| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the use rate of a buffer and to dissolve congestion by selecting a transmission rate operation part based on a result obtained by judging a congestion state at the time when queue length becomes more than prescribed length. SOLUTION: A data cell from a transmission terminal is stored in a cell buffer 20 and queue length information 110 at the time of transmitting the output data cell which is read by an output rate control mechanism 50 to a reception terminal is informed to a timer part 30. The timer part 30 transmits respective pieces of time out information 111 to a rate operation selection part 40 when it exceeds prescribed thresholds and it exceeds prescribed time in accordance with first, second and n-th transmission rate operation parts 60, 70 and 80. One of the transmission rate operation parts is selected by a selection signal CS based on the information and it is outputted as transmission rate information ERnew 113 so as to give it to an outer part. The transmission rate operation part is changed by considering the characteristic of congestion being the continuing time of the congestion state, and the buffer and the transmission rate are effectively controlled.</p> |
