8 replies to this topic

[alanh]

World's first dvb t2 network in sfn mode

No where near as large as Australia with a much smaller population.

AlanH

[MLXXX]

Fascinating. TV broadcasting using a multiplicity of mobile phone tower sites.

Quote

The architecture of the network defined by DNA [broadcaster in Finland] does not follow the conventional rules for DTTV networks that use the deployment of high power transmitters operating within a classical broadcast frequency plan. DNA has chosen to build its network using the existing network of 3G mobile telecom transmitter sites and to operate its multiplexes in SFN mode - claimed to be the first of its kind in the world.

[alanh]

MLXXX,
You should remember that Finland is a very mountainous country making VHF/UHF propagation extremely patchy. We have a totally different terrain. We do use SFNs such as in Cairns, Gold Coast/Sunshine Coast, Newcastle, Central Coast NSW, and a pair in Melbourne. The transmitters in these SFNs are low powered on small towers just like those used in mobile repeaters.

Remember also that Finland's analog TV switchoff is complete. We have not used VHF for SFNs, only UHF. Since the frequencies used in out SFNs are near that used for the phones, it is much better to keep the UHF transmitters away from the mobile phone cell receivers to prevent interference.

AlanH

[MLXXX]

alanh, on Sep 17 2011, 04:19 PM, said:

We have not used VHF for SFNs, only UHF. Since the frequencies used in out SFNs are near that used for the phones, it is much better to keep the UHF transmitters away from the mobile phone cell receivers to prevent interference.

Well if they were powerful UHF DVB-T transmitters there could be trouble.

[M'bozo]

As a popular social media network site shows, this is a subscription service.



Of interest in the presentation, is the antenna, & the instrument used, in what looks like a field test of the system.

[M'bozo]

alanh, on Sep 17 2011, 04:19 PM, said:

The transmitters in these SFNs are low powered on small towers just like those used in mobile repeaters.

The VHF transmitters range from 1 800 - 3 500W ERP, using channels E5 - E12.

I wouldn't call the towers small, either.

Listing of transmitter sites here.

Edited by M'bozo, 17 September 2011 - 08:35 PM.

[bellotv]

They were using a Log periodic to do their testing  

[mtv]

bellotv, on Sep 17 2011, 08:53 PM, said:

They were using a Log periodic to do their testing

Oh my...

[alanh]

M'bozo,
The Finish transmitters are not high powered compared to our 50,000 W digital VHF transmitters. The table is in Watts not kW.

AlanH