HIGH-DENSITY PIN-BOARD MATRIX SWITCH AND ITS CROSSTALK CHARACTERISTICS

The purpose of this study is to realize the automated main distributio n frame (MDF), which is indispensable in the new installation and tran sfer of the telephone set. The switching element, which is the key com ponent in the matrix connection, as well as its crosstalk characterist ics, are investigated. The following results are obtained: (1) systems based on various switching elements are compared, and it is shown tha t the pin-board matrix is the best in the sense of the adaptability at the present stage. A detailed structure of the pin-board matrix is pr oposed; (2) the effects of the shielding layer, the frequency and the defined route (insertion position of the pin) on the crosstalk charact eristics of the single pin-board matrix switch is analyzed experimenta lly; and (3) a method is proposed and established for the probabilisti c analysis of the pin-board matrix switch with the three-stage link co nnection. The proposed method of analysis is applied to the automated MDF. It is shown that the probability that the overall crosstalk does not satisfy the specification of the 320-kbit/s time-compression multi plexing transmission lines is very small (1.2 x 10(-5)). In other word s, it is shown that the automated MDF can accommodate the 320-kbit/s t ime-compression multiplexing transmission lines.