How did Gildor's messages get to Aragorn and Rivendell so fast?

[William Cloud Hicklin]

The silent conversation between the Wise in Dunland, late in RK, is certainly Osanwe (and has nothing to do with the Three Rings, which by then were merely historically-significant jewelry). But the essay on Osanwe-kenta makes it, not clear, but at least fuzzily implies, that conversational long-distance radio comms (as in the movies) was theoretical, not practical, for Incarnates, even the greatest among the Eldar.

It is, as T says of the Eagles, a dangerous 'machine'- otherwise, Gandalf would have been, like, "Elrond! Galadriel! Help! Saruman's a rat-fink and trapped me on top of his tower!" And Gildor would have been all "Elrond, send Glorfindel here ASAP to take over as escort for this Halfling, because Gandalf is missing" etc etc ad nauseam.

At long distances, the best it could manage was to 'transmit' intense emotional states to those to whom the 'sender' was very close- so accordingly there might have been an element of this in Arwen's 'sensing' Aragorn's desire for the Dunedain to join him. But Middle-earth conference calls? I don't think so.

(Also- if the Noldor could use Osanwe for long-distance conversation, why bother making the Palantiri?)