m ob i l e t e r m i n a t e d c a l l t h a t i s s e t u p f r o m t h e T e s t S e t t o t h e m o b i l e w h e n t h e [ C a l l M o b i l e ] a n d

[ U s e r D e f i n e d C al l ] s of t k e y s a r e p r e s s e d . S o m e p a r a m e t e r c o m b i n a t i o n s a r e i n v a l i d ( f o r

e x a m p l e G r o u p w i t h D u p l e x o r H oo k ) , a n d a T E T R A M o b il e d o e s n o t n e c e s s a r il y s u p p o r t e v e r y

v a li d co m b i n a t i o n o f c a l l t y p e p a r a m e t e r s.

W h e n a n o n - s u p p o r t e d c a l l t y p e i s s e t - u p , t h e m o b i l e m a y m o d i f y t h e c a l l t o a t y p e i t d o e s

s u p po r t . I f t h i s o c cu r s t h e T e s t S e t i n di c a t e s t h e a c t u a l c a l l t y p e t h at i s n o w t a k i n g p l a c e .

A l t e r n a t i ve l y , t h e m o b i l e m a y r e j e c t t h e c a l l s e t - u p , i n d i c a t i ng t h a t i t d o e s n o t s u p p o r t t h e

s e r v i ce r e q u e st e d ; i n t h i s c a s e t h e T e s t S e t i n d i c a t e s M C C H / C a l l T o M o b i l e R e j e c t e d o n t h e

Operat ions/S tat us Til e

P T T O pe r at i o n

Dur ing a simple x call o n a TETR A Ne two rk, only on e user at a t ime may t alk ( tra nsmit) . Mo bile u se rs

indicat e thei r w ish to t alk by holdi ng or r eleasi ng the P TT sw itch on the T ETR A Mob ile. T he PT T swi tch

does n ot d irect ly contr ol the mob ile's t ransmit ter - signalin g is se nt t o th e base stat ion r equest ing or

reli nquishin g per mission t o tr ansmit.

R x T x I co n

An icon o n the

Opera tions/ Stat us Ti le

Test Set R F Gener ator . This is show n an d expla ined i n Fig . 5- 34 a nd Fi g. 5- 35.

When a simple x call has been set up on the Test Set , h olding the mobile's PTT swi tch pr essed

req uests tr ansmit permission ; the Test Set grant s tr ansmit pe rmission t o the mobile, the mob ile th en

tur ns on its t ransmit ter , an d th e Test Se t ind icates RxTx. R eleasin g th e mobile 's PT T sw itch

reli nquishes the tra nsmi t pe rmission; the mobile tur ns of f it s tr ansmitt er a nd t he Te st S et i ndicates

RxT x or R x Tx. R efer to t he fol lowin g section title d Sele ction of Tru nking Mode. PT T oper ation does

not ap ply to du plex calls, sin c e the mobi le's tr ansmi tte r and r eceiver are b oth act ive duri ng the cal l.

(Th e Test S et in dicates RxTx. )

F o r s i m p l e x c a l l s , m o b i l e s a r e n o r m a l l y c o n f i g u r e d w i t h a t r a n s m i t t i m e r , t y p i c a l l y o f o n e

m in u t e d u r a t i o n . I f t h e P T T s w i t c h i s h e l d p r e s s e d f o r l o n g e r t h a n t h i s p e r i o d , t h e m o b i l e

a u t o n o m o us l y c e a s e s t r a n s m i s s i o n a s i f t h e us e r h a d r e l e a s e d t h e P T T s w i t c h . T o a v o i d

t r a n s m i ss i o n t i m e - o u t w h e n t e s t i n g a T E T R A M o b i l e , A e r o f l e x r e c o m m e n d s s e t t i n g u p a d u p l e x

c a ll ( i f p o s s i b l e ) t o e xa m i n e t he m o b i l e t r a n s m i t t e r m e a s u r e m e n t s i n d e t a i l . U s i n g d u p l e x a l s o

a v o id s t h e n e e d t o h o l d t h e m o b i l e ' s P T T s w i t c h p r e s s e d du r i n g t r a n s m i t t e r m e a s u r e m e n t s .

T E T R A M S S y s t e m

indicat es th e cur rent stat e of the mobile tra nsmitte r an d the

5-43

C all Types C onf igura tion Tile

w i t h

Table of Contents