provides a reasonable level of protection without a significant increase in complexity of memory management. In this embodiment, the number of handles to be allocated may be based upon experience of die average size of die memory required as a result of each entry in the handle table. In one embodiment, die average size per entry is 50 bytes. In another embodiment, memory itself is allocated by tracking the amount of memory a graphical interactive information system application uses as the memory is reserved, and terminating die application if die application's memory allocation is exceeded. E. Updates. The compact protocol also allows the information provider to update information used by previous definitions so diat die appearance of a form can be modified quickly without resending a large amount of data required to resend the entire application or form. An information provider sends an update record to replace a form, one or more objects on a form, or one or more resource definitions in an application. Referring now to Figure 15, one embodiment of an update record 1508 is shown. Byte 1510 having unique values to identify the record as an update record to update a form, one or more objects on a form, or one or more resources, respectively. Word 1512 identifies the size in bytes of die record. Block 1514 is the handle of a form to replace, die form containing the objects to replace or die resource to replace. Block 1516 contains a form object definition record, one or more button, text, bitmap, picture, timer or list object definition records, or text or bitmap resource definition records described above to replace the object or resource indicated in byte 1514. In one embodiment, entire forms are updated by storing the objects of the form and adjusting the handle to die old form to point to die new form. One or more objects in a form may be updated by storing die new object and then inserting the new object in die linked list making up die form in place of the old object. A resource is updated by storing the new resource and adjusting the resource handle table to point to die new resource. F. Instructions. The compact protocol also allows the information provider to send instructions to die reception component to control die operation of the interactive information system. A form may be displayed using a two byte command. The first byte has a value equal to 5 to indicate the command is a form display command, and the second byte contains the form number. The form display command allows the information provider to display a form widiout any input from the user. A program application may be suspended or resumed by an advertisement application or virtual channel using the single byte commands suspend and resume, having a value of 6 and 7, respectively. An application may be permanently terminated by sending a single byte command having a value equal to 8. G. Interactive Icon Definition. In one embodiment, an interactive icon is shown on the display to indicate an interactive application has been received by the reception component. The user can then press one or more keys on the remote control to display the first form of the application. The information provider may control the icon displayed by sending an interactive icon definition record. Referring now to Figure 16, one embodiment of an interactive icon definition record 1608 is shown. Byte 1610 contains a value of 9 to identify die record is an interactive icon definition record. Bytes 1612, 1614, 1616, 1618 define the distance in coarse coordinate units from die center of the screen of the left edge, top edge, right edge and bottom edge, respectively, of a box in which die interactive icon will be displayed. The upper left edge of the icon is placed at the upper left edge of the box defined. Word 1620 is the resource handle of the resource to be displayed as the icon. H. Scripts. Scripts are a sequence of one or more scripting commands provided by an information provider. A script may be executed when received, or may be executed in response to an action. In one embodiment, die compact protocol allows an information provider to send a script which is executed upon receipt and then discarded. An information provider defines the script to execute using a script execute record. Referring now to Figure 17A, one embodiment of a script execute record 1708 is shown. Byte 1710 having a unique value to identify the record as a script execute record. Word 1712 contains die number of bytes in die script execute record. Block 1714 contains the script resource, containing one or more codes as described in Appendix B. The compact protocol also allows die information provider to provide scripts defining die operation of the system in response to user selections or other events. Four objects may have scripts associated with them: forms, lists, buttons, and timers. The form object script is executed when die form is displayed. A list object script is executed when die user indicates a selection. A button object script is executed when the user selects the button. A timer object script is executed at die end of die timer period. A script can display or hide a form or an object on die form, modify an object's characteristics, such as color or size, or modify which resource an object will use. A script can also declare variables