1-3hit |
Masaharu YASUNAGA Tokuhiro KITAMI
Heat transfer mechanism for the compatible repeater housing, used for coaxial transmission systems, is studied. Temperature rise for the repeater housing and repeater surface is calculated in detail. An efficient improvement plan for the thermal characteristics of the new repeater housing is suggested and confirmed by the experiment.
The cell discard process and the requirements for cell loss compensation methods in ATM (Asynchronous Transfer Mode)-based networks are discussed. In addition to the average cell loss rate, the probability distribution of consecutive cell discard length is slso investigated using computer simaulation of cell multiplexing. Average cell loss rate characteristics show the difficulty of reducing the cell loss rate only by increasing buffer size when cell arrival is bursty. The probability distribution of consecutive cell discard length indicates that cells are consecutively discarded even if cell arrival is less-bursty and the link utilization factor is not large. A simple mathematical model which represents the cell discard process is also derived. Estimation of cell loss compensation effect based on the obtained cell discard process model is presented. It shows that a cell loss compensation method which can only compensate for the isolated cell losses provides a cell loss rate reduction factor of only around 1/2 to 1/5 even if the input signals are not bursty. Therefore, consecutive cell loss compensation is necessary to efficiently reduce cell loss probability regardless of the burstiness of the input cell arrival.
Jonathan TURNER Achille PATTAVINA Tokuhiro KITAMI Iwao SASASE Kenji NAKAGAWA Toshikane ODA Akira HAKATA Takahiko KOZAKI Koji SUZUKI Naoaki YAMANAKA