ɪnðə ɹˈeɪl tɹˈænspoːɹt sˈɛktɚ, ˈɑːptɪkəl lˈɪŋks ɑːɹ jˈuːzd ɪn tˈuː fˈɔːɹmz dᵻpˈɛndɪŋ ˌɔn wˈɛðɚ ðə fˈiːdɪŋ stˈeɪʃən ɪz ɐ mˈeɪn stˈeɪʃən ɔːɹ nˈɑːt.
In the rail transport sector, optical links are used in two forms depending on whether the feeding station is a main station or not.