Perhaps you should try some spelling variations:
railway communication » aided communication, risk communication, oral communication
mobile communication » aided communication, risk communication
optic communication » optical communications, grid communication, oral communication
radar communication » today communications, aided communication, risk communication

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( fiber-((optic communication) or (((radar communication) OR (railway communication)))) ) or ( fiber-mobile communication ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( fiber-((optic communication) OR (((radar communication) OR (railway communication)))) ) OR ( fiber-mobile communication )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( fiber-((optic communication) or (((radar communication) OR (railway communication)))) ) or ( fiber-mobile communication ))".
• Adding a wildcard symbol may retrieve word variants: (( fiber-((optic communication) or (((radar communication) OR (railway communication)))) ) or ( fiber-mobile communication ))*.