Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/20—Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
  • H04N21/23—Processing of content or additional data; Elementary server operations; Server middleware
  • H04N21/238—Interfacing the downstream path of the transmission network, e.g. adapting the transmission rate of a video stream to network bandwidth; Processing of multiplex streams
  • H04N21/2385—Channel allocation; Bandwidth allocation
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/20—Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
  • H04N21/23—Processing of content or additional data; Elementary server operations; Server middleware
  • H04N21/236—Assembling of a multiplex stream, e.g. transport stream, by combining a video stream with other content or additional data, e.g. inserting a URL [Uniform Resource Locator] into a video stream, multiplexing software data into a video stream; Remultiplexing of multiplex streams; Insertion of stuffing bits into the multiplex stream, e.g. to obtain a constant bit-rate; Assembling of a packetised elementary stream
  • H04N21/23614—Multiplexing of additional data and video streams
  • H04N21/23617—Multiplexing of additional data and video streams by inserting additional data into a data carousel, e.g. inserting software modules into a DVB carousel
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
  • H04N21/45—Management operations performed by the client for facilitating the reception of or the interaction with the content or administrating data related to the end-user or to the client device itself, e.g. learning user preferences for recommending movies, resolving scheduling conflicts
  • H04N21/462—Content or additional data management, e.g. creating a master electronic program guide from data received from the Internet and a Head-end, controlling the complexity of a video stream by scaling the resolution or bit-rate based on the client capabilities
  • H04N21/4622—Retrieving content or additional data from different sources, e.g. from a broadcast channel and the Internet
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
  • H04N21/47—End-user applications
  • H04N21/478—Supplemental services, e.g. displaying phone caller identification, shopping application
  • H04N21/4782—Web browsing, e.g. WebTV
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/60—Network structure or processes for video distribution between server and client or between remote clients; Control signalling between clients, server and network components; Transmission of management data between server and client, e.g. sending from server to client commands for recording incoming content stream; Communication details between server and client 
  • H04N21/63—Control signaling related to video distribution between client, server and network components; Network processes for video distribution between server and clients or between remote clients, e.g. transmitting basic layer and enhancement layers over different transmission paths, setting up a peer-to-peer communication via Internet between remote STB's; Communication protocols; Addressing
  • H04N21/64—Addressing
  • H04N21/6405—Multicasting
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/60—Network structure or processes for video distribution between server and client or between remote clients; Control signalling between clients, server and network components; Transmission of management data between server and client, e.g. sending from server to client commands for recording incoming content stream; Communication details between server and client 
  • H04N21/63—Control signaling related to video distribution between client, server and network components; Network processes for video distribution between server and clients or between remote clients, e.g. transmitting basic layer and enhancement layers over different transmission paths, setting up a peer-to-peer communication via Internet between remote STB's; Communication protocols; Addressing
  • H04N21/64—Addressing
  • H04N21/6408—Unicasting
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N7/00—Television systems
  • H04N7/16—Analogue secrecy systems; Analogue subscription systems
  • H04N7/162—Authorising the user terminal, e.g. by paying; Registering the use of a subscription channel, e.g. billing
  • H04N7/165—Centralised control of user terminal ; Registering at central
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N7/00—Television systems
  • H04N7/16—Analogue secrecy systems; Analogue subscription systems
  • H04N7/173—Analogue secrecy systems; Analogue subscription systems with two-way working, e.g. subscriber sending a programme selection signal
  • H04N7/17309—Transmission or handling of upstream communications
  • H04N7/17318—Direct or substantially direct transmission and handling of requests

Definitions

• TITLE BANDWIDTH MANAGEMENT ON A HYBRID POINT TO POINT BROADCAST
• the invention relates to interactive television systems and more particularly to optimization of data delivery in an interactive television system which has both a broadcast channel and a point-to-point channel.
• Interactive television systems can be used to provide a wide variety of services to viewers
• Interactive television systems are capable of delivering typical video program streams, interactive television applications, text and graphic images, web pages and other types of information.
• Interactive television systems are also capable of registering viewer actions or responses.
• Interactive television systems can be used for such purposes as marketing, entertainment and education Users may interact with the systems by ordering advertised products or services, competing against contestants in a game show, requesting specialized information regarding particular programs, or navigating through pages of information
• a broadcast service provider generates an interactive television signal for transmission to a viewer's television.
