Scientific-atlanta, Inc.

Other

Arthur San Woo

Wayne Steven Sheldrick

Keith B Gammie

Alexander Luccisano

Brian Crookes

Gary W Chan

Anthony John Wasilewski

Robert K Yoneda

Cameron Bates

Hrad Hekimian

Keith Beverly Gammie

Wayne S Sheldrick

Gary Wc Chan

Uplink signaling for controlling a plurality of decoders at a remote site. An uplink has a control server for controlling a storage system of the decoders at the remote site. The control server of the uplink controls the storage system by injecting at least one global control stream multiplexed with a transport stream. The transport multiplexed with the global control stream is formed at the uplink for controlling the decoders simultaneously.

Uplink signaling for global decoder control

Control system with global control stream for controlling a plurality of decoders. The control system simultaneously controls a plurality of decoders at a remote location by using a global control data stream. A global control stream is a collection of data used for global applications. There are currently three global data streams&#x2014;disaster recovery, live event control, and storage control. The streams may exist on a shared or independent PID. A control server forms a transport stream and the global control stream is injected into the transport stream by the control server.

Control system with global control stream for controlling a plurality of decoders

A storage control system for a decoder. A decoder with a hardware platform for receiving and decoding coded data and a storage system for temporarily holding the decoded data from the hardware platform. A transport stream containing a global control data stream is used to manage the storage system. The global control data stream has an acquisition table (ACT) for providing a schedule of contents to be recorded, a playout control table (PCT) for providing a schedule of content that is to be played out by the decoder, and a content control table (CCT) for listing content that exists on the decoders.

Storage control system

A teletext system provides teletext services and teletext support services in a multiservice communication system. Multiplexed data streams for a plurality of services, including teletext data, are transmitted in a sequence of frames between a transmitter location and a receiver location. Teletext information is transmitted in the format of a header packet and a data packet. The header packet contains information identifying the teletext information according to page number as well as other filter fields, such as language, time zone, etc. By appropriate selection of the values of the filter fields, the operator is afforded greater flexibility in providing a variety of classes of service and service support to subscribers. In addition, the system may be easily be reconfigured to support the addition of services or the cancellation of services.

System and method for providing compressed digital teletext services and

Authorization information, such as blackout and spotlight regions, circular blackout and spotlight regions, and tier pointers, may be transmitted from an encoder to a decoder in a plurality of sessions of data frames. By spreading the authorization information over a plurality of sessions, more space may be allocated for the provision of services. In addition, the authorization information may be framed by START and STOP fields so that the length of authorization information may be variable. Calculation of a circular blackout/spotlight region can be simplified by transmitting a distortion factor from the encoder to the decoder. Accordingly, complex calculations need not be performed at a microprocessor in the decoder.

System and method for transmitting and receiving variable length

A decoder in a multiservice communication system receives a plurality of services as data streams, including video, audio, teletext, and utility data, multiplexed in sequence of frames. Each service defines a virtual channel. Virtual channel packets contained in the multiplex include information for locating the data streams that compose the virtual channels and information for decrypting the data streams. Each virtual channel packet is transmitted in the multiplex each session of frames. When a user selects more than one virtual channel at a given time, the decoder extracts a virtual channel packet for a first selected virtual channel in a first session. The decoder can then provide the decrypted data streams for the first selected virtual channel to peripheral equipment. The decoder stores the information for locating and decrypting such data streams. In each succeeding session, the decoder extracts another selected virtual channel packet and provides the decrypted data streams for that selected virtual channel and for all previously authorized selected virtual channels. When a virtual channel packet for each selected virtual channel has been processed, the decoder repeats the cycle thereby providing the data streams for each selected virtual channel.

System and method for simultaneously authorizing multiple virtual

Methods and apparatus are described for uniquely encrypting a plurality services at a transmission site and for decrypting selected services at a reception site while reducing the amount of encryption related information that must be transmitted to the reception site for decryption purposes. A unique spreading function is generated at the transmission site for each service to be transmitted. A random quantity is then transmitted, and the random quantity is convolved with each spreading function to produce a unique encryption seed for each service. At least a portion of each service is then encrypted using the unique encryption seeds produced for each service. Only the random quantity is transmitted to the reception site along with the encrypted portions of each service. None of the unique encryption seeds are transmitted. At the reception site, the unique spreading functions generated at the transmission site for each service are regenerated. A selected service is then decrypted by (i) convolving the received random quantity with the regenerated spreading function associated with the selected service to reproduce the unique encryption seed used to encrypt the received encrypted portion of the selected service at the transmission site, and (ii) decrypting the received encrypted portion of the selected service using the reproduced encryption seed. By transmitting only the random quantity, and then reproducing the encryption seeds at the reception site, the amount of encryption related information transmitted to the reception site is greatly reduced.

Method and apparatus for uniquely encrypting a plurality of services at

A method for transmitting information over a communication network between a population of remote terminals and a central location having a capacity of simultaneously communicating with a predetermined number of remote terminals in the population. A first time period is fixed during which every remote terminal may initiate one attempt to communicate with the central location over the communication network. Respective times within the first time period are established at which each of the remote terminals will initiate its attempt to communicate with the central location. A number of the remote terminals which successfully communicate with the central location to transmit information therebetween is monitored. The first time period is then decreased to a second time period if the number of remote terminals which successfully communicate with the central location is less than the capacity of the central location. Respective times within the second time period are then established at which remote terminals which have not initiated their respective attempts to communicate with the central location will initiate their attempts to communicate with the central location. The above steps are repeated to establish a time period at which the number of remote terminals which communicate with the central location is approximately equal to the capacity of the central location. The time period thus set is maintained until each of the remote terminals has initiated its attempt to communicate with the central location.

Data return for a television transmission system

A decoder for descrambling encoded satellite transmissions comprises an internal security module and a resplaceable security module. The program signal is scrambled with a key and then the key itself is twice-encrypted and multiplexed with the scrambled program signal. The key is first encrypted with a first secret serial number (SSN.sub.1) which is assigned to a given replaceable security module. The key is then encrypted with a second secret serial number (SSN.sub.2) which is assigned to a given decoder. The decoder performs a first key decryption using the second secret serial number (SSN.sub.2) stored within the decoder. The partially decrypted key is then further decrypted by the replaceable security module using the first secret serial number (SSN.sub.1) stored within the replaceable security module. The decoder then descrambles the program using the twice-decrypted key. The replaceable security module can be replaced, allowing the security system to be upgraded or changed following a system breach. Either security module may become the active security module to finally decrypt the seed, selectable by a signal transmitted from the encoder. Also disclosed is a method for transmitting the encrypted keys and secret serial numbers to a plurality of broadcasters who may in turn multiplex this signal with their own program signals so that any given channel received by a subscriber contains the key and secret serial numbers. Additionally, the decoder may be upgradeable to accept both analog and digital video signals without significant redundant circuitry.

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Scarborough, Canada

Arthur San Woo