Cable television distribution network with video signal transmission on demand

摘要

There is a wish to offer a video-on-demand service, in addition to the cable television service, to subscribers of a cable television distribution network. Since the optical fibre portion of the cable television distribution networks will not reach the subscribers (111) in the foreseeable future but will end in optical network terminations (ONTi) and will be continued from there to the subscribers in each case through an optical access network (108-110), the problem is how the totality of subscriber-individual video signals can be transmitted to subscribers so that these can receive the video signals in each case requested. According to the invention, the transmission takes place digitally in time-division multiplex and wave-division multiplex from the centre (100) via the optical fibre distribution network (101-107) to the optical network terminations (ONTi). In each optical network termination, only the part of subscriber-individual video signals which is intended for subscribers which are connected to the optical network termination (ONTi) is removed. The removed subscriber-individual video signals are modulated onto subcarriers (N1-M6) and are added in frequency-division multiplex to the cable television signals which are distributed via the electrical access network (108-110) to the subscribers (111) connected to the optical network termination (ONTi).