NCERT Textbook - Alternative Communication Systems during disasters - Class 10 PDF Download

 Page 1


28
Alternative Communication Systems...
during disasters
In Monsoon-2004, severe flood situations in the
States of Assam and Bihar caused major
devastation. Many district head quarters got
totally cut-off from the State head quarter and
neighboring districts due to submerged telephone
exchanges or damaged cables and disrupted
roads and railways communication. In the worst
affected districts the need for relief and rescue
operation could not be communicated to the
State head quarters. Realizing this, State
Government requested National Disaster Management Division of the Government of India to
immediately send the emergency coordination kits containing satellite phones to establish communication
links among the severely affected districts and state headquarters.
From the above case study, we see that during any major disaster or emergency situation, the
communication links are totally disrupted. Therefore, it is crucially important to have completely
functional communication links among Government authorities at various levels to provide adequate
assistance to the affected population. This chapter tries to explain various basic telecommunication
facilities, need for alternative communication systems during the large-scale natural disaster/emergency
situations, and modes of emergency communication systems including satellite based communication
systems.
Alternative Communication Systems...
during disasters
4.
Page 2


28
Alternative Communication Systems...
during disasters
In Monsoon-2004, severe flood situations in the
States of Assam and Bihar caused major
devastation. Many district head quarters got
totally cut-off from the State head quarter and
neighboring districts due to submerged telephone
exchanges or damaged cables and disrupted
roads and railways communication. In the worst
affected districts the need for relief and rescue
operation could not be communicated to the
State head quarters. Realizing this, State
Government requested National Disaster Management Division of the Government of India to
immediately send the emergency coordination kits containing satellite phones to establish communication
links among the severely affected districts and state headquarters.
From the above case study, we see that during any major disaster or emergency situation, the
communication links are totally disrupted. Therefore, it is crucially important to have completely
functional communication links among Government authorities at various levels to provide adequate
assistance to the affected population. This chapter tries to explain various basic telecommunication
facilities, need for alternative communication systems during the large-scale natural disaster/emergency
situations, and modes of emergency communication systems including satellite based communication
systems.
Alternative Communication Systems...
during disasters
4.
29
Can you think of today’s world without the telecommunication links?
Quite difficult, right? The telecommunication links have become a vital part of our daily life. Most popular
means of communication is the public wired telephone, which is known as Public Switched Telephone
Network (PSTN) line. This is the prime network connecting all Government and Private offices, police
stations, fire stations, hospitals and majority of homes and business places by transmitting and receiving
voice, fax and data. The usage of Wireless phones such as mobile (cellular) phones have also become
widespread in recent times.
Why does telecommunication network get disrupted or jammed in
event of a major natural disaster or emergency situation?
Unfortunately at the time of major natural disasters such as
earthquake, cyclone, flood and landslide, the regular
telecommunication infrastructure of public wired and wireless
(mobile) telephones get severely damaged and become non-
functional. This mainly happens because of the damaged cables
and cellular transmission towers or disrupted power supply to operate
the telephone exchanges and cellular transmission towers. The
wireless radio communication network of Police and Civil authorities
also gets affected due to damaged transmission towers. During
this emergency situation, the communication traffic goes beyond its capacity which leads to congestion
of the network or in worst case, complete failure of network.
Do we really need to have alternative communication systems, in case the normal communication lines
fail?
Yes, we do. At the time of any major disaster or emergency situation, it is extremely necessary to have
the communication links operational among Government authorities at various levels and the people/
volunteers working in the disaster affected areas to help the affected population.
It becomes imperative to ensure that the critical needs of search and rescue operations, relief and
response measures are communicated among the authorities of State Government, local administration,
voluntary organizations and the affected population. This situation calls for reliable alternate communication
links, which ensures the rapid movement of the right resources to the right place at the right time. It may
also happen that some severely affected areas get completely disconnected from other parts of the
world. In such situations, the urgent needs of the disaster-affected population are not known or
communicated to the responsible Government authorities, voluntary organizations and unaffected
populations in the vicinity. This may lead to severe losses in terms of human lives, livestock and property.
