HD Radio Now Being Used to Send Traffic Info. to GPS Units

[Barry]

AllAccess.com and some other sources mention that some new Garmin auto GPS units can receive continuous traffic data from NAVTEQ via HD radio signals. Updates are said to be much more frequent than with the older technique, which I believe utilizes RDS signals from regular FM stations.
So in addition to providing another use for HD radio, this may result in some revenue for broadcasters using HD, encouraging them to keep the signals on the air.

List of cities with NAVTEQ Traffic Via HD Radio (includes coverage maps): http://www.navteq.com/hdtraffic/

 

[tomservo]

Interesting. Is it a new thing? I thought HD traffic started a year or two ago.

The Buffalo map is interesting. It shows Toronto with 65+ dBu coverage. I assume that someone is broadcasting in HD in Toronto now?

 

[nd2023]

60 dBu is weak? RDS works even in the 40 dBu contour.

 

[rbrucecarter5]

I certainly hope not - HD radio reception is so unreliable it shouldn't be used for an important service like traffic information.

 

[spunker88]

I certainly hope not - HD radio reception is so unreliable it shouldn't be used for an important service like traffic information.

In an near major cities is the only area that you would need traffic data and this is where HD signals are usually still usable since the towers are close by. For traffic data you wouldn't need a constant HD lock, probably only several seconds to get data and any lost data could be picked up in the next transmission loop.

There is actually an RDS version as well which seems to me like it would be more reliable:
http://www.navteq.com/rdstraffic/

 

[rbrucecarter5]

In an near major cities is the only area that you would need traffic data and this is where HD signals are usually still usable since the towers are close by. For traffic data you wouldn't need a constant HD lock, probably only several seconds to get data and any lost data could be picked up in the next transmission loop.

There is actually an RDS version as well which seems to me like it would be more reliable:
http://www.navteq.com/rdstraffic/

Problem is - in Houston parts of the metro area are 60 miles from the towers. In Dallas, more like 80 miles. In LA, multiple mountain ranges. Maybe in a compact metro area where the towers are close to town - it might work. But only if the approach / departure paths from the local airports are nowhere along the reception path. HD is just not robust enough. 10 more dB won't help. Signal swings more like 60 dB on the airport approachs.

 

[tomservo]

Interesting. I don't think I've ever observed any major signal changes while being under the approach/departure of an airport. Granted, it wasn't LAX, but Memphis' airport is super busy with Fedex traffic and the planes were at various levels above ground.

Traffic (data) doesn't need a steady stream as, like RDS, the data can be re-constructed from blocks of good data until the entire stream has been recreated. Remember that even with a very unreliable HD signal the text display usually still updates pretty quick and that's the kind of data being passed along; not audio that has to be re-built from tons of data. I can usually get the call letters/info to decode well after the audio drops back to analog for good.

In spread out markets like Los Angeles, I'd think they'd have more than one TX sending traffic data just for simple redundancy. But this being iBiquity, it wouldn't surprise me if they didn't think that far ahead, like they didn't seem to think we needed AF (auto frequency) like RDS has.

 

[LynnW]

My 2 year old Gamin Nuvi uses HD for traffic info.

 

[BRNout]

More proof that this HD scam was all about the Benjamins from day one. Not Benjamins from radio programming; Benjamins from squeezing out broadband space on the spectrum.

And the FCC is either blind or corrupt. Perhaps both.

 

[JohnnyElectron]

The FCC is full of retarded lawyers influenced by lobbyists, not engineers; that's the problem.

 

[KB1OKL]

My 2 year old Gamin Nuvi uses HD for traffic info.