CN1273743A - System for selectively downloading information at user terminals from the internet using satellite broadcast system - Google Patents

Abstract

A satellite direct digital broadcast system is provided which broadcasts selected Internet information such as news reports, weather reports and stock market rates, along with radio programs. Broadcast channels comprise Internet information and a service control header to identify the type of Internet information contained therein. User terminals (22) are provided which comprise a radio broadcast receiver (2) to receive programs broadcast via satellite (20). Audio programs are played on a speaker connected to a radio broadcast receiver (21). The user terminals (22) also comprise a multimedia device such as a personal computer (29) connected to the receiver. The multimedia device is programmed to generate a computer display which prompts a user to select a topic of Internet information. The multimedia device stores received packets and selectively retrieves packets to generate displays such as Web pages using those packets which correspond to the topic of information selected by the user.

Description

A system for selectively downloading information from the Internet using a satellite broadcasting system at a user terminal

Field of the invention

The present invention relates generally to a system for providing broadcast Internet information to remote user terminals without the need for a backhaul link from the user terminal to an Internet service provider.

Background of the invention

Due to the expansion and worldwide use of personal computers, communication devices and the Internet, the global economy is currently undergoing an information revolution whose significance can be expected to be comparable to that of the industrial revolution in the 19th century. However, the ability to participate in this information revolution is currently limited by the enormous number of citizens who are often dissatisfied with their underserved communications options. This population is generally located in Africa, Central America, South America and Asia, where communication services have hitherto been characterized by poor sound quality of short-wave broadcasting and limited coverage by terrestrial radio broadcasting systems in the amplitude modulation (AM) and frequency modulation (FM) bands .

A satellite-based direct radio broadcasting system has been proposed which can transmit voice and data signals, including video signals, to low-cost consumer receivers virtually anywhere on earth. Satellite-based direct radio broadcasting systems have many advantages over existing satellite systems, such as being able to serve portable receiver users. Many existing satellite systems cannot provide portable services because they require receivers with large satellite antennas to access such systems. Although many other existing satellite systems can provide portable and mobile communication services, these systems do not provide enough channel capacity to provide the required information transmission from the Internet and WWW (WorldWide Web) to many different users. , High outbound data rate.

However, satellite-based direct radio systems are limited to one-way receivers and do not allow users to transmit voice or other information. Consequently, users of such receivers are unable to communicate two-way via satellite-based direct radio broadcasting systems, and thus to access the Internet. In many conventional Internet access systems, a user connects to an Internet access provider using a computer and a communications link, such as the public switched telephone network. A series of screens are generated on the display of the user's computer which prompts the user to select the type of information he is seeking to obtain from the Internet. For example, a user may select the available Netscape Navigator (navigator) software from Netscape Communications, Inc., Mountain View, California to access files on the WWW portion of the Internet. The Netscape Navigator software allows users to enter keywords related to a selected topic, which are sent to a Web search engine to obtain, for example, information on the selected topic. Existing radio broadcast receivers do not have a communication link between the user and the Internet access provider for interactive selection and download of information to the Internet.

However, the significant amount of information on the Internet lends itself to such a large number of applications that the same information can be made available to different users on different communication channels at different times in response to individual user requests, making bandwidth and other satellite communication systems High resource utilization efficiency. Therefore, there is a need for low-cost user terminals that can provide users with the advantages of satellite-based direct radio broadcasting systems (such as large geographical coverage areas, good voice quality, high outgoing data rates and low price), and the ability to receive broadcast information from selected Internet sources.

Summary of the invention

SUMMARY OF THE INVENTION In view of the above disadvantages and limitations, it is an object of the present invention to provide a satellite direct digital broadcasting system capable of broadcasting selected Internet information to low-cost user terminals. The selected Internet information may be, for example, weather forecasts, news reports, stock quotes, consumer product catalogs, and other types of information.

Yet another object of the present invention is to broadcast selected Internet information types in packets on a broadcast channel. Internet packets are data streams on the broadcast channel of the Satellite Direct Digital Broadcasting system. A broadcast channel can carry one or more types of Internet information, such as news reports, weather forecasts, and stock market price lists. Also, the Internet package can contain information (for example, type of Internet information) required for selecting a specific page by means of a browser.

Yet another object of the present invention is to provide a low-cost user terminal comprising a radio broadcast receiver, which is adapted to be connected to a multimedia device such as a personal computer.

Yet another object of the present invention is to provide a user interface to a user terminal for selecting the type of stored broadcast Internet information for display application on the user terminal. The user terminal examines the stored packages using the selections entered via the user interface and searches for those packages corresponding to the type of Internet information selected by the user. A multimedia device is used to display (play for audio) the packages.

These and other objects of the present invention are achieved in part by providing the remote user with a user terminal equipped with both a broadcast receiver for receiving satellite direct radio broadcast and a multimedia device for storing and Displays selected information from Internet Service Providers. The user terminal is programmed to convert the user information selection items required by the user and specifying the Internet type into such control signals, which instruct the multimedia device to extract those received packets corresponding to the user information selection items for display or play.

So, in one aspect, the Internet service provider is configured with a gateway that directs its routing from the Internet/WWW to a broadcast station for selected multimedia data. The broadcast station formats the Internet packet data into a broadcast program containing the packets and transmits the broadcast program to a satellite in a direct-to-satellite digital broadcasting system. The service provider provides additional information to identify those packages in the broadcast program that correspond to different types of Internet information (eg, news reports, consumer product catalogs, educational programs, etc.).

In another aspect, the invention is directed to a method of providing at least limited access to information services available over the Internet to low-cost, globally portable user terminals. The method includes the steps of generating screen prompts on a multimedia device (eg, a personal computer) connected to a radio broadcast receiver. On-screen prompts allow the user to select from among different types of Internet information broadcast via a satellite direct digital broadcasting system. The receiver demultiplexes and decodes data received from the satellite direct radio broadcast system to obtain a broadcast channel. The computer processes the user's responses to the on-screen prompts, causing the computer to operatively extract selected packets in the broadcast channel that constitute the broadcast program containing Internet information therein. The multimedia device first stores the packets from the broadcast channel in a mass storage device, such as a disk drive, for later access by the user.