unique to die script and change die values of those variables. A script can use standard logic functions, such as "or", "and", "if..dιen", etc. In one embodiment, the script can perform all the math and logic functions of a conventional basic interpreter. Referring now to Figure 17B, one embodiment of a script resource 1718 is shown. Byte 1720 having a unique value to identify die resource as a script resource. Word 1722 contains the number of bytes in die script resource. Byte 1723 contains the handle used as an identifier of die script resource. Block 1724 contains the script resource, containing one or more codes as described in Appendix B. Responses are scripted as well, including the formatting of a response byte or byte containing product information, quantity, or the like. In one embodiment, a script may contain one or more of four unique scripting commands which generate responses. An "order" scripting command allows a user to use the interactive information system to order a product or service from a vendor. An order scripting command contains a one-byte code representing the command, one word of cost information and a one byte variable indicator to allow die information provider to indicate a variable to return as described below. The cost information may be used by die reception component 234 of Figure 2B to check die price of the order to verify diat it does not exceed a user's predefined limit to assist die user for budgeting purposes. The variable indicator is a code to indicate a variable to return as described below. The variable may be built by the information provider using die scripting language, and in one embodiment, die variable is four bytes in lengtii. A "request" scripting command allows a user to request information for no charge. A request scripting command is similar to the order scripting command, but, no cost information byte is passed to the reception component for verification. Two scripting commands are used which generate anonymous responses described below. A "respond" command has a format similar to die request scripting command, to allow the generation of a four byte response to be defined by the information provider using the scripting language. A "vote" scripting command is a single byte command which generates a response having only one byte which contain predefined codes for "yes", "no", "abstain" and "don't know," to allow for simple, compact response generation. Referring now to Figure 2A, scripts are defined by the information provider using die compact protocol generator 210. In one embodiment, die compact protocol generator 210 has a user interface allowing characteristics of objects to be defined or modified or odier actions to be taken using an object oriented format, such as "form 1. show" to display die first form. Odier commands such as assignment of variables and logic functions are defined using a set of commands similar to die BASIC programming language. The protocol generator converts the B ASIC-like commands to one or more numeric codes, and includes die codes in the application broadcast. One embodiment uses die codes described in Appendix B. In one embodiment, scripts are stored in a script resource, which is an area of memory up to 64K bytes long which stores one or more scripts. A script handle table keeps track of all script resources by storing the memory location of the first byte of each script resource. The precise location of the start of each script is provided to the system as an index into die script handle table, and an offset from die location pointed to by die script handle table entry corresponding to the index. Scripts are executed using a command interpreter which performs the functions indicated until it reaches an end of script identifier. In one embodiment, the script instructions are interpreted directiy from die codes which make up die script resource, and in another embodiment, script instructions are first converted into C++ code prior to interpreting them. TV. Broadcaster Information. Referring now to Figures 2A, 2B, 2C and 18C, in one embodiment, an information provider such as a cable television operator uses the provider component 266 to create, insert and broadcast broadcaster information as a graphical interactive information system application for reception and decoding by a reception component 234. In one embodiment, the information provider provides broadcaster information to allow a reception component 234 to build a broadcaster information table. A broadcaster information table organizes some or all broadcaster information to allow the reception component 234 to locate die tuned frequency or other identifier of a broadcaster or an application. Broadcaster information may reach die information provider in a variety of ways. Broadcasters or odier information providers may send broadcaster information relating to tiieir broadcasts to die information provider. For example, die transport a broadcaster uses to broadcast graphical interactive information system applications, such as VBI line 14, and die broadcaster's network identifier, such as CNN, may be provided by the broadcaster to the information provider who will provide broadcaster information. The broadcaster can also identify whether it provides programs, interactivity or both, and any interactive information system protocols