Abstract:
A data delivery system including a transmodulator for converting Internet data modulated using a first modulation protocol to Internet data modulated using a second modulation protocol and a receiver for receiving the Internet data modulated using the second modulation protocol via a transmission link.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    The present application claims benefit of provisional application No. 60/203,889 filed May 12, 2000. 
     
    
     
       FIELD  
         [0002]    The present application generally relates to a data transmission system and method and, more particularly, to a system and method for the delivery of Internet data to a modem via a wireless transmission link.  
         BACKGROUND INFORMATION  
         [0003]    Transmitting Internet data via an asynchronous methodology is well known in the art. Asynchronous delivery of Internet data is common in the Internet industry due to the nature of Internet traffic. Most Internet traffic carried over the Internet is data being sent to end-users in response to data requests made by those end-users. This results in large volumes of data flowing towards end-users while modest amounts of data flow away from end-users. The Internet industry often takes advantage of this fact to reduce costs and maximize utilization of the communication links that comprise the Internet.  
           [0004]    Asynchronous is used herein to describe one or more manners of delivering request traffic on one or more routes and delivering response traffic via one or more other routes, whereby the different routes are chosen due to addressing of the data or routing policies contained in certain routers, or other techniques, specifically for the Internet data in question, as opposed to routing differences due to, but not limited to, congestion and other vagaries of the Internet. Therefore, an asynchronous methodology for purposes of this application represents Further, the use of the term asynchronous herein is not related to the usage of the term for Internet communication links that have different upstream rates versus downstream rates.  
           [0005]    [0005]FIGS. 1 through 4 illustrate four known systems for transmitting Internet data via an asynchronous methodology. Specifically, FIG. 1 illustrates a satellite direct-to-home system  100 , FIG. 2 illustrates a one-way cable modem system  200  using an IP encapsulator, FIG. 3 illustrates a one-way cable modem system  300  using a cable modem termination system (“CMTS”), and FIG. 4 illustrates a two-way cable modem system using a CMTS and an asynchronous delivery of bandwidth to the CMTS.  
           [0006]    Satellite direct-to-home system  100 , shown in FIG. 1, includes end-user  115 , uplink facility  105 , Internet  120  and satellite  110 . Further, uplink facility  105  includes router  125 , encapsulator  130 , modulator  135  and satellite antenna  140 . Up-link facility  105  may also include a network address translation server (“NAT device”) coupled to router  125  for requesting traffic, for readdressing or for proxy functions. End-user  115  includes satellite antenna  145 , satellite modem  150 , operating system  155  and modem  160 .  
           [0007]    End-user  115  establishes a connection to Internet  120  using an industry standard analog dial up modem  160 . There are a variety of possible ways, however, for an end-user to connect to Internet  120 , including using ISDN, DSL, frame relay, a dedicated connection or a very small aperture terminal (“VSAT”). Once a connection is established to Internet  120 , a computer, including software such as operating system  155 , of the end-user makes a data request or sends a reply via the established connection to Internet  120  using standard and well known industry techniques. Internet  120  includes a number of routers that route the data request to the appropriate destination. The destination provides a response comprised of data and routing information, referred to hereafter as response traffic. The response traffic is routed to router  125  at uplink facility  105 . Router  125  forwards the response traffic, with or without intermediary processes, to IP encapsulator  130 . IP encapsulator  130  adds additional address information, including address information pertaining to a destination device, onto the response traffic and formats the data into a digital video broadcast (“DVB”) compliant data stream. The DVB compliant data stream is forwarded, with or without intermediary processes, to modulator  135 . Modulator  135  receives the DVB complaint data stream and converts the data stream to whichever modulation standard is being used on a transponder of satellite  110 , for example, bi phase shift keying (“BPSK”), quadrature phase shift keying (“QPSK”) or eight phase shift keying (“8PSK”). Modulator  135  outputs the modulated data stream through a variety of satellite industry standard devices to uplink satellite antenna  140  in order to get the modulated data stream up to a satellite transponder of satellite  110 . The transponder of satellite  110  rebroadcast the data stream so that the data stream is received at satellite antenna  145  of end-user  115 . The data stream is then forwarded to satellite modem  150 . Satellite modem  150  demodulates the signal and reads the DVB packet information. If the packet is addressed to that satellite modem  150 , satellite modem  150  reads the packet and forwards the IP portion of the packet to operating system  155 .  