Brief description of the drawings

Read the following detailed description in conjunction with accompanying drawing, will more easily understand various purpose, advantage and new characteristic of the present invention, and accompanying drawing is:

Fig. 1 is a schematic example diagram, it broadcasts Internet information to users through a satellite direct radio broadcasting system according to the preferred embodiment of the present invention;

Figure 2 is a block diagram illustrating the operation of the broadcast station described in Figure 1 according to one embodiment of the present invention;

Figure 3 is a schematic illustration of a broadcast channel formatted by a broadcast station as a base rate channel for transmission to the satellite depicted in Figure 1 in accordance with one embodiment of the present invention;

Fig. 4 shows a situation, it is the on-board satellite signal processing that can be realized in the satellite direct radio broadcasting system shown in Fig. 1;

Figure 5 is a simplified block diagram illustrating the on-board processing portion of the satellite depicted in Figure 1;

Fig. 6 is a block diagram showing the configuration of a user terminal, which is equipped with a digital broadcast receiver and a multi-body device such as a personal computer according to a preferred embodiment of the present invention;

Fig. 7 is a flow chart, when according to a preferred embodiment of the present invention downloads selected package from the received broadcast Internet information, it summarizes a series of work that is realized by the user terminal of Fig. 5; And

Fig. 8 is an exemplary computer screen generated by a user terminal according to a preferred embodiment of the present invention.

Throughout the drawings, like reference numerals should be understood to refer to like parts and components.

Detailed description of the preferred embodiment

The satellite communication system 10 of the present invention will be described below in accordance with the following general overview:

I. System work overview

II. Radio stations

III. Satellite

IV. User terminal

I. System work overview

Referring to system 10 on Fig. 1, it allows the user who is located at a distance to receive high-quality sound, data and images using low-priced receivers, and selects one or more broadcast channels that contain Internet information to be connected to a network according to the present invention. to a computer in the receiver for downloading. System 10 is preferably implemented using a satellite direct digital broadcasting system. The Direct Digital Broadcasting system preferably consists of three geostationary satellites (one of which is shown at 20 in Figure 1), low-cost radio receivers or user terminals, and associated terrestrial networks. For the sake of example, a single user terminal 22 is shown comprising a handheld radio receiver 21 connected to a multimedia device such as a computer 29 .

Broadcast programs are transmitted to satellite 20 via one or more broadcast stations. As will be described in further detail below, broadcast station 26 performs encoding, multiplexing, and other signal processing on programs containing voice, data, or both to produce a broadcast channel that is transmitted in uplink 28 to satellite 20 (BC). The uplink 28 is preferably frequency division multiplexed carriers carrying BCs in units of primary code rate channels (PRC). Each PRC provides a base rate increment (PRI) with a baseband of 16 kbps. A BC preferably consists of 1 to 8 PRCs. For each PRC, 224 bits are allocated to BC in a Service Control Header (SCH) every 432 ms. BCs carry packages, some of which constitute Internet-originated programs. According to the invention, the type of Internet information is identified in the SCH. The satellite 20 implements the baseband processing in the uplink 28 to transmit the PRC in the BC to the user terminal 22 in at least one of the three time division multiplexed downlinks 30 .

Continuing to refer to FIG. 1 , broadcast station 26 may be provided with multimedia information (eg, audio bytes, video, and Web pages) directly from Internet 25 via system gateway 23 and hub 27 . The system gateway 23 is capable of operating as one Internet service provider and accomplishes the work common to two or more Internet service providers shown generally at 31 and combined at the hub 27 .

In accordance with one aspect of the present invention, in system 10, news reports, weather forecasts, stock quotes, educational programs, consumer product catalogs and other information accessible via the Internet are provided to broadcast station 26. It is up to the system 10 to determine which type of Internet information to broadcast and when. The system 10 includes a Regional Broadcast Control Facility (RBCF) 39 which is operable to assign channels in the uplink 28 to different broadcast stations 26 . For example, channels within uplink 28 may be assigned to one or more broadcast stations 26 for continuous broadcasting of news 24 hours a day. A broadcast station 26 of the broadcast stations 26 may be directed to provide stock quotes for a particular stock market during its operation. At all other times, the radio station may be scheduled to broadcast stock ticker news commentary and area news every half hour. In addition, a radio station could be scheduled to continuously broadcast weather forecasts on one broadcast channel and simultaneously broadcast educational programs and consumer product catalogs at specific times of the day on another broadcast channel. A schedule of broadcast programs and their corresponding broadcast times and channels are distributed among the users. Therefore, the user can decide when and on which downlink 30 to tune the receiver to receive a particular program, including programs containing Internet information therein.

Additionally, browser pages for different consumer broadcast packages may be combined at a central location (eg, service provider 31a ) and provided on one or more broadcast stations 26 . A browser page for a consumer broadcast package can provide the current day's news highlights and stock quotes, while another consumer broadcast page can provide a browser page dedicated to sports hot spots. Program material can be obtained from the Internet, requiring only that the Internet address be placed in a package for their selective download and display on a multimedia device connected to a receiver.

In accordance with the present invention, each user terminal 22 is configured to receive satellite direct radio broadcast programs via a satellite receiver 21 . Receiver 21 is tuned to receive a broadcast program from a selected one of three downlinks 30, as previously described. The receiver 21 is configured to demultiplex and decode the selected downlink 30 to obtain the broadcast channel transmitted from the broadcast station 26 and provided to the downlink 30 by the satellite 20 . The computer 29 connected to the receiver 21 processes the demultiplexed and decoded data and stores the data, and extracts the packets requested by the user corresponding to the category or type of Internet information selected. The computer 29 stores the information and then announces the information, that is, displays the information on the computer monitor, or plays the audio part of the selected Internet information in a speaker connected to the computer.

Using a multimedia device, a user is able to request viewing, listening and storage of a particular type of information (FIG. 3) that has been demultiplexed, decoded and stored from the broadcast channel 100. An input device (eg, a mouse or a keyboard) may be used to respond to computer 29 generated screen prompts. ScreenTips are desirably one or more screens with menus listing various information types (eg, news, weather, educational programming, consumer products, stock quotes, etc.) and corresponding icons. The user can, for example, use a mouse to click on the icon. The computer 29 processes the mouse input to determine which menu item is selected and announces the stored Internet information corresponding to the user's selection, as will be described in further detail below with reference to FIGS. 7 and 8 .

System 10 is advantageous because it enables user terminals 22 to efficiently and cost-effectively download relatively large amounts of information from one or more Internet service providers using, for example, a satellite direct radio broadcasting system. Various types of information such as news reports and weather forecasts are needed by such a large number of people, broadcasting such information to all user terminals 22 for selective reception, rather than providing the data to the user's requested portion of space at a time , to be more economical and effective. Broadcasting popular Internet information and providing user terminals with a means to select from the broadcasted Internet information does not require modification of the broadcasting system to include a backhaul link for communication with users for Internet services other than the space-saving component Provider requests and responses to communicate in order to obtain Internet information.

