Abstract: A Time Slotted Logical Ring protocol manages the flow of traffic in a duplex media including a cable distribution network with a head end, a local node, and a group of subscribers. The subscriber includes a cable modem which produces an HDLC serial interface which then goes to the subscriber or gets converted to ethernet by a router and then to the subscriber. The Time Slot portion of TSLR protocol manages upstream and downstream access and uses time tick identification frames in the downstream direction to control upstream traffic. A multiple logical ring protocol in TSLR is used to allocate cable bandwidth between the multiple subscribers.

Abstract: A master Timestamp Synchronization Circuit (TSC) in a Cable Modem Termination System (CMTS) estimates a master timestamp value for an upcoming time reference. The master TSC sends the master timestamp value asynchronously over an Internet Protocol (IP) network to slave TSCs in other CMTSs. The slave TSC compares a local timestamp value with the master timestamp value when the upcoming time reference occurs. If the local timestamp value does not match the master timestamp value, the slave TSC is resynchronized using the master timestamp value.

Abstract: An improved addressing scheme is disclosed for use in access networks. According to a specific embodiment, upstream and/or downstream channels may be grouped together based upon logical associations rather than physical associations. Further, according to at least one embodiment of the present invention, various techniques are described for routing selected channel MAP messages to appropriate channels and/or nodes within the access network.

Abstract: A proxy in a cable modem termination system receives IP packets having an address associated with set top box out of band messages. The proxy encapsulates the packets in an Ethernet frame containing an Ethernet address. A cable modem associated with the set top box is preconfigured to detect the Ethernet encapsulated packets and pass the out of band messages in the packets to the set top box.

Abstract: A packet fiber node is described for use in an access network such as, for example, a cable network. The packet fiber node may differ from convention RF fiber nodes deployed in a cable network in that the packet fiber node is configured to communicate with the Head End of the network using baseband optical signals rather than frequency modulated optical signals. According to a specific embodiment of the present invention, one or more packet fiber nodes may be deployed in a cable network to service a plurality of different subscriber groups which are serviced by a single, conventional RF fiber node.

Abstract: A master clock reference signal may be provided to selected packet fiber nodes in order to synchronize the local clock reference signals generated at selected devices in a cable network. In this way, selected portions of the cable network may be synchronized to a common timing reference signal. Additionally, synchronized timestamp information may also be provided to selected network devices in order to achieve synchronization of timestamps across a selected portion of the cable network.

Abstract: A dynamic channel change technique is disclosed which may be implemented between nodes and a Head End of an access network. Initially a network device may communicate with the Head End via a first downstream channel and a first upstream channel. When the network device receives a dynamic channel change request which includes instructions for the network device to switch to a second downstream channel, the network device may respond by switching from the first downstream channel to the second downstream channel. Thereafter, the network device may communicate with the Head End via the second downstream channel and first upstream channel. Further, according to a specific embodiment, the dynamic channel change request may also include an upstream channel change request for causing the network device to switch from a first upstream channel to a second upstream channel.

Abstract: An improved addressing scheme is disclosed for use in access networks. According to a specific embodiment, upstream and/or downstream channels may be grouped together based upon logical associations rather than physical associations. Further, according to at least one embodiment of the present invention, various techniques are described for routing selected channel MAP messages to appropriate channels and/or nodes within the access network.

Abstract: A technique is described which may be used to synchronize a plurality of different access controllers which control a plurality of distinct ports at the Head End of an access network. In the context of a cable network, the technique of the present invention may be used to synchronize desired upstream and/or downstream channels across different line cards within a Cable Modem Termination System (CMTS). The technique involves utilizing a master time reference device which maintains and updates a current time reference, and periodically distributes synchronization signals to desired line cards in the system in order to synchronize these line cards. In a specific embodiment, the synchronization signals include current timestamp data generated from the master time reference device and distributed to all (or selected) line cards in the system.

Abstract: A first packet processing node in a header suppression mode suppresses transmission of one or more packet headers. A second packet processing node receives the packets from the first packet processing node over a network medium and sends the received packets to an endpoint. The second packet processing node includes a memory that contains the packet headers suppressed by the first packet processing node and appends the stored headers to the suppressed packets before sending the packets to the endpoint. Cable modems (CMs) include one or more Service Identifiers (SIDs) for establishing communication channels (microflows) with a Cable Modem Termination System (CMTS) through a cable medium. In another aspect of the intention, a cable modem network protocol is used between the CMTS and the CM to dynamically establish and modify multiple microflows between the CMTS and CM on the same cable modem SID.

Abstract: A synchronizer circuit manages signals in different clock domains by generating clock pulses synchronized with a system clock. The clock pulses are generated at a rate proportional to the frequency of a clock operating in a first clock domain. Digital circuitry is then driven at the frequency of the first clock and in the time domain of the system clock. A hand-shaking protocol prevents the synchronizer circuit from going into a metastable condition when passing clock or data signals into different time domains. A programmable digital filter includes multiple sampling stages that sample an input signal. A detection circuit has inputs coupled to the outputs of the multiple sampling stages and changes the logic state of an output signal when no glitches are detected in the samples of the input signal. A control circuit selectively varies a time period used by the filter for sampling the input signal.