           [0008]    [0008]FIG. 2 illustrates a one-way cable modem system  200  including an IP encapsulator. System  200  includes end-user  205 , Internet  210  and head end  215 . Head end  215  includes router  220 , IP encapsulator  225 , modulator  230  and combiner  235 . In addition, head end  215  can also include a NAT device coupled to router  220  for requesting traffic, for readdressing or for proxy functions. End-user  205  includes modem  240 , operating system  245  and modem  250 .  
           [0009]    End user  205  establishes a connection to Internet  210  using an industry standard analog dial up modem  250 . There are a variety of possible ways, however, for an end-user to connect to Internet  210 , including using ISDN, DSL, frame relay, a dedicated connection or VSAT. Once a connection is established to Internet  210 , a computer, including software such as operating system  245 , of end-user  205  makes a data request or sends a reply via the established connection to Internet  210  using standard and well known industry techniques. Internet  210  includes a number of routers that route the data request to the appropriate destination. The destination provides a response comprised of data and routing information, referred to hereafter as response traffic. The response traffic is routed to the router  220  at head end  215 . Router  220  at head end  215  may be connected to Internet  210  in a variety of manners, including using ISDN, frame relay, a direct connection, or wireless links. Router  220  forwards the response traffic, with or without intermediary process to IP encapsulator  225 . IP encapsulator  225  adds additional address information, including address information pertaining to a destination device, onto the response traffic and formats the data into a DVB compliant data stream. The DVB compliant data stream is forwarded, with or without intermediary processes, to modulator  230 . Modulator  230  receives the DVB complaint data stream and converts the data stream to whichever modulation standard is being used in the cable system, for example, QAM8, QAM32, QAM64, QAM128 or QAM256. Modulator  230  outputs the now modulated data stream into combiner  235 . Combiner  235  combines all the channels in the cable system on specific frequencies for reception by cable subscribers. End-user  205  receives the data stream from combiner  235  via a terrestrial transmission link, for example, a coaxial cable or fiber optic cable, or via a wireless transmission link, such as ultra high frequency (“UHF”) link. The data signal is received by DVB compliant cable modem  240  located at end-user  205 . DVB cable modem  240  demodulates the data signal and reads the DVB packet information. If the packet is addressed to modem  240 , DVB cable modem  240  reads the packet and forwards the IP portion of the packet to operating system  245 .  
           [0010]    [0010]FIG. 3 illustrates a one-way cable modem system  300  using a CMTS. System  300  includes end-user  305 , Internet  315  and head end  320 . Head end  320  includes router  325 , CMTS  330  and combiner  335 . In addition, head end  320  can also include a NAT device coupled to router  320  for requesting traffic, readdressing or proxy functions. End-user  305  includes cable modem  340 , operating system  345  and modem  350 .  
