Test apparatus used in the development of a 420MHz cellular mobile system

Abstract

This paper describes an automated mobile laborat o r y u s e d i n the development of a c e l l u l a r m o b i l e telephone system in the Province of Alberta, Canada. Objectives which the mobile laboratory i s intended t o meet are p r e s e n t e d f i r s t . T h i s i s followed by a description of the various components a n d i n s t r u m n t s s e l e c t e d f o r the test arrangement. The c o n f i g u r a t i o n of the equipment and some methods used i n d a t a a c q u i s t i o n are then outlined. Software routines used t o c o l l e c t and analyze the d a t a are b r i e f l y explained. Some r e s u l t s o f measurements are then discussed. The paper concludes w i t h an assessement of the effectiveness of the mobile laboratory as a t o o l i n developing a c e l l u l a r r a d i o s y s t e m a n d b r i e f l y m e n t i o n s p l a n s f o r f u t u r e u s e s o f the apparatus. I n t r o d u c t i o n The AURORA (Automatic Roaming Radio) 42OMHz medium-capacity F M cellular mobile telephone system which is described elsewherel, i s c u r r e n t l y i n its f i r s t s t a g e s o f i m p l e m e n t a t i o n i n Alberta, Canada. Laboratory experiments were done by Alberta Government Telephones' Mobile Communications Engineering group t o v e r i f y a n d a d a p t t h e t h e o r e t i c a l models. I n conjunction withtfieseexperiments, it became apparent that experiments in a typical mobile environment had t o b e c a r r i e d o u t t o v e r i f y the f i n a l RF model. This gave rise t o the development of a mobile laboratory which w a s i n t e n d e d t o meet a number of objectives. These included: i) a b i l i t y t o c o l l e c t a n d a n a l y z e s t a t i s t i c a l d a t a a b o u t RF propagation and interference c h a r a c t e r i s t i c s a t 420MHz u n d e r t e r r a i n and weather conditions as v a r i e d as t h o s e i n Alberta configuring of the test instruments ii) f l e x i b i l i t y t o a l l o w e a s y and f a s t reiii) r e a s o n a b l e c o s t i v ) b e f a i r l y e a s y t o o p e r a t e v ) c o l l e c t d a t a t o assess the f e a s i b i l i t y o f s p l i t t i n g c h a n n e l s p a c i n g from 25icHz t o 12.5kHZ v i ) s e r v e as a u s e f u l tool i n the f u t u r e development and implementation of the system 800MHz systems. v i i ) a b i l i t y t o g a t h e r d a t a f o r p o s s i b l e f u t u r e I t w a s decided that these o b j e c t i v e s were b e s t m e t by using a desk-top computer t o c o n t r o l a number of instruments via the IEEE-488 standard data bus. The t e r r a i n i n A l b e r t a , an area 600kmby 1200 km, varies widely from flat and treeless t o f o o t h i l l s and mountains covered i n f o r e s t , and from t o t a l l y uninhabited to cities of over + m i l l i o n . I t w a s decided t o s t o r e c o l l e c t e d d a t a i n the mobile l a b o r a t o r y . F o r r e a s o n s o f c o s t , f l e x i b i l i t y and r e l i a b i l i t y , RF d a t a l i n k s were not used. The n e x t s...