your mobile handset and therefore the network is aware of where to locate you when you are leaving one cell and entering the other.

In remote areas, such communication is not possible owing to the absence of cellular network. You may have experienced that, while using your mobile handset, as you passed different zones, at a particular area, you lose your connection. The cell phone network apparently ends there. The network operates on the principle of 'line of sight’, so that the towers, set up for cellular communication, must be able to see each other. Within each cell the communication is limited to about 31 miles, as the crow flies. Communication difficulties arise in places where the tower of the cell that you have just left cannot properly see the tower of your present cell zone. This creates dropped calls or breaking up of voices. There are ofcourse other reasons for such happenings.

Satellite phones do not have such restrictions, except it needs either the clear view of the sky or an external antenna to operate. When you switch on your satellite phone, the signal goes up to the satellites and gets hooked on to that particular one or a set of satellites, with which you are registered. When making a call, the coverage that your call should have, is determined and its relayed from one

With the increase of terrorist attacks, and possible crippling of the cellular networks, people attending conventions have found the viability of renting satellite phones, finding the only way to communicate anywhere with anyone at anytime. If you are a wild life photographer, going for major shoots in the deepest jungles, where the need to communication becomes difficult, the satellite phone will be of much use in times of your need to communicate. Satellite phones are mostly useful in places with no terrestrial infrastructure or in places where the infrastructure is not usable, such as, hurricane inflicted areas, flood affected areas, etc.

Today, leading industries including, Iridium, Globalstar & Thuraya are providing satellite phone solutions, with each of them offering their own unique benefits and advantages. There are various options for you to choose from, with the best phone choice depending upon your application and destination, remembering that a satellite phone does not always offer global coverage or translates into world phone. You may visit the various websites which list of the types of phones available from different companies, highlighting the features with coverage area and rates. It is recommended that you review the facts and figures before contemplating on taking up such a satellite phone.

Satellite phones made its debut in 1990s with a lot of fanfare. While commercial applications of such phones did not commence in earnest till about 3 to 4 years back, the satellite phone companies went through a lot of rough weather, failing financially and technically. Some problems do exist even today, when a satellite operator's network fail. There could be other reasons as well.

Iridium satellite boasts of over 100,000 subscribers with its 66 satellites and is supposed to be just behind Globalstar with 115,000 subscribers. Iridium has applied for another spectrum of 3.1MHz to meet its growing demand of about 1,000 new subscribers per month. Satellite phones are expensive and costly to operate, but yet it serves the purpose in communication where there is no other way of communicating.

A satellite phone, often called 'satphone', is a mobile telephone system, that communicates directly with the orbiting communication satellites and depending on the network architecture, the coverage may be global, or only for specific regions. These types of phones generally operates with the low orbiting satellites (LEOs), which is believed to provide a wider coverage and better communication clarity. The size of a satellite phone is comparable to the size and weight of the mobile phones that were used in the late 1980s or early 1990s and has a large retractable antenna. The phone equipment itself is known as a terminal.

The main difference between a satellite phone and that of a cellular mobile phone is that, while you communicate with the nearest base station in case of a cellular phone, a satellite phone communicates with the nearest satellite. This type of satphone connections do not depend upon any network. Some of this communication technique covers a large area, with the help of multiple low orbiting satellites, relaying the signals from one to the other in order to connect you to the destination that you wish to be connected.

Some of the satellite phones use satellites in geostationary orbit, maintaining almost total global coverage operating between three to four such satellites, thus reducing cost. It is important to note that geostationary orbiting satellites are placed at about 22,000 to 30,000 miles above the Earth. The LEOs, as the name signifies, are much lower in space from the Earth, 400 to 700 miles, and as such, a single satellite has limited coverage. Therefore multiple such satellites direct your call to the required destination. On the other hand, LEOs provide better communication clarity than geostationary satellites, because of the inherent delay that it introduce. The least delay with such satellites is 0.5 seconds and this is a major disadvantage of geo stationary satellites.