Do You Know…
Generally, a perfectly
working PSTN system is
designed so that no more than
5% of the phones connected
to it can be talking at the
same time. During a crisis,
there may be too much
traffic for it to handle as
‘Everyone wants to speak to
everyone’, and hence the
network gets jammed.
The prime communication networks of Government of India.
NIC: National Informatics Centre (NIC) is a premiere Science
& Technology organization of the Government of India in this
field. It functions through a nationwide information and
communication technology (ICT) network called NICNET.
Page 3


28
Alternative Communication Systems...
during disasters
In Monsoon-2004, severe flood situations in the
States of Assam and Bihar caused major
devastation. Many district head quarters got
totally cut-off from the State head quarter and
neighboring districts due to submerged telephone
exchanges or damaged cables and disrupted
roads and railways communication. In the worst
affected districts the need for relief and rescue
operation could not be communicated to the
State head quarters. Realizing this, State
Government requested National Disaster Management Division of the Government of India to
immediately send the emergency coordination kits containing satellite phones to establish communication
links among the severely affected districts and state headquarters.
From the above case study, we see that during any major disaster or emergency situation, the
communication links are totally disrupted. Therefore, it is crucially important to have completely
functional communication links among Government authorities at various levels to provide adequate
assistance to the affected population. This chapter tries to explain various basic telecommunication
facilities, need for alternative communication systems during the large-scale natural disaster/emergency
situations, and modes of emergency communication systems including satellite based communication
systems.
Alternative Communication Systems...
during disasters
4.
29
Can you think of today’s world without the telecommunication links?
Quite difficult, right? The telecommunication links have become a vital part of our daily life. Most popular
means of communication is the public wired telephone, which is known as Public Switched Telephone
Network (PSTN) line. This is the prime network connecting all Government and Private offices, police
stations, fire stations, hospitals and majority of homes and business places by transmitting and receiving
voice, fax and data. The usage of Wireless phones such as mobile (cellular) phones have also become
widespread in recent times.
Why does telecommunication network get disrupted or jammed in
event of a major natural disaster or emergency situation?
Unfortunately at the time of major natural disasters such as
earthquake, cyclone, flood and landslide, the regular
telecommunication infrastructure of public wired and wireless
(mobile) telephones get severely damaged and become non-
functional. This mainly happens because of the damaged cables
and cellular transmission towers or disrupted power supply to operate
the telephone exchanges and cellular transmission towers. The
wireless radio communication network of Police and Civil authorities
also gets affected due to damaged transmission towers. During
this emergency situation, the communication traffic goes beyond its capacity which leads to congestion
of the network or in worst case, complete failure of network.
Do we really need to have alternative communication systems, in case the normal communication lines
fail?
Yes, we do. At the time of any major disaster or emergency situation, it is extremely necessary to have
the communication links operational among Government authorities at various levels and the people/
volunteers working in the disaster affected areas to help the affected population.
It becomes imperative to ensure that the critical needs of search and rescue operations, relief and
response measures are communicated among the authorities of State Government, local administration,
voluntary organizations and the affected population. This situation calls for reliable alternate communication
links, which ensures the rapid movement of the right resources to the right place at the right time. It may
also happen that some severely affected areas get completely disconnected from other parts of the
world. In such situations, the urgent needs of the disaster-affected population are not known or
communicated to the responsible Government authorities, voluntary organizations and unaffected
populations in the vicinity. This may lead to severe losses in terms of human lives, livestock and property.
Do You Know…
Generally, a perfectly
working PSTN system is
designed so that no more than
5% of the phones connected
to it can be talking at the
same time. During a crisis,
there may be too much
traffic for it to handle as
‘Everyone wants to speak to
everyone’, and hence the
network gets jammed.
The prime communication networks of Government of India.
