Abstract:
A coax server acts as a proxy between a coax transmission infrastructure and an Internet Protocol (IP) transmission infrastructure. An incoming request is received from a particular one of a plurality of coax client devices on the coax infrastructure. A request for specific media content is transmitted to a media-on-demand server in response to receiving the incoming request. A media stream is received over the IP infrastructure from the media-on-demand server, the media stream corresponding to the specific media content, and the coax server allocates a coax channel of sufficient bandwidth on the coax infrastructure and transmits the media stream on the coax channel utilizing the RF modulation scheme. A pointer indicating the coax channel on which the media stream is being transmitted is sent to the particular coax client device. The coax channel is unknown to other of the coax client devices besides the particular coax client device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a continuation of U.S. patent application Ser. No. 12/463,993 filed on May 11, 2009, which is a non-provisional of U.S. Provisional Patent Application Ser. No. 61/164,253 filed on Mar. 27, 2009. Both of these applications are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    (1) Field of the Invention 
         [0003]    The present invention relates to providing digital information and/or data services over hybrid network infrastructures including both IP and coax transmission media. 
         [0004]    (2) Description of the Related Art 
         [0005]    Current practice within enhanced digital television and video-on-demand (VOD) systems is to deliver digital TV and VOD services either using RF frequencies over existing coaxial cable (coax) infrastructure (e.g., via QAM data transfer or highly segmented coax loops with IP-over-coax data transfer), or via Internet Protocol (IP) solutions (e.g., via Ethernet cable infrastructure using IP). 
         [0006]    In the hospitality industry, a large segment of the market for such services still relies heavily on coax infrastructure; some entirely, and others having newer parts of their infrastructures being IP-based while older parts still employ coax. 
         [0007]    IP-over-coax solutions are characterized by an inherent problem in that coax does not have the available bandwidth to deliver the television and video services people demand using this approach; particularly high definition video. IP-over-coax also requires fairly radical modifications to conventional coax infrastructure to make it work at all. That is, in order to provide sufficient bandwidth, the long loops employed by conventional coax infrastructures must be segmented into much smaller loops or segments. 
         [0008]    Cable television providers have long provided television and video services over coax using quadrature amplitude modulation (QAM) in the downstream direction, and IP-over-coax for the return path (which typically has much lower bandwidth requirements). The combination of QAM in one direction and IP-over-coax in the other allows such solutions to avoid having to make the alterations to the existing coax infrastructure required by a fully IP-over-coax solution. 
         [0009]    However, these solutions do not address the needs of facilities having infrastructures which include both IP and coax. An example would be a hotel with an older wing that only has a coax network infrastructure, and a newer wing having an IP infrastructure. In such facilities, separate solutions are typically required to provide data and video services to the guest rooms on both infrastructures. 
       BRIEF SUMMARY OF THE INVENTION 
       [0010]    Various methods and apparatus are provided for providing digital information and/or data services over hybrid network infrastructures including both IP and coax transmission media. 
         [0011]    According to a particular class of embodiments, a network is provided which includes a first transmission infrastructure comprising coaxial cable over which data are transmitted using a radio frequency (RF) modulation scheme. The network also includes a second transmission infrastructure over which data are transmitted using the Internet Protocol (IP). One or more data servers are configured to provide data services including both digital television services and video-on-demand services. One or more coax servers are configured to receive via the second transmission infrastructure first data transmissions originating from the one or more data servers and intended for first client devices connected to the first transmission infrastructure. The one or more coax servers are further configured to convert the first data transmissions for transmission to the first client devices over the first transmission infrastructure using the RF modulation scheme. The one or more data servers provide the data services to the first client devices via the one or more coax servers and the first transmission infrastructure, and to second client devices connected via the second transmission infrastructure. 
         [0012]    According to another class of embodiments, a coax server is provided for use in a network including a first transmission infrastructure comprising coaxial cable over which data are transmitted using a radio frequency (RF) modulation scheme, and a second transmission infrastructure over which data are transmitted using the Internet Protocol (IP). The network further includes one or more data servers configured to provide data services including both digital television services and video-on-demand services. The coax server includes one or more coax ports configured for connection to the first transmission infrastructure. The coax server further includes one or more IP ports configured for connection to the second transmission infrastructure and to receive first data transmissions originating from the one or more data servers and intended for first client devices connected to the first transmission infrastructure. The coax server further includes an up-converter configured to convert the first data transmissions for transmission to the first client devices over the first transmission infrastructure using the RF modulation scheme. The coax server further includes a program stream manager configured to provide coax channel mapping information to at least one of the one or more data servers. The coax channel mapping information including coax channel tuning information for specific program streams generated by the one or more data servers. The coax channel mapping information is configured to enable the first client devices to receive selected ones of the specific program streams. 
