08:45 Jan 16 

What is this overall document describing? In particular, are these 'sites radios capillaires' specifically related to a cellphone system? The reason I ask is that I too thought the same as CC — except for the fact that a cellphone-type distribution is not in fact dendritic in the same way, since it is in fact primarily a distributed (rather than hierarchical) system.

Hence the use of capillary might seem out of place, if this in fact refers specifically to cellphones rather than other forms of telecomms, e.g. broadcasting.

08:38 Jan 16 

refers to the fact that the transmission extends into the environment dendritically, like blood capillaries or a tree root system, spreading out but getting smaller and smaller. Here I guess it would mean that repeater stations get smaller and smaller, but more numerous, the further out you go. It's a rather beautiful image, but I have never come across it in our less poetic English. The nearest I can think of is just "spreading out", which is far more prosaic.

05:30 Jan 16 

my bad, its a mistake. the term is "sites radio capillaires"

I need to translate "capillaire" actually.

05:14 Jan 16 

does not seem to be in the ST that you posted. Could you post the text that contains the phrase in question?