NIC: National Informatics Centre (NIC) is a premiere Science
& Technology organization of the Government of India in this
field. It functions through a nationwide information and
communication technology (ICT) network called NICNET. 30
Modes for Emergency Communication
RADIO COMMUNICATIONS
In the scenario where normal telephone and mobile phone network is disrupted or such services have
never existed in the disaster affected area, we need to find out other reliable means of communicating
urgent messages from the site to shorter and longer distances. The first obvious choice is to establish
a wireless radio communication network limited to the area of operations. Any wireless communication
link is based on the Radio waves either using the terrestrial or satellite systems.
A radio wave is an electromagnetic wave propagated by an antenna. Radio waves have different
frequencies, and by tuning a radio receiver to a specific frequency you can pick up a specific signal.
Hand held wireless sets (walky talky) are considered to be more suitable for local communication in
case of such emergencies.
Amateur (Ham) Radio
In the event of major disasters/emergencies, it has been experienced that Amateur Radios have worked
successfully when no other communications worked.
Amateur radio, also known as ‘Ham radio’, does not refer to special kind of radio but
to a special set of rules which apply to certain frequencies as defined by the International
Telecommunications Union (ITU) and regulated in India by Wireless Planning and
Coordination Wing, Ministry of Communications. The laid down rules allow these
frequencies to be used only for research, education and personal purpose. The word
Amateur implies the use of radio communications for non-commercial purposes.
Amateur Radio operation does not use the ground based infrastructure, and has
limited power requirements which can be easily met by batteries and generators and
thus work successfully in emergencies.
Amateur radio is getting popular in India as a creative hobby and there are around 15,000 licensed
Amateur Radio Operators (Hams) in India. Amateur Radio is an unbeatable way of learning about
radio communications, and not only will you learn much, but you would also be able to help
at the time of emergency. Licensed Amateur Radio Operators are known as Amateurs
or Hams. Most Governments expect their Amateurs to provide emergency
communication support in case of an emergency and Amateurs always come
forward to provide their services voluntarily for establishing crucial
BSNL: The Department of Telephone Operations, Government of India became a corporation
on October 1, 2000 and was christened Bharat Sanchar Nigam Limited (BSNL). Today, BSNL
is a leading telecommunication company and the largest public sector undertaking of India. It
has a network of over 45 million lines covering 5000 towns with over 35 million telephone
connections. Its responsibilities include improvement of the quality of telecom services,
expansion of telecom network, introduction of new telecom services in all villages and instilling
confidence among its customers.
Page 4


28
Alternative Communication Systems...
during disasters
In Monsoon-2004, severe flood situations in the
States of Assam and Bihar caused major
devastation. Many district head quarters got
totally cut-off from the State head quarter and
neighboring districts due to submerged telephone
exchanges or damaged cables and disrupted
roads and railways communication. In the worst
affected districts the need for relief and rescue
operation could not be communicated to the
State head quarters. Realizing this, State
Government requested National Disaster Management Division of the Government of India to
immediately send the emergency coordination kits containing satellite phones to establish communication
links among the severely affected districts and state headquarters.
From the above case study, we see that during any major disaster or emergency situation, the
communication links are totally disrupted. Therefore, it is crucially important to have completely
functional communication links among Government authorities at various levels to provide adequate
assistance to the affected population. This chapter tries to explain various basic telecommunication
facilities, need for alternative communication systems during the large-scale natural disaster/emergency
situations, and modes of emergency communication systems including satellite based communication
systems.
Alternative Communication Systems...
during disasters
4.
29
Can you think of today’s world without the telecommunication links?
Quite difficult, right? The telecommunication links have become a vital part of our daily life. Most popular
means of communication is the public wired telephone, which is known as Public Switched Telephone
Network (PSTN) line. This is the prime network connecting all Government and Private offices, police
stations, fire stations, hospitals and majority of homes and business places by transmitting and receiving
voice, fax and data. The usage of Wireless phones such as mobile (cellular) phones have also become
widespread in recent times.
Why does telecommunication network get disrupted or jammed in
event of a major natural disaster or emergency situation?
