Project Background Scopes of work

CHAPTER I INTRODUCTION

1.1 Project Background

Attenuation has been identified as a major problem for terrestrial and satellite links beyond 10GHz. High frequency, usually higher than 10GHz mostly suffer attenuation when facing a rainfall. The problem becomes more critical in tropical regions where there is high intensity rainfall a year. Most of terrestrial and satellite links designed for these regions must consider the attenuation given by each condition of rainfall, so that the communication is available all the time.[1] Determine the specific attenuation for the specific rainfall rate is very important. It is impossible to specify the accurate value of attenuation for a certain rainfall rate; however a prediction is a best method to find the nearest and persistent attenuation value. Lots of research has been carried out in order to determine and predict the attenuation by considering the rainfall rate, elevation angel, effective slant path length, storm and also polarization used. Thus, each research contributed its own model for predicting the attenuation.[2] Rainfall rate statistics specified on a percent of time basis, that is the percent of time in a year or a month that the rain rate equal or exceeds a specific value is used in the rain rate attenuation [3]. Thus, this project will gather all measurement data in tropical region from other researcher, and predicting the attenuation given by these data. The model of prediction which produces attenuation precisely stated by ITU-R model will be chosen as the best model to represent all the data.

1.2 Scopes of work

This project is limited to the following aspects: 1. Literature review. Reviews on the existing research done on the rain rate attenuation prediction all over tropical regions. The prediction model used also being discussed. 2. Selection of appropriate data. Data will be filtered where only data from tropical region measurement is valid. 3. Prediction. The rain rate attenuation will be predicted by using different models. 4. Comparison. The rain rate attenuation produces by each model will be compared to standard ITU-R for validity and consistency.

1.3 Project Objectives