II. Radio stations

Direct radio broadcasting systems employ digital audio coding techniques. Each satellite 20 transmits a direct radio audio signal giving a quality equivalent to AM mono, FM mono, FM stereo and CD stereo throughout its coverage area, together with direct transmission of ancillary data to user terminals 22 , such as paging, video and text messages. The system is also capable of delivering multimedia services such as huge databases downloaded to personal computers (PCs) for business applications, maps and printed text information for traveler applications, and color graphics for advertising and entertainment to enhance sound programming.

Referring now to FIG. 2, signal processing, which converts a digital data stream from one or more broadcast stations 26 into parallel data streams for transmission to satellite 20, will be described. For purposes of illustration, four program information sources 60, 64, 68 and 72 are shown. The two sources 60 and 64 or 68 and 72 are encoded separately and transmitted together as part of a single broadcast program or service. The encoding of a program comprising combined sources 60 and 64 will now be described. The signal processing is the same for programs that comprise information from sources 68 and 72.

Broadcast station 26 combines information from one or more sources 60 and 64 for a particular program into individual broadcast channels, each broadcast channel desirably characterized by a code rate increment of 16 kbps. This increment is called the basic rate increment or PRI. Therefore, as shown in FIG. 3 , the bit rate carried in the broadcast channel 100 is n×16 kbps, where n is the number of PRIs used by a specific broadcast service provider. In addition, each 16kbps PRI can be further divided into two 8kbps segments 101 and 103 (FIG. 3), which are routed or switched together through the system 10. Sections 101 and 103 provide a means of carrying two different service items in the same PRI, such as a data stream of a low-bit speech signal, or two low-bit-rate speech channels for two separate languages, etc. The number of PRIs is preferably predetermined, ie set according to the program code. However, the number n is not a physical limitation of system 10 . The value of n is usually set on a commercial basis, involving things such as the price of a single broadcast channel and the service provider's willingness to pay.

For example, the value of n for the first broadcast channel 59 of sources 60 and 64 is equal to four. The value of n for broadcast channel 67 for sources 68 and 72 is set to six in the illustrated embodiment. As mentioned earlier, the value of n can be changed. For example, if one of the sources 60, 64, 68 or 72 is one used for broadcasting Internet information, particularly if the information includes a video portion, a greater number of PRIs will be required.

Continuing to refer to FIG. 2 , there may be more than one broadcast service provider accessing a single broadcast station 26 . For example, a first service provider may generate broadcast channel 59 while a second service provider may generate broadcast channel 67 . The signal processing described here and in accordance with the present invention enables digital data streams from several broadcast service providers to be broadcast to a single satellite in parallel data streams, which reduces the service provider's broadcast costs and enables spatially distributed segment is utilized to the maximum. By utilizing space segmentation for maximum efficiency, less expensive components can be used to make broadcast station 26 less expensive. For example, the radio on broadcast station 26 may be a Very Small Aperture Terminal (VSAT) antenna. Payloads on satellites require less memory, less processing power, and thus less powerful power supplies, which will reduce the weight of the payload.

The broadcast channel 59 or 67 is characterized in that, as shown in FIG. 3, the frame 100 has a period length of 432 ms. This period length is chosen to facilitate the use of the MPEG source coder described below; however, the frame period in system 10 could be set at a different predetermined value. If the cycle length is 432ms, each 16kbps PRI requires 16,000×0.432s=6912 bits per frame. As shown in Figure 3, a broadcast channel thus contains n values of these 16kbps PRIs grouped in a frame 100. These bits are scrambled to enhance demodulation capability in the radio receiver 29, as will be explained below. The scrambling work also provides a means of employing service encryption in service provider solution selection. Each frame 100 is assigned n×224 bits corresponding to a service control header (SCH) 102, resulting in a total of n×7136 bits per frame and a bit rate of n×(16,518+14/27) bps. The role of the SCH 102 is to transmit data to each radio receiver 29 tuned to receive the broadcast channel 59 or 67, to control the reception mode for various multimedia services, to display data and images, to transmit key information for decryption, to address specific receiver, and give other characteristics. The SCH 102 can be provided with the information required to select the Internet information, and provided with the information required for deciphering the payment method for each type of use of the Internet information.

As shown in Figure 2, sources 60 and 64, respectively, are encoded using eg MPEG2.5, Layer 3 encoders 62 and 66. The two sources are then summed together via mixer 76 and then processed using a processor in broadcast station 26, as indicated by processing block 78 in FIG. That is, n×7136 bits per frame including the SCH. In addition, the information type identification data can also be provided in the SCH of the BC.

The various blocks indicated in broadcast station 26 on FIG. 2 correspond to programmed modules executed by a processor and associated hardware, such as digital memory and encoder circuits. The individual bits in frame 100 are then encoded for FEC protection, where digital signal processing (DSP) software, application specific integrated circuits (ASICs) and conventional large scale integration (LSI) chips are used to make two cascaded encoding processes . First, a Reed-Solomon (R/S) encoder 80a is used to generate 255 bits for every 223 bits input to the encoder. The individual bits in frame 100 are then reordered according to a known interleaving pattern, as indicated at reference numeral 80b. Interleaving codes provide further protection against burst errors that occur during transmission because the interleaving method spreads the erroneous bits across several channels. Continuing with processing block 80, it implements a known convolutional encoding scheme with a constraint length 7 using a Viterbi encoder 80c. The Viterbi encoder 80c produces two output bits for each input bit, for a 6912 bit increment per frame given in the broadcast channel 59, yielding a net result of 16320 FEC coded bits per frame. Therefore, each FEC-coded broadcast channel (e.g., channel 59 or 67) contains n×16320 bits of information that have been encoded, reordered, and re-encoded so that the originally broadcast 16kbps PRI can no longer be identified. However, the bits encoded by FEC are organized according to the original 432ms frame structure. After bit error protection, the total coding rate is (255/223)×2=2+(64/223).

