MikeB
28-01-2006, 12:18
The editorial in the latest EBU technical review is entitled spectrum efficiency, it says in paragraph 8:
"So where does this leave the concept of spectrum efficiency? First, we must acknowledge that measuring spectrum efficiency in bit/s/Hz is inadequate and inappropriate. Secondly, we need to extend the definition of spectrum efficiency to take account of other factors, such as transmitter powers, the overall cost of networks and, crucially, the potential for interference to (or from) other services."
and goes on to discuss the effect of interference on digital systems from licenced and unlicenced sources and includes this quote on DRM:
"One regulator personally told me that the objective of extending the use of broadband access to the Internet was politically far more important than the need to protect old-fashioned AM radio services (especially in the HF bands) – but he was surprised to learn that Digital Radio Mondiale has spent a huge amount of time and money developing a new digital radio system to operate in these bands."
It's an interesting read and I have two questions:
1. What level of interference will give rise to DRM on MF and HF dropping out relative to its signal strength, does the interference have to be stronger than the DRM signal? Are some types of interference more troublesome than others?
2. In the UK I have always, perhaps too optimistically, taken the view that broadband over power lines will not prove commercially viable, basically as other systems have taken the market and it would require a heavy investment by the power companies. There have been tests by two companies at Crieff but no announcement of roll out nor any real marketing of HomePlug or similar power line networking devices mentioned earlier this year by BBC Click Online:
http://news.bbc.co.uk/1/hi/programmes/click_online/4080566.stm
Am I correct in this assumption and is the technology likely to be commercially viable in Germany, France, the Benelux and other parts of Europe DRM is initially targeting?
The EBU Technical Review editorial is at:
http://www.ebu.ch/en/technical/trev/trev_305-editorial.html
Mike
"So where does this leave the concept of spectrum efficiency? First, we must acknowledge that measuring spectrum efficiency in bit/s/Hz is inadequate and inappropriate. Secondly, we need to extend the definition of spectrum efficiency to take account of other factors, such as transmitter powers, the overall cost of networks and, crucially, the potential for interference to (or from) other services."
and goes on to discuss the effect of interference on digital systems from licenced and unlicenced sources and includes this quote on DRM:
"One regulator personally told me that the objective of extending the use of broadband access to the Internet was politically far more important than the need to protect old-fashioned AM radio services (especially in the HF bands) – but he was surprised to learn that Digital Radio Mondiale has spent a huge amount of time and money developing a new digital radio system to operate in these bands."
It's an interesting read and I have two questions:
1. What level of interference will give rise to DRM on MF and HF dropping out relative to its signal strength, does the interference have to be stronger than the DRM signal? Are some types of interference more troublesome than others?
2. In the UK I have always, perhaps too optimistically, taken the view that broadband over power lines will not prove commercially viable, basically as other systems have taken the market and it would require a heavy investment by the power companies. There have been tests by two companies at Crieff but no announcement of roll out nor any real marketing of HomePlug or similar power line networking devices mentioned earlier this year by BBC Click Online:
http://news.bbc.co.uk/1/hi/programmes/click_online/4080566.stm
Am I correct in this assumption and is the technology likely to be commercially viable in Germany, France, the Benelux and other parts of Europe DRM is initially targeting?
The EBU Technical Review editorial is at:
http://www.ebu.ch/en/technical/trev/trev_305-editorial.html
Mike