it uses. Thus, a broadcaster may be an information provider for interactive information system applications it broadcasts, and provide content to anodier information provider, die cable operator, who broadcasts die broadcaster information via its own provider component 206. The information provider who will broadcast die broadcaster information can assemble information received by others, provide its own broadcaster information or both. For example, die cable operator can provide the channel guide containing a frequency identifier such as the frequency or channel number and call letters for each of die broadcasters on die cable system in addition to information it receives from broadcasters or odier parties. In one embodiment, an information provider broadcasts a broadcaster information table by broadcasting broadcaster information such as broadcast channels available to die user, die broadcast frequency corresponding to die channel, call letters corresponding to a broadcaster on die channel, network identifiers for die broadcasters, or interactive information protocol or location information for a broadcast or an application 1810, whether a broadcaster broadcasts programs, graphical interactive information system applications or both 1811, a broadcast program tuned frequency location identifier 1812, and interactive information system application tuned frequency identifiers 1814 for die broadcaster or for particular applications broadcast by the broadcaster or otiiers. Referring now to Figures 2B and 18B, in one embodiment, the reception component receives die broadcaster identifiers 1820, whether a broadcaster broadcasts programs, graphical interactive information system applications or botii 1821, broadcast program tuned frequency location identifiers 1822, and interactive information system application tuned frequency identifiers 1824 and stores this information in storage device 226. Referring now to Figures 2B and 18C, a desired frequency is located given any of die entries in the broadcaster information table by locating a desired entry 1830, identifying the tuned frequency of the desired broadcaster or interactive information system application 1832 and tuning the desired frequency 1834. for example, if channel 4 contains KRON, the NBC affiliate, broadcasting graphical interactive information system applications on line 14 of the VBI on channel 9, this information is stored in the reception component 234 as described above. An interactive application corresponding to channel 7 may instruct the reception component 234 to switch the tuned frequency of the program channel to the NBC affiliate using a command which only identifies NBC as die target channel. The interactive information system reception component 234 may dien identify the proper channel corresponding to the NBC affiliate as channel 4 by locating die desired broadcaster in the broadcaster information table, identifying die tuned frequency or channel of die desired broadcaster from e entry containing die broadcaster information 1832 and switch the tuned frequency of a tuner in reception component to the channel or frequency of die desired broadcaster or application 1834. When tuner 216 is changed to channel 4, either by the user or an interactive information system application, reception component 234 under control of microprocessor 222 using the broadcaster information table can switch tuner 252 to channel 9 and decode die line 14 of die VBI to obtain interactive information system applications corresponding to the broadcast program on channel 4. In one embodiment, die previous channel or application information is stored in storage device 226 to allow die interactive information system to return the user to die original channel 7, for example if die user exits the new application or die interactive information system application on line 14 of the VBI of channel 9 is not received. Referring now to Figure 2B, as described above, in one embodiment, information related to interactive information system applications may also be broadcast, received and stored as a part of die broadcaster information table. If graphical interactive information system application number 5407138 will be broadcast by KRON, this information may also be a part of die broadcaster information table, allowing die interactive information system to locate tiiis application upon command, for example, from anodier interactive information system application, without changing the program channel, for example by changing die tuned frequency of tuner 217 widiout changing die tuned frequency of tuner 252. In one embodiment, the developer uses the compact protocol generator and formatter 276 to create interactive information system applications which refer to other applications by using application identifiers, and die graphical interactive information system application server 270 allows die broadcaster to further modify the application by adding available broadcaster information regarding die other applications to allow the reception component to locate the other applications. V. Image Generation. An application may display die first form when die reception component receives the application header record, the first form definition, including objects for that form, and resources related to die objects on die form. Additional forms