@JP
Portals don’t hinder the visible spectrum. There’d have to be a specific limitation preventing other types of electromagnetic radiation from ing through, which is unlikely. Also, stepping through a portal (assumedly) doesn’t disrupt bioelectric functions (e.g. the nervous system, cell and tissue regulation, the electrical conduction system of the heart).
So I’d say yes. If the portal introduces interference, the signal might be weaker but it’d get across.