Abstract: A cable distribution system that includes a head end connected to a plurality of customer devices through a transmission network that includes a remote fiber node that converts digital data to analog data suitable for the plurality of customer devices, where the head end includes a processor. A packetized elementary stream of a video is provided from the head end to customer devices through the transmission network, wherein the packetized elementary stream includes a plurality of groups comprising pairs of packetized elementary stream headers and packetized elementary stream payloads. A first one of the plurality of groups corresponding to a non-predicted coded picture of the video of the packetized elementary stream is determined. The first one of the plurality of groups is encrypted while not encrypting all of the plurality of groups of the video.

Abstract: A cable distribution system that includes a head end connected to a plurality of customer devices through a transmission network that includes a remote fiber node that converts digital data to analog data suitable for the plurality of customer devices, where the head end includes a processor. A packetized elementary stream of a video is provided from the head end to customer devices through the transmission network, wherein the packetized elementary stream includes a plurality of groups comprising pairs of packetized elementary stream headers and packetized elementary stream payloads. A first one of the plurality of groups corresponding to a non-predicted coded picture of the video of the packetized elementary stream is determined. The first one of the plurality of groups is encrypted while not encrypting all of the plurality of groups of the video.

Abstract: A method and system for modulating data onto a carrier signal in a plurality of channels, each of the channels having a channel bandwidth, can be created for use in any two-way satellite communication system or other wireless communication application where frequency hopping with or without Doppler compensation is desired. The system preferably includes a digital modulator that outputs a modulated baseband signal, an intermediate frequency modulator that receives the modulated baseband signal and outputs an intermediate frequency signal derived from the modulated baseband signal, a frequency synthesizing system that outputs a synthesized intermediate frequency signal to the intermediate frequency modulator, and a circuit (numerically controlled oscillator) connected to the digital modulator which provides a signal to the digital modulator.

Abstract: A method and system for modulating data onto a carrier signal in a plurality of channels, each of the channels having a channel bandwidth, can be created for use in any two-way satellite communication system or other wireless communication application where frequency hopping with or without Doppler compensation is desired. The system preferably includes a digital modulator that outputs a modulated baseband signal, an intermediate frequency modulator that receives the modulated baseband signal and outputs an intermediate frequency signal derived from the modulated baseband signal, a frequency synthesizing system that outputs a synthesized intermediate frequency signal to the intermediate frequency modulator, and a circuit (numerically controlled oscillator) connected to the digital modulator which provides a signal to the digital modulator.