In case of satellite phones communicating with geostationary satellites, the main disadvantage is that, the phone requires a large antenna system for signal transmission and reception. In such cases, the antenna needs to be of high gain, which needs more power to operate. Consequently the size of the phone also increases and can be compared to the size of terrestrial mobile phones in the past, relative to the current tiny terrestrial mobile phones. Satellite phones require a clear view of the sky to operate and will not function inside a building, car or a boat. It would require external antenna system to operate in such environments. This is clearly a serious disadvantage.

In working of a cellular phone, the principle is based on dividing an area into zones or base stations called 'cells'. As you communicate while you move, you leave a particular zone and enter another. Your call is handed over from your previous cell where you were, to the new one where you are currently passing through. Your communication is electronically switched to the cell where you are in. Every cell phone and your Sim card with hold adequate information regarding the identity of your mobile handset and therefore the network is aware of where to locate you when you are leaving one cell and entering the other.

In remote areas, such communication is not possible owing to the absence of cellular network. You may have experienced that, while using your mobile handset, as you passed different zones, at a particular area, you lose your connection. The cell phone network apparently ends there. The network operates on the principle of 'line of sight’, so that the towers, set up for cellular communication, must be able to see each other. Within each cell the communication is limited to about 31 miles, as the crow flies. Communication difficulties arise in places where the tower of the cell that you have just left cannot properly see the tower of your present cell zone. This creates dropped calls or breaking up of voices. There are ofcourse other reasons for such happenings.

Satellite phones do not have such restrictions, except it needs either the clear view of the sky or an external antenna to operate. When you switch on your satellite phone, the signal goes up to the satellites and gets hooked on to that particular one or a set of satellites, with which you are registered. When making a call, the coverage that your call should have, is determined and its relayed from one

satellite phone.

Satellite phones made its debut in 1990s with a lot of fanfare. While commercial applications of such phones did not commence in earnest till about 3 to 4 years back, the satellite phone companies went through a lot of rough weather, failing financially and technically. Some problems do exist even today, when a satellite operator's network fail. There could be other reasons as well.

Iridium satellite boasts of over 100,000 subscribers with its 66 satellites and is supposed to be just behind Globalstar with 115,000 subscribers. Iridium has applied for another spectrum of 3.1MHz to meet its growing demand of about 1,000 new subscribers per month. Satellite phones are expensive and costly to operate, but yet it serves the purpose in communication where there is no other way of communicating.

A satellite phone, often called 'satphone', is a mobile telephone system, that communicates directly with the orbiting communication satellites and depending on the network architecture, the coverage may be global, or only for specific regions. These types of phones generally operates with the low orbiting satellites (LEOs), which is believed to provide a wider coverage and better communication clarity. The size of a satellite phone is comparable to the size and weight of the mobile phones that were used in the late 1980s or early 1990s and has a large retractable antenna. The phone equipment itself is known as a terminal.

The main difference between a satellite phone and that of a cellular mobile phone is that, while you communicate with the nearest base station in case of a cellular phone, a satellite phone communicates with the nearest satellite. This type of satphone connections do not depend upon any network. Some of this communication technique covers a large area, with the help of multiple low orbiting satellites, relaying the signals from one to the other in order to connect you to the destination that you wish to be connected.

Some of the satellite phones use satellites in geostationary orbit, maintaining almost total global coverage operating between three to four such satellites, thus reducing cost. It is important to note that geostationary orbiting satellites are placed at about 22,000 to 30,000 miles above the Earth. The LEOs, as the name signifies, are much lower in space from the Earth, 400 to 700 miles, and as such, a single satellite has limited coverage. Therefore multiple such satellites direct your call to the required destination. On the other hand, LEOs provide better communication clarity than geostationary satellites, because of the inherent delay that it introduce. The least delay with such satellites is 0.5 seconds and this is a major disadvantage of geo stationary satellites.

