630 BELL SYSTEM TECHNICAL JOURNAL 



q = frequency taper in db per repeater section. 



Rl = the representative reflection coefficient (see paper 



by G. Crisson referred to above). 

 Sh = the irregularity function (see paper by G. Crisson 



referred to above). 

 Sn' = the frequency function (see paper by G. Crisson 



referred to above). 

 Sa = the attenuation function (see paper by G. Crisson 



referred to above). 

 Sf = the distribution function (see paper by G. Crisson 



referred to above). 

 S — Sh + Sw — Sa -\- Sf- 



Si = S - Sf = Sh + Sw — Sa = — 10 logio 2/r. 



^2 = Same as ^i but for terminal return loss. 



S^ = oil — 2.5. 



S:-, = end path loss with fixed termination. 



5ii and Sn = values, respectively, toward the West and the East 



of active or passive single frequency return loss 



for Sf — 0, made up of intermediate paths only, 

 ^21 and S22 — same as Sn and 5i2 but for end paths. 

 531 and ^32 = same as 5ii and 5i2 but for combination of inter- 



mediate and end paths. 

 Si = return loss which is actually obtained on a particular 



case. 

 Sc — return loss in a particular case with equipment. 



Se = equipment return loss. 



Sp = — 20 log a — distribution function of two return 



losses in series, where each such return loss has a 



distribution curve of the form 5 + Sf- 

 Sf' = function corresponding to Sf after equipment has 



been added. 

 SqQ)) = distribution function of singing points or singing 



margins ; i.e., a normal law with an average of zero 



and a standard deviation of h. 

 Sg(d) = distribution functions of active return losses with 



fixed terminations. 

 i = 10-(n20)_ 



T = taper in db per repeater section. 



V = 1 - p. 



Vm = 1 - Prn- 



