Network Leakage Limits

Downstream is the term used in CATV networks for signals being sent from the transmitter (cable head-end) to the receiver (customers’ TV) and generally fall within the range 45 - 1000 MHz. Upstream is the return path for interactive TV and telecommunication services (Internet etc.) and use frequencies within the range 5 - 70 MHz. EN50083-8 is a voluntary CENELEC standard concerning radiation from CATV networks from both upstream and downstream directions. It is NOT a standard mandated by the European Commission in respect of the EMC Directive. However it does provide an indication of typical limits specified in Europe concerning CATV emissions. Similar limits have been specified in CEPT ECC Recommendation ECC/REC 05-04 , which includes reference field strength limits for the assessment of interference. However a peak rather quasi peak detector is specified, which in practice has produced a set of criteria 3dB more severe (for cable networks) than EN50083-8 . In the United States downstream limits are specified in Part 76 of the Federal Regulations.

Other national netork requirements from the English speaking world are referenced here. The complete text of all the United Kingdom standards MPT 1510 (downstream), MPT 1520 (upstream) and MPT 1570 (networks utilising frequencies in the range 9kHz to 1.6 MHz) can be downloaded by following the appropriate hypertext link. Irish technical requirements for analogue and digital CATV networks can be downloaded from COMREG, the Irish regulator. The full text of the US FCC Part 76 regulation can be obtained from the FCC’s Media Bureau here.

The European Commission in Mandate 313 has tasked the European Standardisation Bodies to develop a harmonised EMC standard for electronic communications networks including CATV. CENELEC and ETSI have established a Joint Working Group to undertake this work. 

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