olemus
füüsiline signaalikandja elektersides
= a wire- or cable-based physical signalling line

ülevaateid
https://en.wikipedia.org/wiki/Wired_communication
https://eng.libretexts.org/Bookshelves/Electrical_Engineering/Book%3A_Electrical_Engineering_(Johnson)/06%3A_Information_Communication/6.03%3A_Wireline_Channels