RELIABILITY OF RADIO TELEPHONE CIRCUITS 



195 



in Fig. 8. As for the generalized reliability curve of Fig. 6, the 

 reference point adopted is 50 per cent lost circuit time. Consequently 

 the curve of Fig. 8 marked "50 per cent lost circuit time" is also des- 

 ignated as "0 db Transmission Improvement." Knowing the per- 



500 

 400 



20 



2 'I "Z ^2 ^2 ^2 °2 '2 °2 =" 2 '"2 "2 '^2 '-^2 



AVERAGE DURATION OF INTERRUPTIONS IN HOURS SHOWN 



Fig. 8— An estimate of probable duration versus number of interruptions for full 



time operation. 



centage lost time experienced on a certain circuit the position of the 

 corresponding interruption curve in Fig. 8 may be determined by 

 interpolation. The effect of, say, 10 db transmission improvement 