Continuing to refer to FIG. 2, the FEC-coded broadcast channel frame of n×16320bit is then divided or demultiplexed into n channels of parallel basic code rate signals and (PRC) in the channel allocator 82, each of which carries 8160 2bit symbols Set of 16320bit. This process is further illustrated in FIG. 3 . The illustration of the broadcast channel 59 is characterized by one SCH 102 in a frame 100 of 432 ms. The remaining part 104 in the channel frame is composed of n 16kbps PRIs, and for each of the nPRIs, the remaining part 104 corresponds to 6912 bits per frame. As stated above for module 80, the FEC encoded broadcast channel 106 is obtained after concatenated R/S 255/223, interleaving and FEC 1/2 convolutional encoding.

As mentioned above, the FEC-encoded broadcast channel frame 106 contains 16320 bits corresponding to 8160 2-bit symbol sets, and each symbol is identified by a reference number 108 for the sake of example. According to the present invention, the distribution of symbols on PRC 110 is shown in FIG. 3 . The symbols are thus spread out according to time and frequency, which further reduces bit errors at the radio receiver 21 due to interference in the transmission. For the sake of example, assume that the service provider of broadcast channel 59 has purchased 4 PRCs and the service provider of broadcast channel 67 has purchased 6 PRCs. Fig. 3 illustrates the situation that the first broadcast channel 59 and symbols 114 are respectively allocated in n=4 PRCs 110a, 110b, 110c and 110d. In order to recover each set of 2-bit symbols 114 at the receiver, a PRC synchronization header or preamble 112a, 112b, 112c, and 112d are respectively placed in front of each PRC. The PRC sync header (hereinafter, generally referred to by reference number 112) contains 48 symbols. A PRC sync header 112 is placed before each group of 8160 symbols, thereby increasing the number of symbols to 8208 symbols per 432 ms frame. Therefore, the symbol rate becomes 8208/0.432, which is 19,000 (ksym/s) for each PRC110. The 48-symbol PRC preamble 112 is used essentially for the synchronization of the radio receiver PRC clock to recover the symbols from the downlink satellite transmission 27 . In on-board processing 116, the PRC preamble is applied to absorb timing differences between the symbol rate of the arriving uplink signal and the symbol rate applied on-board, which is used to switch signals and combine out the downlink for TDM data streams. The way to do this is to add a "0" or subtract a "0" to each 48-symbol PRC in the symbol rate calibration used in the satellite 20 on board, or to do no addition or subtraction . Thus, the PRC preamble carried on the TDM downlink is determined to have 47, 48 or 49 symbols during the symbol rate calibration process. As shown in FIG. 3 , each symbol 114 is assigned to successive PRCs in a round-robin manner, such that symbol 1 is assigned to PRC110a, symbol 2 is assigned to PRC110b, symbol 3 is assigned to PRC110c, symbol 4 is assigned to PRC110d, symbol 5 is assigned to PRC110a, So on and so forth. This PRC demultiplexing process is implemented by a processor on broadcast station 26 and is represented by channel allocation (demultiplexing) module 82 in FIG. 2 .

The preamble module 84 and the adder module 85 are used so that the assignment of the PRC channel preamble marks the beginning of the PRC frames 110a, 110b, 110c and 110d in the broadcast channel 59. The nPRC is then differentially coded by precession, and then the nPRC is QPSK modulated onto the IF carrier frequency using an array of QPSK modulators 86 as shown in FIG. Four of the QPSK modulators 86a, 86b, 86c and 86d are applied to the PRCs 110a, 110b, 110c and 110d in the broadcast channel 59, respectively. Accordingly, there are four PRC IF carrier frequencies making up broadcast channel 59. Each of the four carrier frequencies is upconverted in upconverter 80 to their assigned frequency in the X-band for transmission to satellite 20. The up-converted PRC is then passed through amplifier 90 onto antennas (eg, VSAT antennas) 92a and 92b.

The SCH 102 inserted in each coded PRC preferably contains a control word identifying the program channel to which the PRC belongs and carrying instructions for the receiver to reassemble the coded PRCs to reconstruct the coded program channel. An example 80bit control word is: #bit indicates

2 Number of correlation sets (00 = no correlation, maximum 4 correlation sets)

2 Set identification number (00 = set #1, 11 = set #4)

4 episode types

(0000=audio, 0001=video, 0010=data, other types or reserved)

3 The number of 16kbps basic code rate channels (PRC) in the set (000=1 channel,

001 = 2 channels, ..., 111 = 8 channels)

3 basic code rate channel (PRC) identification number (000 = channel 1, ..., 111 = channel 8)

3 Number of subsets (000=1,...,111=8)

3 The number of 16kbps basic code rate channels (PRC) in the subset (000=1,...,111=8)

2 Subset identification number (000 = subset #1, ..., 111 = subset #8)

3 set/subset blocking (000 = no blocking, 000 = type 1 blocking, ..., 111 = type

7 blocking)

11 reserved

40 CRC

The control word input bits for the number of related sets allow a relationship to be established between groups of sets. For example, radio stations may offer associated audio, video and data services, electronic newspapers such as voice text and additional information. The set identification number identifies the set number of the channel portion therein. The number of 16kbps PRCs in the set determines the number of basic code rate channels in the set. The number of subsets and the number of 16kbps within a subset determine a relationship within a set such as a CD quality stereo set, using 4 PRCs for the "left stereo" signal and another 4 PRCs for the "right stereo" signal. Alternatively, a music signal may be associated with voice signals of multiple announcers, each voice signal in a different language. The number of 16kbps PRCs in the subset determines the number of basic code rate channels in the subset. The subset identification number identifies the subset number of the channel portion in it.

The set/subset blocking bits may cooperate to block broadcast messages. For example, some countries may prohibit advertising of alcohol. Subscriber terminals 22 produced in that country may be preset with a code, or alternatively be loaded with a code that causes the subscriber terminal to block specific messages in response to blocking signals. The blocking function can also be used to restrict the dissemination of sensitive information (such as military or government information), or to restrict certain users from broadcasting services for which they are taxed.

As previously described, each coded program source is partitioned into individual PRCs. As an example, an audio source may contain 4 PRCs, which represent an FM-quality stereo signal. In another case, a sound source can contain 6 PRCs, which can be used as a "near-CD" quality stereo signal, or an FM quality stereo signal linked to a 32bit data channel (for example, used to transmit a signal to for display on a radio receiver liquid crystal display (LCD). In yet another case, 6 PRCs can be used as a 96kbps broadcast channel. An image source may contain only one 16kbps channel and or several channels. As will be described in further detail below, depending on the set information included in the TDM frame and in each PRC, the user terminal 22 preferably automatically selects those PRCs that are responsible for generating user-selected digital audio programs or other digital service programs. required.

