Abstract: Systems and methods for digitizing broadband signals using multiple analog-to-digital converters (ADCs) and a calibration system for adjusting the phase and bias of the sampled signal such that the output digitized, sample closely approximates the input broadband analog signal. A calibration signal is combined with the broadband signal and the combined signal is converted to digital. The combined signal splits into portions equal to the number of ADCs in the system. An off-line digital signal processor (DSP) analyzes samples representing a portion of the combined signal and computes any necessary adjustments to phase and amplitude of the digitized samples. If adjustments are required, a real-time DSP adjusts the phase and amplitude of the digitized sample, by use of a multiplier and/or adder included in the real-time DSP. The separate portions of the digitized sample are recombined by a multiplexer to create a single digitized output representing the broadband analog signal.

Abstract: An optical fiber (10) made with a central core (12), a first cladding layer (16), and a second cladding layer (18) having a series of perturbations or irregularities formed into the otherwise generally circular outer boundary of the first cladding layer (16). The irregularities in the first cladding layer (16) interrupt the propagation of skew rays and encourage coupling into the core (12).

Abstract: Techniques for determining an output rate for a bit stream, the output rate being determined by applying information read from the bit stream to available bandwidths. The techniques are employed to construct a statistical multiplexer 80 that multiplexes varying bit-rate bit streams. Minimum and maximum output rates for each bit stream are determined such that neither a queue for the bit stream in the multiplexer nor the bit stream's decoder will underflow or overflow. The multiplexer first allocates each bit stream its minimum bandwidth and then allocates any remaining bandwidth to the bit streams in proportion to the difference between the minimum and maximum output rates for the bit streams, with no bit stream receiving more than its maximum output rate. If there is not enough bandwidth to give every bit stream its minimum rate, glue frames may be inserted, or low priority channels dropped.

Abstract: An asymmetrical network for coupling customer-premises Internet hosts such as personal computers to the Internet. The head end of a CATV system has a high-bandwidth connection to the Internet. The down link connecting the personal computers to the Internet is the cables provided by the CATV system; the up link is a telephone connection to the head end. A router is connected to the down link by means of an RF modem, to the up link by means of an analog modern, and to a LAN which is connected to the Pcs. The router routes IP packets for the hosts that are received on the CATV cable to the hosts via the LAN; it routes IP packets from the hosts that are destined for the Internet to the head end via the telephone line. The asymmetrical network conserves IP addresses and addresses on the CATV cable by dynamically allocating the IP addresses for an RF modem's hosts and an address on the CATV cable for the RF modem in response to a request made by the RF modem via the telephone line.

Abstract: A broadcast file system organizes data sent to a client by broadcast via a high capacity data broadcast delivery network from a plurality of servers. The data is organized into a hierarchical file system including a directory index. A server registers to send data via the broadcast file system of the present invention and is assigned a respective directory. The server may create, modify, or delete a subdirectory or a file under the respective directory of that server. The directory index is periodically broadcast. The client caches this directory index and presents the directory index to a client application. The client application may request a portion of data from the directory index. The data available from the plurality of servers is periodically broadcast to the client, and the client filters out the requested portion of data to be provided to the client application.

Abstract: A cable television tap (500) for receiving a forward signal including an information signal and a power signal. The tap (500) includes a diplex filter (520) for receiving the forward signal and for separating the information signal from the power signal at outputs of the diplex filter (520) and a plurality of subscriber ports (535) coupled to an output of the diplex filter (520) for receiving the information signal such that the information signal can be accessed at each of the plurality of subscriber ports (535). The tap (500) also includes a removable port device (555) coupled to the other output of the diplex filter (520) for receiving the power signal, and the port device (555) has a connector (550) so that the power signal can be accessed. According to the present invention, when the port device (555) is coupled to the tap (500), the information signal can only be accessed at the subscriber ports (535), and the power signal can only be accessed at the connector (550) of the port device (555).

Abstract: A computer-implemented method and apparatus for restoring operating systems within a set-top box system. The restoration provides for operating a first operating system in a first memory. An application program is operated in a second memory. The first operating system is stored in a second memory so that a second operating system is loaded into the first memory. When a predetermined condition which is associated with the second operating system is detected, the first operating system is loaded into the first memory in response to the detected predetermined condition. Such a system provides such non-limiting advantages to the set-top box as the ability to robustly recover from errors or anomalies associated with downloading an operating system.

Abstract: An electronic module that includes a housing and electronics that has a divider (215) that is substantially conductive, rectangular, and planar. The divider (215) is hingeably coupled to the housing with hinges (225). The divider (215) defines an upper section (210) and a lower section (205) within the housing, wherein the divider (215), in an open position, allows access to electronics (223) within the lower section (205), and the divider (215), in a closed position, allows access to electronics (223) within the upper section (210). The divider (215), in the closed position, provides electromagnetic shielding between the electronics (223) in the upper section (210) and the electronics (223) in the lower section (205).

Abstract: A cable television system (100) having forward and reverse paths includes, in the reverse path, a digital optical transmitter (200) for receiving an RF signal, converting it to a digital signal, and adding a digital pilot tone thereto. A laser is driven in accordance with the summed digital signal to generate a digital optical signal representative of the pilot tone and the RF signal. The cable television system (100) also includes an optical receiver (305)for receiving the digital optical signal and recovering therefrom the RF signal and the pilot tone. The optical transmitter (200) and receiver (305) are coupled by fiber optic communication media (110).