         [0013]    According to another class of embodiments, methods and apparatus are provided for providing data services in a network including a first transmission infrastructure comprising coaxial cable over which data are transmitted using a radio frequency (RF) modulation scheme, and a second transmission infrastructure over which data are transmitted using the Internet Protocol (IP). The network further including one or more data servers configured to provide the data services. The data services including both digital television services and video-on-demand services. First data transmissions are received which originate from the one or more data servers and are intended for first client devices connected to the first transmission infrastructure. The first data transmissions are converted for transmission to the first client devices over the first transmission infrastructure using the RF modulation scheme. Coax channel mapping information is provided to at least one of the one or more data servers. The coax channel mapping information includes coax channel tuning information for specific program streams generated by the one or more data servers. The coax channel mapping information is configured to enable the first client devices to receive selected ones of the specific program streams. 
         [0014]    According to an exemplary embodiment, disclosed is a system including a coax transmission infrastructure formed by coaxial cable over which data are transmitted using a radio frequency (RF) modulation scheme. The system further includes a plurality of coax client devices each including an RF tuner supporting the RF modulation scheme connected to the coax transmission infrastructure. The system further includes an Internet Protocol (IP) transmission infrastructure formed by twisted pair wire over which data are transmitted using IP. The system further includes a media on demand server connected to the IP transmission infrastructure; and a coax server coupled to both the coax transmission infrastructure and the IP transmission infrastructure for acting as a proxy between these two infrastructures. When acting as the proxy between the coax transmission infrastructure and the IP transmission infrastructure, the coax server is operable to transmit a request for specific media content to the media on demand server in response to receiving an incoming request from a particular one of the coax client devices, and receive a media stream over the IP transmission infrastructure from the media on demand server, the media stream corresponding to the specific media content. The coax server is further operable to allocate a coax channel of sufficient bandwidth on the coax transmission infrastructure and transmit the media stream on the coax channel utilizing the RF modulation scheme; and send to the particular coax client device a pointer indicating the coax channel on which the media stream is being transmitted. The coax channel on which the media stream is transmitted is unknown to other of the coax client devices besides the particular coax client device. 
         [0015]    According to another exemplary embodiment, disclosed is a method of acting as a proxy between a coax transmission infrastructure and an Internet Protocol (IP) transmission infrastructure. The method includes receiving an incoming request from a particular one of a plurality of coax client devices coupled to the coax transmission infrastructure. The coax transmission infrastructure is formed by coaxial cable over which data are transmitted using a radio frequency (RF) modulation scheme, and the coax client devices each include an RF tuner supporting the RF modulation scheme. The method further includes transmitting a request for specific media content to a media on demand server in response to receiving the incoming request from the particular coax client device. The IP transmission infrastructure is formed by twisted pair wire over which data are transmitted using IP, and the media on demand server is connected to the IP transmission infrastructure. The method further includes receiving a media stream over the IP transmission infrastructure from the media on demand server, the media stream corresponding to the specific media content; and allocating a coax channel of sufficient bandwidth on the coax transmission infrastructure and transmitting the media stream on the coax channel utilizing the RF modulation scheme. The method further includes sending to the particular coax client device a pointer indicating the coax channel on which the media stream is being transmitted. The coax channel on which the media stream is transmitted is unknown to other of the coax client devices besides the particular coax client device. 
         [0016]    A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is a simplified network diagram illustrating a network architecture implemented according to a specific embodiment of the invention having a coax modem IP return path. 
           [0018]      FIG. 2  is a block diagram of coax server implemented according to a specific embodiment of the invention. 
           [0019]      FIG. 3  is a block diagram of a slave coax server implemented according to a specific embodiment of the invention. 
           [0020]      FIG. 4  is a simplified network diagram illustrating a network architecture implemented according to another embodiment of the invention having a WiFi IP return path. 
           [0021]      FIG. 5  shows an example program / frequency allocation according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    Reference will now be made in detail to specific embodiments of the invention including the best modes contemplated by the inventors for carrying out the invention. Examples of these specific embodiments are illustrated in the accompanying drawings. While the invention is described in conjunction with these specific embodiments, it will be understood that it is not intended to limit the invention to the described embodiments. On the contrary, it is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. In the following description, specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be practiced without some or all of these specific details. In addition, well known features may not have been described in detail to avoid unnecessarily obscuring the invention. 
