Patent Publication Number: US-2022231876-A1

Title: Gateway for Transporting Out-Of-Band Messaging Signals

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 14/988,460 filed on Jan. 5, 2016, which is a continuation of U.S. application Ser. No. 12/970,364 filed on Dec. 16, 2010, now U.S. Pat. No. 9,264,250, which is a continuation of U.S. application Ser. No. 10/570,830 filed on Mar. 6, 2006, now U.S. Pat. No. 7,961,742, which is a National Stage Entry of International Application Serial No. PCT/US2004/028909 filed Sep. 7, 2004, which claims the benefit of U.S. provisional application Ser. No. 60/501,231 filed on Sep. 5, 2003. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to Cable Modem Termination Systems (CMTSs) of the type having a gateway for transporting out-of-band (OOB) messaging signals. 
     BACKGROUND OF THE INVENTION 
     A cable modem termination system (CMTS) is generally a system located at a headend or other location of a cable service provider for transporting data packets from one location to another, such as between an internet service provider (ISP) and a subscriber station. In particular, the CMTS may be configured for downstream communication such that it is configured to receive IP packets from the ISP, to convert the IP packets to digital cable packets, and to deliver the digital cable packets to the subscriber station. In addition, the CMTS may be configured for upstream communication such that it is configured to receive digital cable packets from the subscriber station, to convert the digital cable packets to IP packets, and to deliver the IP packets to the ISP. 
     A need exists for a CMTS to include capabilities for transporting OOB messaging signals. 
     SUMMARY OF THE INVENTION 
     The present invention contemplates a number of features and configurations for the CMTS, including the CMTS having a gateway configured to output signals on at least two types of data tunnels for transfer over a cable network to Customer Premises Equipment (CPE). Each data tunnel is preferably characterized as a one-way data stream of out-of-band (OOB) messaging signals and each type of data tunnel is preferably associated with a different type of OOB messaging signals such that different types of data tunnels transfer different types of OOB messages. 
     In one aspect of the present invention, the system includes a CMTS configured to include a gateway configured to output signals on a plurality of data tunnels for transfer over a cable network to Customer Premises Equipment (CPE). Each data tunnel is preferably characterized as a one-way data stream of out-of-band (OOB) messaging signals. The CMTS preferably includes a plurality of output ports for transferring the OOB messaging signals from the gateway to the cable network, wherein each output port is capable of transferring different types of OOB messaging signals. 
     The above features and advantages, along with other features and advantages of the present invention, are readily apparent from the following detailed description of the invention when taken in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a cable system in accordance with one aspect of the present invention; 
         FIG. 2  illustrates Customer Premises Equipment (CPE) in accordance with one aspect of the present invention; 
         FIG. 3  illustrates a Cable Modem Termination System (CMTS) in accordance with one aspect of the present invention; 
         FIG. 4  illustrates an interface of the CMTS in accordance with one aspect of the present invention; 
         FIG. 5  illustrates a data tunnel in accordance with one aspect of the present invention; and 
         FIG. 6  illustrates a Downstream Channel Descriptor (DCD) message in accordance with one aspect of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
       FIG. 1  illustrates a cable system  10  in accordance with one aspect of the present invention. The system  10  includes a management network  12  and a High Speed Data (HSD) network  14  that respectively provide management and HSD services over a hybrid fiber coax (HFC)  18 , or other communication medium, to a subscriber station  20 , which includes Customer Premises Equipment (CPE)  22  and a cable modem (CM)  24 . 
     The management network  12  generally comprises two portions, a control portion  30  and an application portion  32 . The control portion  30  includes a settop box (STB) controller to control, provision, manage, and secure the CPE  22  through out-of-band (OOB) messaging. The application portion  32  provides applications to the CPE  22 , such as video on demand (VOD), interactive television (iTV), and other services. 
     The HSD network  14  provides data services for the system  10 , including services for the CM  24  to access the Internet  36 . It includes a network provisioning unit (NPU)  38  having capabilities for Dynamic Host Configuration Protocol (DHCP), Trivial File Transfer Protocol (TFTP), and the like, in addition to a Domain Name System (DNS) server. 
