Hi,

I've noticed that FM radio stations continue to work while driving through tunnels on autobahns.

I assume there must be a FM signal repeater somewhere inside, to provide for continuous reception. It can be noted also, once I am leaving the tunnel, radio in the car 'tunes back' to outside FM signal (you can hear small almost unnoticeable hiss and then all is back to normal).

My question is - who is providing those repeaters? What is the business model here? Who pays for installation and maintenance?

Are radio-stations the ones to pay for 'continuous broadcast' service in tunnels to road maintenance authority? Or is this considered to be part of highway driving experience, and it is provided (and paid for) from vignettes?

Who pays for all that?

Cheers,
M.

Most likely a safety thing. There are signs telling you where to tune in case of emergency.

Must be a perk for those highfalutin Swiss Germans. Never noticed it in the tunnels between Yverdon and Neuchatel (quite a few in that short stretch).

As I recall, our company made some of them, and our customer was the PTT, so I guess it would be Swisscom nowadays, as they provide all the normal transmitters in CH as well.

Tom

But why would PTT buy such devices? What is their business interest?

BTW - those are not safety thing, those are normal commercial FM radio stations.

I don't know what car you drive...but most tunnels unless it's a really short one cut off the radio frequency shortly after entering....

That IS their business, i.e. they own all transmitters in CH!

Tom

I drive years old car, with generic radio. If I had driven car that fancy, I'd have asked my concierge and not EF


Seriously - I can assure you, however, that on the Basel-Zurich stretch FM reception continues inside tunnels. Since normal FM signal doesn't penetrate that deep there must be some FM repeaters in the tunnel. (not sure about AM reception, never tried that).

It's called service publique...

It's just the steel grid in the re-enforced concrete of the tunnel wall, acting like one big aerial/signal amplifier for any radio signals it cares to pick up, which is why it is sometimes intermittent; and totally removed from whichever radio in whatever car ...

[Sorry?! ... having just walked thru' a cow field, I think I can smell something on my shoe]

OK, I get it if it's service publique; as in that company that owns FM transmitters must ensure 'uninterrupted transmission' to all the good Swiss people, even if they are driving through tunnel and such.

So then it's the obligation of the service provider to put it in some tunnels (probably on key roads, or longer than x meters). I am sure that it may be Kanton-specific

Cell phone reception in tunnels is not public service, it's the commercial interest that puts cell sites inside tunnels.

But I wouldn't think that concrete steel reinforcement picks up and transmits the signal. It is not an intermittent reception, some tunnels just have perfect reception all the way, and some don't have anything at all.

It's for safety reasons.

Nationalrat's call to expand radio reception in tunnels (1985): http://www.parlament.ch/afs/data/d/g...850618_002.htm

Digital Radio (DAB) in tunnels: http://www.broadcast.ch/portal.aspx?pid=588

TCS on tunnel safety: http://www.astra.admin.ch/themen/nat...x.html?lang=en

Astra on tunnel safety: http://www.astra.admin.ch/themen/nat...x.html?lang=en

No, it's federal.

All radio programs, public or private, regardless of where the studio is, first go to Zurich (even if the studio is in Lugano, Lausanne, etc.). There, they are encoded at 256kbps MPEG1/Layer2 and distributed via E1 lines to the 170 transmitting stations throught Switzerland. The programs are then decoded and sent to the transmitters.

This I know, as I designed the encoders/decoders, and the company I work for built them (and all the stuff that goes with them).

Tom

The same goes for commercial (privately owned) radio stations. Some years ago when the first tunnel transmitters went into service, only the DRS1/RSR1/RSI1 stations were transmitted, being the official traffic message stations. These days many commercial radio stations operate tunnel transmitters as well, probably because they were losing some of their audience every time people were driving through a tunnel and switched to a different station after losing reception.

Aha, ok, this gets clearer now.

I suspect, then, that different radio stations are emitted in different Cantons; I have noticed that Coleur3 (great station) can be heard south of Bern and Lausanne, but not here in Basel.

So I guess then FM Radio stations can choose the region where it's emitted. And supposedly they pay more if they want to be heard inside tunnels?