Things to know if you’re a technician:
- The ACMA’s spectrum planning arrangements do not support overseas satellite free-to-air TV reception.
- The ACMA does not provide diagnostic or investigation services in relation to interference impacting these types of services.
- Overseas signals on ‘big dish systems’ can be affected by mobile broadband and licensed mobile phone transmissions.
- The commencement of terrestrial mobile broadband services in the 3.6 GHz band has been affecting satellite TV reception in the C-band (3.7 to 4.2 GHz).
The ACMA’s role and responsibilities
Consumers may be able to view overseas free-to-air TV services via their satellite dish and receiving equipment. Reception of these services is not supported by the ACMA’s spectrum planning arrangements.
The ACMA considers overseas satellite free-to-air TV reception as fortuitous and susceptible to reception problems. For these reasons, these types of services are not protected from interference and the ACMA does not provide diagnostic or investigation services.
Why interference happens
Overseas satellite free-to-air TV is more likely to experience reception issues from a range of other services due to the weaker nature of the satellite signal and the operation of terrestrial systems in adjacent frequency bands.
TV reception in C-band (3.7 to 4.2 GHz)—commonly known as ‘big dish systems’— has been affected by transmissions on adjacent frequency bands such as mobile broadband services from nearby mobile towers.
This is due to signal overload of the low-noise block downconverter (LNB). This overload occurs when a strong signal, close in frequency to the weak satellite signal, is received by the dish antenna. The LNB responds to the stronger signal and degrades the performance of LNB.
Recently, the ACMA has also been alerted to incidents of satellite TV reception in the C-band being affected by the commencement of terrestrial mobile broadband services operating in the adjacent 3.6 GHz band.
Some reception problems caused by signal overload can be fixed by:
- Relocating the dish antenna to a more sheltered location less prone to picking up stronger signals from nearby transmission towers.
- Using LNBs with built-in filters.
- Installing a separate enhanced C-band filter to avoid signal overload.
However, it may not always be possible to resolve satellite TV interference caused by licensed terrestrial radiocommunications services.