MICROWAVE/RADIO FREQUENCY WAVE

Description

ABSTRACT

Wireless communication is observing a fast development in today’s communication era. In mobile communication the Base Transceiver Station (BTS) to Base Station Controller (BSC) or Mobile Switching Centre (MSC) link is based on microwave link.

Therefore, analysis and planning of a microwave link is very much important. The microwave equipment can be installed after a careful planning and detailed analysis a microwave radio system. A poorly designed path can result in periodic system outages, resulting in increased system latency, decreased throughput, or worst case, a complete failure of the system.

Planning a good, stable and reliable microwave network can be quite challenging. At the same time, it poses several interesting optimization problems. The theme of thesis work an iterative technique has been presented to explain the sequential communication of signal transmission for long and short distance radio communication through microwave link with better efficiency.

TABLE OF CONTENTS

 TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

• INTRODUCTION
• DEFINITION OF MICROWAVE/RADIO FREQUENCY WAVE
• PURPOSE OF THE PROJECT
• PROPERTIES OF MICROWAVE LINK
• MICROWAVE APPLICATION
• MICROWAVE ADVANTAGES OVER CABLE/FIBER BASED TRANSMISSION
• USES OF MICROWAVE LINK
• LIMITATION OF THE STUDY
• OBJECTIVE OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT

CHAPTER TWO

LITERATURE REVIEW

2.0      LITERATURE REVIEW

2.1      HISTORICAL BACKGROUND OF THE STUDY

2.2      DESCRIPTION OF MICROWAVE LINK

2.3      MICROWAVE POWER TRANSMISSION

2.4      HISTORICAL BACKGROUND OF MICROWAVE POWER TRANSMISSION

2.5      SAFETY CONCERN  MICROWAVE TRANSMISSION

2.6      MICROWAVE LINK PLANNING

2.7      MICROWAVE FREQUENCY BANDS

CHAPTER THREE

3.0      METHODOLOGY

3.1      BASICS OF THE STUDY

3.2     OPERATING PRINCIPLE OF THE STUDY

3.3      MICROWAVE COMMUNICATION AND CONSIDERABLE PARAMETERS

3.4      PATH LOSS AND DISTANCE CALCULATION

3.5      CCIR PATH LOSS MODEL (LCCIR)

3.6       LINK BUDGET

3.7      MICROWAVE RADIATION SAFETY

3.8      MICROWAVE RADIO LINK PLANNING

CHAPTER FOUR

4.0                   ADAPTIVE MODULATION, MODELING AND SIMULATION

4.1   ADAPTIVE MODULATION AND CODING SCHEME (AMC)

4.2 ADAPTIVE MODULATION IN MICROWAVE LINK

4.3  KEY BENEFITS
4.4  ADAPTIVE MODULATION

CHAPTER FIVE

5.0      CONCLUSIONS AND REFERENCES

• CONCLUSIONS
• RECOMMENDATION
• SEVERAL ADVANTAGES OF MICROWAVE RADIO LINKS
• ABBREVIATIONS AND ACRONYMS

5.5     REFERENCES

 CHAPTER ONE

1.0                                                        INTRODUCTION

A microwave link is described as a communications system that uses a beam of radio waves in the microwave frequency range to transmit information between two fixed locations on the earth. They are crucial to many forms of communication and impact a broad range of industries. Broadcasters use microwave links to send programs from the studio to the transmitter location, which might be miles away. Microwave links carry cellular telephone calls between cell sites. Wireless Internet service providers use microwave links to provide their clients with high-speed Internet access without the need for cable connections. Telephone companies transmit calls between switching centers over microwave links, although fairly recently they have been largely supplanted by fiber-optic cables. Companies and government agencies use them to provide communications networks between nearby facilities within an organization, such as a company with several buildings within a city.

 

Today wireless technology is used in many applications well integrated into our everyday life. Planning a good, stable and reliable microwave network can be quite challenging. Careful planning and detailed analysis is required for a microwave radio system before the equipment can be installed. A poorly designed path can result in periodic system outages, resulting in increased system latency, decreased throughput, or worst case, a complete failure of the system.

1.1                DEFINITION OF  MICROWAVE/RADIO FREQUENCY WAVE

The term microwave refers to alternate current signals with frequencies between 300 MHz and 300 GHz with a corresponding electrical wavelength between λ= c/f = 1 m and λ= 1 mm respectively. Signals with wavelengths on the order of millimeters are called millimeters waves. The relation between the frequency f and wavelength λ being f λ= c, where c is velocity of propagation of the radio wave, which is equal to that of light waves in frees pace 3×10⁸m/sec.