may be broadcast while die first form is being displayed. In one embodiment, if the user response causes the application to display a form for which the form definition or one of the required object or resource definitions has not been received by die reception component, the application will wait for 10 seconds for die receipt of die missing information, and if not received, abort die application and display an error message. Referring now to Figure 2B, display generator 228 contains an addressable video RAM. When a VGA color code is written into die video RAM of the display generator 228, a pixel appears on die display 230 corresponding to the address of die code written. Thus by sending various bitmaps, the form is displayed. The use of bitmaps and video display adapters is described in Kliewer, EGA/VGA Programmer's Reference Guide (2nd. ed., McGraw Hill 1990). In one embodiment, all color codes are broadcast as VGA color codes. VGA color codes are described in Kliewer, EGA/VGA Programmer's Reference Guide (2nd. ed., McGraw Hill 1990). In anodier embodiment, a different set of color codes are used. In one embodiment, die color code is converted at display time to a color suitable for die reception component by mapping it to another color. For example, some of die VGA color codes are too bright for use on certain displays, such as color televisions, and thus, a 256 entry lookup table is used to convert die VGA code into the acceptable code. In one embodiment, the result of die lookup reduces the saturation of the RGB values by 25%. In anodier embodiment, codes indicating saturation of die RGB values in die top 25% are held to 75% of die maximum. The 25% value was selected to accommodate die color restrictions imposed by the NTSC video signal standards, and conventional color television circuitry. The lookup table approach can map to any number of colors. In one embodiment, 100 colors are used, anodier embodiment uses sixteen colors, and another embodiment uses only two colors. The reception component stores bitmap resources defined using bitmap resource definitions described above in storage device 226. In one embodiment, all text characters in various fonts, styles and type sizes are stored as predefined bitmaps in storage device 224 to allow for rapid display of diese characters. In another embodiment, these text characters are stored as outline fonts, and bitmaps are generated from die outline fonts. Odier predefined resources are also stored to allow commonly-used objects such as bitmaps of credit cards. Predefined resources are listed in Appendix C. Referring now to Figure 19, a method of generating die images from die form object and other object definitions is shown. When a display form command is received, either via the broadcast or via a script, the video RAM is erased 1910 and die objects and resources are drawn. In one embodiment, die form object is drawn first 1912, followed by the objects and resources appearing on the form 1914, 1916 until all objects and resources are drawn 1920. This allows die objects and resources to appear overlaid onto the form. Objects and resources are located using die handle tables described above. Referring now to Figure 20, one embodiment of a method of drawing an object is shown. An object is drawn by reading the corresponding object definition 2010, generating a bitmap corresponding to the object definition read 2012 and sending it to the graphics display generator 2014. In one embodiment, die entire bitmap is generated 2012 prior to sending 2014. In another embodiment, portions of the bitmap are generated 2012 and sent 2014 until the entire bitmap is complete 2016, 2018. Generating the bitmap is accomplished by rendering the color of each pixel within the boundary of the object as specified by die object definition. Referring now to Figure 21, one embodiment of a method of drawing a resource is shown. Each bit in die bitmap of a resource is read 2108 and translated 2110 into the format of the graphics display generator if required. For example, each bit in a four-color bitmap resource may be translated into a modified VGA color code as described above. The translated bit is sent 2112 to the graphics display generator using die position information in die resource definition for display by die display device. In one embodiment, all of the bits are assembled 2110 into a bitmap prior to sending 2112, and in another embodiment, each bit is sent after translation 2112. The method continues until the resource is drawn 2114, 2116. VI. Response Generation When an application allows a response and die user has a reception component capable of transmitting die response, the user may provide response information to a response collector. Referring now to Figure 2B, in one embodiment, each reception component 234 is assigned a unique code at the time of manufacture and this code is stored in die storage device 224. Individual users of die reception component 234 may also be assigned a unique code. When die user responds to an object which generates a response, die reception component generates a response record to allow die response collector to route the response as described below. Referring now to Figure 22, one embodiment of a response record 2208 is shown. Long word 2210 contains die unique code of the reception component, and