Abstract: The disclosed invention relates to a pick list generator which displays selectable terms for inclusion in a selection field. One embodiment of the pick list generator is in assisting an Internet user in the user's population of search fields without the use of a keyboard containing all 26 letters and 10 digits. Accordingly, through application of the present invention, browsing and searching of the Internet is enhanced for the keyboardless user.

Abstract: A cable television system (100) for transmitting information in forward and reverse directions includes forward and reverse paths over which information is transmitted and a reverse path transmitter (305) and a reverse path receiver (405), both located in the reverse path. The reverse path transmitter (305) receives an analog electrical signal and an external digital signal from an external source, such as a PCS terminal or router. The transmitter (305) then generates a single digital bit stream from the external digital signal and the digital electrical signal and transmits the single digital bit stream modulated at a first wavelength over a fiber optic communication medium (110) that couples the transmitter (305) and the reverse path receiver (405).

Abstract: A cable television system (700) includes a clock source (710) for generating a clock signal, an optical receiver (605) coupled to the clock source (710) for recovering the information in accordance with the clock signal, and an optical transmitter (800) that has input ports (720) for receiving first and second information signals and a clock port (760) for receiving the clock signal. An interleaver (745) within the transmitter (800) is coupled to the input ports (720) and to the clock port (760). The interleaver (745) interleaves bits of the information signals in accordance with the clock signal to generate a serial bit stream that is used to modulate a laser diode (750), thereby generating a digital optical signal that is transmitted to the optical receiver (605) over an optical communication medium (110).

Abstract: An amplifier (600) includes a first terminal (605) for receiving forward signals in a first frequency band and a second terminal (655) for receiving reverse signals in a second frequency band. A single gain block (630) is coupled between the first terminal (605) and the second terminal (655) for amplifying the forward signals and the reverse signals. The forward signals, after amplification, are provided to the second terminal (655) for transmission from the amplifier (600), and the reverse signals, after amplification, are provided to the first terminal (605) for transmission from the amplifier (600). In this manner, both forward and reverse signals, which are transmitted in separate frequency bands, can be amplified by a single gain block (630).

Abstract: Apparatus for a cable television subscriber to log onto a computer network with a modem over an upstream path using a USERID and password. The network validates the subscriber USERID and subscriber password with a stored database of valid USERIDs and associated passwords. After the USERID and password are validated, the modem then provides its electronic serial number to the network for validation against a stored database of authorized serial numbers. Upon additional validation of the modem's serial number, the subscriber is authorized to use the network.

Abstract: Systems and methods for providing for a single piece, hinged cable routing device for use with cables. The device includes sections hingedly connected allowing each section to flex and bend. The device can include fingers on an upper portion of the device. Upon pushing a cable through the fingers, the cable securely remains in position within the device. In a preferred embodiment, the device connects cables to an amplifier housing in a cable television network. When the amplifier housing closes, the device folds securely within the amplifier housing ensuring the cable remains in a position within the amplifier housing that avoids electrical interference and noise.

Abstract: Apparatus for recording and collecting usage and other statistical data from components of a cable data network comprises a network manager for maintaining and collecting the statistics. Internet protocol addresses are associated with components of the network. The component maintains a software agent that manages a statistics database. Responsive to a manager request generated at a service provider defined time interval, the component software agent provides the usage statistics to the network manager in real-time during an Internet session with a host. When the host to Internet or other data connection is torn down due to failure, disconnect or inactivity time-out, remaining usage statistics data is collected and the session duration updated with the time of tear down.

Abstract: A video memory handling system and method for providing a graphic computer-implemented process with a predetermined amount of video memory to be used by the graphic process to perform a predetermined graphic-related operation within a set-top box environment. A first video memory portion is provided which has an allocation status with respect to the graphic process. A video memory handling data structure indicates the allocation status of the first video memory portion. A video memory manager which is connected to the video memory handling data structure reallocates the first video memory portion based upon the video memory handling data structure. The reallocated first video memory portion is utilized by the graphic process to perform the predetermined graphic-related operation.

Abstract: An asymmetrical network for coupling customer-premises Internet hosts such as personal computers to the Internet. The head end of a CATV system has a high-bandwidth connection to the Internet. The down link connecting the personal computers to the Internet is the cables provided by the CATV system; the up link is a telephone connection to the head end. A router is connected to the down link by means of an RF modem, to the up link by means of an analog modem, and to a LAN which is connected to the Pcs. The router routes IP packets for the hosts that are received on the CATV cable to the hosts via the LAN; it routes IP packets from the hosts that are destined for the Internet to the head end via the telephone line. The asymmetrical network conserves IP addresses and addresses on the CATV cable by dynamically allocating the IP addresses for an RF modem's hosts and an address on the CATV cable for the RF modem in response to a request made by the RF modem via the telephone line.

Abstract: A communication system (300) includes amplifiers (325) having an improved thermal response. The amplifiers (325) include a Bode circuit (208) for attenuating the signals and a thermal compensation circuit (320) for adjusting the gain in response to changes in temperature. The thermal compensation unit (320) provides a non-linear impedance to offset for the non-linear performance of the amplifiers gain versus control current. The thermal compensation unit (320) has circuit paths that are selectively turned on to provide the non-linear relationship of impedance versus input control voltage.