ðə pɹˌɑːbəbˈɪlᵻɾi ðˌæɾə pˈoːɹʃən əvə kəmjˌuːnɪkˈeɪʃənz sˈɪstəm, sˈʌtʃ ɐz ɐ lˈaɪn, sˈɜːkɪt, tʃˈænəl ɔːɹ tɹˈʌŋk, wɪl mˈiːt spˈɛsᵻfˌaɪd pɚfˈoːɹməns kɹaɪtˈiəɹɪə ɪz ˈɔːlsoʊ sˈʌmtaɪmz kˈɔːld ðə "tɹænsmˈɪʃən kˌoʊɪfˈɪʃənt" ʌv ðæt pˈoːɹʃən ʌvðə sˈɪstəm.
The probability that a portion of a communications system, such as a line, circuit, channel or trunk, will meet specified performance criteria is also sometimes called the "transmission coefficient" of that portion of the system.