• the mteractive television signal may include an mteractive portion consisting of application code or control information, as well as an audio-video portion consisting of a television program or other informational displays.
• the broadcast service provider combmes the audio-video and interactive portions mto a single signal for transmission to a receiver connected to the user's television.
• the signal is generally compressed p ⁇ or to transmission and transmitted through typical broadcast channels, such as cable television (CATV) lines or direct satellite transmission systems.
• the interactive functionality of the television is controlled by a set-top box connected to the television.
• the set-top box receives the signal transmitted by the broadcast service provider, separates the interactive portion from the audio-video portion and decompresses the respective portions of the signal.
• the set-top box uses the interactive information, for example, to execute an application while the audio-video mformation is transmitted to the television.
• the set-top box may combine the audio-video mformation with mteractive graphics or audio generated by the mteractive application prior to transmitting the mformation to the television.
• the interactive graphics and audio may present additional information to the viewer or may prompt the viewer for mput.
• the set-top box may provide viewer put or other information to the broadcast service provider via a modem connection.
• interactive television systems provide va ⁇ ous different pieces of information which may be displayed to a particular viewer.
• the mteraction of the viewer with the system determines which of the information is presented to him or her as well as what information is transmitted from the viewer back to the system
• Interactive television systems may therefore have to transmit large amounts of mformation to a group of viewers because each of the viewers may request different pieces of the mformation.
• the bandwidth of the system may be insufficient to provide the mformation to the viewers within a sufficiently short response time.
• the invention provides a method and apparatus for managing an interactive television system to optimize usage of the available bandwidth and minimize the system's response time.
• the interactive television system comprises a broadcast station, a plurality of receiving stations, a broadcast channel through which data can be transmitted from the broadcast station to the receiving stations, and a plurality of point-to-point channels, each of which is between a corresponding one of the receiving stations and the broadcast station. Data can be transmitted from the broadcast station over each of the point-to-point channels to the respective receiving stations, as well as from the receiving stations to the broadcast station.
• the broadcast station monitors the demand for particular pieces of information and determines whether the information should be delivered via the broadcast channel or the point-to-point channels.
• the interactive television system is configured to deliver requested web pages from the broadcast station to the receiving stations.
• Each of the receiving stations is configured to transmit requests for particular web pages to the broadcast station and to display the requested pages when they are received from the broadcast station.
• the broadcast station is configured to cyclically broadcast a certain number of web pages on the broadcast channel. After each of the pages has been broadcast once, the series repeats and each of the pages is broadcast again.
• the broadcast station is also configured to transmit individual web pages on the point-to-point channels.
• the broadcast station monitors the requests from the receiving stations and determines which of the requested pages are in higher demand.
• the pages which have the greatest demand are transmitted to all of the receiving stations on the broadcast channel. Pages which were requested by a particular receiving station are displayed by that receiving station. Pages which were not requested are ignored. Pages which have been requested by fewer receiving stations can be transmitted via the point-to-point channels of the respective receiving stations.
• the broadcast channels are used primarily to transmit pages which are requested by a large number of viewers, while the point-to-point channels are used to transmit pages which are requested by a small number of viewers.
• the use of the system's available bandwidth is thereby used in a way that minimizes the response time between a receiving station's request for a page and delivery of the page to the receiving station. While this embodiment comprises a system for delivering web pages, it is understood that other embodiments may be configured to deliver interactive television applications, multimedia data, or other types of information.
• Fig. 1 is a block diagram illustrating the distribution of interactive television applications and television programs from their sources to a series of viewers.
• Fig. 2 is a block diagram illustrating the interconnection of a broadcast station and several receiving stations in one embodiment of the invention.
• Fig. 3 is a functional block diagram illustrating the flow of information through the broadcast station in one embodiment of the invention.