Any frequency within the electromagnetic spectrum associated with radio wave propagation is referred as Radio Frequency (RF). When an RF current is supplied to an antenna, an electromagnetic field is created that then is able to propagate through space. Many wireless technologies are based on RF field propagation.

1.2                                              PURPOSE OF THE PROJECT

The basic purpose of microwave link of communication system is to ensure the exchange of information in between the people. When this communications without wired then it’s refereed to wireless communications. Now a day this wireless communications gets more attention from the Communication industry and provide better quality information transfer between portable devices. Autonomous sensor networks, Multimedia, Videoconferencing, Distance learning and Internet enabled cell phone are the Valuable Applications of this technology.

1.3                                     PROPERTIES OF MICROWAVE LINKS

• Involve line of sight (LOS) communication technology
• Affected greatly by environmental constraints, including rain fade
• Have very limited penetration capabilities through obstacles such as hills, buildings and trees
• Sensitive to high pollen count
• Signals can be degraded during Solar proton events

1.4                                            MICROWAVE APPLICATIONS

The main part of radio frequency microwave signals can be classified in following terms.

1.4.1 Communication

The communication part concludes satellite and space systems, extensive distances, wired telephone, naval, mobiles telephone, airbus, roads vehicle, personal, and WLAN other than that there are also two significant subcategories of communications should be considered which are optical communication and television and radio broadcasting.

 

1.4.2 Television and Radio Broadcasting

In this category of communication radio frequency or microwaves are utilized as the carriers for audio and video signals. Direct Broadcast System (DBS) is an example which is deliberately designed to connect or link satellites systems directly to home users.

 

1.4.3 Optical Communications

In optical communication microwave modulator is used in the broadcasting part of a low pass optical fiber and microwave demodulator on the other side. The microwave signal operates as a transforming signal with the carrier optical signal. In case of larger frequency channels, optical communication is useful.

1.4.4 Radar and Navigation

This part comprises of air defense, airbus, ships direction, elegant weapons, police and weather and collision avoidance. The navigation system is used for the direction and supervision of airbus, ship and road vehicles. The typical applications are:

1. Microwaves Landing System – MLS used to direct airbus to land securely at airports.
2. Global Positioning System – GPS used to find exact positioning or spot on the globe.

1.4.5 Remote Sensing

In remote sensing many satellite systems monitor globe consistently for weather situations meteorology, ozone layer, soil, agriculture, crop protection from frost, forests, thickness of snow, sea icebergs and other parts such as examining and discovery of resources.

1.4.6 Domestic and Industrial Application

This area deals with microwave ovens, clothes dryers (microwaves), liquefied heating systems, humidity sensors, tank gauges, automatic doors opener, automatic toll tax detection, control and monitoring of motorway traffic, chip fault recognition, power transmission, food protection, bug control etc.

1.4.7 Medical applications and Surveillance

This deals with breeding of cats, heart functional reaction, bleeding control, sterilization. On the other hand surveillance concludes security alarm systems, burglar detection and Electronics Warfare (EW) receivers for monitoring of traffic signals.

1.4.8 Astronomy and Space Exploration

The astronomy and space deals with enormous dish antennas which are used for monitoring, collecting and record incoming microwave signals from external space, giving critical information about other planets, stars, other objects and galaxies.

1.5 Wireless Application and Mobile Cellular Networks

The smaller distance communication in and between buildings in a local area network (LAN) can be accomplished using RF and microwaves. Connecting buildings via cables creates serious problems in congested metropolitan areas because the cable has to be run underground from the upper floors [2]. Cellular companies frequently use to get hard schedules to make sure of services for clients to produce abrupt profits. In order to revolve up their networks, companies require replacing the data of cell sites to their mobile switching stations. They must have taken microwave due to its consistency, speed of employment and cost payback over fiber or leased wired line. Microwave radio is deeply deployed in the rising 2.5G and 3G mobile infrastructures to maintain data handling. The larger numbers of cell sites required to support a new generation mobiles.

 

1.5.1 Last Mile Access

A considerable section of business grounds require broadband connectivity.

Wireless networks give the ideal means for connecting new clients to defeat the last mile bottleneck. If an operator prefers to use non-licensed or multi-point wireless tools to fix customers, even then high ability microwave offers the perfect way out for backhaul of client traffic from contact hubs to the nearby fiber point.

 

1.5.2 Private Networks and Developing Nations

These days’ companies may have high speed LAN and WAN network necessities.

They need to unite elements of their industry on same ground, city or country.

However, microwave radio communication is capable to offer fast, high capacity links which are compatible with quick and gigabit Ethernet connections, enabling LANs to be comprehensive without dependence on fiber.