In case of satellite phones communicating with geostationary satellites, the main disadvantage is that, the phone requires a large antenna system for signal transmission and reception. In such cases, the antenna needs to be of high gain, which needs more power to operate. Consequently the size of the phone also increases and can be compared to the size of terrestrial mobile phones in the past, relative to the current tiny terrestrial mobile phones. Satellite phones require a clear view of the sky to operate and will not function inside a building, car or a boat. It would require external antenna system to operate in such environments. This is clearly a serious disadvantage.

In working of a cellular phone, the principle is based on dividing an area into zones or base stations called 'cells'. As you communicate while you move, you leave a particular zone and enter another. Your call is handed over from your previous cell where you were, to the new one where you are currently passing through. Your communication is electronically switched to the cell where you are in. Every cell phone and your Sim card with hold adequate information regarding the identity of your mobile handset and therefore the network is aware of where to locate you when you are leaving one cell and entering the other.

In remote areas, such communication is not possible owing to the absence of cellular network. You may have experienced that, while using your mobile handset, as you passed different zones, at a particular area, you lose your connection. The cell phone network apparently ends there. The network operates on the principle of 'line of sight’, so that the towers, set up for cellular communication, must be able to see each other. Within each cell the communication is limited to about 31 miles, as the crow flies. Communication difficulties arise in places where the tower of the cell that you have just left cannot properly see the tower of your present cell zone. This creates dropped calls or breaking up of voices. There are ofcourse other reasons for such happenings.

Satellite phones do not have such restrictions, except it needs either the clear view of the sky or an external antenna to operate. When you switch on your satellite phone, the signal goes up to the satellites and gets hooked on to that particular one or a set of satellites, with which you are registered. When making a call, the coverage that your call should have, is determined and its relayed from one

phones that were used in the late 1980s or early 1990s and has a large retractable antenna. The phone equipment itself is known as a terminal.

The main difference between a satellite phone and that of a cellular mobile phone is that, while you communicate with the nearest base station in case of a cellular phone, a satellite phone communicates with the nearest satellite. This type of satphone connections do not depend upon any network. Some of this communication technique covers a large area, with the help of multiple low orbiting satellites, relaying the signals from one to the other in order to connect you to the destination that you wish to be connected.

Some of the satellite phones use satellites in geostationary orbit, maintaining almost total global coverage operating between three to four such satellites, thus reducing cost. It is important to note that geostationary orbiting satellites are placed at about 22,000 to 30,000 miles above the Earth. The LEOs, as the name signifies, are much lower in space from the Earth, 400 to 700 miles, and as such, a single satellite has limited coverage. Therefore multiple such satellites direct your call to the required destination. On the other hand, LEOs provide better communication clarity than geostationary satellites, because of the inherent delay that it introduce. The least delay with such satellites is 0.5 seconds and this is a major disadvantage of geo stationary satellites.

In case of satellite phones communicating with geostationary satellites, the main disadvantage is that, the phone requires a large antenna system for signal transmission and reception. In such cases, the antenna needs to be of high gain, which needs more power to operate. Consequently the size of the phone also increases and can be compared to the size of terrestrial mobile phones in the past, relative to the current tiny terrestrial mobile phones. Satellite phones require a clear view of the sky to operate and will not function inside a building, car or a boat. It would require external antenna system to operate in such environments. This is clearly a serious disadvantage.

In working of a cellular phone, the principle is based on dividing an area into zones or base stations called 'cells'. As you communicate while you move, you leave a particular zone and enter another. Your call is handed over from your previous cell where you were, to the new one where you are currently passing through. Your communication is electronically switched to the cell where you are in. Every cell phone and your Sim card with hold adequate information regarding the identity of your mobile handset and therefore the network is aware of where to locate you when you are leaving one cell and entering the other.

In remote areas, such communication is not possible owing to the absence of cellular network. You may have experienced that, while using your mobile handset, as you passed different zones, at a particular area, you lose your connection. The cell phone network apparently ends there. The network operates on the principle of 'line of sight’, so that the towers, set up for cellular communication, must be able to see each other. Within each cell the communication is limited to about 31 miles, as the crow flies. Communication difficulties arise in places where the tower of the cell that you have just left cannot properly see the tower of your present cell zone. This creates dropped calls or breaking up of voices. There are ofcourse other reasons for such happenings.