long word 2212 contains die unique application code sent in the application header. Byte 2214 contains a user identifier, to allow die user to distinguish himself from others who may use the reception component. In one embodiment, anonymous responses do not contain the reception component or user identifier 2210, 2214 to allow for the user to maintain anonymity. Block 2216 contains the defined response information byte or bytes described above to designate quantity or product information according to the user's response. In one embodiment, a passcode is maintained in the reception component, and the user is required to enter it to generate the response to the response collector. Referring now to Figure 23, a response network containing three reception components, one response collector, and two vendors is shown. User reception components 2310, 2312, 2314 are coupled to response collector forwarding equipment 2316 via communication lines 2311. Communication lines 2311 may be permanently connected or temporarily arranged as needed. In one embodiment, communications lines 2311 are arranged dirough die public switched telephone network when a reception component 2310, 2312, 2314 dials a telephone number of the response collector. In anodier embodiment, communications lines 2311 are cable television cables. Any form of communication, even using an intermediary such as telephone equipment owned by the telephone company, will allow operation of die present invention. In one embodiment, response collector forwarding equipment 2316 is an industry standard UNIX-based computer system coupled to at least one modem to receive and/or transmit data. The response collector forwarding equipment 2316 is coupled to vendor ordering equipment 2318, 2320 using communication lines 2319 similar to communication lines 2311 to allow the response collector equipment 2316 to react to the receipt of responses sent by a reception component 2310, 2312, 2314 by sending user information and other information to vendor ordering equipment 2318, 2320 as described below. Referring now to Figure 24 a method of collecting and sending confidential user information such as credit card number to a vendor is shown. The response collector obtains user information such as reception component number, user number, name and address, and confidential information such as credit card number 2408, 2410. In one embodiment, this is accomplished by mail. In another embodiment, this step is accomplished by telephone. In one embodiment, die information is verified, for example by checking die credit card billing address with die address provided by die user 2411. The response collector obtains routing information and an application identifier from the information provider 2412, and associates die routing information with the application identifier. The application identifier broadcast to die user as described above and a user reception component and user identifiers are sent to die response collector 2414. Because no confidential information is sent, unsecure communication lines may be used to send die information. The response collector then forwards die user information including user confidential information and response information to die vendor associated widi the application identifier received 2416. This step may be accomplished using a secure facility, such as mail or telephone line. The vendor may en provide a service or products to the users address widi less likelihood of fraud. Appendix A Hints Null Invisible Disable Foreground Color Background Color Border Color Border Style Border Width Border Options Form Transition Effect (Fade Out, etc.) Form Background Gradient Fill Clip Scale to Fit Scale Text Private (Not seen - use for passwords, etc.) Text Numeric Text Editable Appearance of Buttons Key 0 Key 1 Key 2 Key 3 Key 4 Key 5 Key 6 Key 7 Key 8 Key 9 Key Select Key Up Key Down Key Left Key Right Key Enter Key Exit Key Cancel Key Buy No Legend Keycap Custom Keycap Round Keycap Square Keycap Diamond Keycap Over Keycap Under Keycap Left Keycap Right Cursor Related Hints for Systems with Cursors Box (when cursor is inside box, user may press enter) No Box (no box needed around object) List Hints Highlight Color List Exclusive List Exclusive None List Non Exclusive List Horizontal List Vertical List Sort Ascending List Sort Descending List Control Up (Indicates button which makes list scroll) List Control Down List Control Left List Control Right Timer Hints Timer Random During Period Appendix B Script Codes Statements Token Value 5 IF 0x10 WHILE 0x11 {function call statement} 0x12 RETURN 0x13 {integer assignment} 0x14 10 {string assignment} 0x15 {boolean assignment} 0x16 Expressions Token Value Arguments Return Value {integer variable} 0x20 none Integer 15 {string variable} 0x21 none String {boolean variable} 0x22 none Boolean {integer constant} 0x30 none Integer {string constant} 0x31 none String {boolean constant} 0x32 none Boolean <= 0x40 Integer, Integer Boolean < 0x41 Integer, Integer Boolean {integer equal} 0x42 Integer, Integer Boolean {string equal} 0x43 String, String Boolean 25 {boolean equal} 0x44 Boolean, Boolean Boolean {string compare} 0x45 String, String Boolean {is substring} 0x46 String, String Boolean AND 0x47 Boolean, Boolean Boolean OR 0x48 Boolean, Boolean Boolean 30 NOT 0x49 Boolean Boolean + 0x60 Integer, Integer Integer - 0x61 Integer, Integer Integer * 0x62 Integer, Integer Integer 35 / 0x63 Integer, Integer Integer {mod divide} 0x64 Integer, Integer Integer {string concatenation} 0x70 String, String String {string extraction} 0x71 String, Integer, Integer String 40 {integer object access} 0x80 Integer, Integer, Integer Integer {string object access} 0x81 Integer, Integer, Integer String {boolean object access} 0x82 Integer, Intege r, Integer Boolean 45 Delimiters {end of string} 0x00 {end of statement list} 0x01 Appendix C Predefined Resources Navigation & System: 20 Checkmark "X" mnm i in a blue circle Close icon: down arrow. Back arrow: 180 degree loop Right Arrow: 12 styles Padlock Magnifying glass Polls: 4 Thumbs up YES Thumbs down NO Payment/ Delivery/Ordering: 21 Visa card Mastercard American Express card Optima Card Discover card FedEx Logo UPS Logo DHL logo USPS logo Airborne Express logo Dollar Sign Phone Fax machine Coins Money bills Price tag Brochure Pen & paper Envelope Stamp Grocery cart Entertainment: 10 Television Admission ticket Musical notes • CD Audio Cassette Video Cassette film strip film camera/projector • Knife & fork Wine bottle & glass News/Info: 19 Watch UIOCK Alarm clock Globe USA map Newspaper US flag Capitol dome stock grid car airplane van train bus Book Calendar Suitcase Beakers Nuclear energy symbol Weather/Almanac: 17 • Sun Cloud Sun w/cloud Cloud w/rain Rain drops Cloud w/snow Snowflake Lightning Tornado Hurricane • Fog Full Moon Last Quarter New Moon First Quarter Waves Thermometer Sports: 18 Skier Referees whistle Combo sports image: baseball, football, basketball Soccer ball Baseball Official baseball logo Football NFL logo Basketball NBA logo ice skates Hockey puck & stick Bowling ball & bowling pins Tennis racquet Golf putter, golf ball, and tee Sailboat Boxing gloves Horse Misc: 7 Key LigniDuio Graduation cap Construction hard hat Picture (photograph) Road work sign Rose

Claims: What is claimed is: I . A graphical interactive information system for broadcasting and receiving graphical interactive information system applications having a graphical user interface comprising: a provider component for broadcasting graphical interactive information system application information; and a reception component for receiving the graphical interactive information system application information broadcast, displaying a graphical interactive information system application user interface and operating the graphical interactive information system application. 2. The system of claim 1, wherein the provider component comprises: a protocol generator and formatter having an input for accepting information from an information provider, for generating, formatting and presenting at an output a protocol for a graphical interactive information system application corresponding to die information input from the information provider; a protocol inserter having a first input coupled to the protocol generator and formatter output, for inserting the protocol into a broadcast signal and presenting at an output the broadcast signal containing the inserted protocol; and a transmitter having an input coupled to the protocol inserter output, for broadcasting die broadcast signal containing the inserted protocol. 3. The system of claim 2 wherein the transmitter is an FM transmitter. 4. The system of claim 2 wherein the transmitter is a pager transmitter. 5. The system of claim 2 wherein the transmitter is a cellular telephone transmitter. 6. The system of claim 2 wherein the transmitter is a television transmitter. 7. The system of claim 2 wherein the transmitter is a cable television head-end amplifier. 8. The system of claim 2 wherein die transmitter is an out-of-band transmitter. 9. The system of claim 2 wherein the data inserter is a VBI data inserter 10. The system of claim 2 wherein: the provider component additionally comprises a program generator for generating at an output a broadcast signal; and the protocol inserter additionally has a second input coupled to the program generator output, for receiving the broadcast signal into which die protocol is inserted. I I . The system of claim 10 wherein the transmitter is a television transmitter. 12. The system of claim 10 wherein the transmitter is a cable television head-end amplifier. 13. The system of claim 1 wherein the reception component comprises: a first tuner for receiving a broadcast signal and tuning at least one desired frequency at an output; a data extractor coupled to the first tuner output for extracting a graphical interactive information system application from the desired frequency; a microprocessor coupled to the data extractor output for controlling the operation of the reception component and interpreting interactive information system application commands and scripts; a graphics display generator having a first input coupled to the microprocessor for generating at an output a graphical user interface display signal; a display having an input coupled to die graphics display generator output, for displaying a graphical user interface from the graphical user interface display signal; and a storage device coupled to the microprocessor for storing interactive information system application information; 14. The system of claim 13 wherein die graphics display generator has a second input coupled to the first tuner, and the graphics display generator is also for displaying a broadcast program. 