There are various countries which resist with distantly telephone communications and require upgrading their systems to the most recent digital technology. The microwave radio has habitually permitted developing nations the way of setting up telecommunications rapidly over usual immature and unusable land such as desert, forest and frozen land where spreading cable would be all but impracticable. The modern digital microwave radio systems shape the foundation for several worldwide public networks.

 

1.5.3 Disaster Recovery

In case of natural disasters, it usually shatter pre established network. Thus, microwave is often used to reinstate connections when communication means i.e. equipment has been broken by earthquakes, water floods, hurricanes or human conflicts such as assault by terrorist or wars etc. These days microwave communication is used widely for speedily restore infrastructure in countries like Kuwait, Iraq, Serbia, Afghanistan and Kosovo, where existing communications has

been mostly destroyed or damaged.

1.5.4 Control and Monitoring Railroads and public transport organizations are the most important users of microwave and play an important role for these companies to control and monitoring information and switching stations.

1.5                                            USES OF MICROWAVE LINKS

• In communications between satellites and base stations
• As backbone carriers for cellular systems
• In short range indoor communications
• Telecommunications, in linking remote and regional telephone exchanges to larger (main) exchanges without the need for copper/optical fibre lines.

1.6  MICROWAVE ADVANTAGES OVER CABLE/FIBER BASED TRANSMISSION

Microwave radio offers a number of compelling advantages over cable/fiber based transmission. The various advantages pertaining to the wide use of microwaves are described as bellow:

1. Rapid Deployment – Microwave link can installed less than a day.
2. Reliability – In Radio communication MF/HF band, varies widely with time, weather condition and giving rise to fading effect. But a microwave frequencies, there is less fading since the propagation of microwaves from transmitter to receiver takes place by line of sight propagation.
3. No Right-of-Way Issues – Microwave radio can overcome barrier such as railways, road and ponds as well and avoiding taking any permission to establish the communications and introduce time delay or cost.
4. Flexibility– At minimal or even no cost microwave link capacity can easily increased. If network needs any changes we can redeploy radios as a result of customer demand.
5. Easily Crosses City Terrain – In many cities there enormously restricted street digging to in install any cable/fiber in this situation Microwave radio is the best solution.
6. Operator Owned Infrastructure – no dependence on competitors.
7. Required negligible operational costs.
8. Radio infrastructure is already acquired by many networks in existing radio transmission towers, rooftops, and cellular masts.
9. Microwave radio can be repaired in minutes instead of hours or days where as the cable systems takes long time to fault diagnosis and fix it.
10. In natural disasters microwave link can give better flexibility

 

1.7                                           LIMITATION OF THE PROJECT

Microwave radio offers various limitation and problems as well over different circumstances.

Following are the disadvantages:

1. Microwave engages huge capital investment in start if there is no vendor to finance it.
2. Microwave networks required maintenance because if a healthy planned, correctly implement network with quality equipment are not installed by good reputed vendor then maintenance required for longer run [3].
3. Microwave faces trouble like signals loss.
4. Microwave subject to Radio Interference from different environmental factors such as: ¾ Thermal Inversion – a setback of the normal reduction of air temperature above sea level [4]. ¾ Passing Airplanes, birds and rain

¾ Stellar Flare and Sunspots – stellar flare or solar flare is known as big explosion in atmosphere of Sun which affects layers. They generate electromagnetic radiations from radio waves to gamma rays to the entire wavelengths. Whereas sunspot is dark sports on sun occurred by severe magnetic action which earth temperature [5].

5. Microwave required a line-of-sight because signals travel in straight lines.
6. Microwave towers, repeaters and other equipment are very much expensive as compare to fiber optic [6].

1.8                                       OBJECTIVE OF THIS THESIS WORK

In this thesis work an iterative technique has been presented to explain the sequential communication of signal transmission for long and short distance radio communication through microwave link with better efficiency. The objective of our work is to analysis different path loss model and modulation technique that can help to build efficient microwave link to established wireless communication.

1.9                                         SIGNIFICANCE OF THE PROJECT

One of the reasons microwave links are so adaptable is that they are broadband. That means they can move large amounts of information at high speeds. Another important quality of microwave links is that they require no equipment or facilities between the two terminal points, so installing a microwave link is often faster and less costly than a cable connection. Finally, they can be used almost anywhere, as long as the distance to be spanned is within the operating range of the equipment and there is clear path (that is, no solid obstacles) between the locations. Microwaves are also able to penetrate rain, fog, and snow, which means bad weather doesn’t disrupt transmission.