In accordance with the present invention, the transmission method used by the broadcast station 26 combines a plurality of n single-channel single-carrier, frequency division multiple access (SCPC/FDMA) carriers into the uplink 28 . The center frequencies of these SCPC/FDMA carriers are spaced apart in a grid pattern, preferably 38,000 Hz apart from each other, and are arranged in groups of 48 consecutive center frequencies or carrier channels. The organization of these 48 carrier channel groups facilitates the on-board demultiplexing and demodulation processing within satellite 20 . The individual groups of 48 carrier channels are not necessarily connected to each other. The carriers associated with a particular broadcast channel (ie, channel 59 or 67) need not be contiguous within a 48-carrier channel group and need not be allocated within the same 48-carrier channel group. Therefore, the transmission method described with respect to Fig. 2 and Fig. 3 allows flexibility in the choice of frequency location, optimizes the filling capacity of the applicable spectrum, and avoids interference with other users sharing the same radio frequency spectrum.

FIG. 1 illustrates the overall operation of a system 10 for broadcasting Internet information and other broadcast programs according to a preferred embodiment of the present invention. Where satellite is the way to handle the payload, the uplink signal 28 is given by the broadcast provider via a separate Frequency Division Multiple Access (FDMA) channel from each broadcast station 26, which may be located on the ground to Anywhere the satellite 20 is visible at elevation angles greater than 10°. Each broadcast provider can directly uplink to one of the satellites 20 from its own facility by placing one or more 16kbps PRCs on the FDMA carrier. In another case, a broadcast provider that does not have direct access to the satellite 20 itself can access it through a tandem station. For example, system gateway 23 may broadcast a Web page to one of direct radio broadcast satellites 20 either directly or indirectly via hub 27 . Applying FDMA to the uplink 28 gives the greatest possible flexibility between multiple independent broadcasting stations.

III. Satellite

The preferred satellites 20 used by the direct radio broadcasting system 10 can cover the Africa-Arab region, the Asia region, and the Caribbean and Latin America regions from the following geostationary orbits:

· 21°E orbital position, providing services to Africa and the Middle East.

95°W orbital position, serving Central and South America.

·105°W orbital position, providing services to Southeast Asia and the Pacific Rim.

Coverage for other regions, such as North America and Europe, may be provided by additional satellites.

The direct radio broadcasting system preferably uses the frequency band 1467 to 1492 MHz, which was allocated for Direct Audio Broadcasting (DAB) of the Broadcasting Satellite Service (BSS) at the WARC92 meeting, that is, according to ITU Resolutions 33 and 528. Broadcast station 26 implements an uplink feed in the X-band from 7050 to 7075 MHz. Each satellite 20 is preferably configured with three downlink spot beams, each having a beamwidth of approximately 6°. The coverage area of each spot beam is about 14 million square kilometers for a power distribution profile 4dB down from the center of the beam, and about 28 million square kilometers for a 8dB downside profile. When based on a gain-to-temperature ratio receiver of -13dB/K, the beam center power margin is 14dB.

Each satellite 20 carries two types of payloads. One is the "processed" payload, which regenerates the uplink signal and combines the three TDM downlink carriers, and the other is the "transparent" payload, which is retransmitted on the three TDM downlink carriers uplink signal. Each of the TDM signals from the two payloads is carried in three beams, the processed and transparent signals in each beam have opposite circular polarizations (LHCP and RHCP). Each TDM downlink signal carries 96 PRCs in the allocated time slot. For a user terminal 22, all TDM downlink signals appear to be the same, except that the carrier frequency is different. The total capacity of each satellite is 2*3*96=576 PRCs.

By means of an on-board processor, the FDMA signal 28 of the uplink in the direct radio broadcasting system of FIG. conversion between. On satellite 20, each PRC transmitted by broadcast station 26 is demultiplexed and demodulated into a separate 16 kbps baseband signal. The individual channels are routed through a switch to one or more of the downlink beams 30, each of which is a single TDM signal. This baseband processing gives a high level of channel control in uplink frequency allocation and routing between uplink and downlink. The uplink signal in the X-band is received on the satellite, and is transformed into the L-band by the on-board processor. A MCPC/TDM carrier is applied to the downlink 30 of the user terminal 22 . One such carrier is used in each of the three beams of each satellite 20 . Where direct radio broadcasting systems format the FDMA uplink and perform payload processing to produce the TDM downlink, this allows low-cost receivers to receive large amounts of data, including high-quality sound programming, and also There are other advantages.

For the transparent payload approach, the TDM signal is combined at the broadcast station, the structure is exactly the same as the satellite 20 behaves when the payloads are processed on-board to combine them. The TDM signal is transmitted to the satellite in the X-band and retransmitted in the L-band in one of three downlink beams. The power level of the downlink TDM signal is the same as that generated in the processing payload mode. Therefore, the technology described here and carried out in accordance with the present invention to provide digital transmission of all information services (such as voice, music, data, images, and multimedia information available on the Internet) can also be applied to on-board In the payload and transparent payload mode. When the transparent payload method is used, processing such as determining routing performed on the satellite 20 can be performed on the earth station.

FIG. 4 shows the redistribution of the PRC satellite from the uplink FDMA channel to the downlink MCPC/TDM channel in the way the satellite 20 in FIG. 1 handles the payload. The total uplink capacity is preferably 288 to 384 PRCs within the uplink channel box 116, each of 16.519 kbps. 96 PRCs are selected and multiplexed within the downlink channel block 118 for transmission in each downlink beam 30, and as shown in block 120, they are time division multiplexed on one carrier of approximately 2.5 MHz bandwidth superior. Each uplink channel may be routed to all, some, or none of the downlink beams. The order and location of the PRCs in a downlink beam can be substantially selected through a command link from the Telemetry, Direction and Control (TRC) facility 38 shown in FIG. 1 .

Within the Regional Broadcast Control Facility (RBCF) 39, software is preferably provided for one or more broadcast stations 26 present in the system 10 for assigning space segmented channels to the satellites 20 in the uplink beams. RBCF 39 is preferably coupled to TRC facility 38 via a communication link. The software is enabled to optimally utilize the uplink spectrum by assigning PRC carriers when space is available in the 48 channel groups. The carriers associated with a particular broadcast channel need not be contiguously within a 48-carrier channel group and need not be assigned within the same 48-carrier channel group.

