標準號：BS EN 50083-10-2002
中文標準名稱：電視和聲音信號的電纜分配系統.回程線路的系統性能
英文標準名稱：Cabled distribution systems for television and sound signals - System performance for return paths
標準類型：M60
發布日期：2002/4/18 12:00:00
實施日期：2002/4/18 12:00:00
中國標準分類號：M60
國際標準分類號：33.060.40
適用范圍：1 General Standards of EN 50083 series deal with cable networks for television signals, sound signals and interactive services including equipment, systems and installations - for headend-reception, processing and distribution of television and sound signals and their associated data signals, and - for processing, interfacing and transmitting all kinds of signals for interactive services using all applicable transmission media. All kinds of networks like - CATV-networks - MATV-networks and SMATV-networks - individual receiving networks and all kinds of equipment, systems and installations installed in such networks, are within this scope. The extent of these standardisation work is from the antennas, special signal source inputs to the headend or other interface points to the network up to the system outlet or the terminal input, where no system outlet exists. The standardisation of any user terminals (i.e. tuners, receivers, decoders, multimedia terminals etc.) as well as of any coaxial and optical cables and accessories therefor is excluded. 2 Specific scope of this part 10 This standard is dealing with the transparent return path of cable networks operated in the frequency range between 5 MHz and 65 MHz or parts thereof. Higher frequencies may be used in fibre based networks. NOTE In addition it is possible to use the frequency range from 0 MHz to 5 MHz for return path transmissions, e.g. for NMS or other control, monitoring and signalling purposes. Applications below 5 MHz are not covered by this standard. An active return path carries typically only return signals. A passive return path can be used for both return and forward signals. This standard lays down the basic methods of measurement for signals typically used in the return path of cable networks in order to assess the performance of those signals and their performance limits. All requirements refer to the performance limits which shall be obtained between the reference points (Figure 1) of the return path system. One reference point is the network termination close to the subscriber. It is the last point where all forward and return signals are present and carried on the same cable. If no network termination point exists, the reference point is the system outlet. The other reference point is the input of the return signal receiver (or transceiver). At this point the transparent signal path ends and behind this point the signal is treated in a non-transparent way. The return signal receiver can be situated at the headend but can also be at the node of the coaxial cell or at any other point of the network. In addition to the system performance requirements for the transparent return path, system performance recommendations were laid down in this standard e.g. for the overall frequency allocation, for the use of specific modulation techniques for different interactive multimedia services or for different sub-bands within the return path frequency range, etc. Specific equipment installed in cable networks for the operation of such return paths is standardised in the relevant equipment standards, parts 3 to 6 of the EN 50083 series. Transmission systems are not within the scope of this standard.