Scientific-atlanta, Inc.

Cisco Technology, Inc.

Other

Keith B Gammie

Wayne Steven Sheldrick

Arthur San Woo

Alexander Luccisano

Kenn W Heinrich

Brian E Crookes

David Verbrugge

Brian Crookes

Anthony John Wasilewski

Robert K Yoneda

Cameron Bates

Gary W Chan

Hrad Hekimian

Systems and methods for combining a plurality of transport streams into a single transport stream for transmission to, e.g., a single frequency network via a satellite. Embodiments provide receiving a plurality of original, e.g., MPEG-compliant, data streams, where each original data stream has its own timing information, combining the plurality of original data streams into a single combined data stream which is also, e.g., MPEG compliant, modulating the single combined data stream for uplink to a satellite, receiving a downlink transmission from the satellite, where the downlink transmission includes the single combined data stream, de-combining the single combined data stream into the plurality of original data streams, and passing respective original data steams to, e.g., one or more DVB-T modulators for broadcast into a single frequency network.

Secure combined interoperable multiplexing

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 decoder for descrambling encoded satellite transmissions comprises an internal security element and a replaceable 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) which is assigned to a given replaceable security module. The key is then encrypted with a second secret serial number (SSN) which is assigned to a given decoder. The decoder performs a first key decryption using the second secret serial number (SSN) stored within the decoder. The partially decrypted key is then further decrypted by the replaceable security module using the first secret serial number (SSN) 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.

External security module for a television signal decoder

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

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

In a data transmission system comprising a plurality N of transmission sites and at least one reception site, a set of data at each transmission site is uniquely encrypted by (a) providing each transmission site with a broadcast key unique to that transmission site and a system key that is the same for all transmission sites, the system key comprising a plurality S of bits and each of the broadcast keys comprising a unique plurality B of bits, wherein B is less than S; (b) convolving in a predetermined manner at each transmission site the system key and the broadcast key unique to that transmission site to generate a unique data encryption key for that transmission site; (c) encrypting the set of data at each transmission site with the unique data encryption key generated at that site. The sets of data uniquely encrypted at each transmission site are then transmitted to the reception site. There is stored, in a memory at the reception site, the system key and the of said broadcast keys to enable a selected one of the encrypted sets of data to be decrypted at the reception site. The memory capacity necessary to store the system key and the broadcast keys at the reception site is no greater than ((N.times.B)+S) bits. Alternatively, a plurality N of data sets at a single transmission site are encrypted in this manner.

Methods and apparatus for uniquely encrypting data at a plurality of

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.

Independent external security module for a digitally upgradeable

A decoder for use in a television system. The decoder includes a receiver for receiving a television signal having at least one channel. Each channel of the television signal includes video and audio components. A channel maps the channel received by the receiver to a plurality of virtual channels. A first virtual channel utilizes a first combination of video and audio components of the received channel and a second virtual channel utilizes a second combination of video and audio components of the same received channel different than the first combination. A selector allows a subscriber to select one of the virtual channels. Linked text pages may also be mapped to one or more of the virtual channels.

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Markham, Canada

Keith B Gammie