The carrier frequency in each downlink beam 30 is different to enhance the isolation between beams. Each TDM downlink channel operates at saturation in the satellite payload, giving the maximum possible power efficiency in terms of link performance. The use of single-carrier operation for each transponder achieves maximum efficiency in the operation of the SATCOM payload in terms of conversion of solar energy to RF power. This is much more efficient than techniques that require simultaneous amplification of many FDM carriers. This kind of system can give high receiving margin, suitable for indoor and outdoor fixed reception and mobile reception.

System 10 uses MPEG2.5, Layer 3 to implement audio source coding, and can achieve the above-mentioned quality at bit rates of 16, 32, 64, and 128 kbps respectively, and also includes the ability to implement 8 kbps bit rate coding. Image encoding is implemented using the JPEG standard. The bit error rate of the whole system is less than 10-10, so it is suitable for high-quality digital image and data transmission for multimedia services. For the same sound quality, MPEG2.5, layer 3 coding gives better bit rate efficiency than the previous MPEG1, layer 2 (Musicam) or MPEG2 standard. For sound broadcasting, the digitally encoded source bit rates are:

· The common mono quality is 8kbps;

16kbps for non-public mono quality;

32kbps for quasi-FM quality mono music;

64kbps for quasi-FM quality stereo music; and

· Near CD quality stereo music at 128kbps.

In a preferred embodiment of the satellite direct radio broadcasting system, the capacity of each satellite 20 is a total of 3072 kbps per beam transmission (including 2 TDM carriers for handling payload mode and transparent payload mode), which can be the above Any combination of voice services. The capacity per beam will correspond to:

192 mono voice channels; or

96 mono music channels; or

· 48 stereo music channels; or

· 24 CD stereo music channels; or

• Any combination of the above signal qualities.

Because system 10 provides a direct digital channel for digital transmission of broadcast services, system 10 is capable of broadcasting any type of data, images, moving pictures, and other multimedia information via satellite 20, such as information obtained from the Internet and multimedia sources, and voice and music. According to one aspect of the present invention, system 10 is capable of transmitting to user terminal 22 pushed Internet information, that is, Internet information that may be transmitted via satellite 20 without requiring approval from the user.

The bit error rate (BER) of the digital signal transmitted by the whole satellite direct radio broadcasting system is 10 ^-4 or lower, which can provide the various qualities of service identified above. For each downlink beam transmitted by satellite 20 in the L-band. The coverage edge EIRP of the TDM carrier is 49.5dBW. This EIRP value together with dedicated forward error correction guarantees a minimum 9dB margin at 10 ^-4 BER when using a basic radio receiver antenna. This margin helps against signal loss at the user terminal 22 due to obstacles in the path between the satellite 20 and the receiver, thereby providing perfect quality reception within the intended coverage area.

For a user terminal 22 in an obstructed location, it can be connected to a high-gain antenna, or to an antenna located in an unobstructed location. For example, reception within a large building may require a common rooftop antenna, with indoor retransmission for whole building applications, or individual receive antennas placed near windows. The channels have an estimated 10dB margin relative to the required power density at a BER of ^10-4 at a 4dB drop in ground coverage. At the center of the beam, this margin is estimated to be 14dB.

For higher bit rates, the operating margin of the direct direct radio broadcasting system does not change. In the 4 dB range, most user terminals 22 view the satellite 20 at elevation angles greater than 60° such that interference from buildings is virtually zero. In some beams, the elevation angle to the satellite 20 is greater than 50° in the range of 8 dB, and interference sometimes occurs due to reflection or obstruction from buildings. For certain beams pointing toward the horizon, line-of-sight reception is often possible even at low elevation angles (10° to 50°) with a small 8dBi gain antenna.

As previously stated, the direct radio broadcast system includes baseband processing of the payload within the satellite 20 . Baseband processing can give improved system performance for uplink and downlink budgets, management of broadcast stations and control of downlink signals. Figure 5 illustrates satellite signal processing in a satellite direct radio broadcasting system. Within the X-band receiver 122, an encoded base code rate uplink carrier is received. The multiphase demultiplexer and demodulator 124 receive the respective FDMA signals in 6 48-channel groups to generate 6 analog signals, and the data of the 288 signals are divided into 6 time-multiplexed streams, and each demodulation of the serial data of the data stream. Routing switch and modulator 126 selectively routes individual serial data channels to all or some of the three downlink signals (carrying 96 channels in each) or none of them, further in Modulation is performed on three downlink L-band TDM signals. The traveling wave tube amplifier (TWTA) 128 amplifies the power of the three downlink signals, and radiates to the ground through the L-band transmitting antenna 130 . Also included in the path of the transparent payload is a demultiplexer and downconverter 132 and an amplifier bank 134 configured in the usual "bent pipe" signal path for uplink TDM/MCPC signal frequency conversion for retransmission on the L-band.

satellite 20 is operated by ground control (e.g., software applicable on a single broadcast station 26 or on an RBCF 39 serving multiple broadcast stations 26) and is managed by flight control during orbital life in accordance with service volume requirements . Bit rates, and thus quality of service, can be mixed in either beam to meet service requirements. The bit rate/quality status of the service can be easily changed by command from the ground and can be changed at different times of the day. In the preferred embodiment, channel assignments can be changed on an hourly basis according to a preset program schedule for a 24 hour period. However, it should be understood that channel assignments can be changed on a more or less frequent basis.

Referring to Figure 2, within each QPSK modulation block 86 there is a separate QPSK modulator to modulate each base rate channel to an intermediate frequency. The up-converter 88 moves the frequencies of the respective basic code rate channels to the FDMA uplink band, and the up-converted channels are then transmitted through the amplifier 90 and the antenna 91 . The uplink broadcast station preferably uses a small antenna (2 to 3 meters in diameter) to transmit the basic (16 kbps) channel with a VSAT signal.

Each basic code rate uplink channel is transmitted to satellite 20 on a separate FDMA carrier. As previously stated, up to 288 uplink base rate carriers can be transmitted to satellite 20 within their global uplink beams. From a location in the country where the program is sent out, a 128 kbps program channel (of which Contains 8 basic code rate channels). Alternatively, a leased PSTN terrestrial link could connect the program channel to a shared uplink earth station terminal. The system has enough uplink capacity for each country to use in its global coverage, so that each country has its own satellite radio broadcasting channel.

