Fujitsu Corporation

Toshiyuki Hijikata

Tetsuo Tachibana

Toshio Irie

Tatsuru Nakagaki

Masayuki Yamanaka

Katsutoshi Inoko

Hiroyuki Suzuki

Takashi Hatano

Osamu Isono

Toshimasa Fukui

Kosuke Nobuyasu

Emi Kawasaki

Yoshinori Matsunaga

The present invention aims at providing an ascending transmission speed controlling method and a communication system in an ATM-PON (asynchronous transfer mode-passive optical network), in which ascending transmission speeds on the PON are dynamically allocated corresponding to actual transmission states of communication channels of a best effort type, to thereby effectively utilize respective bands. To this end, according to the present invention, in an OLT (optical line termination) constituting the ATM-PON system, active/inactive states of communication channels are identified based on receiving states of ascending data cells transmitted from ONU's of subscriber side, respectively, and a congestion state of the ATM network is recognized by extracting B-RM (backward resource management) cells from descending data cells, respectively, transmitted from the ATM network, so that ascending transmission speeds on the PON are allocated to communication channels corresponding to service categories, based on such as the thus recognized information.

Ascending transmission speed controlling method and communication system in ATM-PON system

By transmitting an analog CATV signal output from a CATV-HE (CAble TeleVision-Head End) to an HDT (Host Digital Terminal), an analog transmission channel for transmitting the analog CATV signal to an ONU (Optical Network Unit) is included in a path housing a digital transmission channel for transmitting a digital service signal for individual distribution service to the ONU. Furthermore, a digital service signal for multicast service is modulated and converted into an analog service signal by a modulator in the HDT. Then, the converted signal is mixed with the analog CATV signal, and transmitted to the ONU. Accordingly, each of the ONUs is equipped with only a built-in modulator for modulating the digital service signal for individual distribution service.

Mixed analog-digital service distribution system and method

A media information distribution service system, such as a video-on-demand service system, is disclosed which, even if the capacity of a line is small and the number of lines connected to a media server, such as a video server, has to be increased accordingly, permits an uneconomical increase in the number of line circuits in the media server to be checked. In the system, a subscriber group that a distributor accommodates can be associated with a plurality of distributor-side paths on a distributor-side line. Each of the distributor-side paths is connected to a respective one of server-side paths on separate server-side lines connecting the media server and an exchange. In sending media information to a subscriber group, an in-server path control unit installed in the media server is permitted to select a free one out of server-side paths on server-side lines allocated for that subscriber group and activates a line interface corresponding to the free server-side path.

Media information distribution services system and method

The invention provides a picture phone terminal and an exchange for use, for example, with a picture phone interrupt service system for a broadband ISDN which makes it possible to confirm, when an incoming call arrives, during communication between a plurality of picture phones, at one of the picture phone terminals from a third picture phone terminal, the incoming call during the communication without disturbing the communicating condition at present. The picture phone terminal or the exchange comprises means for receiving image information from a second picture phone terminal with which the picture phone terminal is communicating, means for receiving interrupt notifying image information representing that an incoming call from a third picture phone terminal has arrived, image composing means for composing the image information from the second picture phone terminal with which the picture phone terminal is communicating and the interrupt notifying image information from the third picture phone terminal, and display means for displaying the composite image information composed by the image composing means.

Picture phone terminal interrupt function and picture phone terminal

The present invention, in an ATM (Asynchronous Transfer Mode) which houses data in fixed length packets known as cells and transmits them to a receiving end, has as its object to provide a technology which can relay and transmit, within an ATM exchange, overhead section control information and can effectively perform maintenance and management of a communication network. Also, the order wire apparatus of the present invention comprises a network end device between a subscriber terminal and an exchange, this network end device comprising a frame data preparing means for simultaneously mapping communication data transmitted from a subscriber terminal into the payload section of frame data and mapping control information input by a maintenance worker into the overhead section of the frame data. And, the exchange comprises data separating means for separating the frame data transmitted from the network end device into the payload section and overhead section, a cell producing means for forming the payload section and overhead section into individual cells, and a multiplexing means for multiplexing these cells and transmitting them to the receiving end exchange.

Order wire relay method and apparatus

A length of an I field of an I frame in the data link layer is controlled in accordance with a rate of cells lost in an ATM layer. The loss rate of cells is calculated by watching sequence numbers included in the cells in an ATM adaptation layer.

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Kawasaki, Japan

Toshiyuki Hijikata