High‐density pin‐board matrix switch and its crosstalk characteristics

The purpose of this study is to realize the automated main distribution frame (MDF), which is indispensable in the new installation and transfer of the telephone set. the switching element, which is the key component in the matrix connection, as well as its crosstalk characteristics, are investigated. the following results are obtained: (1) systems based on various switching elements are compared, and it is shown that 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 proposed; (2) the effects of the shielding layer, the frequency and the defined route (insertion position of the pin) on the crosstalk characteristics of the single pinboard matrix switch is analyzed experimentally; and (3) a method is proposed and established for the probabilistic analysis of the pin-board matrix switch with the threestage link connection. 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 multiplexing transmission lines is very small (1.2 × 10-5). In other words, it is shown that the automated MDF can accommodate the 320-kbit/s time-compression multiplexing transmission lines.