IV. User terminal

A block diagram of one of the user terminals 22 in FIG. 1 is given in FIG. 6 . The user terminal 22 receives the L-band signal from the satellite 20, demodulates and extracts the useful sound or image signal from the TDM data stream, and restores the required sound or image information. The user terminal can be equipped with a small patch antenna 80 with a gain of about 4 to 6 dBi, which does not actually need to be pointing. User terminal 22 automatically tunes to the selected channel.

As mentioned above, time division multiplexing, multiple single carrier (MCPC/TDM) technology is applied in the downlink for transmission to the user terminal 22 . Each basic rate channel occupies its own time slot in the time-division data stream. These base rate channels combine to carry program channels in the range of 16 to 128kbps. The use of digital technology allows for ancillary services over the radio including low-bit-rate video, paging, e-mail, fax, the use of flat-panel display screens, or serial data interfaces. This data and information can be multiplexed within the audio digital signal channel. In addition, the base rate channel can carry a program channel displaying the main screen (e.g. home page from WWW) on the user terminal, with or without audio programs, and the downloaded data available for storage and/or printing .

Each user terminal 22 may tune to one of the TDM carriers transmitting within one of the beam coverage areas. As shown in FIG. 6 , the user terminal 22 includes a digital broadcast receiver 21 , an antenna 136 and a computer 29 . Receiver 21 may be connected to a serial port of computer 29, for example. An Internet service provider such as the system gateway 23 in FIG. 1 can operate within the beam coverage of one, two or all of the three satellites 20 . The system 10 is able to change the FDM uplink 28 assigned to the Internet service provider and control the on-board routing of information on the satellite 20 through software and telemetry, changing how it goes to one or more downlink beams.

Within the digital broadcast receiver 21 , the signal is amplified by a low noise amplifier (LNA) 138 and the amplified signal is received by a radio frequency front end and a QPSK demodulator 140 . The output of the radio frequency front end and the QPSK demodulator is fed to the first time-division multiplexer 142 and the second time-division multiplexer 144, the former recovers the sound basic code rate channel (PRC), and the latter recovers the carried data (including image) basic bit rate channel.

After rearranging the n PRCs in the received broadcast channel, blocks 142 and 144 are applied to demultiplex the symbols of each PRC into an FEC-coded broadcast channel. The output of block 142 is a baseband digital signal carrying audio information, and the output of block 144 is a baseband digital signal carrying data.

Thus, the recovered, reassembled coded program channels are decoded and deinterleaved to recover the baseband basic rate bit stream originally input to the system at the broadcast station earth station 26 . In the case of an audio signal, the recovered bitstream is converted back to an analog audio signal by an audio decoder 146 and a digital-to-analog converter 148 . The analog signal is amplified by amplifier 150 and reproduced by speaker 152 . Depending on the bit rate of the program channel, the user terminal can reproduce different sound qualities, from AM mono to CD stereo. In the case of a data signal, the recovered bitstream may be converted to a displayable format by the data/image decoder 154 . In addition to displaying, received data may be stored in a memory device, or printed.

The instructions required by the user terminal 22 to recombine the coded base rate channels into coded program channels are preferably contained within each coded base rate channel at the original baseband base rate In the control word in the bit stream (eg in the SCH or PRC preamble). The receiver 21 is programmed to process the instructions in the control word.

According to an embodiment of the present invention, as shown in FIG. 3, one SCH 102 is provided in each BC. Data from data decoder 154, including broadcast channels and SCH, is provided to computer 29 via a broadcast channel input/output (BCIO) port. Computer 29 stores data on a disk drive 176 (FIG. 6). Computer 29 processes the data to check the packages. The package information is compared with user selections made using the keyboard 170, mouse 174 or other input device connected to the computer 29 to determine which of the stored packages are to be used for output. Information identification data may be provided as part of the service control header (SCH) 102, identifying packets originating from the same Internet source.

Essential components in computer 29 include microprocessor 156 , along with appropriate amounts of random access memory (RAM) 160 and read only memory (ROM) 162 , as well as real time clock 164 and display controller 166 . Display controller 166 controls the format of image data, such as Web page data, to display 168 . Microprocessor 156 is also preferably coupled to keyboard 170 , printer/plotter 172 , mouse 174 and disk drive 176 . The illustrated microprocessor input/output (I/O) interface 158 represents the serial and parallel ports of the microprocessor 156 . As shown in Figure 6, data decoded by receiver 21 may be provided to computer 29 via a serial port connection. Keyboard 170 and mouse 172 are used to select broadcast programs, adjust sound levels, make menu selections, and the like. Menus and screen monitors can be generated on display 168 based on program code for microprocessor 156 or received Web pages. Printer/plotter 172 enables a user to obtain a hard copy output of any received data, including images, in addition to viewing the images on display 168 . Finally, disk drive 176 can load data or programs into computer 29 and can also store received data, such as Web pages, for later viewing, listening, and printing. Another possible function of the disk drive 176 is, for example, to allow the computer 29 to fuse images or other data received by the digital broadcast receiver 21 in real time with pre-existing data stored on a disk. This facilitates, for example, the updating of existing images or other data with transferred or modified information without the need to transfer existing images or data.

The components in Figure 6 can be designed to fit into a single case for portable or mobile use. Alternatively, as shown in FIG. 1 , the receiver 21 may be a hand-held device that can be connected to a separate computer 29 . Power supply may be by means of batteries, solar cells or generators driven by clockwork or handles. If the user terminal 22 is mounted on a vehicle such as a ship, an aircraft, or a motor vehicle, the power may be supplied by a power source on the vehicle. Instead of all components of subscriber terminal 22 being housed in a single housing, alternatively subscriber terminal 22 may be constructed from a system or network of discrete components interconnected by suitable cables.

FIG. 7 is a flowchart summarizing a series of operations performed by the user terminal of FIG. 5 when receiving audio and data programs. It will be appreciated that since the downlink channel 30 is in TDM format, the user terminal 22 is able to receive and view audio programs and data simultaneously. Therefore, the user does not need to stop listening to the sound program in order to receive images or other types of data. As a result, a user who, for example, wants to obtain selected data from the Internet can continue to listen to the sound program on the sound program channel while doing so.

Now, refer specifically to the logic sequence shown in FIG. 7 . In block 180, the first step of the procedure is to power up and initialize the receiver 21 . In block 182, the receiver 21 tunes to one of the three TDM downlinks 30 for reception. The receiver 21 demultiplexes and decodes the base rate channels from the received downlink 30 and remultiplexes them into a broadcast channel including its SCH 102 . The broadcast channel may contain real-time audio and video programming. In block 184 , the user terminal begins playback of the audio program on speaker 152 and the video program on display 168 . Broadcast channels may also include Internet information, which are stored on disk drive 176 for non-real-time applications. In block 186 , the computer 29 generates on the display 168 a screen 220 of the example sub-FIG. 8 . Screen 220 is an initial browser screen that presents the user with a list of different information topics derived from Internet broadcasts.

