Panasonic Communications Co., Ltd.

Matsushita Graphic Communication Systems, Inc.

Genzou Takagi

Yoshihiro Noguchi

Nobuhiko Noma

Tsukasa Sakai

A data communication apparatus includes a communication section that performs pre-communication protocol to exchange a communication function with a communication destination terminal, and transmits data to the communication destination terminal after the pre-communication protocol. A detector detects whether or not the communication destination terminal can perform a short protocol in which at least a communication protocol for line probing is omitted. When the detector detects that the communication destination terminal can perform the short protocol, a controller obtains communication parameters from the communication destination terminal, stores the obtained communication parameters in a memory in association with the communication destination terminal. The stored communication parameters are utilized to perform the short protocol.

Data communication apparatus

A data communication apparatus includes a communication section that performs a pre-communication protocol and transmits data to a destination terminal. A memory stores data and communication parameters corresponding to each destination terminal, the communication parameters being utilized to perform communication with the destination terminal. When data corresponding to a destination terminal data is stored in the memory, a controller performs the pre-communication protocol with the destination terminal, using the stored communication parameters corresponding to the destination terminal. When a communication error occurs in a communication with a particular destination terminal having data stored in the memory, a memory controller deletes communication parameters corresponding to the particular destination terminal from the memory.

A data communication apparatus includes a communication section that performs a pre-communication protocol with a destination terminal and transmits data to a destination terminal. A memory stores data and communication parameters corresponding to each destination terminal, the communication parameters being utilized to perform communication with the destination terminal. When destination terminal data is stored in the memory, a controller reads the communication parameters corresponding to the destination terminal from the memory, performs the pre-communication protocol with the destination terminal, using the read communication parameters, and omits at least a communication protocol for line probing. When destination terminal data is not stored in said memory, the controller performs the pre-communication protocol with the destination terminal, using communication parameters acquired from the destination terminal under the pre-communication protocol without omitting the communication protocol for line probing.

This invention eliminates a time needed for communication handshaking by executing pre-communication protocol based on a prestored communication parameter. Specifically, at the time of carrying out a normal protocol, a modulation mode, a communication protocol, a modem parameter and a modem's optimal training time, etc., which are set by four communication channels, e.g., a communication channel for selecting a modulation mode, a communication channel for implementing line probing, a communication channel for modem training, and a communication channel for setting a modem parameter, are stored for each destination communication apparatus, and subsequent communication is implemented based on the stored information.

Data communication equipment

When carrying out pre-processing of image signal transmission using the control channel of a full-duplex modem and switching image signal transmission to the primary channel of a half-duplex modem, the answer modem stops the transmission carrier upon confirmation that all &ldquo;1&rdquo; signals with 40 bit or more have been received from the calling modem, restarts the reception of all &ldquo;1&rdquo; signals after the elapse of a certain period of time, confirms the end of all &ldquo;1&rdquo; signals and switches to the primary channel.

Growing community of inventors

Ageo, Japan

Genzou Takagi