Satellite phones do not have such restrictions, except it needs either the clear view of the sky or an external antenna to operate. When you switch on your satellite phone, the signal goes up to the satellites and gets hooked on to that particular one or a set of satellites, with which you are registered. When making a call, the coverage that your call should have, is determined and its relayed from one

elay that it introduce. The least delay with such satellites is 0.5 seconds and this is a major disadvantage of geo stationary satellites.

In case of satellite phones communicating with geostationary satellites, the main disadvantage is that, the phone requires a large antenna system for signal transmission and reception. In such cases, the antenna needs to be of high gain, which needs more power to operate. Consequently the size of the phone also increases and can be compared to the size of terrestrial mobile phones in the past, relative to the current tiny terrestrial mobile phones. Satellite phones require a clear view of the sky to operate and will not function inside a building, car or a boat. It would require external antenna system to operate in such environments. This is clearly a serious disadvantage.

In working of a cellular phone, the principle is based on dividing an area into zones or base stations called 'cells'. As you communicate while you move, you leave a particular zone and enter another. Your call is handed over from your previous cell where you were, to the new one where you are currently passing through. Your communication is electronically switched to the cell where you are in. Every cell phone and your Sim card with hold adequate information regarding the identity of your mobile handset and therefore the network is aware of where to locate you when you are leaving one cell and entering the other.

In remote areas, such communication is not possible owing to the absence of cellular network. You may have experienced that, while using your mobile handset, as you passed different zones, at a particular area, you lose your connection. The cell phone network apparently ends there. The network operates on the principle of 'line of sight’, so that the towers, set up for cellular communication, must be able to see each other. Within each cell the communication is limited to about 31 miles, as the crow flies. Communication difficulties arise in places where the tower of the cell that you have just left cannot properly see the tower of your present cell zone. This creates dropped calls or breaking up of voices. There are ofcourse other reasons for such happenings.

Satellite phones do not have such restrictions, except it needs either the clear view of the sky or an external antenna to operate. When you switch on your satellite phone, the signal goes up to the satellites and gets hooked on to that particular one or a set of satellites, with which you are registered. When making a call, the coverage that your call should have, is determined and its relayed from one

your mobile handset and therefore the network is aware of where to locate you when you are leaving one cell and entering the other.

In remote areas, such communication is not possible owing to the absence of cellular network. You may have experienced that, while using your mobile handset, as you passed different zones, at a particular area, you lose your connection. The cell phone network apparently ends there. The network operates on the principle of 'line of sight’, so that the towers, set up for cellular communication, must be able to see each other. Within each cell the communication is limited to about 31 miles, as the crow flies. Communication difficulties arise in places where the tower of the cell that you have just left cannot properly see the tower of your present cell zone. This creates dropped calls or breaking up of voices. There are ofcourse other reasons for such happenings.

Satellite phones do not have such restrictions, except it needs either the clear view of the sky or an external antenna to operate. When you switch on your satellite phone, the signal goes up to the satellites and gets hooked on to that particular one or a set of satellites, with which you are registered. When making a call, the coverage that your call should have, is determined and its relayed from one satellite to the other. On reaching the destination, the signal is directed to the relevant Earth station, from where it is directed by the gateway the to the call destination. If you should be calling a satellite phone from your mobile, a reverse action takes place. The gateway processes the call and switches the call information. If you should be calling another compatible satellite phone from yours, your call information is sent up to the satellites, which is then transmitted to the Earth station. In turn the Earth station transmits it back to the satellites and then connects you to the called satellite phone.

Satellite telephony is becoming more and more necessary with the radio frequency bandwidths getting exhausted and also that he cable lines cannot be fixed to all the parts of the earth. Satellite phone technology is considered to be a formidable invention to keep communication going in this world, with its ability to let you communicate even on the move and to any part of this planet, no matter where you are. When you are lost in an expedition, a satellite phone with you would prove to be a life-saver. You will be constantly in touch with any part of the world with your phone.