     The system  10  includes a cable modem termination system (CMTS)  42  to send and receive signals to and from the CPE  22  and the CM  24  over the HFC  18 . In general, the CMTS  42  transfers IP packets from the HSD network  14  and the management network  12  to the CPE  22  and CM  24  for processing. Preferably, the signals are outputted from the CMTS  42  on downstream output channels, which preferably include one-way output data tunnels, such as for OOB messaging. In addition, the CMTS  42  is configured to receive signals from the CPE  22  and the CM  24  to support two-way communication therewith, such as for transfer of IP packets from the CPE  22  and/or the CM  24  to the Internet  36  and/or the VOD or STB controller portions  32  and  30 . 
     The system  10  includes a conditional access router (CAR)  46  to connect the management network  12  to the CMTS  42 . The CAR  46  transports signals therebetween using IP protocols and provides firewall separation for the VOD or STB controller portions  32  and  30  from the HSD network  14 , enhancing security from any devices attempting to associate with devices and signaling on the management network  12 . In operation, signaling traffic transported between the management network  12  and the CMTS  42  may be wrapped into addressable packets, such as Ethernet, IP, or other packets. 
     The system  10  includes a video unit  50  for delivering video signals to the subscriber station  20  over the HFC  18 . The video unit  50  can deliver any number of video signals, including network television, cable television, pay-per-view, video on demand, and the like. 
       FIG. 2  illustrates the CPE  22  in accordance with one aspect of the present invention. The CPE  22  is preferably configured to communicate with the CMTS  42  through digital cable signals, such as through signaling defined by the Data Over Cable Service Interface Specification (DOCSIS) and/or through other protocols authorized through DHCP registration. 
     The CPE  22  includes a radio frequency (RF) splitter  60 , an embedded cable modem (eCM)  62 , an embedded set-top box (eSTB)  64 , an audio visual (A/V) port  66 , and an optional conditional access (CA) unit  68 . The RF splitter  60  splits the RF signal into two portions—one for OOB control functions and two-way application traffic and one for video delivery. The OOB and two-way application traffic is relayed to the eCM  62  and the video is relayed to the eSTB  64 . 
     The eSTB  64  outputs video and other media signals to a media output device (not shown) or other device connected to the A/V port  66 , such as to a television (TV), digital video recorder (DVR), personal video recorder (PVR), or the like. 
     The eCM  62  processes control and other non-media signals, such as DOCSIS and other IP packets, and bridges or relays the signals to the eSTB  64  through an internal communications link  70 . In particular, the communications link  70  is used to transfer data tunnels tuned to by the eCM  62  to the eSTB  64  so that OOB messaging signals can be delivered to the eSTB  64  for processing. 
     The CA unit  68  provides conditional access control for the subscriber station  20 . It can be a CableCard, SmartCard, or other item for controlling security and access to the data, video, and control signals transmitted over the HFC  18 . It is illustrated as a standalone item, however, it can be included with or embedded on the eSTB  64  or the eCM  62  to perform similar functions. 
     The eCM  62 , eSTB  64 , and CA unit  68  are logically separate entities, however, they may physically share hardware and software. Other items, such as control logic and applications may be included on the CPE  22  for controlling operation of the eSTB  64  and/or the eCM  62 . 
       FIG. 3  illustrates the CMTS  42  in accordance with one aspect of the present invention. The CMTS  42  includes a first interface  80  and a second interface  82  for sending and receiving signals to and from the management and HSD networks  12 ,  14 , respectively. The CMTS  42  further includes a third interface  86  for sending and receiving signals to and from the CPE  22  and CM  24  over the HFC  18 . A processor  90 , which is in communication with a memory  92 , processes the signals for communication with the first, second, and third interfaces  80 ,  82 ,  86  according to instructions stored on the memory  92 . 