Abstract: The invention uses a novel signaling protocol for conducting call waiting-caller ID messaging. Instead of waiting for an acknowledge back from the caller ID box, an acknowledge signal is generated locally at a gateway. This allows the packet switched network to meet the timing requirements of the circuit switched network. The gateway tricks the central office switch into believing an actual acknowledge signal was sent from the caller ID box. The central office switch accordingly sends the caller ID information. This ID information is then propagated across the IP network to the caller ID box.

Abstract: A wideband cable modem system increases available bandwidth of a single channel by encoding a data stream into wideband packets. The wideband packets are associated with a logical wideband channel that extends over multiple physical downstream cable channels.

Abstract: Unsolicited grants are allocated a selected time interval for scheduling transmission of audio packets at a network endpoint. A network processing node switches from outputting unsolicited grants to polling for packet transmission requests when Voice Activity Detection (VAD) at the transmitting endpoint stops generating audio packets. The network processing node switches back to outputting unsolicited grants when the endpoint resumes generation of audio packets. The unsolicited grants include one or more additional grants within the selected time interval that flush out one or more audio packets that may already be queued for transmitting. These additional grants reduce the latency normally caused when Voice Activity Detection (VAD) stops and then restarts audio packet transmission.

Abstract: A first packet processing node in a header suppression mode suppresses transmission of one or more packet headers. A second packet processing node receives the packets from the first packet processing node over a network medium and sends the received packets to an endpoint. The second packet processing node includes a memory that contains the packet headers suppressed by the first packet processing node and appends the stored headers to the suppressed packets before sending the packets to the endpoint. Cable modems (CMs) include one or more Service Identifiers (SIDs) for establishing communication channels (microflows) with a Cable Modem Termination System (CMTS) through a cable medium. In another aspect of the intention, a cable modem network protocol is used between the CMTS and the CM to dynamically establish and modify multiple microflows between the CMTS and CM on the same cable modem SID.

Abstract: A Time Slotted Logical Ring protocol manages the flow of traffic in a duplex media including a cable distribution network with a head end, a local node, and a group of subscribers. The subscriber includes a cable modem which produces an HDLC serial interface which then goes to the subscriber or gets converted to ethernet by a router and then to the subscriber. The Time Slot portion of TSLR protocol manages upstream and downstream access and uses time tick identification frames in the downstream direction to control upstream traffic. A multiple logical ring protocol in TSLR is used to allocate cable bandwidth between the multiple subscribers.

Abstract: An add/drop multiplexer in a cable network multiplexes data from different sources together on a common cable television channel without corrupting MPEG time stamps. An idle insertion circuit coupled to a first data source inserts, if necessary, a selectable guaranteed minimum number of idle frames into a first bit stream. If the number of naturally occurring idle frames is above the guaranteed minimum number, the idle insertion circuit does not force idle frames into the first bit stream. A multiplexer is coupled between the idle insertion circuit and a second data source and replaces data with idles in the first bit stream from the second data source. The idles inserted into the bit stream are used to control the amount of bandwidth allocated to the second data source.

Abstract: A first packet processing node in a header suppression mode suppresses transmission of one or more packet headers. A second packet processing node receives the packets from the first packet processing node over a network medium and sends the received packets to an endpoint. The second packet processing node includes a memory that contains the packet headers suppressed by the first packet processing node and appends the stored headers to the suppressed packets before sending the packets to the endpoint. Cable modems (CMs) include one or more Service Identifiers (SIDs) for establishing communication channels (microflows) with a Cable Modem Termination System (CMTS) through a cable medium. In another aspect of the intention, a cable modem network protocol is used between the CMTS and the CM to dynamically establish and modify multiple microflows between the CMTS and CM on the same cable modem SID.

Abstract: A generic serial interface includes any one of multiple transition cables having a first connector conforming to one of several different serial interface standards. A second generic connector is connected to a second end of the transition cables. A configurable interface circuit is coupled to the generic connector and is automatically reconfigured according to the physical interface type associated with the transition cable. The interface circuit includes a termination resistor array that can connect different termination resistor values to the same generic signals on the generic connector according to the interface type. The termination resistor array in combination with a unique designation of generic signals allow a single interface to operate with many different serial interface standards both in DCE and DTE modes while requiring substantially fewer connector pins and simpler interface circuitry than existing generic interfaces.

Abstract: An electrical cable includes a connector that contains an electrically conductive shunt. The shunt includes multiple electrically conductive clips that shunt selected wires in the connector together. The chips are removable so that different combinations of wires can be shunted together. The clips each comprise a pair of vertically aligned fingers extending perpendicularly from a top surface of a mounting plate. The fingers on each clip include oppositely aligned tapered top ends forming a wide opening for receiving the cable wire. The clips extend longitudinally along an entire front end and longitudinally along an entire rear end of the mounting plate. The clips on the front end of the shunt are offset from the clips in the rear end so that each clip aligns with only one wire in the connector.