Abstract: A digital headend architecture and full service network are provided to selectively demodulate and decode a variety of digital and analog feeds into baseband signals or pass digital programming through the headend. In accordance with one embodiment, the head end is provided with digital-turn-around capability to allow precompressed signals to passed through the head end with out any decompress or decoding into baseband signals. The head end includes at least one receiver for receiving signals sent by satellite, at least one antenna for receiving over-the-air signals as baseband composite video and audio signals, and a decoder connected to the at least one receiver for converting received satellite signals into baseband video and audio signals. At least one MPEG encoder is provided for encoding the baseband video and audio composite signals into multiplexed Single Program Transport Streams (SPTS).

Abstract: A VDSL based broadband data communication network system is provided that utilizes ATM/IP all the way to an end user PC, thereby allowing selectable bit rate delivery to the end users, with a Class of Service (COS) and Quality of Service (QOS) selection. A headend is connected to external Internet service providers and a network central office, and is arranged to receive and send multi-protocol signals to the Internet service provider, and receive and send ATM signals to the central office. This VDSL data architecture is very functional and flexible with the capability of supporting such services as streaming video and audio, voice over IP, digital advertisements, videoconferencing, gaming, business-to-business service, E-commerce, video-on-demand, and interactive TV. The VDSL data network will support very high-speed two-way data services over fiber optics using SONET, Dense Wavelength Division Multiplexing, IP, ATM, and other transport systems.

Abstract: A digital headend architecture and full service network are provided to selectively demodulate and decode a variety of digital and analog feeds into baseband signals or pass digital programming through the headend. In accordance with one embodiment, the head end is provided with digital-turn-around capability to allow precompressed signals to passed through the head end with out any decompress or decoding into baseband signals. The head end includes at least one receiver for receiving signals sent by satellite, at least one antenna for receiving over-the-air signals as baseband composite video and audio signals, and a decoder connected to the at least one receiver for converting received satellite signals into baseband video and audio signals. At least one MPEG encoder is provided for encoding the baseband video and audio composite signals into multiplexed Single Program Transport Streams (SPTS).

Abstract: An improved Mach-Zehnder integrated optical electro-optic modulator is achieved by application and incorporation of a DC bias box containing a laser synchronized trigger circuit, a DC ramp and hold circuit, a modulator transfer function negative peak detector circuit, and an adjustable delay circuit. The DC bias box ramps the DC bias along the transfer function curve to any desired phase or point of operation at which point the RF modulation takes place.