           [0011]    End-user  305  establishes a connection to Internet  315  using an industry standard analog dial up modem  350 . There are a variety of possible ways, however, for an end-user to connect to the Internet, including using ISDN, DSL, frame relay, a dedicated connection or VSAT. Once a connection is established to Internet  315 , a computer, including software such as operating system  345 , of end-user  305  makes a data request or sends a reply via the established connection to Internet  315  using standard and well known industry techniques. Internet  315  includes a number of routers that route the data request to the appropriate destination. The destination provides a response comprised of data and routing information, referred to hereafter as response traffic. The response traffic is routed to router  325  at head end  320 . Router  325  at head end  320  may be connected to Internet  315  in a variety of manners, including using ISDN, frame relay, a direct connection or a wireless link. Router  325  forwards the response traffic, with or without intermediary process to CMTS  330 . CMTS  330  adds additional address information, including address information pertaining to a destination device, onto the response traffic and formats the data into a data over cable service interface specification (“DOCSIS”) compliant data stream. CMTS  330  modulates the data stream using an appropriate modulation protocol for the cable system to utilize. The DOCSIS compliant modulated data stream is output to combiner  335 . Combiner  335  combines all the channels in the cable system on specific frequencies for reception by cable subscribers. End-user  305  receives the data stream from combiner  335  via a terrestrial transmission link, for example, a coaxial cable or fiber optic cable, or via a wireless transmission link, such as UHF or LMDS. The data stream is received at DOCSIS compliant cable modem  340  located at end-user  305 . Cable modem  340  demodulates the cable signal and reads the DOCSIS packet information. If the packet is addressed to that cable modem  340 , cable modem  340  reads the packet and forwards the IP portion of the packet to operating system  345 .  
           [0012]    [0012]FIG. 4 illustrates a two-way cable modem system  400  including a CMTS. System  400  includes end-user  405 , Internet  410 , uplink facility  415 , satellite  445  and head end  420 . Uplink facility  415  includes router  425 , encapsulator  430 , modulator  435 , and satellite antenna  440 . Further, head end  420  includes satellite antenna  450 , satellite receiver with router and/or NAT device  455  (“satellite receiver”), CMTS  460 , and combiner  465 . End-user  405  includes cable modem  470  and operating system  475 .  
           [0013]    End user  405  has a full-time connection to CMTS  460  via DOCSIS complaint cable modem  470  and a transmission link. Since the connection is established in either a proprietary or open standard way, end-user  405  makes a request or sends a reply at any time via the established connection to CMTS  460 . CMTS  460  forwards the request to either an internal or external satellite receiver  455  coupled to CMTS  460  via an Ethernet connection. CMTS  460  or satellite receiver  455  modify the addressing information of the request traffic or repackage the request traffic so that a response will be returned via the route designated for response traffic. Satellite receiver  455  routes the request traffic via a transmission link to Internet  410  designated to handle such traffic. For example, routers used in Internet  410  ultimately route the request to the appropriate destination, such as router  425  located at uplink facility  415 . A NAT device or proxy device located at uplink facility  415  forwards the request to the appropriate devices in Internet  410 . The response is returned via Internet  410  to router  425 . The response traffic is routed via encapsulator  430 , modulator  435 , and transmission link  445  designated for response traffic to satellite receiver  455  at head end  420 . Satellite receiver  455  may be connected to Internet  410  in a variety of manners including using ISDN, frame relay, a direct connection or a wireless transmission link. Satellite receiver  455  forwards the response traffic, with or without intermediary processes, to CMTS  460 . CMTS  460  adds additional address information, including address information pertaining to a destination device, onto the response traffic and formats the data into a DOCSIS compliant data stream. CMTS  460  modulates the data stream using an appropriate modulation protocol for the cable system to utilize. The DOCSIS compliant modulated data stream is output to combiner  465 . Combiner  465  combines all the channels in the cable system on specific frequencies for reception by cable subscribers. End-user  405  receives the data stream from combiner  465  via a transmission link, for example, a coaxial cable. The cable signal is received at DOCSIS compliant cable modem  470  located at end user  405 . DOCSIS compliant cable modem  470  demodulates the cable signal and reads the DOCSIS packet information. If the packet is addressed to that DOCSIS cable modem, DOCSIS cable modem  470  reads the packet and forwards the IP portion of the packet to operating system  475 .  
           [0014]    [0014]FIG. 5 illustrates television system  500  wherein television signals are transmitted from a satellite to a head end. System  500  includes end-user  505 , uplink facility  510  and head end  515 . Uplink facility  510  includes DVB MPEG2 encoder  520 , modulator  525  and satellite antenna  530 , and head end  515  includes satellite antenna, trans-modulator  545  and combiner  550 . In addition, end-user  505  includes television  555 .  
