Hitachi, Ltd.

Toshiaki Koyama

Tohru Hoshi

Naoko Iwami

Kazuma Yumoto

Keiko Takahara

Susumu Matsui

Naoya Ikeda

Osamu Takada

Hiromichi Enomoto

Akira Murayama

Shigeki Morimoto

Yasushi Izunaga

Sigeaki Kuroda

Katsuyoshi Onishi

Fumio Yoshinaga

Noriyuki Tanaka

Shintaro Sado

Toshio Hirai

Tadao Ochiai

Tadashi Fukuishi

Shouji Kikuchi

The packet communication system enables communication between a communication unit connected in a conventional telephone network and a communication unit in a packet communication network. A device for exclusively selecting the connection network is provided so that, at the time of transmission of a signal from one communication unit to another, the connection path is selected according to the kind of the network to which the other communication unit belongs. At the time of signal reception, the communication unit is connected to only one of the conventional telephone network and the packet communication network. The packet communication system includes a packet processor for converting an information signal, such as speech, inputted from an input unit (for example, a transmitter microphone of a handset) into the form of a packet.

Packet communication system

The packet communication system enables communication between a communication unit connected in a conventional telephone network and a communication unit in a packet mode network. A device for exclusively selecting the connection network is provided so that, at the time of transmission of a signal from one communication unit to another, the connection path is selected according to the kind of the network to which the other communication unit belongs. At the time of signal reception, the communication unit is connected to only one of the conventional telephone network and the packet mode network. The packet communication system includes a packet processor for converting an information signal, such as speech, inputted from an input unit (for example, a transmitter microphone of a handset) into the form of a packet. The packet is transmitted to the packet mode network and converted into the original information signal stream to reproduce the signal stream by an output unit (for example, a receiver of the handset). A conventional telephone network interface controller is provided for reproducing the speech or like information signal received from the conventional telephone network by the output unit. An exclusive selector selects either the conventional telephone network or the packet mode network at the time of signal reception.

A communication system and communication method adapted so that the user of one of the communication terminals can more easily communicate with another one connected to the internet through the public network. Connection management servers for relay and manage the communication are provided at nodes between the internet and the public network. Each of the connection management servers assigns an IP address to the communication terminal connected to the internet through the public network, and registers the IP address and the telephone number. When receiving a communication request, the connection management server specifies a communication route to the communication terminal on the basis of the telephone number of the called-side communication terminal set in the communication request. The server checks if the called-side communication terminal is connected to the internet on the basis of the above registration. If it is connected to the internet, the server relays the communication request. If it is not connected thereto, the notice that it is not connected is transmitted to the calling-side communication terminal. If it is not connected yet, the server regards the called-side terminal as having its telephone connected to the telephone channel, and causes speech transmission between that telephone and the calling-side communication terminal.

Communication method and communication system

A communication system which can communicate with a party user even when an originator user of a communication terminal does not know the terminal address of a communication terminal of the party user with whom the originator user wants to communicate. When its own user A does not know the terminal address of a communication terminal of a user B, a communication terminal of the user A sends an outgoing file having its own terminal address stored therein as an electronic mail directed to the user B. When receiving the outgoing file as the electronic mail, the communication terminal of the user B displays an icon on its display unit to prompt the user B to enter an instruction of performing reply communication. In response to it, when the user B clicks a mouse on the icon, the communication terminal of the user B can perform the reply communication to the communication terminal corresponding to terminal address stored in the outgoing file.

Communication system using electronic mail

In mail terminal equipment for receiving and reproducing a mail which has been produced using multi-media data containing a plurality of continuous audio data and a plurality of drawing data synchronized with at least a part of the audio data and has been transmitted thereto. Where reproduction of the drawing data is later than that if the audio data, the drawing data is synchronized with the audio data without interrupting reproduction of the audio data. When the drawing data still remains which at certain timing (e.g., timing when supplementing the audio data to a audio buffer for storing the audio data waiting for reproduction), should be reproduced until that time point, but is not reproduced resulting from the delay of reproduction of the drawing data due to the drawing processing, the loading situation and the like, the drawing data of interest is skipped so as not to be reproduced, and the next drawing data is reproduced.

Mail terminal equipment

An internetworking apparatus which handles a scale of a network flexibly without degrading high speed operation. A router manager and a plurality of routing accelerator modules for performing routing are connected to one another through a high speed bus, and a plurality of communication ports are connected to the respective routing accelerators independently of one another. The plurality of routing accelerators can perform the routing for reception data packet at high speed. If more routing accelerators are provided, the disposal to the networks having a small scale to a large scale can be readily realized.

Internetworking apparatus for connecting plural network systems and

A scroll type compressor having a pair of scroll type compression units which are encased in the same casing so as to make a common use of a lubricating oil reservoir provided in the casing, wherein the compression units have compression elements, drive shafts, driving motors and other components which are of the same constructions and specifications, and wherein each of the compression units are adapted to be driven selectively by commercial electrical power or through a frequency-variable inverter so as to operate at different speeds. Since both compression units can be made up from the same components such as the compression elements, loads in the production, service and administration, are greatly reduced contributing to a reduction in the labor and cost, while eliminating any mounting error. Various operation patterns are obtainable by selecting the combination of the direct commercial power and the power supplied through the inverters, so as to provide delicate control of refrigeration capacity over a wide range in accordance with the level of the load demand. Common use of the lubricating oil reservoir by both compression units eliminates necessity for specific measure for preserving oil levels equally for both compression units.

Scroll type compressor and refrigeration cycle using the same

In communications control unit for sequentially scanning a plurality of line sets to which full-duplex lines are connected, for reading out line control word provided in correspondence to the line from a memory when a data transmission/reception request exists in the line set, and for executing the data transmitting and receiving operations with the relevant line set, one line control word including both of transmission control information and reception control information is read out in the time slot assigned to one full-duplex line, and the data transmitting and receiving operations are simultaneously executed.

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Zama, Japan

Toshiaki Koyama