       FIG. 4  illustrates the third interface  86  in accordance with one aspect of the present invention. The third interface  86  includes a number of blades, referred to with reference numerals  96 - 102 , which each include a number of output ports, referred to with reference numerals  106 - 120 , and a number input ports, referred to with reference numerals  126 - 140 . The blades  96 - 102  may be removable items, such as cards. The input ports  126 - 140  receive signals from the CPE  22  and the CM  24  and the output ports  106 - 120  send signals to the CPE  22  and the CM  24 . The ports  106 - 140  are preferably radio frequency (RF) ports. The third interface  86  can include any number of blades  96 - 102  and any number of input and output ports  106 - 140  without deviating from the scope and contemplation of the present invention. 
     The CMTS  42  may be configured to output and receive any number of data streams over the ports  106 - 140 , including OOB messaging signals, HSD signals, management layer signals, video signals, and other signals. The CMTS  42  may be configured to support multiple data streams through time or frequency division multiplexed for delivery to the CPE  22  and CM  24 . In this manner, multiple data streams may be included on the HFC  18  to facilitate communication with the CPE  22  and the CM  24 . Each output port  106 - 120  is preferably separately configurable such that each output port may output different OOB messaging signals. In this manner, each blade  96 - 102  may include output ports having the same or different OOB messaging signals. 
       FIG. 5  illustrates data outputted from one of the output ports  106  in accordance with one aspect of the present invention. Preferably, OOB messaging signals are outputted on data tunnels  150  that are one-way data streams and include instructions to provision, manage, and secure the CPE  22 , and which are delivered from the CMTS  42  to the eCM  62  according to protocols defined in the DOCSIS. The OOB messaging signals may assigned to different tunnel types, such as a common broadcast tunnel type  154 , a conditional access tunnel type  156 , an application data tunnel type  158 , a code download tunnel type  160 , and an other tunnel type  162 . The broadcast tunnel  154  may be used to communicate signals for multiple subscriber stations  20 , such as Emergency Alert System (EAS) signals and other standardized messages. The conditional access tunnel  156  may be use to communicate entitlement management messages and the like. The application tunnel  158  may be used to communicate program guide data, such as for electronic programming guides (EPGs). The code download tunnel  160  may be used to deliver new operating codes and updates to the subscriber station  20 . 
     Referring to  FIG. 6 , each tunnel type  182  is preferably associated with a unique network address  184 , such as a media access control access (MAC) address. The MAC address of each tunnel type  182  may be used by the CPE  22  or other downstream device to locate desired tunnels  154 - 162 . A downstream channel descriptor (DCD) message  180 , as shown in  FIG. 6 , may be outputted over a management layer data stream  166  ( FIG. 5 ), which is preferably separate from the data tunnels  150 , for mapping or associating the different tunnel types  182  with their network addresses  184  so that devices located downstream thereof may interpret the DCD message  180  to located desired tunnel types  182 . 
       FIG. 6  illustrates a diagram of the DCD message  180  in accordance with one aspect of the present invention. The illustrated DCD message  180  is in a table format, however, the message  180  may have any form. It includes a tunnel type column  182 , a network address column  184 , and a tunnel identifier column  186 . The tunnel type column  182  identifies the tunnel types of the tunnels identified in the DCD message  180 . The network address  184  associated with the tunnel types  182  are shown in the network address column  184 . Tunnel identifiers  186  associated with the network address  184  are shown in the tunnel identifier column  186 . The tunnel identifiers  186  are unique identifiers associated with each tunnel type  182 . The tunnel types  182  are common identifiers, i.e. broadcast, conditional access, application, etc, such that the same DCD message  180  or different DCD message  180  may include the same tunnel type. In contrast, the tunnel identifier  186  is a unique identifier for each tunnel  154 - 162 , regardless of the tunnel type  182  assigned to the tunnel  154 - 162 , such that the tunnel identifier  186  may be used to differentiate between different tunnels  1542 - 162  identified with the same tunnel type  182 . For example, the CMTS  42  may be required to support CPEs  22  of different vendors such that each vendor requires a particular set of conditional access signals. In this case, the conditional access signals are provided through different conditional access tunnels  156 , whereby each conditional access tunnel  156  is identifiable by the tunnel identifier  186  associate therewith. In this manner, multiple conditional access tunnels  156  may be used within the system  10  and assigned to different CA units  68  based on the unique tunnel identifier  186 , which is preferably referred to as its conditional access identification. 
     While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.