Luke was explaining about Satellite Phones to the students. He thought that the children were good students with a thirst of knowledge. He thought he should tell them all he knew about Satellite Phones. Thereafter, he would try to connect with any passing LEO satellite.
"I am going to give you a short lecture on Satellite phones, so listen carefully. You can add this in your essay when we get back to the city." Luke said and started the lecture.
Technology changed the look of the thick heavy walkie-talkie cell phones to the smart phones with which you can do anything provided the towers are there and so is the connectivity and signal strength does not fall.
Satellite phones are different. They need to be used where cell phones cannot connect. You can use them to make calls from anywhere as their infrastructure is different. Satellite phones do not rely on a land or cell phone network. Instead, they beam their data directly to and from the satellites that are orbiting Earth.
These are communications devices of choice in areas where practically no cell coverage exists, like where there is sparse population or poor countries, locations where there are government restrictions, where there is internet access issue or where natural disaster wreaks havoc. Satellite Phones are referred to as terminals that need to be connected to the satellite. Most use it primarily to call or send text messaged, transfer data via its satellite connection.
These phones depend on different technologies, some opting for geosynchronous satellites or Low Earth orbit (LEO) system.
Geosynchronous satellites are also called GEO orbit or high earth orbit satellites. These follow the Earth as it spins on its axis. They are more or less fixed at a particular location in space. Their altitude is about 35,000 kilometers; in addition they are centered at the equator. These are huge satellites and even one can serve a huge geographical area of the earth. If the company has 3 or 4 satellites, it can provide service for the entire earth. These satellites can handle large amounts of data. Meaning that they will transfer data, do the voice calls, video streaming, file sharing, texting, television and a lot more. Most famous companies in this field are Inmarsat and Thuraya.
However, there are a few drawbacks.
The first drawback is that due to them being high orbits means a delay in transmission, so when you are speaking to someone using this process, you will need to wait for a few seconds to get a response. You may also constantly hear an echo which is really disturbing.
The second drawback is that when the satellite needs to be maintained or has a malfunction, the area it covers will lose service till the malfunction is resolved.
The third being that there are few satellites and the chances of them have greater outrage risk.
The fourth is that as they are placed at the equator, the poles are not properly covered.
The fifth is that to connect with these satellites you need a device that looks like a laptop, a directional antenna that needs to be calibrated and pointed in the direction of the satellite to get a good reception.
On the other hand the LEO satellites have lower orbits of about 1500 km and operate by companies like Iridium and Globalstar. These satellites are much more in space but smaller and lighter. Due to their small size and low orbits, the network for the coverage of most of the earth would require about 60 such satellites. At any given time you could be within a range of two or more of these satellites. These satellites travel the planet at around 27,359 kilometers/ per hour. Thus, each one of them completes a circle in around two hours. Hence, they give reliable service for many areas in emergency situations.
These have superior call quality, lower delay and are dependable. They need less battery. However, their data transmission is slower than the GEO. They cost less and you do not require a large antenna. They are slighter bigger than the normal smartphone and can be placed in the pocket.
Governments all over the world prefer to control and monitor the communication available for their people and are averse to satellite phones. In times of war etc., they can stop operation of cell towers, disrupt or destroy wireless communications as well as Internet service.
Satellite phones are good for disaster management as well as in covert or overt operations by the military.
But the bad side is that these phones have been used by terrorist organizations all over the world. Technology has caught up and these phones with terrorists can be tracked.
The possession of satellite phones is restricted. Many countries require you to get a license to possess one.
The satellite phone given to me is a prototype. It has not yet been launched and I have been asked to take a trial on it. Yes, I do have a license; it is in the name of the college. Presently, I am the custodian of the phone. We are to use it in emergency situations.
Even I have not tested it. A call from satellite phone is expensive. Furthermore, if we use it, we can come under the scanner of the government. When we get back we will need to file explanation papers.
At present these phones are issued to the Defense services working in remote areas like the national borders, the navy that mans the seas, and then there is the air force to some extent. The merchant navy needs to communicate with their companies and staff with their families. They connect through their mobile phones via the satellite network.
Ok, who will now help me assemble the phone? All the boys were ready to help.
Luke took out the satellite phone from the outside pocket of his backpack and turned it on. Everyone was amazed on seeing it. It looked like an ordinary smart phone. It was just slightly bigger. There was an antenna at the top left side of the phone like you see antenna on radios, cars and walkie talkies.
The phone's display page opened up. Its features were like a smart phone too. Luke pulled out the antenna which was enclosed in a number of smaller and smaller pieces. As Luke kept pulling the antenna, it kept becoming longer and longer. After it could no longer be pulled, he started to wave it around pointing it to the sky.
At that time there was no signal showing on the satellite phone. But as Luke waved it in the air the antenna caught the signal of a passing LEO satellite.
He quickly tried to call someone to get a map of the area. Satellites have a tendency of taking pictures at short intervals. The call was connected as per the call numbers already fed into the phone, which Luke had checked earlier. He told the receiver of their predicament.
The receiver promised to send the maps within 2 minutes. He also informed that their problem will be conveyed to their government who will convey to the local area in charge to follow up. With the maps in hand, they can progress towards getting out of their problem. Tomorrow at the same time he will connect with the camping group again. They be ready with the satellite phone.
But it took 5 minutes for the map to be sent and downloaded.
After that everyone tried to see the downloaded map and match it with the surroundings.