Tuesday, February 23, 2016
What is Radio?
Radio is the transmission of signals by modulation of electromagnetic waves with frequencies below those of visible light.
Definitions
• Frequency
Radio frequency (RF) is the rate of oscillation in the range of about 30 kHz to 300 GHz, which corresponds to the frequency of electrical signals normally used to produce and detect radio waves
• Modulation
Adding information to a carrier signal is a process called modulation. To modulate a radio carrier means that it is changed in some way to correspond to the speech, music, or data it is to carry
• Electromagnetic Waves
Radio signals exist as a form of electromagnetic wave. These radio signals are the same form of radiation as light, ultra-violet, infra-red, etc., differing only in the wavelength or frequency of the radiation. Electromagnetic waves have two elements. They are made from electric and magnetic components that are inseparable
Medium of Mass Communication
• Easily accessible and affordable.
• Oral medium of Communication.
• low production cost and extreme versatility.
• Capacity to provoke dialogue.
• Participation of local population is possible.
• Information dissemination is simple.
• A tool for democratization.
• A platform for expression of ideas .
• An agent for social change.
• Tool for exchange of knowledge and technologies.
• Tool for cultural expression and entertainment.
Characteristics of Radio
• Audio medium of communication
• Portable
• Affordable
• Greatest reach
• Easy educational medium
Example: In rural areas-high illiteracy rate…
• Alternative media to the imperfections of public and commercial media
Types of Radio Stations
• National Radio serving the whole of the country
• Regional Stations covering areas or a group of city areas
• Local Radio, smaller local area transmission (similar say to a local newspaper area coverage.)
• Community Radio, not for profit radio station broadcasting to particular defined communities
• RSL, short term time restricted service licences
• DAB stations transmitting only via a digital network
• Internet, satellite and cable stations
• Hospital, Student or campus radio
• Pirate radio, illegal and unlicensed broadcasting
Modes of Transmission
• Amplitude Modulation
• Frequency Modulation
• Short Wave
• Medium Wave
• Amplitude modulation (AM) is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave.
• AM works by varying the strength of the transmitted signal in relation to the information being sent.
• The frequency remains constant.
• Frequency Modulation
• It conveys information over a carrier wave by varying its instantaneous frequency.
• Was invented by Edwin Howard Armstrong.
• It requires a wider signal bandwidth than AM.
• Signal robust against Noise.
• High frequency and fidelity radio transmission is achieved.
Short Wave
• It refers to the high frequency portion of the radio spectrum
• The frequency ranges between 3,000–30,000 kHz (3–30MHz).
• Shortwave radio received its name because its frequencies were higher (and wavelengths shorter) than the medium and low frequency bands then used for radio communications.
Advantages of Short wave
• Government authorities have technical difficulties to monitor which stations are being listened to unlike Internet.
Eg: During the coup against President Mikhail Gorbachev, when his access to communications was limited, Gorbachev was able to stay informed by means of the BBC World Service on shortwave.
• Low-cost shortwave radios are widely available in all but the most repressive countries in the world.
• Many newer shortwave receivers are portable and can be battery operated, making them useful in difficult circumstances.
• Shortwave radios can be used in situations where Internet or satellite technology is unavailable (or unaffordable).
• Shortwave radio travels much farther than broadcast FM.
• Shortwave broadcasts can be easily transmitted over a distance of several thousands of kilometers
Eg: from one continent to another, especially at night particularly in tropical regions.
• SW is somewhat less prone to interference from thunderstorms than Mediumwave and is able to cover a large geographic area with relatively low power
Disadvantages of Short wave
• Shortwave broadcasts often suffer from serious interference problems because of overcrowding on the wavebands, atmospheric disturbances and electrical interference problems (particularly in cities) from TV sets, computers, poorly designed domestic appliances, and substandard electrical installations.
• Even under ideal reception conditions, the audio quality of a shortwave broadcast is usually inferior to that of domestic stations, particularly FM stations, and it is always in mono.
Medium Wave
• It is that part of the medium frequency (MF) radio band used mainly for AM broadcasting.
• Medium wave signals have the property of following the curvature of the earth (the ground wave) at all times, and also refracting off the ionosphere at night (sky wave).
This makes this frequency band ideal for both local and continent-wide service, depending on the time of day.