           [0015]    Trans-modulator  545  is used in the TV industry in order to forward television signals transmitted via satellite through cable systems. Trans-modulators may be one or more pieces in design, for example, a demodulator and one or more modulators.  
           [0016]    As shown in FIG. 5, television signal  560  is received at satellite uplink facility  510  where the television signal can be converted into a compressed digital data stream such as DVB MPEG2 by DVB MPEG2 encoder  520 . The television signal, whether compressed or not, is input into modulator  525  which converts the data stream to whichever modulation standard is being used on a transponder of satellite  535 , for example, BPSK, QPSK or 8PSK. The modulated data stream passes through a variety of devices, not all of which are shown in FIG. 5, to be transmitted via the satellite antenna  530  to the transponder of satellite  535 . Satellite  535  rebroadcasts the data stream to satellite antenna  540  at head end  545  or an individual subscriber&#39;s satellite antenna. The data stream is forwarded to trans-modulator  545  which converts the data stream modulated using the satellite modulation protocol to a modulated data stream that can be used in a cable system, for example, QAM for terrestrial cable systems or QAM or COFDM for wireless cable systems.  
           [0017]    The respective systems shown in FIGS. 1 through 5 can also include more than one end-user and more than one head end.  
           [0018]    Moreover, in the systems shown in FIGS. 1 through 5 Internet traffic requires readdressing or packaging by a centralized server such as a Proxy server or a NAT server to properly route the Internet traffic.  
           [0019]    There is a need for providing Internet data to modems of end-users via a wireless transmission link without requiring the end-users to have antennas and without requiring head ends to have expensive, hard to manage devices. A need also exist for first routing Internet data responsive to an end-user request to a transmission facility having an associated source address and then transmitting the data to an end-user via a wireless transmission link.  
         SUMMARY OF THE INVENTION  
         [0020]    An aspect of the present application provides for a data delivery system, including a trans-modulator for converting Internet data modulated using a first modulation protocol to Internet data modulated using a second modulation protocol, and a modem for receiving the Internet data modulated using the second modulation protocol via a transmission link.  
           [0021]    Another aspect of the present application provides for a data delivery system, including a modulator for modulating Internet data using a first modulation protocol, a trans-modulator coupled to the modulator via a wireless transmission link for converting the Internet data modulated using the first modulation protocol to Internet data modulated using a second modulation protocol, the trans-modulator being located at a head end, and a modem for receiving the Internet data modulated using the second modulation protocol via a transmission link.  
           [0022]    A further aspect of the present application provides for a data delivery system, including a first modem for transmitting a data request via the Internet, at least one server in the Internet for retrieving data responsive to the data request, an encapsulator for receiving the responsive data from the Internet and for generating encapsulated data, a modulator coupled to the encapsulator for receiving the encapsulated data and for generating modulated data using a first modulation protocol, a wireless transmitter for transmitting the modulated data via a wireless transmission link, an antenna for receiving the modulated data transmitted via the wireless transmission link, a trans-modulator coupled to the antenna for converting the modulated data to data modulated using a second modulation protocol, and a second modem coupled to the trans-modulator for receiving data modulated using the second modulation protocol via a transmission link.  
           [0023]    A still further aspect of the present invention includes a data delivery method, including modulating Internet data using a first modulation protocol, transmitting the Internet data modulated using the first modulation protocol via a wireless transmission link to a head end, converting at the head end the Internet data modulated using the first modulation protocol into Internet data modulated using a second modulation protocol, and transmitting the Internet data modulated using the second modulation protocol via a transmission link to a modem.  
           [0024]    A still further aspect of the present application provides for a method for routing Internet response data in an asynchronous data transmission system, including authenticating a device of an end-user, forwarding an IP source address associated with a transmission facility to the end-user device upon authentication, and receiving the Internet response data responsive to a data request of the end-user at the transmission facility.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]    [0025]FIG. 1 illustrates a system having a satellite signal transmitted directly to a home;  
         [0026]    [0026]FIG. 2 illustrates a one-way cable modem system including an IP encapsulator;  
         [0027]    [0027]FIG. 3 illustrates a one-way cable modem system including a cable modem termination system;  
         [0028]    [0028]FIG. 4 illustrates a two-way cable modem system including a cable modem termination system;  
         [0029]    [0029]FIG. 5 illustrates a cable television system including a trans-modulator;  
         [0030]    [0030]FIG. 6 illustrates an exemplary data transmission system of the present application; and  
         [0031]    [0031]FIG. 7 illustrates an exemplary method of addressing Internet data. 