Unfortunately at the time of major natural disasters such as
earthquake, cyclone, flood and landslide, the regular
telecommunication infrastructure of public wired and wireless
(mobile) telephones get severely damaged and become non-
functional. This mainly happens because of the damaged cables
and cellular transmission towers or disrupted power supply to operate
the telephone exchanges and cellular transmission towers. The
wireless radio communication network of Police and Civil authorities
also gets affected due to damaged transmission towers. During
this emergency situation, the communication traffic goes beyond its capacity which leads to congestion
of the network or in worst case, complete failure of network.
Do we really need to have alternative communication systems, in case the normal communication lines
fail?
Yes, we do. At the time of any major disaster or emergency situation, it is extremely necessary to have
the communication links operational among Government authorities at various levels and the people/
volunteers working in the disaster affected areas to help the affected population.
It becomes imperative to ensure that the critical needs of search and rescue operations, relief and
response measures are communicated among the authorities of State Government, local administration,
voluntary organizations and the affected population. This situation calls for reliable alternate communication
links, which ensures the rapid movement of the right resources to the right place at the right time. It may
also happen that some severely affected areas get completely disconnected from other parts of the
world. In such situations, the urgent needs of the disaster-affected population are not known or
communicated to the responsible Government authorities, voluntary organizations and unaffected
populations in the vicinity. This may lead to severe losses in terms of human lives, livestock and property.
Do You Know…
Generally, a perfectly
working PSTN system is
designed so that no more than
5% of the phones connected
to it can be talking at the
same time. During a crisis,
there may be too much
traffic for it to handle as
‘Everyone wants to speak to
everyone’, and hence the
network gets jammed.
The prime communication networks of Government of India.
NIC: National Informatics Centre (NIC) is a premiere Science
& Technology organization of the Government of India in this
field. It functions through a nationwide information and
communication technology (ICT) network called NICNET. 30
Modes for Emergency Communication
RADIO COMMUNICATIONS
In the scenario where normal telephone and mobile phone network is disrupted or such services have
never existed in the disaster affected area, we need to find out other reliable means of communicating
urgent messages from the site to shorter and longer distances. The first obvious choice is to establish
a wireless radio communication network limited to the area of operations. Any wireless communication
link is based on the Radio waves either using the terrestrial or satellite systems.
A radio wave is an electromagnetic wave propagated by an antenna. Radio waves have different
frequencies, and by tuning a radio receiver to a specific frequency you can pick up a specific signal.
Hand held wireless sets (walky talky) are considered to be more suitable for local communication in
case of such emergencies.
Amateur (Ham) Radio
In the event of major disasters/emergencies, it has been experienced that Amateur Radios have worked
successfully when no other communications worked.
Amateur radio, also known as ‘Ham radio’, does not refer to special kind of radio but
to a special set of rules which apply to certain frequencies as defined by the International
Telecommunications Union (ITU) and regulated in India by Wireless Planning and
Coordination Wing, Ministry of Communications. The laid down rules allow these
frequencies to be used only for research, education and personal purpose. The word
Amateur implies the use of radio communications for non-commercial purposes.
Amateur Radio operation does not use the ground based infrastructure, and has
limited power requirements which can be easily met by batteries and generators and
thus work successfully in emergencies.
Amateur radio is getting popular in India as a creative hobby and there are around 15,000 licensed
Amateur Radio Operators (Hams) in India. Amateur Radio is an unbeatable way of learning about
radio communications, and not only will you learn much, but you would also be able to help
at the time of emergency. Licensed Amateur Radio Operators are known as Amateurs
or Hams. Most Governments expect their Amateurs to provide emergency
communication support in case of an emergency and Amateurs always come
forward to provide their services voluntarily for establishing crucial
BSNL: The Department of Telephone Operations, Government of India became a corporation
on October 1, 2000 and was christened Bharat Sanchar Nigam Limited (BSNL). Today, BSNL
is a leading telecommunication company and the largest public sector undertaking of India. It
has a network of over 45 million lines covering 5000 towns with over 35 million telephone
connections. Its responsibilities include improvement of the quality of telecom services,
expansion of telecom network, introduction of new telecom services in all villages and instilling
confidence among its customers.
31
communications among the emergency response
managers.  Such Amateur volunteers provided
commendable services during the Orissa super
cyclone in 1999 and Gujarat earthquake in 2001.