         [0023]    According to various embodiments of the invention, a system is provided in which a single solution simultaneously provides information and/or data services via both types of infrastructure, i.e., over both IP (e.g., implemented using CAT-5 or CAT-5e cabling and/or wireless networking components) and coax (implemented using coaxial cable) transmission media. One or more coax servers are provided in the system which operate as media converters, converting traffic between the IP and coax domains. Thus, if a property or installation includes both types of network infrastructure, its data and video needs may be provided with a single solution. In addition, if a property plans to convert its infrastructure from coax to IP (either gradually or all at once), the solution provided by the present invention allows for such conversion without a substantial re-investment during or after the conversion. The coax server sits between the IP infrastructure and the coax infrastructure and acts as a proxy for the coax infrastructure, i.e., the multimedia IP infrastructure is not aware of the existence of the coax infrastructure. 
         [0024]      FIG. 1  is a network diagram of a hybrid IP and coax system implemented in accordance with a specific embodiment of the invention. In this example, the hybrid infrastructure is deployed in a hotel property, and provides a variety of services including digital television and video-on-demand (VOD) (in both standard and high definition, SD and HD), Internet access, and a variety of other guest services including, for example, remote checkout, wake up calls, room service, etc. It should be noted that this is merely one example of a context in which such a hybrid infrastructure might be implemented in accordance with the invention. Other implementation contexts as well as a broad range of services and service sets are contemplated to be within the scope of the invention. That is, any infrastructure context in which both types of network infrastructure exist or are desirable may benefit from the present invention. For example,  FIG. 4  illustrates another architecture example with a WiFi IP return path. 
         [0025]    A core server  102  provides the set top boxes (STBs) in the system, e.g., STB  104 , with user interfaces (including language translation), firmware updates, billing management, etc. It also hosts the system database and billing system. Core server  102  is what the system&#39;s STBs communicate with to facilitate access to and/or the purchase of services by hotel guests. According to a specific implementation, core server  102  employs Apache web server and Apache Tomcat which is an implementation of the Java Servlet and JavaServer Pages technologies. 
         [0026]    Head end server  106  (typically an array of servers) receives the digital television channels from any of a variety of sources (e.g., European DVB-C signals, U.S. proprietary satellite signals, etc.) and makes them available for transmission to STBs on both parts of the infrastructure. Head end server  106  may encrypt the signals, or employ the encryption required by the content provider. 
         [0027]    VOD server  108  (again typically an array of servers) hosts the “on demand” video content (e.g., feature films) and makes this content available for transmission to requesting users. VOD server  108  enables video control functionality such as play, pause, fast forward, rewind, skip forward, skip back, etc. Examples of VOD servers that may be employed with systems implemented according to specific embodiments are provided by BitBand Technologies Ltd. of Netanya, Israel. 
         [0028]    Media server  110  provides content previews (e.g., movie trailers) and other promotional content with a stripped down set of the typical video control functions, e.g., skip forward and back, but no fast forward or rewind. Media server  110  also provides backdrop videos. 
         [0029]    Core switch  112  (e.g., a network switch from Cisco Systems, Hewlett-Packard, etc.) provides the connections between the various IP-based servers and coax server  114  and IP-coax modem  116 . As described in greater detail below, coax server  114  provides the media conversion from the IP domain to the coax domain for the IP-based servers, i.e., head end server  106 , VOD server  108 , and media server  110 . Cable modem termination system (CMTS)  116  provides the conversion to and from IP-over-coax for the transmissions between core server  102  and the STBs on the coax infrastructure, e.g., STB  104 . That is, in the depicted embodiment, the lower bandwidth requirements of the traffic to and from core server  102  allow for the use of IP-over-coax as the transmission mechanism on the coax infrastructure. Thus, in this particular implementation, the return path from the STBs is an IP-over-coax path. 
         [0030]    An IP-coax modem  118  is in the guest rooms on the coax infrastructure to demodulate the downstream IP-over-coax signals to standard Ethernet for STB  104  as well as to modulate the signals from STB  104  for transmission upstream. A QAM tuner (not shown) in STB  104  is connected to the coax infrastructure for receiving the program streams from the Coax Server  114  originating from the IP-based servers. STB  104  then provides its output to television  120 . STB  104  also receives input from a remote control (not shown) in the guest room which is the primary mechanism used by the guest to navigate user interfaces on TV  120  and to select from among and purchase the variety of available services. 
