Abstract: An apparatus and method provide non-intrusive in-service testing of audio/video synchronization testing without using traditional audio marker tones. The network includes an A/V synchronous test signal generator which injects video and audio markers into the video and audio non-intrusively and routes the two signals into a switch where they are switched into a channel for encoding and transmission via the ATM network. At the distant end the signal is decoded and routed by a switch into the A/V test generator and measurement set where the markers are detected and the A/V skew calculated, after which the audio and video are routed to the subscriber. The A/V test set signal generator includes a Video Blanking Interval (VBI) test signal generator and a white noise generator, the former injecting a marker into the video signal and the later injecting an audio marker into the audio signal.

Abstract: A switched, digital high-broadband network provides automated control and in-service and out-of-testing of analog video signals, encoded and decoded real time, into MPEG 2 digitized format with a high level of security and protection of content and without attendant degradation of the analog signal sometimes experienced in satellite transmissions. The switch network, typically an asynchronous transfer mode (ATM) network, has multiple gateways for connection to video signal sources and sinks. Each gateway includes an analog/digital video switch for receiving the video signals and distributing them to an MPEG 2 encoder for conversion into digital packets. A multiplexer is coupled to the encoder and a digital switch for inserting the multiplexed signal into the switched ATM network. The multiplexer and the digital switch encode destination address information into the digital packets to ensure proper routing.

Abstract: A switched digital video broadcast network provides in-service testing of digitized broadcast video signals subject to analog-to-digital and digital-to-analog conversion. The network includes a plurality of gateways, each gateway coupled to video signal sources and sink. Video frames transmitted on the network are subject to analog-to-digital and digital-to-analog conversion and compression in an MPEG 2 encoder/decoder. Each gateway and includes a test pattern generator and test measurement analyzer for in-service testing of the video signals. The test pattern generator inserts a test signal on pre-selected lines (22, 23 or 261,262) in a Video Blanking Interval (VBI) and time periods of a video frame. The test signal may be dynamically placed at any location in the frame using concealment techniques The video lines are not seen by television viewers.

Abstract: A high degree of stabilization of flexible PVC is achieved by using a perchlorate and a terminal epoxide compound.

Abstract: Use of a di- or polysaccharide alcohol and an inorganic or organic zinc, aluminum or rare-earth compound allows a high degree of stabilization of a halogen-containing polymer or polymer recyclate.

Abstract: A high degree of stabilization of polyvinyl chloride is achieved by using a perchlorate, a terminal epoxide compound and an antioxidant.