In efforts to popularize the Amateur Radio in the country
and develop a trained force of licensed Amateurs,
Department of Information Technology has initiated a
nation wide programme to establish Amateur Radio
Stations at various places and provide the necessary
training for interested Amateur Station Operators.
SATELLITE BASED COMMUNICATIONS SYS-
TEMS
Satellite based Communication systems mean
communication systems intended for users on the Earth
but which have some equipment in space, i.e. a satellite.
Different satellites carry out different jobs, such as taking
weather pictures or finding accurate positions on earth
in terms of latitudes and longitudes. Communications satellites are essentially radio relay stations in
space and are sometimes referred to as COMSATs. The other words you may hear are SATCOMS for
satellite communications in general and SATPHONE for a satellite phone terminal.
The most important feature of a communications satellite is the transponder - a radio that receives a
conversation at one frequency and then amplifies it and re-transmits it back to Earth on another frequency.
HAM operator helps families connect
with tsunami victims
New Delhi, December 28 .The Tribune
An amateur radio
enthusiast based
in the Capital has
succeeded where
most government
agencies have
failed. Sandeep Baruah, a licensed HAM
operator who works in a government
organisation by day and pursues his hobby
from home at night, has managed to
establish communication links with Port Blair,
the capital of Andaman and Nicobar Islands,
and has helped relay messages between
the people stranded on the island and their
families back home.
When deadly floods struck
central and southern T exas-USA
in mid-October 1998, amateur
radio operators from four states
volunteered their time. A
volunteer is shown helping with
communications at a Red Cross
office.
A Ham operator is on the radio,
reporting a new flare up during
the forest fires that broke out in
several counties in Florida-USA
during June and July of 1998.
YOU CAN ALSO BECOME AN AMA TEUR AT
THIS AGE BY PASSING THE AMATEUR
STATION OPERATORS LICENSE (ASOL)
EXAMINATION TAKEN BY WPC WING ,
MINISTRY OF COMMUNICATION, GOVT .
OF INDIA
A young operator enjoys making friends
over the radio. Amateur radio is a
fascinating hobby for people of all ages
and all walks of life irrespective of
educational qualifications and status.
A satellite normally contains hundreds or thousands of transponders. Data, television, image
and some telephone transmissions are routinely received and re-broadcasted by these
transponders of communication satellites.
Present operational Indian space systems include Indian National Satellite
(INSAT) for tele-communication, television broadcasting, meteorology
Page 5


28
Alternative Communication Systems...
during disasters
In Monsoon-2004, severe flood situations in the
States of Assam and Bihar caused major
devastation. Many district head quarters got
totally cut-off from the State head quarter and
neighboring districts due to submerged telephone
exchanges or damaged cables and disrupted
roads and railways communication. In the worst
affected districts the need for relief and rescue
operation could not be communicated to the
State head quarters. Realizing this, State
Government requested National Disaster Management Division of the Government of India to
immediately send the emergency coordination kits containing satellite phones to establish communication
links among the severely affected districts and state headquarters.
From the above case study, we see that during any major disaster or emergency situation, the
communication links are totally disrupted. Therefore, it is crucially important to have completely
functional communication links among Government authorities at various levels to provide adequate
assistance to the affected population. This chapter tries to explain various basic telecommunication
facilities, need for alternative communication systems during the large-scale natural disaster/emergency
situations, and modes of emergency communication systems including satellite based communication
systems.
Alternative Communication Systems...
during disasters
4.
29
Can you think of today’s world without the telecommunication links?
Quite difficult, right? The telecommunication links have become a vital part of our daily life. Most popular
means of communication is the public wired telephone, which is known as Public Switched Telephone
Network (PSTN) line. This is the prime network connecting all Government and Private offices, police
stations, fire stations, hospitals and majority of homes and business places by transmitting and receiving
voice, fax and data. The usage of Wireless phones such as mobile (cellular) phones have also become
widespread in recent times.
Why does telecommunication network get disrupted or jammed in
event of a major natural disaster or emergency situation?
