US 2002/0118388 A1Published application

Data transmission apparatus controlling transmission of a required amount of data and a data transmission control method therefor

AssigneeOki Electric Industry Co., Ltd.

InventorsTakeshi Honda, Akihiro Takahashi

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Abstract

A data transmission apparatus transmits, in response to a permission signal received from a higher-level data receiver, a required amount of data to the data receiver in a burst. The required amount of data is determined by data transmission control. Data transmission between the apparatus and the data receiver is effected at a preselected timing in such a manner as to absorb a difference between the amount of data to be transmitted over a preselected management time period and the data amount indicated by an expected control value. For this purpose, the apparatus calculates an adequate amount of data to be transmitted over the management time period as a unit amount. The apparatus then manages the maximum amount of data to be transmitted over the management time period for thereby leveling the amounts of data transmitted. This successfully enhances accurate data transmission.

Claims18

Dependent claims

A data transmission apparatus for sending out a transmission request signal to a data receiver unit and transmitting, on receiving a transmission permission signal from said data receiver unit, data to said data receiver unit, said data transmission apparatus comprising:

a data transmitter for transmitting data input thereto to said data receiver unit;
a transmission time calculator for calculating a transmission time period up to a time when the data transmitted reaches an amount determined in accordance with a plurality of parameters, which are input from an outside of said data transmission apparatus;
and
a control circuit for setting, based on the transmission time period, a maximum amount of data to be transmitted next and controlling transmission of the data;
said control circuit comprising:
a management time calculator for converting the transmission time period to a unit management time period representative of a transmission in unit time for management, determining allowable unit management time periods allowable for the unit management time, selecting one of said allowable unit management time periods as a management time period, calculating the maximum amount of data, and generating a timing signal indicative of an elapse of the management time period;
an accumulator manager for holding and managing a total amount of data transmitted;
a maximum transmission amount generator for generating the maximum amount of data to be transmitted next as a limit while updating the limit;
and
a monitor/controller for comparing the total amount of data with the maximum amount, inhibiting, based on a result of comparison, said data transmitter from transmitting data or canceling an inhibition while holding, when the total amount exceeds the maximum amount, a difference between the total amount and the maximum amount, and feeding the difference to said maximum transmission amount generator.

7 more elements

A method of controlling data transmission comprising:

a first step of sending out a transmission request signal to a data receiver unit;
a second step of transmitting, on receiving a transmission permission signal from the data receiver unit, data to the data receiver unit;
a third step of setting a plurality of parameters;
a fourth step of determining a transmission time period up to a time when the data transmitted reaches an amount matching with the plurality of parameters and a unit management time period representative of a transmission time period for managing the transmission time period;
a fifth step of selecting, as a management time period, one of allowable unit management time periods lying in a range allowable for the unit management time period;
a sixth step of generating a maximum amount of data to be transmitted for the management time period as a limit;
a seventh step of holding and managing a total amount of data transmitted;
an eighth step of comparing the total amount with the maximum amount;
a ninth step of counting, if the total amount is smaller than the maximum amount, a time interval for which the data is transmitted in a burst to thereby determine whether or not the time interval has expired;
a tenth step of interrupting, if the total amount is greater than the maximum amount, transmission of the data and holding an excess value produced by subtracting the maximum amount from the total amount;
an eleventh step of determining whether or not the management time period has expired;
a twelfth step of repeating said third step if the management time period has not expired;
a thirteenth step of setting, if the management time has expired, a difference between the maximum amount and the excess value as a new limit;
a fourteenth step of canceling interruption of the transmission of the data after the limit has been updated;
and
a fifteenth step of resetting the total amount, the excess value and the management time period after cancellation of the interruption, said fifteenth step being followed by said second step.

13 more elements

Dependencies are inferred from the claim text.