Types of Microphones
On the basis of sensitivity
• Dynamic Microphone
• Condenser Microphone
• Electret Microphone
• Ribbon Microphone
On the basis of Direction
• Omnidirectional
• Unidirectional
• Bi-directional
Dynamic Microphones
• The dynamic microphone uses a wire coil and magnet to create the audio signal.
• The diaphragm is attached to the coil.
• When the diaphragm vibrates in response to incoming sound waves, the coil moves backwards and forwards past the magnet.
• This creates a current in the coil which is channelled from the microphone along wires.
• They are versatile and ideal for general-purpose use.
• They use a simple design with few moving parts.
• They are relatively sturdy and resilient to rough handling.
• Better suited to handling high volume levels, such as from certain musical instruments or amplifiers.
• They have no internal amplifier and do not require batteries or external power.
Condenser Microphone
• It has two plates with a voltage between them.
• One of these plates is made of very light material and acts as the diaphragm.
• The diaphragm vibrates when struck by sound waves, changing the distance between the two plates.
Electret Capsule Microphone
• The electret mic uses a special type of capacitor which has a permanent voltage built in during manufacture.
• This acts like a permanent magnet, this doesn't require any external power for operation.
• Though, good electret condenser mics usually include a pre-amplifier which does require power.
Ribbon Microphone
• Ribbon microphones have a very similar look to capacitor mics.
• Very popular with radio stations in the 1920s and 1930s .
• They are directional in nature, meaning that you must point them towards the sound you are hoping to pick up.
• Early models were very frail, but newer technology has helped their durability.
Directionality
Every microphone has a property known as directionality. This describes the microphone's sensitivity to sound from various directions. Some microphones pick up sound equally from all directions, others pick up sound only from one direction or a particular combination of directions.
Unidirectional Microphones
They pick up sound predominantly from one direction. They are more suitable for use in smaller studios. This includes cardioid and hypercardioid microphones.
a) Cardioid Microphones
• Cardioid means "heart-shaped", which is the type of pick-up pattern these mics use.
• Sound is picked up mostly from the front, but to a lesser extent the sides as well.
• Emphasising sound from the direction the mic is pointed while leaving some latitude for mic movement and ambient noise.
• The cardioid is a very versatile microphone, ideal for general use. Handheld mics are usually cardioid.
b) Hypercardioid Microphones
• This is exaggerated version of the cardioid pattern.
• It is very directional and eliminates most sound from the sides and rear.
• Due to their long thin design, they are often referred to as shotgun microphones.
• Isolating the sound from a subject or direction when there is a lot of ambient noise.
• Picking up sound from a subject at a distance.
• By removing all the ambient noise, unidirectional sound can sometimes be a little unnatural.
• It may help to add a discreet audio bed from another mic (i.e. constant background noise at a low level).
• You need to be careful to keep the sound consistent. If the mic doesn't stay pointed at the subject you will lose the audio.
• Shotguns can have an area of increased sensitivity directly to the rear.
Bi-directional Microphones
• It uses a figure-of-eight pattern and picks up sound equally from two opposite directions.
Eg: One possibility would be an interview with two people facing each other (with the mic between them).
Omnidirectional Microphones
• It captures ambient noise.
• Omni pattern mics tend to be the most technically accurate, but they may well pick up sounds not intended for them.
Omni sound is very general and unfocussed - if you are trying to capture sound from a particular subject or area it is likely to be overwhelmed by other noise.
Saturday, February 20, 2016
Role of cyber media in development
Cyber: connected with electronic communication networks, especially the Internet.
The communication landscape in the country has been undergoing major changes largely due to technological developments during the last two decades. Use of computers has revolutionized the process of collection and dissemination of information. Internet is widely used by corporate houses, educational organizations, inter-governmental organizations, non-governmental organizations and voluntary bodies.
The new technology, in fact is being increasingly used for governance (Electronic governance) and during emergencies.
E-Governance: At the most basic level, it's about putting services online and making it easier for people to access them. On a broader definition, it involves an effort by the government to lead society from an industrial to an information age.