Unfortunately at the time of major natural disasters such as
earthquake, cyclone, flood and landslide, the regular
telecommunication infrastructure of public wired and wireless
(mobile) telephones get severely damaged and become non-
functional. This mainly happens because of the damaged cables
and cellular transmission towers or disrupted power supply to operate
the telephone exchanges and cellular transmission towers. The
wireless radio communication network of Police and Civil authorities
also gets affected due to damaged transmission towers. During
this emergency situation, the communication traffic goes beyond its capacity which leads to congestion
of the network or in worst case, complete failure of network.
Do we really need to have alternative communication systems, in case the normal communication lines
fail?
Yes, we do. At the time of any major disaster or emergency situation, it is extremely necessary to have
the communication links operational among Government authorities at various levels and the people/
volunteers working in the disaster affected areas to help the affected population.
It becomes imperative to ensure that the critical needs of search and rescue operations, relief and
response measures are communicated among the authorities of State Government, local administration,
voluntary organizations and the affected population. This situation calls for reliable alternate communication
links, which ensures the rapid movement of the right resources to the right place at the right time. It may
also happen that some severely affected areas get completely disconnected from other parts of the
world. In such situations, the urgent needs of the disaster-affected population are not known or
communicated to the responsible Government authorities, voluntary organizations and unaffected
populations in the vicinity. This may lead to severe losses in terms of human lives, livestock and property.
Do You Know…
Generally, a perfectly
working PSTN system is
designed so that no more than
5% of the phones connected
to it can be talking at the
same time. During a crisis,
there may be too much
traffic for it to handle as
‘Everyone wants to speak to
everyone’, and hence the
network gets jammed.
The prime communication networks of Government of India.
NIC: National Informatics Centre (NIC) is a premiere Science
& Technology organization of the Government of India in this
field. It functions through a nationwide information and
communication technology (ICT) network called NICNET. 30
Modes for Emergency Communication
RADIO COMMUNICATIONS
In the scenario where normal telephone and mobile phone network is disrupted or such services have
never existed in the disaster affected area, we need to find out other reliable means of communicating
urgent messages from the site to shorter and longer distances. The first obvious choice is to establish
a wireless radio communication network limited to the area of operations. Any wireless communication
link is based on the Radio waves either using the terrestrial or satellite systems.
A radio wave is an electromagnetic wave propagated by an antenna. Radio waves have different
frequencies, and by tuning a radio receiver to a specific frequency you can pick up a specific signal.
Hand held wireless sets (walky talky) are considered to be more suitable for local communication in
case of such emergencies.
Amateur (Ham) Radio
In the event of major disasters/emergencies, it has been experienced that Amateur Radios have worked
successfully when no other communications worked.
Amateur radio, also known as ‘Ham radio’, does not refer to special kind of radio but
to a special set of rules which apply to certain frequencies as defined by the International
Telecommunications Union (ITU) and regulated in India by Wireless Planning and
Coordination Wing, Ministry of Communications. The laid down rules allow these
frequencies to be used only for research, education and personal purpose. The word
Amateur implies the use of radio communications for non-commercial purposes.
Amateur Radio operation does not use the ground based infrastructure, and has
limited power requirements which can be easily met by batteries and generators and
thus work successfully in emergencies.
Amateur radio is getting popular in India as a creative hobby and there are around 15,000 licensed
Amateur Radio Operators (Hams) in India. Amateur Radio is an unbeatable way of learning about
radio communications, and not only will you learn much, but you would also be able to help
at the time of emergency. Licensed Amateur Radio Operators are known as Amateurs
or Hams. Most Governments expect their Amateurs to provide emergency
communication support in case of an emergency and Amateurs always come
forward to provide their services voluntarily for establishing crucial
BSNL: The Department of Telephone Operations, Government of India became a corporation
on October 1, 2000 and was christened Bharat Sanchar Nigam Limited (BSNL). Today, BSNL
is a leading telecommunication company and the largest public sector undertaking of India. It
has a network of over 45 million lines covering 5000 towns with over 35 million telephone
connections. Its responsibilities include improvement of the quality of telecom services,
expansion of telecom network, introduction of new telecom services in all villages and instilling
confidence among its customers.
