Abstract: A wireless communication system performs high-quality communication using Multicast communication where re-transmission processing is performed. The wireless communication system includes a program distribution unit for distributing a program using the Multicast communication; a first communication path for transmitting the program distributed from the program distribution unit; first communication units; user terminals; and a second and the user terminal and is also a wireless communication path where the re-transmission of a frame is performed, wherein the first communication unit selects a Multicast frame of a program requested by the user terminal from the first communication path, converts the selected Multicast frame into a Unicast frame, and transmits the converted Unicast frame to the user terminal.

Abstract: A packetized transport stream for protecting viewing content from unauthorized access and methods for manufacturing and using same. The transport stream includes a plurality of content frames, each having a frame header and a frame payload. Each frame header includes information for handling the content frame; whereas, the frame payload includes selected viewing content for which protection from unauthorized access is desirable. By encrypting only the frame payload, the header remains unencrypted and can be applied to prepare the encrypted frame payload for presentation. The viewing content thereby can be stored in an encrypted format and can be decrypted on-the-fly as the viewing content is needed for presentation. The combination of the unencrypted frame header and the encrypted frame payload advantageously enables the viewing content to be protected against unauthorized use, copying, and dissemination without impairing the presentation of the viewing content.

Abstract: A packetized transport stream for protecting viewing content from unauthorized access and methods for manufacturing and using same. The transport stream includes a plurality of content frames, each having a frame header and a frame payload. Each frame header includes information for handling the content frame; whereas, the frame payload includes selected viewing content for which protection from unauthorized access is desirable. By encrypting only the frame payload, the header remains unencrypted and can be applied to prepare the encrypted frame payload for presentation. The viewing content thereby can be stored in an encrypted format and can be decrypted on-the-fly as the viewing content is needed for presentation. The combination of the unencrypted frame header and the encrypted frame payload advantageously enables the viewing content to be protected against unauthorized use, copying, and dissemination without impairing the presentation of the viewing content.

Abstract: A packetized transport stream for protecting viewing content from unauthorized access and methods for manufacturing and using same. The transport stream includes a plurality of content frames, each having a frame header and a frame payload. Each frame header includes information for handling the content frame; whereas, the frame payload includes selected viewing content for which protection from unauthorized access is desirable. By encrypting only the frame payload, the header remains unencrypted and can be applied to prepare the encrypted frame payload for presentation. The viewing content thereby can be stored in an encrypted format and can be decrypted on-the-fly as the viewing content is needed for presentation. The combination of the unencrypted frame header and the encrypted frame payload advantageously enables the viewing content to be protected against unauthorized use, copying, and dissemination without impairing the presentation of the viewing content.

Abstract: A radio communication system includes radio terminal apparatuses each arranged at a previously determined position, radio base station apparatuses for holding radio communications with these apparatuses, and a communication system controller for communicating with the respective radio terminal apparatus via the respective radio base station apparatuses connected thereto via a LAN.

Abstract: A network system includes a transmitting apparatus; a transmission path; a relaying apparatus that receives real time information transmitted through the transmission path; a wireless network; and a receiving apparatus that receives data transmitted through the wireless network. The relaying apparatus has a reference time generating part that generates a reference time independently of the transmitting apparatus; and a network transmitting part that transmits both the real time information received from the transmitting apparatus and the reference time via the wireless network.

Abstract: High-quality communication using Multicast is realized in wireless communication where re-transmission processing is performed. The present invention includes: a program distribution unit (100) for distributing a program using the Multicast communication; a first communication path (Y1) for transmitting the program distributed from the program distribution unit (100); first communication units (102a, 102b); user terminals (105a to 105h); and a second communication path (103) which is a communication path between the first communication unit (102a, 102b) and the user terminal and is also a wireless communication path where the re-transmission of a frame is performed, wherein the first communication unit (102a or 102b) selects a Multicast frame of a program requested by the user terminal (105a to 105h) from the first communication path (Y1), converts the selected Multicast frame into a Unicast frame, and transmits the converted Unicast frame to the user terminal (105a to 105h).