Corresponding icons and names may be given on screen 220 for such information topics as news reports, weather forecasts, stock markets, consumer product catalogs and maps. In block 188, the user may select one of the themes using the keyboard 170, mouse 174, or other input device.

According to a preferred embodiment of the present invention, in block 190 and 192, by computer 29, process the stored information that obtains from SCH102, have marked the package data type, to select and reproduce the Internet information selected by the user type. In block 198, as indicated by the "Y" branch of decision block 194 and block 198, the computer extracts the packages matching the user's selection and generates a screen on display 168 based on these packages. For example, these packages may contain data to make Web pages or computer screens with text but no graphics, or video data. Additionally, some packets may contain an audio byte which can be provided to an auxiliary speaker 178 connected directly to the computer. If the selected data is accompanied by a sound byte, the sound byte can be reproduced while the sound program is played back through the speaker 152. In block 196, the computer 29 disregards packages whose information identification data does not correspond to the user's selection on the screen 220.

The information topics currently stored in disk drive 176 are displayed on screen 220 . At the same time, disk drive 176 can be loaded with a new set of Internet information, that is, currently received information for later viewing by the user. Thus, while the disc drive is storing new Internet information, it is possible to allow the user to retrieve and view already stored information. Computers can also store information such as distance education in real time for later use by users.

The system 10 of the present invention has the advantage of being able to provide digital transmission channels to remote user terminals for broadcasting voice, music and different types of data, such as images and moving pictures; and multimedia information. Therefore, user terminals that do not have access to the Internet can receive push (push) Internet information, ie broadcast Internet information, which does not require approval from the remote user. According to another aspect of the invention, a user terminal may be provided with a terrestrial link, such as a public switched telephone network (PSTN) link, for communicating with an information provider. For example, a user may receive broadcast educational programming, including voice, text and image data, via satellite 20 from a distance education center. The user can transmit a response to the educational program via the PSTN link to the distance education center or another location. This structure is of great advantage when the PSTN link lacks sufficient bandwidth to carry the voice, text and image data of the program.

Although the invention has been described with reference to preferred embodiments, it will be understood that the invention is not limited to those details. Various substitutions and modifications have been suggested in the foregoing description, and other changes may also be suggested by those skilled in the art. All such substitutions and modifications are deemed to be included within the scope of the present invention as defined in the appended claims.

Claims (10)

1. A system for providing information from at least one telecommunications network to a user terminal, comprising: a receiver; a satellite configured to receive a broadcast channel comprising packets containing said information associated with at least one of a plurality of topics, said broadcast channel comprising data which indicating which of said packets correspond to which of said plurality of topics, and said satellite is in operation to transmit said broadcast channel to said receiver; a processing device connected to the receiver; a user input device connected to said processing device; and a display device connected to said processing device, said processing device being programmable to generate a screen display on said display device to prompt the user to select one of said plurality of themes, said receiver being in operation The packets are provided to the processing means which, when the user makes a selection using the screen, processes an input signal generated by the user input means on the fly and checks the said data in order to determine which of said packets correspond to an input signal, said display means being controlled by said processing means to display said information corresponding to said input signal. 2. The system according to claim 1, further comprising a multimedia device connected to the receiver, the information at least includes one of the following information: data, graphics, still images, moving images, text, sound, Web page, and video; the multimedia device performs at least one of multiple tasks depending on the input signal in operation, that is, the input signal contains at least one of the following information displayed: the data, the graphics , the still image, the moving image, the text, the Web page and the video, and play the sound. 3. The system of claim 1, further comprising at least one Internet service provider computer and a system gateway connected to said telecommunication network and a broadcasting system connected to said at least one Internet service provider and a system gateway a station, said broadcast station is operative to receive said information from said at least one Internet service provider and a system gateway, format said information into which one of a plurality of themes), and transmit the broadcast channel to the satellite. 4. The system of claim 3, further comprising a hub for connecting said broadcast station to said system gateway. 5. A method of broadcasting information via satellite from an Internet service provider to a user terminal comprising a radio receiver and a multi-coal device, with no backhaul link between the user terminal and the service provider, the method comprising step: formatting a broadcast channel containing packets of Internet information relating to a plurality of topics and identification data for transmission to said user terminal, said identification data identifying that said packets correspond to said Which of the multiple themes; transmitting the broadcast channel to the user terminal via a satellite; receiving said broadcast channel on a plurality of said user terminals; using the multimedia device to generate a menu listing the plurality of topics; determining a user input corresponding to a theme selected from said plurality of themes on said menu; using said identification data to determine which of said packets corresponds to said user input signal; and The multimedia device is applied to output the packets corresponding to the user input signal. 6. The method as claimed in claim 5, wherein said formatting step includes the step of formatting Internet information, which at least includes one of the following information: news reports, weather forecasts, stock market price lists, Educational programming, and consumer product information. 7. The method of claim 6, wherein the step of generating a menu comprises: identifying at least one of the following information using the multimedia device as a menu option: the news report, the weather forecast, the stock market price list, the educational program, and the consumer product information; and A prompt is given to instruct the user to select one of the menu options. 8. The method as claimed in claim 5, wherein said formatting step further comprises a step of formatting program information, the program information indicating said plurality of topics and corresponding programs for receiving on said user terminal broadcast time. 9. The method of claim 8, wherein said user terminal is programmed to update said menu using said program information. 10. A satellite broadcast communication system for broadcasting Internet information, comprising: multiple receivers; at least one broadcasting station for transmitting a broadcast channel comprising packets of different Internet message types and data identifying which of said packets correspond to said different Internet message types which type of a satellite for receiving said broadcast channel and for transmitting said broadcast channel to said plurality of receivers; Wherein, at least one receiver of the plurality of receivers receives the broadcast channel, and the receiver includes a multimedia device having a memory device for storing packets obtained from said broadcast channel, an output device for prompting a user to make a selection from a plurality of different types of Internet information, an input device allowing the user to make said selection, and a processor programmed to retrieve selected ones of said packages stored in said memory device, which correspond to said selection, and transfer said selected ones of said packages to provided to the output device.

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