Computer Aided Design Of Microwave Line Of Sight Radio - Relay Systems With Special Application To Kenya Posts And Telecommunications Corporation

Abstract

The propagation of radio waves at microwave frequencies and the various types of noise that affect the performance of terrestrial microwave line of sight radio-relay systems are discussed. A computer terrain database is developed for a region within central Kenya covering an area of approximately 200km by 200km. Three computer programs to assist a microwave radio link system designer have been developed. The program PROFILE is used to draw radio path pro files and the associated Fresnel zones between any two points within the region covered by t.he database. Examples of path profiles drawn by t.he program are given. An example of the output of the second program, REPEATER, is also given. REPEATER has been developed to inform the radio link designer of all the possible sites which may be used as radio repeater locations between two radio terminal stations. The third program, LINK, is developed to assist the link designer in assessing all the possible radio routes in in up to 3-repeat.er radio-relay systems. Using LINK, the radio link system designer is able to determine the most cost-effective and reliable radio route connecting any two terminaI stations within the area covered by the database. Two radio links containing 3 repeater stations between Nairobi and Nakuru has been designed. The first of these has been designed manually whereas the second has been designed with the assistance of LINK program. It has been been through a comparative study of the two links that the radio system developed with the assistance of LINK is superior in terms of cost and performance than t.he manually designed Link