15. The system of claim 13 wherein the reception component additionally comprises a second tuner for receiving a broadcast signal and tuning a second desired frequency comprising a broadcast program at its output; and the graphics display generator has a second input coupled to the second tuner, and die graphics display generator is also for displaying a broadcast program 16. The system of claim 13 wherein die reception component additionally comprises a user input receiver having an output, for receiving input from a user. 17. The system of claim 16 wherein the user input receiver is a keypad. 18. The system of claim 16 wherein die user input receiver is a infrared receiver. 19. The system of claim 16 wherein the reception component additionally comprises a user input decoder having an input coupled to die user input receiver input and an output coupled to the microprocessor, for decoding input commands from a user. 20. The system of claim 13 wherein the reception component additionally comprises an infrared emitter having an input for controlling an external device. 21. The system of claim 20 wherein the reception component additionally comprises an infrared encoder having an input coupled to the microprocessor and an output coupled to die infrared encoder input for encoding microprocessor commands into infrared signals compatible with the external device. 22. The system of claim 13 wherein the reception component additionally comprises a data line driver having an input coupled to die microprocessor and an output for allowing die microprocessor to communicate with an external device. 23. The system of claim 22 wherein die data line driver is a modem. 24. The system of claim 22 wherein the data line driver is a DTMF tone dialer. 25. The system of claim 22 wherein the data line driver is an addressable CATV set-top converter controller. 26. The system of claim 13 wherein the the display comprises a television set. 27. The system of claim 13 wherein the display comprises an LCD display. 28. The system of claim 13 wherein the first tuner is additionally coupled to the microprocessor for allowing the microprocessor to control the tuned frequency of die first tuner. 29. The system of claim 13 wherein the first tuner is additionally coupled to die microporcessor for allowing the microprocessor to determine information relating to available frequencies in the first tuner. 30. The system of claim 15 wherein the first tuner is additionally coupled to die microprocessor for allowing die microprocessor to control the tuned frequency of die first tuner. 31. The system of claim 15 wherein die first tuner is additionally coupled to the microporcessor for allowing the microprocessor to determine information relating to available frequencies in the first tuner. 32. The system of claim 13 wherein the broadcast signal comprises a broadcast program having a content related to a content of die interactive information system application. 33. The system of claim 32 wherein the data extractor extracts the interactive information system application from the vertical blanking interval. 34. The system of claim 13 wherein the broadcast signal comprises a broadcast advertisement having a content related to a content of the interactive information system application. 35. The system of claim 34 wherein the data extractor extracts die interactive information system application from the vertical blanking interval. 36. The system of claim 15 wherein the interactive information system application comprises a content related to a content of the broadcast program. 37. The system of claim 36 wherein the data extractor extracts the interactive information system application from an out-of-band frequency. 38. The system of claim 36 wherein the data extractor extracts the interactive information system application from an FM frequency. 39. A method of transmitting a graphical interactive information system application for display to, and control by, a user, comprising: describing a set of characteristics for at least one graphical object to produce at least one graphical object description; broadcasting at least one of the graphical object descriptions; receiving at least one of the graphical object descriptions broadcast; and creating a graphical interactive information system display based upon at least one graphical object description received. 40. The method of claim 39 wherein at least one graphical object description comprises a form object definition record. 41. The mediod of claim 39 wherein at least one graphical object description comprises a button object definition record. 42. The mediod of claim 39 wherein at least one graphical object description comprises a text object definition record. 43. The me od of claim 39 wherein at least one graphical object description comprises a bitmap object definition record. 44. The mediod of claim 39 wherein at least one graphical object description comprises a picture object definition record.

Inventors: DEL SESTO ERIC E, DOUGHERTY BRIAN P, DEL SESTO, ERIC, E., DOUGHERTY, BRIAN, P.
Applicants: WINK COMMUNICATIONS INC, WINK COMMUNICATIONS, INC.
Application year: 1996
Main classification: H04H1
IPC codes: G06F13, H04H20, H04N5, H04N7