Cisco Systems Canada Co.

Cisco Technology, Inc.

Marc Morin

John Ditner

Xiang Wan

Alexander I Leyn

The present invention relates to systems and methods for processing and transmitting data that preserves the timing relationship of the data being transmitted and/or processed. In one embodiment, the present invention uses a timestamp. The timestamp stores the timing relationship of data in the bitstream as it appeared before any processing that may alter the timing relationship of the data. The data may then be processed. By storing the original timing relationship of data, before any processing that alters the timing relationship of data, the present invention allows for the recreation of the original timing relationship between data. Thus, any jitter introduced by processing the data may be removed or substantially reduced. When the bitstream is transmitted through a processing system of the present invention, the present invention allows the processing system to process data in a manner that changes the timing relationship of the data being transmitted and transmit the data while essentially maintaining the timing relationship of the data as it was received by the processing system.

Jitterless processing of bitstreams

The present invention discloses a method and system for embedding a digital signature into an MPEG stream. In the preferred embodiment, the digital signature is embedded in a plurality of PCR fields of a transport stream and is encrypted and scrambled to avoid detection and removal. Other embodiments are disclosed, each of which is designed to place a digital signature in a pre-compressed MPEG stream while requiring minimal computing resources to encode and decode the signature.

Method and system for digitally signing MPEG streams

A system and method for the switching of control between redundant controllers is presented. The status of the redundant controllers is monitored to determine if switching of control between controllers is required. The monitoring and switching system is hardware based with control being implemented via a state machine.

System and method of operation of dual redundant controllers

A system and method of operation for connecting at least one USB function to at least two USB hosts is presented. The system of provides a USB tree between each USB host and the at least one USB function. The system further contains provisions for isolating a given USB host from the at least one USB function.

Fault tolerant communications using a universal serial bus

The invention is for a system and method for performing forward error correction on an MPEG-2 transport stream that has optional error correction information embedded within the sport stream. An error correction operation is performed on a super group of packets within the transport stream. The error correction data is inserted into a created trailer group of MPEG-2 compliant transport stream packets having no payload, but only an adaptation field The trailer group packets are optional and therefore can be discarded by a standard MPEG-2 decoder, but can also be used to recover data lost in the transmission of the transport stream. The invention results in a system and method to correct an MPEG-2 transport stream that can be used in any one of the digital video broadcast (DVB) formats, without the need for error correction decoders which are specific to the DVB format.

Forward error correction at MPEG-2 transport stream layer

The invention is for a system and method for performing forward error correction on an MPEG-2 transport stream that has optional error correction information embedded within the transport stream. An error correction operation is performed on a super group of packets within the transport stream. The error correction data is inserted into a created trailer group of MPEG-2 compliant transport stream packets having no payload, but only an adaptation field The trailer group packets are optional and therefore can be discarded by a standard MPEG-2 decoder, but can also be used to recover data lost in the transmission of the transport stream. The invention results in a system and method to correct an MPEG-2 transport stream that can be used in any one of the digital video broadcast (DVB) formats, without the need for error correction decoders which are specific to the DVB format.

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Waterloo, Canada

Marc Morin