| 摘要 |
PURPOSE:To enhance the using efficiency of the transmission line with an extremely simple and low-cost structure through the transmission after replacing the area of the nonvoice data of the sound data with the terminal data. CONSTITUTION:In case digital subscriber line 12 1ed to exchange 11 is shared by telephone terminal 13 and data terminals 14-14''', multiplying device 17 is required to multiply the signals sent from these terminals. And the sound/data simultaneous service system becomes possible with the use of device 17. Multi-step type waveform 22 is obtained by applying modulation to actual sound waveform 21 (solid lines) in the optional analog waveform (A). Noncall section T exists at the fixed section of wafeform 21, and the terminal data is transmitted between the data terminals with use of section T. While, at the reception side, terminal data D is recognized as the effective data in the data terminal system and also recognized as the sound data as it is in the telephone terminal system each by inserting (B) data D obtained by converting the original terminal data with some regularity into section T. |