         [0031]    Guests may connect their personal computing devices, e.g., guest laptop  122 , to the system via wireless access points, e.g., WAP  124 , which are in turn connected to Internet access server  126  via switch  128 . The final connection to the Internet for the traffic to and from both core switch  112  and switch  128  is provided via router  130 . Internet access server may be provided, for example, by iBAHN of Salt Lake City, Utah. As shown, guests may also establish a wired connection to the Internet by plugging their laptops into STB  104  (e.g., via an Ethernet port) which then employs the IP return path provided by IP-coax modems  116  and  118 . Alternatively, the return path through IP-coax modems  116  and  118  may be established via a wireless access point (not shown) situated between laptop  122  and IP-coax modem  118 . 
         [0032]    According to various embodiments, coax server  114  operates primarily as a media converter that converts from Ethernet in the IP domain to QAM in the coax domain. According to a specific implementation, coax server  114  operates on a Linux platform and converts multiple MPEG-2 (SD or HD) or H.264 (HD) Single Program Transport Streams via Ethernet (IPTV) to several Multiple Program Transport Stream via coax using the DVB-C standard at QAM256. It should be noted that other standards may be employed. 
         [0033]    A coax program refers to a single television, VOD, or data program stream. Multiple programs are multiplexed together and broadcast on a coax channel which is defined by a center frequency. Each transport stream is allocated a slot in the available bandwidth of an output channel. It should be noted that QAM is merely one example of a modulation scheme by which bandwidth in a coax infrastructure may be allocated. Other modulation schemes (e.g., quadrature phase shift keying (QPSK)) are within the scope of the invention. 
         [0034]    According to a particular implementation, the programs from head end server  106  and from VOD server  108  are handled differently. IPTV streams from head end server  106  are always allocated coax programs since these are essentially always on. By contrast, and depending on viewer demands, VOD streams are assigned a coax program when requested. As described below, because STB  104  communicates with coax server  114  rather than directly with VOD server  108 , coax server  114  includes a Real-Time Streaming Protocol (RTSP) Proxy Server/Client to manage VOD content. 
         [0035]      FIG. 2  is a block diagram illustrating implementation of a coax server  114  according to a specific embodiment of the invention. The core process of coax server  114  is stream pump  202  which is a multi-threaded manager that manages the streams of data directed to STBs on the coax infrastructure. Stream pump  202  allocates the program streams in the coax channel multiplex and performs streaming of IP data into the multiplex. Stream pump  202  receives data from multiple external sources, i.e., head end server  106 , VOD server  108 , and media server  110 , and manages operation of QAM up-converter  204  which generates the QAM output transmitted on the coax infrastructure. According to a particular implementation, stream pump  202  receives the IP stream source details (e.g., multicast/unicast protocol, interface, IP address, port number) and the required data bandwidth. Stream pump  202  then allocates bandwidth within a suitable channel on a “best fit” basis. According to a specific implementation, up-converter  204  is the Q8 PCI adapter provided by VideoPropulsion Interactive Television, Inc. of Slinger, Wis. 
         [0036]    Clients are returned a pointer to a structure containing the program details including the Program ID and frequency.  FIG. 5  shows an example program/frequency allocation. In this example, programs  1 - 10  are allocated to channel  1  at 177 MHz. A tuner tuned to 177 MHz will be able to select one of the ten programs available. 
         [0037]    The data from head end server  106  are multicast data because users can selectively receive live broadcasts. The data from VOD server  108  are unicast data because they are responsive to a request for specific video content by a guest in a particular room. The data from media server  110  may be both multicast (e.g., backdrop videos) and unicast (e.g., content previews and other promotional content). 
         [0038]    As discussed above, coax server  114  includes RTSP proxy  206  which mediates requests from RTSP client  208  in STB  104  for unicast content from VOD server  108  and media server  110 . With input from RTSP proxy  206  and the relevant server, stream pump  202  places the unicast content on a specific coax channel unknown to any other parts of the system beside the STB from which the request originated, e.g., STB  104 . According to a particular implementation, RTSP proxy  206  instructs stream pump  202  to allocate a coax channel of sufficient bandwidth to suit the content and creates a unicast connection to VOD server  108 . Proxy  206  then establishes an RTSP connection with VOD Server  108  and maintains the connection, e.g., using keep-alive notices. STB  104  also uses keep-alive notices with proxy  206 . The assigned coax program tuning information is returned to STB  104  via proxy  206  in the responses that make up the RTSP connection. 
