Radio Transmission into Buildings at 35 and 150 mc

l.i Background W i t h t h e a d v e n t of mobile telephone service h a s come a considerable f u n d of i n f o r m a t i o n concerning t h e n a t u r e of VHF radio p r o p a g a t i o n in c i t y a n d s u b u r b a n streets. 1 P l a n s a r e n o w being m a d e to e x t e n d t h e use of t h e mobile land t r a n s m i t t e r s t o provide o n e - w a y personal radio signaling services. I n t h e s e services, t h e t r a n s m i t t e r signals will be d e t e c t e d by small pocket-carried receivers issued to subscribers. C o v e r a g e will be desired n o t o n l y in t h e s t r e e t s b u t also i n t h e v a r i o u s buildings a n d o t h e r s t r u c t u r e s which subscribers m i g h t n o r m a l l y b e expected t o f r e q u e n t . T h e e x t e n t of useful coverage f r o m a mobile l a n d t r a n s m i t t e r will be s o m e w h a t less for personal signaling t h a n it is for mobile voice t r a n s mission. T h i s is p r i m a r i l y d u e to t w o f a c t o r s : (1) t h e i n h e r e n t l y poorer sensitivity of a pocket-carried receiver d u e to its small a n t e n n a a n d (2) t h e increase in p a t h loss to a location inside a building in c o m p a r i s o n with 197