     
    
     DETAILED DESCRIPTION  
       [0032]    [0032]FIG. 6 illustrates an exemplary data transmission system  600  of the present application. Data transmission system  600  includes end-user  615 , uplink facility  605 , head end  610 , Internet  675  and satellite  640 . Further, uplink facility  605  includes, for example, one or more routers  620 , one or more encapsulators  625 , one or more modulators  630  and one or more wireless transmitters  635 , for example, a satellite antenna. Head end  610  includes antenna  645 , for example, a satellite antenna, trans-modulator  650  and combiner  655 , and end-user  615  includes modem  660 , for example, a DVB complaint cable modem, operating system  665  and modem  670 . In alternative embodiments, more than one end-user and/or more than one head end can be included in data transmission system  600 .  
         [0033]    Head end  610  can be coupled to end-user  615  via a terrestrial or wireless transmission link and can be, for example, a head end of a cable system servicing one or more locations. Cable systems referred to hereafter may transmit data signals and/or television signals via wire or wireless transmission link. In addition, head end  610  can be a terrestrial head end or a wireless head end. Examples of terrestrial head ends include a cable television head end, a private cable operator head end, a multiple dwelling unit head end and a single master antenna television system head end. Examples of wireless head ends are a very high frequency head end, an ultra high frequency head end, a multipoint, multi-channel distribution system head end and a low power microwave distribution system head end.  
         [0034]    In data transmission system  600 , end user  615  establishes a connection to Internet  675  using an industry standard analog dial up modem  670 . There are a variety of possible ways, however, for an end-user to connect to Internet  675 , including, but not limited to, using ISDN, DSL, frame relay, a dedicated connection or VSAT. Once a connection is established to the Internet  675 , a computer, including software such as operating system  665 , of end-user  615  makes a data request or sends a reply via the established connection to Internet  675 , for example, using a tunneling technique. The embodiment described with reference to FIG. 7 can be also be used as opposed to the tunneling technique. Internet  675  includes a number of routers, not shown in FIG. 6, that route the data request to the appropriate destination. For example, when using a tunneling technique, the initial destination could be a proxy server or NAT device, nor shown in FIG. 6. Such device can be located at uplink facility  605 . The proxy server or NAT device addresses the data request or reply to the appropriate destination replacing the original end user  615  return IP address with the proxy server&#39;s or NAT device&#39;s return IP address. The destination provides a response comprised of data and routing information, referred to hereafter as response traffic. The response traffic is routed to the return address provided on the data request or reply which is router  620  at uplink facility  605 .  
         [0035]    Router  620  forwards the response traffic, with or without intermediary processes, to IP encapsulator  625 . IP encapsulator  625  adds additional address information, including address information pertaining to a destination device, for example, DVB complaint cable modem  660 , onto the response traffic and formats the data into a DVB compliant data stream. In alternative embodiments, the data stream may be formatted in other transmissible manners. Thus, all references to the DVB format is merely illustrative. The DVB compliant data stream is forwarded, with or without intermediary processes, to modulator  630 . Modulator  630  receives the DVB complaint data stream and converts the data stream into the first of two modulation protocols. The first modulation protocol is used to transmit the data stream via a transponder of satellite  610 . For example, the first modulation protocol can be BPSK, QPSK or 8PSK.  