Benefits of E-governance: e-Governance sees the people in government, business and citizens working together for the benefit of all. If properly implemented, the benefits of e-Governance are enormous. Some of its obvious benefits are:
Integrated Information: e-Governance targets to use a government-wide electronic information infrastructure to simplify service delivery, reduce duplication, and improve the level and speed of service to clients at a lower cost. It recommends creating, managing, and prudently sharing information electronically among the various government departments and the different services offered by them.
Integrated Services: Different types of services offered by different government departments like collecting taxes, granting licenses, administering regulations, paying grants and benefits, can be availed at one place.
Anywhere Services: Provision of fully interactive on-line services by e-Governance gives public access to government services with quicker responses at convenient times. This on-line accessibility of stored information from remote locations allows government officials to serve any citizen from a government office located in any part of the state or country.
Anywhere, Anytime Information: Delivery of services may require interaction between government officials and citizens, but delivery of public-domain information to citizens can be done without any such interaction. Citizens can obtain information related to government processes and procedures through an on-line system without interacting with any government official. There is no pressure on individuals to physically visit a Government Office.
Improved Overall Productivity: e-Governance will significantly contribute to improved overall productivity of both the government officials and the citizens, as it ensures faster interaction among them by electronic mail instead of moving paper files and letters, and in streamlining the workflow of internal government administrative processes. On the other hand, improved productivity of citizens results because of the facility of anytime, anywhere services and information.
Better Decision Making and Planning: The integrated information base of e-Governance helps planners and decision makers to perform extensive analysis of stored data to provide answers to the queries of the administrative cadre. This facilitates taking well informed policy decisions for citizen. This in turn helps them to formulate more effective strategies and policies for citizen facilitation.
Better Security and Protection of Information: E-Governance uses the integrated information approach for keeping all information at one place in electronic form. Thus, keeping the information secure against theft or leakage. Proper backup mechanisms also help in protecting the valuable information from getting lost due to natural calamities such as fires, earthquakes, and floods.
Successful E-governance projects in states:
BHOOMI of Karnataka: The first e-governance project of on Land Records Computerization System.
WARANA of Maharashtra: ‘Wired Village’ concept at Warana cooperative complex in Kolhapur and Sangli districts in Maharashtra.
RASI (Rural Access to Services through Internet) of Tamil Nadu: Rural IT infrastructure in Tamil Nadu.
E-SEVA of Andhra Pradesh: Provides services relating to payment of Utility Bills, Certificates, Permits / licenses, reservation etc.
CARD of A.P: System of registration through electronic delivery of all the registration services.
Tax Administration: Better, faster, easier: In order to ensure that tax administration, including that of VAT, is faster and easier, the Empowered Committee of State Finance Ministers has flagged off an initiative called the National Tax Information Exchange System (TINXSYS) project across the country.
IT for Railways: Railway Reservation Systems and online delivery of tickets.
Community Benefits: Community centres with IT: The Government of India has set up Community Information Centres (CICs) in the North East and Sikkim. These CICs provide broadband Internet access at each block.They provide services such as birth and death registration, and act as e-Suvidha service facilitation centres for marriage and SC/ST certificates. They also provide information about agricultural prices and related matters, and educational and employment opportunities.
Computerising the Police: Connecting the cops: The Kolkata Police has built a WAN that connects the police headquarters and important bureaus with more than 400 police stations across the state of West Bengal. This network is in its final stage of implementation. The older special messenger system has been abolished, and all information is sent over the new network.
Sukhmani: The government of Punjab commissioned a project called Sukhmani as the citizen gateway for over 120 services provided by the government.
E-Governance is also referred to as SMART Governance because it aims at using IT to the processes of Government functioning to bring about Simple, Moral, Accountable, Responsive and Transparent Governance.
Emergencies: During/after natural disasters, it is difficult to install radio communication stations for establishing contacts with the outside world. However, much easier to communicate through cyber media.
During the 2001, Bhuj (Gujrat) earthquake, cyber media played an important role in establishing contact, treatment of the injured and other relief and rehabilitation operations
The communication landscape in the country has been undergoing major changes largely due to technological developments during the last two decades. Use of computers has revolutionized the process of collection and dissemination of information. Internet is widely used by corporate houses, educational organizations, inter-governmental organizations, non-governmental organizations and voluntary bodies.
The new technology, in fact is being increasingly used for governance (Electronic governance) and during emergencies.
