TMC and TMCPro are broadcasted FM signals from
radio stations which usually do the ordinary one
too. they are sub-carried RDS signals, therefore your
device needs an extra FM areal.
but the variation in radio service quality regarding
traffic information is generally the bottleneck for all
devices depending on it. some stations send a signal
only once an hour prior to the news.
Last edited by Sewage; 5th March 2011 at 07:23 PM.
Last edited by Giomen; 8th March 2011 at 02:18 AM.
We're talking about Garmin PNDs--not smart phones with GPS capabilities and special downloaded apps. Most PNDs currently used on the road have no GSM capability--with the exception of maybe the Garmin Mobile devices. The traffic systems deployed currently in, at least, the US, Canada, Europe and Australia operate as Sewage described requiring an independent or integrated FM receiver in order for a Garmin PND to receive traffic info.
There is a differencial antene system. For best receiving values is important to let the wires in one line - on to the both side from center.