• Fig 4 is a block diagram of a set-top box used in one embodiment of the mvention
• an mteractive television system mcludes a broadcast station and a number of receivmg stations
• the broadcast station and receivmg stations are coupled by a broadcast channel such as direct satellite transmission ("Broadcast” is used herem to refer to transmission of a smgle signal to all subsc ⁇ bmg receivers "Direct" satellite transmission as used herem contemplates transmissions received by the mteractive television receiver, through its antenna, directly from the satellite )
• the broadcast station and receivmg stations are also connected by several pomt-to-pomt channels, each of which forms a direct channel between the broadcast station and one of the receivmg stations
• the broadcast and pomt-to-pomt channels may both be used to transmit va ⁇ ous pieces of data to the receivmg stations
• the data may be audio-video-interactive mformation, such as mteractive application modules, or any other type of data, such as web pages
• the embodiment desc ⁇ bed below is configured to transmit web pages
• the desc ⁇ ption of this embodiment is mtended to be illustrative rather than limiting, and the transmitted data can represent any type of mformation, such as application code, raw data or graphical information
• the receivmg stations are configured to transmit mformation requests to the broadcast station
• the mformation requests transmitted by a particular receivmg station correspond to web pages which the user at the receivmg station wishes to view
• the broadcast station receives the requests and retrieves the requested pages from the appropnate sources After the requested pages have been retrieved by the broadcast station, they must be transmitted to the receivmg stations which submitted the corresponding requests
• the retrieved pages may be transmitted to the receivmg stations via either the broadcast channel or the pomt-to-pomt channels Data transmitted via the broadcast channel is dist ⁇ ted to all of the receivmg stations, whether they requested the transmitted pages or not Data transmitted via the pomt-to-pomt channels is dist ⁇ ubbed only to those receivmg stations which requested it, but the broadcast station can only transmit a limited amount of data at one time
• this embodiment of the mvention can use both That is, a particular piece of data such as a web page can be transmitted over either channel Because the pomt-to-pomt channel is not limited to transmitting only narrow-band data, entire web pages can be transmitted over this channel.
• the broadcast stanon need not st ⁇ p out narrow-band data for transmission over the pomt-to-pomt channel while wide-band data is transmitted over the broadcast channel Similar data (e g , wide-band data) can be transmitted over either the broadcast channel or the pomt-to-pomt channel. Consequently, the decision to transmit particular data over one channel or the other can be based on delivery times or other quahty-of-service c ⁇ te ⁇ a.
• smce some of the ret ⁇ eved pages may have been requested by more than one receivmg station, it may be more efficient to transmit these pages via the broadcast channel, while pages requested by a smgle receivmg station may be more efficiently transmitted via the pomt-to-pomt channel
• mteractive application modules which are needed by larger numbers of subsc ⁇ bers may be transmitted via the broadcast channel, while modules which are needed by fewer subsc ⁇ bers may be transmitted via the pomt-to- pomt channels
• the broadcast channel is selected for transmission of the data.
• the broadcast station may therefore momtor the requests from the receivmg stations to determine which of the pages are m greater demand (i.e., which are requested by a greater number of receivmg stations.) When the requested pages are ret ⁇ eved, those which are m the greatest demand are transmitted via the broadcast channel.
• a module which has been requested by a smgle subsc ⁇ ber via the pomt-to-pomt channel.
• m which the transmission quality of the pomt-to-pomt channel is greater than that of the broadcast channel, m which case certain modules may need to be transmitted via the point-to-pomt channel.
• Fig. 1 a block diagram illustrating the dist ⁇ bution of mformation such as web pages from their sources to a se ⁇ es of viewers is shown.
• Broadcast station 10 has several program sources 11.
• sources 11 are web servers which may be accessed by broadcast station 10 to obtam web pages.
• the sources may include remote broadcast network feeds, videotape recorders, computers, data storage devices, and the like
• Sources 11 provide audio- video mformation which is to be mcluded m the mteractive television signal.
• the mformation from sources 11 is transmitted to receiving station 20 via either a broadcast channel or a pomt-to-pomt channel
• the broadcast channel is depicted m the figure as a direct satellite broadcast channel formed by broadcast antenna 12, communications satellite 15 and receivmg antenna 19
• the figure illustrates a satellite transmission, it is contemplated that any broadcast medium, including non-satellite, CAIN (cable), telco (telephone), MMDS (microwave) and terrest ⁇ al transmissions, may be used.
• the web pages may be compressed by compression units 22 m order to conserve bandwidth Any one of a number of compression algo ⁇ thms may be used if approp ⁇ ate for a particular program or application. Some web pages may not be easily or effectively compressed, so some of the mformation may bypass compression units 22 and be passed from the modem to packetization units 23 without compressmg the mformation. Packetization units 23 accept the compressed (or uncompressed) mformation and format it mto packets for transmission over the broadcast channel.
• the figure also shows storage unit 24, which may provide previously obtained mformation, stored data or some other type of mformation to compression unit 22 and packetization unit 23.
• the components of broadcast station 10 are coupled to a control unit (not shown) which manages the functions of the broadcast station.