         [0036]    Modulator  630  outputs the modulated data stream to wireless transmitter  635 , for example a satellite antenna. Wireless transmitter  635  transmits the modulated data stream to a satellite transponder of satellite  640 . The transponder of satellite  640  rebroadcasts the data stream so that the data stream is received at antenna  645  located at head end  610 . Alternatively, the transmitted data stream can be received at satellite antenna  145  located at end-user  115 , shown in FIG. 1. Other wireless transmission links and associated devices can be utilized as well. Thus, the use of a satellite, a satellite transmission link and satellite antennas are merely illustrative.  
         [0037]    The data stream is forwarded to trans-modulator  650 . Trans-modulator  650  converts the data stream modulated with the first modulation protocol used by satellite  640  to a data stream modulated with a second modulation protocol that can be used by a wireless or terrestrial cable system. For example, if the data stream was transmitted via satellite  640  using QPSK modulation, trans-modulator  650  can convert the data stream to a QAM modulated data stream. These two modulation protocols are merely illustrative and therefore any other combination of modulation protocols can be utilized as well. Trans-modulators may be one or more pieces in design, for example, a demodulator and one or more modulators coupled together.  
         [0038]    Trans-modulator  650  outputs the modulated data stream directly to combiner  655  or via one or more other devices. Combiner  655 , for example, combines all the channels in the cable system on specific frequencies for reception by cable subscribers.  
         [0039]    End-user  615  receives the data stream from combiner  235  via a terrestrial transmission link, for example, a coaxial cable or fiber optic cable, or via a wireless transmission link, such as a UHF link. The modulated data stream is received at modem  660  located at end-user  615 . Modem  660  demodulates the data stream and reads the packet information, for example, DVB packet information. If the packet is addressed to modem  660 , modem  660  reads the packet and forwards the IP portion of the packet to operating system  665 .  
         [0040]    Thus, data transmission system  600  enables an asynchronous, geographically dispersed, terrestrial and/or wireless Internet data system.  
         [0041]    [0041]FIG. 7 illustrates an exemplary method of addressing Internet data so that Internet data is not returned to the originating device or computer, but rather redirected to another device or computer.  
         [0042]    An end-user first accesses an Internet service provider (“ISP”), in  705 , and requests authentication, in  710 . In an exemplary embodiment, the ISP has an arrangement with an operator of, for example, system  600 . The arrangement requires that for end-users that intend to utilize system  600  and connect to ISP, authentication of those end-users is from one or more authentication servers of the operator via one or more ISP authentication servers, for example, proxy radius. Other protocols, software or systems and can be used as well.  
         [0043]    Upon authentication, the authentication server of the operator forwards an IP address from, for example, the operator&#39;s pool of IP addresses to the ISP authentication server. The ISP authentication server forwards the IP address from the authentication server of the operator to a user device or computer as the IP address to use for the current session, in  715 . The end-user&#39;s device or computer will use the forwarded IP address as the end-user&#39;s device or computers source address for the current session. The IP address assigned to the end-user by the authentication server of the operator results in data responses to be routed, for example, to encapsulator  625 , shown in FIG. 6. Data responses can be routed to any type of transmission facility.  
         [0044]    By redirecting Internet traffic, for example, in systems shown in FIGS. 1 and 6, versus using, for example, a tunneling technique, latency, cost and/or hardware requirements may be reduced.  
         [0045]    Once the current session is established, in  720 , the end-user makes a request or response, referred to hereafter as request traffic, in  725 . The data request is routed as a synchronous request to the destination device or server, for example, www.CNN.com, in  730 . Destination device or server responds and addresses the response to the source IP address, referred to hereafter as response traffic, in  735 . Response traffic is routed via Internet  675  to a transmission facility, for example, a satellite uplink facility  605  and eventually to encapsulator  625 , in  740 . Response traffic is thereafter forwarded via an asynchronous downstream link, such as a wireless transmission link, to an end-user connected to such a link, in  745 . The end-user can thereafter make another request or send a reply, in  750 .  
         [0046]    The embodiments described above are illustrative examples of the present injention and it should not be construed that the present invention is limited to these particular embodiments. Various changes and modifications may be effected by one skilled in the art without departing from the spirit or scope of the invention as defined in the appended claims.