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: Because wired connections make changing the seating configuration difficult, a wireless client device enables stable wireless transmission. The wireless client device wirelessly transmits to and receives data signals from an access point inside an aircraft. The wireless client device has a seat unit with a seat portion on which aircraft passengers sit, an antenna for sending and receiving the data signals, a signal processing arrangement operable to handle data signal receiving and transmitting processes, and a signal output arrangement operable to output processed reception signals. The antenna arrangement, signal processing arrangement, and signal output arrangement are disposed to the seat unit.

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: In a wireless communication system including a plurality of wireless stations provided in a structure having a radio wave shield arranged at a fixed position, at least one of two wireless stations using an identical wireless channel and two wireless stations using wireless channels adjacent to each other are allocated on both sides of the radio wave shield, respectively. In this case, the structure is an aircraft, and the two wireless stations are allocated on different aisles of the aircraft, respectively. In addition, the two wireless stations are allocated to be apart from each other in a longitudinal direction of the aircraft.

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: When a packet data is transmitted, a sync pattern comprising ‘q’ words (‘q’=m+n) is added to the data. The ‘q’ words is formed by combining a fixed pattern comprising ‘m’ words (‘m’ is an integer greater than 0) with plural types of variable patterns each comprising ‘n’ words (‘n’ is an integer greater than 1). In this case, a bit structure included in at least two consecutive packets should include different types of variable patterns.

Abstract: The invention provides a digital data delivery system that delivers video data of a content and audio data of the same content respectively to a first receiver and a second receiver, which are independent of each other, to reproduce the video data and the audio data at the first and second receivers in such a manner as to secure synchronous reproductions between the two data.

Abstract: Because wired connections make changing the seating configuration difficult, a wireless client device enables stable wireless transmission. The wireless client device wirelessly transmits to and receives data signals from an access point inside an aircraft. The wireless client device has a seat unit with a seat portion on which aircraft passengers sit, an antenna for sending and receiving the data signals, a signal processing arrangement operable to handle data signal receiving and transmitting processes, and a signal output arrangement operable to output processed reception signals. The antenna arrangement, signal processing arrangement, and signal output arrangement are disposed to the seat unit.

Abstract: Changing the seating configuration when there are wired connections to each seat is difficult. A wireless transmission system and method communicate wirelessly while also preventing interference with the ground communication system. The wireless transmission system wirelessly transmits data signals inside the aircraft, and has an altitude zone identification arrangement f or determining in which of N altitude zones the aircraft is flying, access points that can transmit the data signals wirelessly on any one frequency band selected from among M frequency bands, client units for receiving the data signals, and a selection unit for selecting one of the M frequency bands based on the altitude zone in which the aircraft is flying. The altitude zone identification arrangement includes an aircraft altitude detection unit and system control unit, and the selection unit includes the system control unit.

Abstract: A wireless network system arranges a plurality of access points along the aisles in a vehicle having two or more aisles. The positions of the access points on the first aisle and the positions of the access points on the second aisle are arranged in a zigzag pattern. The distance between neighboring access points is thus great, and there is no signal interference between adjacent access points.

Abstract: There is disclosed a packet transmission apparatus for transmitting in a packet form a transmission unit including a data string arranged so as to divide predetermined data into a plurality of blocks, each block having a fixed length, block information for specifying the block type being added to each block. A DIF data processing circuit generates a transmission header having a new identifier by deleting predetermined redundancy information from the block information belonging to the plurality of blocks based on inputted data string, and then, generates a transmission unit having the generated transmission header. Next, a transmission terminal unit transmits the generated transmission unit by way of a transmission line.

Abstract: A transmission apparatus for stably transmitting or receiving data of high priority is provided. In the transmission apparatus of the present invention, processing of the priority packet to be transmitted and processed by priority and processing of the non-priority packet are conducted separately. At transmission side, the above-mentioned priority packet is transmitted by priority by making its average transmission interval shorter than its average generation interval, and said non-priority packet is transmitted during the transmit margin period caused by the above-mentioned processing. At receive side, in the layer of processing the receive frame as a layer lower than the layer of processing the priority packet and non-priority packet, the priority packet and the non-priority packet is sorted based on the communication protocol header of the receive packet stored in the receive frame, and processing of the priority packet and that of the non-priority packet are conducted separately.