• the packets from packetization units 23 are fed mto multiplexing unit 25, which may intersperse the packets with each other or with control information p ⁇ or to transmission.
• the interspersed packets are then passed to proxy server 26
• Proxy server 26 monitors the web page requests submitted by the users and determines the demand for the different web pages Typically, high-demand pages are transmitted on the broadcast channel, while lower-demand pages are transmitted via the point-to-pomt channel
• the pomt-to-pomt channel is represented by modem 27, which transmits the page to a smgle user via a phone lme (not shown).
• a proxy server is used m this embodiment.
• the proxy server can perform other flmctions, such as filtermg the requests or cachmg mformation responsive to the requests.
• the use of a proxy server may also mcrease the scalability of the system, as more proxy servers can be added to handle the load from the receivmg stations
• Pages transmitted via the broadcast channel are received by all users, pages which have been requested by a large number of users are most efficiently dist ⁇ ubbed over this channel. Each of the requests can be serviced simultaneously and the response time is kept to a minimum Pages which are requested by smaller numbers of users may be more efficiently transmitted via the pomt-to-pomt channels between the broadcast station and the respective receivmg stations. It is also contemplated that the choice of channels may be based on anticipated demand, rather than the actual number of requests for particular pages For example, if a commercial for a certain manufacturer is broadcast, it may be anticipated that a large number of requests for that manufacturer's web page will be received The manufacturer's web page may therefore be transmitted over the broadcast channel while other web pages are transmitted over the pomt-to-pomt channels
• the receivmg station may be configured to transmit pieces of information m a cyclic manner That is, a certain number of these pieces of mformation (e g , web pages) are transmitted one after the other and then, after each of the pieces of information has been transmitted a first time, they are transmitted a second time and a third time and so on
• the broadcast station thus continuously broadcasts data, with each piece of information bemg re-broadcast at regular intervals (1 e , each piece of mformation is re-broadcast with a certain frequency)
• the broadcast station may also be configured to transmit multiple carousels which have different pe ⁇ odicities As noted above, the pieces of mformation which are broadcast m this manner may be referred to as a carousel Because there may be a limited number of positions or slots m the carousel, the broadcast station must p ⁇ o ⁇ tize the requested pieces of mformation The determination of whether a piece of mformation will be transmitted via the broadcast channel or the pomt-to
• Va ⁇ ous strategies may be used to determine which pages are transmitted by which channel If one or more pages are m particularly high demand, they may be allocated two slots m the carousel so that it is transmitted with a greater frequency Responses to requests for these pages will therefore have a reduced latency (response time ) If there is a particularly large number of pages for which there is only a low or moderate demand, the size of the carousel may be mcreased (It should be noted that the carousel is not a hardware structure, and that the number of slots m the carousel is determined by the system software based on system and performance constraints )
• the strategy for routmg data via the respective channels may also take into account other factors, such as degraded quality of transmissions on the pomt-to point channel For example, if a modem channel is too noisy to transmit error-free data, or if this channel simply doesn't meet the quahty-of-service cnte ⁇ a, the cyclic broadcast of high
• Tuner 31 selects a particular broadcast channel on which the broadcast audio-video-interactive signal is transmitted and passes the signal to processing unit 32. (Tuner 31 may be replaced by other means, such as simple input ports, for receiving signals from various signal sources.)
• Processing unit 32 demultiplexes the packets from the broadcast signal if necessary and reconstructs the information embodied in the signal. The information is then decompressed by decompression unit 33. The information is then conveyed to display unit 34, which may perform further processing and conversion of the information into a suitable television format, such as NTSC or HDTV audio/video. If the information includes interactive applications, these applications are reconstructed and routed to random access memory (RAM) 37. The applications are then executed by control unit 35.
• RAM random access memory
• Control unit 35 may include a microprocessor, micro-controller, digital signal processor (DSP), or some other type of software instruction processing device.
• RAM 37 may include memory units which are static (e.g., SRAM), dynamic (e.g., DRAM), volatile or non-volatile (e.g., FLASH), as required to support the functions of the set-top box.
• control unit 35 executes operating system code which is stored in ROM 36.
• the operating system code executes continuously while the set-top box is powered in the same manner the operating system code of a typical personal computer (PC) and enables the set-top box to act on control information and execute interactive and other applications.
• the set-top box also includes modem 38.
