View Single Post
Old 12-04-2008, 11:04 AM
KiwiJochen KiwiJochen is offline
Join Date: Dec 2006
Location: Switzerland
Posts: 2,575
KiwiJochen is on a distinguished road
Originally Posted by ccfj1
The TMC can trigger and place an icon on screen though
Yes, based on pre-defined locations, as stored in the TMC database on the map disc, and as managed by each countries authority.

The TMC data protocol provides a numeric location ID. One of 64,000 for the country. There is no lat/long transmitted.

Originally Posted by ccfj1
Car know where it is (GPS),
TMC broadcasts data on problems (with GPS loctaion)
Nope, it broadcasts a numeric location ID with a problem ID and problem extent, and a few other details.

Originally Posted by ccfj1
TMC enabled Map discs listen and store TMC info,
If car GPS location and TMC info GPS location are close then
Trigger correct display icon and audio alert.
Essentially. A map disc doesn't listen or store the data, that's what the nav OS does.

Originally Posted by ccfj1
Somewhere in the OS the TMC signal carries the info for the correct icon and the correct audio alert,
A location ID from 0 to 64,000 is broadcast over the radio.
The correlation between location ID and lat/long is held on the TMC database on the map disc.
The location IDs are specified by the countries authority
An event ID is broadcast - also from 0 to I think 30,000. The correlation between event ID and event type is defined by the TMC standard and the text is held on the TMC database on the map disc and then displayed in the appropriate user language.

Originally Posted by ccfj1
Hmmm I see, the problem is the camera DB, how will the TMC part be able to access the POI db on the map disc...
It cannot. It's not part of the TMC standard.

Anyway, to do what you want requires the operating system to be re-written.
You'd have to translate between the POI lat/long and the nearest known predefined TMC location ID. What if there is no location ID? What if the POI location lies 2km from the closest location ID?

And who can modify the operating system of the nav computer?

And that is not something I can do. It's something only the original software designers can do.
Reply With Quote

Sponsored Links