angles appearance communicating communications communications-equipment concave connecting dish distant distinctive electrical-signals electromagnetic equipment exterior external height high light mobile-phones modern parabolic parabolic-reflector radio-waves receivers receiving round satellite-dish satellite-dishes sending Signals steel steel-structure technical technology telecommunications telephones tower towering transmission transmissions transmitters transmitting water-tower air-traffic-control aircraft airport architectural architecture aviation command control control-tower directions directives flight fly flying safety tower-signals tower-views tracking traffic visibilty construction cranes foliage greenery hill trees slender tall telephony