Fujitsu Corporation

Masayuki Yamanaka

Tetsuo Tachibana

Tatsuru Nakagaki

Toshio Irie

Katsutoshi Inoko

Toshiyuki Hijikata

Hiroyuki Suzuki

Takashi Hatano

Kenji Nemoto

A communication system is proposed which efficiently performs an interface control of QoS of ATM and QoS of IP and improves the quality and reliability of a network. A QoS information setting part sets QoS information of IP in a packet and sets QoS information of ATM corresponding to the QoS information when an IP-based communication takes place between networks, and sets QoS information of ATM in a cell when an ATM-based communication takes place. An information sending part sends the packet of the cell. An information receiving part receives the packet or the cell. A QoS guaranteed communication part performs a communication control with QoS being guaranteed on the basis of the QoS information.

Communication system interfacing control of quality of service (QOS) of asynchronous transfer mode (ATM) and internet protocol (IP)

An ATM apparatus includes an ATM device, and a plurality of devices arranged in a multistage formation in which the ATM device is located at a top of the multistage structure. The ATM device and the plurality of devices employ a given interface using an address signal and a control signal, and transfer routing information including address information on at least one of the devices by using the address signal and a data signal written into a given field of an ATM cell.

Asynchronous transfer mode apparatus

The inside of a managed side device managed by a manager of a managing device has a tree-structure consisting of points &num; to &num; of the first to third layers. When a failure occurs, at the point &num; of the bottom layer, loss priority is allocated to a PDU and is transmitted to the point &num; in a higher order. When the number of PDUs is greater than the threshold of the number of alarms, at the point &num; a buffer is prevented from overflowing by instructing a lower order point not to transmit a PDU, or by eliminating PDUs with loss priority lower than the threshold of loss priority. By executing these processes at each point, congestion due to the concentration of PDUs can be locally processed.

Communication control apparatus and method for controlling communications on a network having a tree-shape to improve the usage of buffers and reduce undesirable discard of data

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

CPCS-UU in the CPCS-PDU trailer defined by the AAL Type 5 in an ATM network is used as a sequence number for error handling. CPCS-UU in the CPCS-PDU trailer is used as a sequence number of an MPEG-2 transport stream packet contained in CPCS-PDU; by monitoring the number of packets, and based on the check results of CRC-32, LI, and cell count, error handling is performed at the receiving end, and for corrupted packets, null packets are inserted in place of the corrupted packets.

Error handling in transmission of data that cannot be retransmitted

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.

Growing community of inventors

Kawasaki, Japan

Masayuki Yamanaka