E-Governance: At the most basic level, it's about putting services online and making it easier for people to access them. On a broader definition, it involves an effort by the government to lead society from an industrial to an information age.
Benefits of E-governance: e-Governance sees the people in government, business and citizens working together for the benefit of all. If properly implemented, the benefits of e-Governance are enormous. Some of its obvious benefits are:
Integrated Information: e-Governance targets to use a government-wide electronic information infrastructure to simplify service delivery, reduce duplication, and improve the level and speed of service to clients at a lower cost. It recommends creating, managing, and prudently sharing information electronically among the various government departments and the different services offered by them.
Integrated Services: Different types of services offered by different government departments like collecting taxes, granting licenses, administering regulations, paying grants and benefits, can be availed at one place.
Anywhere Services: Provision of fully interactive on-line services by e-Governance gives public access to government services with quicker responses at convenient times. This on-line accessibility of stored information from remote locations allows government officials to serve any citizen from a government office located in any part of the state or country.
Anywhere, Anytime Information: Delivery of services may require interaction between government officials and citizens, but delivery of public-domain information to citizens can be done without any such interaction. Citizens can obtain information related to government processes and procedures through an on-line system without interacting with any government official. There is no pressure on individuals to physically visit a Government Office.
Improved Overall Productivity: e-Governance will significantly contribute to improved overall productivity of both the government officials and the citizens, as it ensures faster interaction among them by electronic mail instead of moving paper files and letters, and in streamlining the workflow of internal government administrative processes. On the other hand, improved productivity of citizens results because of the facility of anytime, anywhere services and information.
Better Decision Making and Planning: The integrated information base of e-Governance helps planners and decision makers to perform extensive analysis of stored data to provide answers to the queries of the administrative cadre. This facilitates taking well informed policy decisions for citizen. This in turn helps them to formulate more effective strategies and policies for citizen facilitation.
Better Security and Protection of Information: E-Governance uses the integrated information approach for keeping all information at one place in electronic form. Thus, keeping the information secure against theft or leakage. Proper backup mechanisms also help in protecting the valuable information from getting lost due to natural calamities such as fires, earthquakes, and floods.
Successful E-governance projects in states:
BHOOMI of Karnataka: The first e-governance project of on Land Records Computerization System.
WARANA of Maharashtra: ‘Wired Village’ concept at Warana cooperative complex in Kolhapur and Sangli districts in Maharashtra.
RASI (Rural Access to Services through Internet) of Tamil Nadu: Rural IT infrastructure in Tamil Nadu.
E-SEVA of Andhra Pradesh: Provides services relating to payment of Utility Bills, Certificates, Permits / licenses, reservation etc.
CARD of A.P: System of registration through electronic delivery of all the registration services.
Tax Administration: Better, faster, easier: In order to ensure that tax administration, including that of VAT, is faster and easier, the Empowered Committee of State Finance Ministers has flagged off an initiative called the National Tax Information Exchange System (TINXSYS) project across the country.
IT for Railways: Railway Reservation Systems and online delivery of tickets.
Community Benefits: Community centres with IT: The Government of India has set up Community Information Centres (CICs) in the North East and Sikkim. These CICs provide broadband Internet access at each block.They provide services such as birth and death registration, and act as e-Suvidha service facilitation centres for marriage and SC/ST certificates. They also provide information about agricultural prices and related matters, and educational and employment opportunities.
Computerising the Police: Connecting the cops: The Kolkata Police has built a WAN that connects the police headquarters and important bureaus with more than 400 police stations across the state of West Bengal. This network is in its final stage of implementation. The older special messenger system has been abolished, and all information is sent over the new network.
Sukhmani: The government of Punjab commissioned a project called Sukhmani as the citizen gateway for over 120 services provided by the government.
E-Governance is also referred to as SMART Governance because it aims at using IT to the processes of Government functioning to bring about Simple, Moral, Accountable, Responsive and Transparent Governance.
Emergencies: During/after natural disasters, it is difficult to install radio communication stations for establishing contacts with the outside world. However, much easier to communicate through cyber media.
During the 2001, Bhuj (Gujrat) earthquake, cyber media played an important role in establishing contact, treatment of the injured and other relief and rehabilitation operations
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