Some of the nation’s leading broadcast specialists tuned into ATDI to find out more about avoiding interference.
The company’s latest online webinar, conducted by technical director Nick Kirkman, looked at single-frequency networks and was the last in a series of three sessions on interference analysis.
“It goes without saying that interference is the enemy of all radio spectrum users,” Nick notes. “The problem is bad enough if you’re running a mobile phone network and you have lots of unhappy customers. It’s even worse when you are a broadcaster and your biggest advertiser starts asking why its commercials are not being transmitted clearly. The BBC is just as sensitive to the issue because its charter gives it a legal obligation to get out its signal to the maximum number of people with the minimum of interference.
“It was, then, gratifying but not surprising to have so many broadcast specialists joining the webinar to find out how to avoid problems.”
Overall the three webinars looked at:
-Understanding the process of creating coverage analysis and interference calculations which can often be disguised by terrain and clutter effects
-The three methods of calculating interference: carrier to noise ratio (C/I), threshold impairment (TI) and interference to noise ratio (I/N). This was demonstrated using a typical TDAB system.
This latest one focussing on single frequency broadcast also considered guard intervals and inter symbol interference as well as assessing synchronisation strategies which are key to assessing and mitigating interference in SFN. In addition, Nick looked at how ATDI’s software tool ICS telecom manages interference and coverage using the features batch mode and time of arrival.
Finally, he discussed how to analyse SFN interference and using launch delay as a mitigating solution to maximise coverage and minimise interference.
“All that, and nobody had to leave their desk,” Nick says.