Abstract: A personal computer (101) includes a control signal output unit (104) that outputs, to a display device (113), a control signal for switching between a TV format video signal and a computer format video signal while the display device (113) includes an input switching unit (114) operable to perform, based on the control signal outputted from the personal computer (101), input switching, for display, between the TV format video signal and the computer format video signal.

Abstract: A network system includes a transmitting apparatus; a transmission path; a relaying apparatus that receives real time information transmitted through the transmission path; a wireless network; and a receiving apparatus that receives data transmitted through the wireless network. The relaying apparatus has a reference time generating part that generates a reference time independently of the transmitting apparatus; and a network transmitting part that transmits both the real time information received from the transmitting apparatus and the reference time via the wireless network.

Abstract: A packetized transport stream for protecting viewing content from unauthorized access and methods for manufacturing and using same. The transport stream includes a plurality of content frames, each having a frame header and a frame payload. Each frame header includes information for handling the content frame; whereas, the frame payload includes selected viewing content for which protection from unauthorized access is desirable. By encrypting only the frame payload, the header remains unencrypted and can be applied to prepare the encrypted frame payload for presentation. The viewing content thereby can be stored in an encrypted format and can be decrypted on-the-fly as the viewing content is needed for presentation. The combination of the unencrypted frame header and the encrypted frame payload advantageously enables the viewing content to be protected against unauthorized use, copying, and dissemination without impairing the presentation of the viewing content.

Abstract: A personal computer (101) includes a control signal output unit (104) that outputs, to a display device (113), a control signal for switching between a TV format video signal and a computer format video signal while the display device (113) includes an input switching unit (114) operable to perform, based on the control signal outputted from the personal computer (101), input switching, for display, between the TV format video signal and the computer format video signal.

Abstract: The present invention provides a video and audio signal multiplex transmitting apparatus having a video and audio signal multiplex sending apparatus for grouping audio data to packets of a fixed length in the sending side, and multiplexing video and audio signals by multiplexing horizontal and vertical phase signal outputs from horizontal and vertical counters that are in synchronization with a video signal to an audio data as video phase information, and a video and audio signal multiplex receiving apparatus provided with an audio packet interpolating device for separating the signal received to video and audio signals, detecting, if any audio data is lost, a lost audio data from a data block number of the audio data and audio clock phase information, and recovering an audio clock by means of horizontal and vertical counters and the clock phase information transmitted.

Abstract: A video data transmitter includes: chrominance-data multiplexer which multiplexes parallel data obtained by digitizing a chrominance signal Pb, which is a component signal of an analog HDTV video signal, with parallel data obtained by digitizing a chrominance signal Pr; a word multiplexer which multiplexes parallel data obtained by digitizing a luminance signal Y, which is a component signal of analog HDTV video signal, with the output data of the chrominance-data multiplexer, and a parallel-to-serial converter which converts the parallel data output from the word multiplexer. A video data receiver includes a serial-to-parallel converter which converts received serial data into parallel data and a word separator which separates the output data of the serial-to-parallel converter into parallel data in the Y channel and parallel data in the Pb/Pr channel.

Abstract: A frame synchronizing apparatus is disclosed which includes a serial-parallel converter for converting input serial data into parallel data of a plurality of channels; a plurality of intra-channel synchronization detecting circuits each for detecting a synchronization pattern and a pseudo-synchronization pattern in one channel, and generating a channel synchronization detect signal and a pseudo-synchronization detect signal in one channel; a plurality of bit-shift error pattern detecting circuits each for detecting a bit-shift error pattern in one channel, and generating a bit-shift error pattern signal in one channel; a synchronization/bit-shift error detecting circuit for detecting a synchronization between channels and specifying the amount of erroneously shifted bits, and generating a frame synchronization detect signal and bit-shift error detect signals; and a bit-shift signal generating circuit for calculating the number of erroneously shifted bits in the serial-parallel converter based on the bit-shift