Abstract: This invention presents an apparatus for composing an ATM wrapper transmission block capable of handling plural pieces of program information transmitted in SDTI or IP packet commonly by a low overhead. Since the ATM wrapper transmission block conforms to both AAL1 system and AAL5 system, sequential connection is possible by changing over the AAL1 transmission and AAL5 transmission in the ATM wrapper layer. Further, by the AAL5 system, live transmission output of minimum transmission delay, and contribution output free from error can be issued at the same time, and therefore the error is corrected by referring to the reception data in the former, and the error is corrected by re-sending the error position data in the latter.

Abstract: In a transmitter side of an image packet communications system, a transmission clock signal is generated subordinately synchronized to a reference clock signal. Based on the transmission clock signal, a transmission standard signal is generated as synchronous with the reference clock signal. Further, a packet generator generates image packets based on the timing of the transmission clock signal with reference to the transmission standard signal, with image packet headers attached thereto. In a receiver side of the image packet communications system, a reception clock signal is generated subordinately synchronized to the reference clock signal, so that the reception clock signal is synchronized with the transmission clock signal.

Abstract: A coding device encodes image data with the coding self-contained within specific image data units, and supplies the encoded data stream to a packetizer to generate packets from the encoded image data stream, and a packet header adding device adds to each packet a packet header containing time information whereby the temporal position of the packet is determined. Thus, temporal information associated with data received after recovery of an error can be known immediately by the receiver even when an error occurs on the communications network over which a data stream containing image data, audio data, and other information is transmitted.

Abstract: A communications system has a real time signal generating part for generating the real time signal of data rate R with one frame as one unit; a transmission part, having a transmission rate C (C>R), over which the real time signal is transmitted; and a real time signal outputting part for outputting the real time signal stored in a real time signal receive buffer part, wherein after storing the real time signal for a prescribed number, N, of frames in the real time signal receive buffer part, the real time signal outputting part is activated, thereby performing control so that all generated portions of the real time signal can be output at the receiving end without interruption.

Abstract: To reduce an amount of image data to transmit, and thereby achieve efficient utilization of a data transmission line, only coarse image information containing at least DC components of compressed image data stored in compressed form in a video server is transferred into a personal computer for display, and based on the displayed image, an editor performs edit work on the image of interest and produces additional information relating to the image.

Abstract: A video image processing apparatus for processing compressed video image signals received at a speed of n for display on a video image display device. The apparatus comprises signal selecting circuits for selecting and passing components of a compressed video image signal from a specific frame or field, video image information memories for storing the components selected by the signal selecting circuits, a video image information control circuit for dividing the display screen of a video image display device into a plurality of regions, and controlling the video image information memories so that the components of the video image signal may be read in a sequence suitable for display, and a video image processing circuit for processing the video image information from the video image information memories for display on the video image display apparatus.

Abstract: In an apparatus for processing input N-bit digital video data with an error correction parity, the input N-bit digital video data includes each one sample of higher-order-N-bit data and a plurality of samples of lower-order-(M-N)-bit data, wherein M>N. An error correction circuit corrects an error of input N-bit digital video data, outputs error-corrected N-bit digital video data, and generates an error detection signal representing an error which can not be corrected. Further, a data combining circuit converts the error-corrected N-bit digital video data into M-bit digital video data, and an error classifying circuit classifies the error detection signal into a first error detection signal representing an error of the each one sample of the higher-order-N-bit data and a second error detection signal representing an error of the plurality of samples of the lower-order-(M-N)-bit data.

Abstract: A digital video signal recording apparatus records a video signal expressed by four digital components such that even numbered pixel is expressed by a first type luminance signal component and two color difference signal components, and odd numbered pixel is expressed by a second type luminance signal component. For the 525/60 NTSC system with 3-segment and 4-channel arrangement, one field video signal is stored in three segments. The recording apparatus has a standard channel order generator for generating a standard channel order of a recurring channel pattern. The four digital components are aligned based on the recurring channel pattern so that the first type luminance signal component and two color difference signal components for the even numbered pixel are stored in a same segment by the same channel. As a result, the samples for the same-position pixels are recorded by the same recording head, adjacent samples are recorded by different heads, and error concealment functions effectively.