         [0039]    TV Manager  210  is responsible for assigning coax program details for the digital television channels configured on core server  102  based on bandwidth requirements, e.g., HD vs. SD. TV Manager  102  also provides tuning information back to core server  102  mapping the assigned coax channels to the IP addresses of the corresponding digital television channels. This information is then provided to STB  104  (via the IP-over-coax path) so that tuner  212  can tune to the channels selected by the guest via the IP-over-coax path from STB  104  to core server  102 . 
         [0040]    TV Manager  210  fetches the TV channel line-up from core server  102  and instructs stream pump  202  to allocate a coax program for each TV channel. If the line-up changes during operation, an update multicast message is sent from core server  202 , and TV manager  210  adjusts its stream allocation instructions to stream pump  202  accordingly. TV Manager  210  then communicates the new tunings back to core server  102  (via an xml file). The STBs then receive the new tunings for the updated channel line-up from core server  102 . 
         [0041]    Configuration daemon  214  is responsible for managing the configuration settings from the core server to processes operating on coax server  114 , and watching for activity on the other servers in the system. Media Channel Manager  216  is responsible for managing the loop of content previews from media server  110 . Media Channel Manager  216  generates metadata that are associated with the content loop so that the IP side of the system knows which preview is currently being viewed so that, if a guest chooses to purchase that content (or some other related service), the content is properly identified in the communication from STB  104  to core server  102  via the IP-over-coax return path. 
         [0042]    To support larger installations that require more coax channels, any number of additional coax servers can be configured as slave coax servers (e.g., slave  250 ) to integrate with a master coax server (e.g., coax server  114 ). Such a slave coax server  250  may be implemented as shown in the block diagram of  FIG. 3 . The depicted processes operate in a manner similar to the corresponding processes in master coax server  114 . The difference between master coax server  114  and slave coax server  250  is that the TV Manager and Media Channel Manager processes in server  114  are not required in server  250 . That is, according to this particular implementation, only one TV Manager and one Media Channel Manager process are included in the system, each of which assigns jobs to the stream pumps in the all of the coax servers. In such a system, each coax server has a fixed frequency range and is assigned a base frequency. A suitable frequency range might be, for example, 64 MHz (i.e., 8 channels with 8 MHz spacing) with a starting base frequency of 50 MHz. 
         [0043]    According to various embodiments, coax servers implemented in accordance with the invention operate independently of any encryption scheme encoded in the media streams. That is, such coax servers are not required to decrypt or alter the encryption data associated with such schemes in any way. According to a specific embodiment, coax servers are implemented to operate with unencrypted MPEG-2, H.264, ETVCrypt3, and Verimatrix. 
         [0044]    While the invention has been particularly shown and described with reference to specific embodiments thereof, it will be understood by those skilled in the art that changes in the form and details of the disclosed embodiments may be made without departing from the spirit or scope of the invention. For example, specific details have been described herein that are specific to the context in which the implementation is intended to be deployed, e.g., DVB-C, the European digital television standard. However, those of skill in the art will appreciate that such details may be modified for implementation in a different context without departing from the scope of the invention, e.g., the relevant standards in the U.S. or any other country or region. Other examples of this relate to the use of solutions from specific vendors in implementing particular system components, e.g., a VideoPropulsion up-converter in the coax server. Suitable alternatives will be apparent to those of skill in the art. And the types of information and data services provided in accordance with the invention are not intended to be limited to the services described herein, e.g., digital television and video-on-demand. Rather, any type of information or data service that may be delivered in a program stream may be delivered according to the invention. 
         [0045]    In addition, the functionality described herein may be implemented in a wide variety of ways without departing from the scope of the invention. For example, functionalities described herein may be implemented using computer program instructions stored in physical memory, e.g., any type of RAM or ROM, associated with the particular computing devices performing the described functions. Any of the various computing and programming tools and languages known to those of skill in the art which may be adapted for such purposes are within the scope of the present invention. Alternatively, at least some of the described functionality may be implemented using other types of hardware such as, for example, programmable logic devices, field-programmable gate arrays, application-specific integrated circuits, and the like. Again, suitable alternatives will be apparent to those of skill in the art. 
         [0046]    Finally, although various advantages, aspects, and objects of the present invention have been discussed herein with reference to various embodiments, it will be understood that the scope of the invention should not be limited by reference to such advantages, aspects, and objects. Rather, the scope of the invention should be determined with reference to the appended claims.