31
communications among the emergency response
managers.  Such Amateur volunteers provided
commendable services during the Orissa super
cyclone in 1999 and Gujarat earthquake in 2001.
In efforts to popularize the Amateur Radio in the country
and develop a trained force of licensed Amateurs,
Department of Information Technology has initiated a
nation wide programme to establish Amateur Radio
Stations at various places and provide the necessary
training for interested Amateur Station Operators.
SATELLITE BASED COMMUNICATIONS SYS-
TEMS
Satellite based Communication systems mean
communication systems intended for users on the Earth
but which have some equipment in space, i.e. a satellite.
Different satellites carry out different jobs, such as taking
weather pictures or finding accurate positions on earth
in terms of latitudes and longitudes. Communications satellites are essentially radio relay stations in
space and are sometimes referred to as COMSATs. The other words you may hear are SATCOMS for
satellite communications in general and SATPHONE for a satellite phone terminal.
The most important feature of a communications satellite is the transponder - a radio that receives a
conversation at one frequency and then amplifies it and re-transmits it back to Earth on another frequency.
HAM operator helps families connect
with tsunami victims
New Delhi, December 28 .The Tribune
An amateur radio
enthusiast based
in the Capital has
succeeded where
most government
agencies have
failed. Sandeep Baruah, a licensed HAM
operator who works in a government
organisation by day and pursues his hobby
from home at night, has managed to
establish communication links with Port Blair,
the capital of Andaman and Nicobar Islands,
and has helped relay messages between
the people stranded on the island and their
families back home.
When deadly floods struck
central and southern T exas-USA
in mid-October 1998, amateur
radio operators from four states
volunteered their time. A
volunteer is shown helping with
communications at a Red Cross
office.
A Ham operator is on the radio,
reporting a new flare up during
the forest fires that broke out in
several counties in Florida-USA
during June and July of 1998.
YOU CAN ALSO BECOME AN AMA TEUR AT
THIS AGE BY PASSING THE AMATEUR
STATION OPERATORS LICENSE (ASOL)
EXAMINATION TAKEN BY WPC WING ,
MINISTRY OF COMMUNICATION, GOVT .
OF INDIA
A young operator enjoys making friends
over the radio. Amateur radio is a
fascinating hobby for people of all ages
and all walks of life irrespective of
educational qualifications and status.
A satellite normally contains hundreds or thousands of transponders. Data, television, image
and some telephone transmissions are routinely received and re-broadcasted by these
transponders of communication satellites.
Present operational Indian space systems include Indian National Satellite
(INSAT) for tele-communication, television broadcasting, meteorology
32
INMARSAT Satellite
Phone
and disaster warning and Indian Remote Sensing Satellite (IRS) for resources monitoring and
management.
This mode of communication is most reliable as the radio relay stations, Communications satellites, are
in space and not at all vulnerable to any natural disasters on the earth, while global communications links
can be established with very small, portable and easy to install satellite antennas.
Most widely used means of satellite communications in disaster management is
‘satellite phone’. For these phones the satellite works as a telephone exchange.
These phones provide very reliable voice and data communication and are very
handy and can be to transported to any location.
Government of India is equipping the Disaster/Emergency managers in multi-hazard
prone Districts/States with portable Satellite phones so that proper communication
among the administrations at local and State level can be maintained in case the
main communication lines fail.
Radio communications and setellite based communication system are highly reliable and widely used.
All India Radio, Doordarshan and Press Trust of India also play a key role in collecting and disseminating
information.
Reference for further reading:
? http://home.nic.in
? www.isro.org
? http://www.dotindia.com/wpcc/spectrum-home.htm
? www.itu.int
? www.howstuffworks.com
1. Why should the alternative communications systems be installed?
2. Name two prime communication networks of Government of India and explain their functions.
3. How is Amateur (Ham) radio different from the common radio communication?
4. What makes the Satellite based communication systems more reliable in case of large-scale
natural/manmade emergencies?