摘要 |
<p>A digital data transmission system comprising a data transmission network formed by several node stations (A1-A4) and interconnecting high-speed trunk lines (1-5). Each node station comprises several low-speed parallel subscriber interfaces controlled by a network management system (6), subscriber stations (B1-B5) being connectable to the subscriber interfaces either directly or through a serial modem link (10-13), depending on the distance. The network management can be extended up to the subscriber stations so that said modem link (10-13) transfers all signals of the parallel subscriber interface in serial form in both directions, forming, at the end close to the subscriber station (B2-B5), a parallel slave interface corresponding to the subscriber interface.</p> |