• Modem 38 is connected to the telephone line which provides the point-to-point channel between the receiving station and the broadcast station. This channel may serve both as a means for transmitting requested data from the broadcast station to the receiving station and as a return path by which the user can transmit information requests to the broadcast station.
• Set-top box 22 may include a module manager unit 30 contained within control unit 35. Since the receiving station is not aware of the whether it has requested modules which are in high demand from other receiving stations, module manager unit 30 monitors tuner 31 and modem 38 for the requested information. (Tuner 31 in this case is the receiving station's connection to the broadcast channel and modem 38 is its connection to the point-to-point channel.) In other embodiments, the receipt of requested information may be controlled in a different manner. For example, the broadcast station may be configured to transmit notification to the receiving station on a predetermined channel to inform the receiving station which of the channels will be used to transmit the requested information. In one embodiment, module manager unit 30 is implemented in software, but it may also be implemented in hardware or a combination of hardware and software. Module
• Manager unit 30 may be used to control the receipt of audio-video information via the broadcast and point-to- point channels.
• set-top box refers to any receiver or processing unit for receiving and processing a transmitted signal and conveying the processed signal to a television or other monitor.
• the set-top box may be in a housing which physically sits on top of a television, it may be in some other location external to the television (e.g., on the side or back of the television or remotely located from the television), or it may be incorporated into the television itself.
• Set-top box 22 serves to demodulate the signal received from broadcast station 10 and to separate the components of the signal, such as web pages, television programs and interactive applications.
• the television set may be a television or a video monitor employing any suitable television format (e.g., NTSC or HDTV), or it may be replaced by other devices, such as a video recorder.
• the broadcast channel is a direct satellite transmission channel.
• the broadcast channel may alternately utilize various transmission media and is contemplated to include media such as coaxial cable and free space (e.g., as used for direct satellite transmissions.)
• the return path typically consists of a pair of modems, one in the receiving station and one in the broadcast station, each connected to a standard telephone line. Other means for establishing a return path, however, are also contemplated. For example, a portion of the bandwidth of the transmission path could be used as the return path. If the return path utilizes a portion of the broadcast bandwidth, it is contemplated that the broadcast station may still employ a separate point- to-point channel (e.g., a telephone line) to transmit requested data to the receiving station.
• a separate point- to-point channel e.g., a telephone line
• the channels of communication between the broadcast station and receiving station may be displayed as three logical links: a broadcast link; a point-to-point link; and a return link.
• the broadcast link is used to transmit data to multiple receiving stations.
• the point-to-point link is used to transmit data to individual receiving stations.
• the return link is used to transmit data to the broadcast station.
• These logical links may be mapped to a wide variety of physical media, some of which are shared (e.g., satellite transmissions) and some of which are separate, or point- to-point (e.g., telephone lines). More specifically, the broadcast logical link must be mapped to one of the shared media.
• the point-to-point and return links may be mapped to either the shared media, or the separate media. It is even possible to split the logical links and map them to more than one medium. For example, a point-to-point logical link may be mapped to a shared medium such as a satellite (for transmissions to the receiving station) and at the same time mapped to a separate medium such as a telephone line (for transmissions to the broadcast station).
• a shared medium such as a satellite (for transmissions to the receiving station) and at the same time mapped to a separate medium such as a telephone line (for transmissions to the broadcast station).

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• Engineering & Computer Science (AREA)
• Multimedia (AREA)
• Signal Processing (AREA)
• Databases & Information Systems (AREA)
• Computer Networks & Wireless Communication (AREA)
• Computer Security & Cryptography (AREA)
• Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)

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• 2000
  • 2000-04-06 BR BR0009645-8A patent/BR0009645A/pt not_active IP Right Cessation
  • 2000-04-06 CN CN00806074A patent/CN1346572A/zh active Pending
  • 2000-04-06 JP JP2000611500A patent/JP2003521838A/ja active Pending
  • 2000-04-06 CA CA002369649A patent/CA2369649A1/en not_active Abandoned
  • 2000-04-06 EP EP00921847A patent/EP1175782A1/en not_active Withdrawn
  • 2000-04-06 WO PCT/US2000/009276 patent/WO2000062547A1/en not_active Application Discontinuation
  • 2000-04-06 AU AU42111/00A patent/AU4211100A/en not_active Abandoned
• 2002
  • 2002-07-30 HK HK02105615.2A patent/HK1045621A1/zh unknown

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