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INTRODUCTION

Communication is something that cannot be escaped at any point in our lives. It is a very wide aspect of

our lives that involves an exchange of information, thoughts, ideas and emotions. The components of a

communication process are: a sender who encodes and sends the message, the communication channel

through which the message is sent, and the receiver who decodes the message, processes the

information and sends an appropriate reply via the same communication channel back to the sender.

Communication can occur via various processes and methods, and depending on the channel used and

the style of communication, there can be various types of communication.

On any network, the various entities must communicate through some form of media. Just as humans

can communicate through telephone wires or sound waves in the air, computers can communicate

through cables, light, and radio waves. Transmission media enables computers to send and receive

messages but do not guarantee that the messages will be understood.

Communication is possible only if any information is encoded in a signal, and the signal is carried on a

transmission the characteristics of the signal and of the medium both determine the quality of the

communication medium.

There are two main groups of transmission media, namely the guided medium and the unguided

medium (wireless). For the guided medium, there is a physical path (such as a cable) for electromagnetic

propagation. There four basic types of guided media: Open Wire, Twisted Pair, Coaxial Cable,

and Optical Fibre. For the wireless medium, however, the electromagnetic wave is transmitted through

air, water, or vacuum without using a physical conductor. This is done through radio communication,

satellite communication and microwave communication.

In this paper, we set out to design a microwave communication system between two rural areas in

Agusan del Norte, Bolo-bolo and Lawigan. This article also describes the process for designing

microwave links, which involves picking the sites, plotting the path profile, predicting the path loss and

calculating the path availability. We will be focusing our transmission on unguided media because it

offers several advantages compared to other transmission media. It is noted that higher the frequency,

means higher the bandwidth. Thus, high frequency gives us facility of transferring large quantities data.

Objective

This project aims to design a microwave link between two sites in Mindanao, specifically in Agusan delNorte. The main goal of this project is to transmit information from one place to another without much

interruption as possible and a clear reproduction at the receiver. Based on our inputs, this will guide us

regarding height of tower, expected Receive Signal Level (RSL) and antenna sizes. We also consider in

our design plan the materials availability and the system reliability, as we try to implement this project

by the year 2014.

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Significance

This project really provides great communication opportunities between these two isolated rural

stations. The communication links will enable the residences of these towns to easily communicate with

other regions in Mindanao and throughout the Philippines. This will be more or less a factor to the

development of telecommunication in Mindanao.

BACKGROUND OF THE STUDY

Microwave Communication

Microwave radio signals are electromagnetic waves with high frequencies (between 500 MHz to 300

GHz) and short wavelengths. According to Electronic Communications System: Fundamentals Through

Advanced, 5/e, approximately 35 percent of all terrestrial communication is maintained by microwave

radio relay systems. There are various types of microwave radio communication systems, operating

anywhere between 15 miles to 4,000 miles, including feeder service or intrastate microwave systems

and long-haul microwave systems.

Microwave communication has the capacity to broadcast great quantities of information because of

their higher frequencies. These signals are sent between transmitters and receivers that lie on top of

towers which allow transmitting thousands of data channels between two points without relying on a

physical transmitting medium. It has relatively low construction costs compared with other forms of

data transmission, such as wire-line technologies. Mountains, hills and rooftops provide inexpensive and

accessible bases can be used for microwave transmission towers.

Like any other communication system, a microwave communication system uses transmitters, receivers,

and antennas. The same modulation and multiplexing techniques used at lower frequencies are also

used in the microwave range. The RF part of the equipment, however, is physically different because of

the special circuits and components that are used to implement the components.

Fig. 1 shows a basic block diagram of a communication system, which comprises three primary sections:

a source, a destination, and a transmission medium (or channel).

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The voice, video, or data channels are combined by a technique known as multiplexing to produce a BB

signal. This signal is frequency modulated to an IF and then up converted (heterodyned) to the RF for

transmission through the atmosphere. The reverse process occurs at the receiver. The microwave

transmission frequencies are within the approximate range 2 to 24 GHz.

Fig. 2 below shows block diagram of microwave link transmitter and receiver section.

In its simplest form the microwave linkcan be one hop, consisting of one pair of antennas spaced as

little as one or two kilometers apart, or can be a backbone, including multiple hops, spanning several

thousand kilometers. A single hop is typically 30 to 60 km in relatively flat regions for frequencies in the

2 to 8 GHz bands. When antennas are placed between mountain peaks, a very long hop length can be

achieved. Hop distances in excess of 200 km are in existence.

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The "line-of-sight" nature of microwaves has some very attractive advantages over cable systems.

Nevertheless, in order to overcome the problems of line-of-sight and power amplification of weak

signals, microwave systems use repeaters at intervals of about 25 to 30 km in between the transmitting

receiving stations. The first repeater is placed in line-of-sight of the transmitting station and the last

repeater is placed in line-of-sight of the receiving station. Two consecutive repeaters are also placed in

line-of-sight of each other. The data signals are received, amplified, and re-transmitted by each of these

stations.Optical line of sight:

Effective line of sight:

d = distance between antenna and horizon (km) h = antenna height (m) K = adjustment factor to account for refraction, rule of thumb K = 4/3

Microwave Link Design

Microwave Link Design is a methodical, systematic and sometimes lengthy process that includes

Picking the sites Plotting the path profile Predicting the path loss Calculating the path availability

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