dB (8) where: : percentage time for which the prediction is required t : lower nominal percentage time tinf : upper nominal percentage time tsup = (t/100) Qt Qi = (tinf /100) Qinf Qi = (tsup /100) Qsup Qi : transmission loss value for time percentage Linf tinf : transmission loss value for time percentage Lsup tsup where (x) is the inverse complementary cumulative normal distribution function described in § 7. Qi 7 An approximation to the inverse complementary cumulative normal distribution function The following approximation to the inverse complementary cumulative normal distribution function, (x), is for 0.01 0.99: Qi x ≤ ≤ if 0.5 (9a) x ≤ if > 0.5 (9b) x where: (9c) (9d) = 2.515517 C0 = 0.802853 C1 = 0.010328 C2 = 1.432788 D1 = 0.189269 D2 = 0.001308 D3 Values by the above equations are given in Table 1. TABLE 1 Approximate inverse complementary cumulative normal distribution values (q/100) (q/100) (q/100) (q/100) q% Qi q% Qi q% Qi q% Qi 1 2.327 26 0.643 51 76 –0.025 –0.706 2 2.054 27 0.612 52 77 –0.050 –0.739 3 1.881 28 0.582 53 78 –0.075 –0.772
dB (8) where: t : percentage time for which the prediction is required tinf : lower nominal percentage time tsup : upper nominal percentage time Qt = Qi (t/100) Qinf = Qi (tinf /100) Qsup = Qi (tsup /100) Linf : transmission loss value for time percentage tinf Lsup : transmission loss value for time percentage tsup where Qi (x) is the inverse complementary cumulative normal distribution function described in § 7. 7 An approximation to the inverse complementary cumulative normal distribution function The following approximation to the inverse complementary cumulative normal distribution function, Qi (x), is for 0.01 ≤ x ≤ 0.99: if x ≤ 0.5 (9a) if x > 0.5 (9b) where: (9c) (9d) C0 = 2.515517 C1 = 0.802853 C2 = 0.010328 D1 = 1.432788 D2 = 0.189269 D3 = 0.001308 Values by the above equations are given in Table 1. TABLE 1 Approximate inverse complementary cumulative normal distribution values q% Qi (q/100) q% Qi (q/100) q% Qi (q/100) q% Qi (q/100) 1 2.327 26 0.643 51 –0.025 76 –0.706 2 2.054 27 0.612 52 –0.050 77 –0.739 3 1.881 28 0.582 53 –0.075 78 –0.772
R-REC-P.528-3-201202-I!!MSW-E.docx