Almost all communication systems become inoperable during and after natural calamities like earthquakes, floods, tsunamis, cyclones etc. Often it takes months to at least restore a fraction of it. If they are restored as soon as possible many lives can be saved and losses reduced. In the present scenario, the only reliable communication equipment used for search and resue is HAM radio. But the present communication bandwidth cannot be handled by HAM radio alone. Thats why we designed such a system.
The system we designed is a High Altitude Platform (preferably a tethered helium balloon) based emergency communication system which can be quickly deployed as soon as the disaster strikes. The system will be based on packet data communication and supports Internet Protocol. It will provide a raw data rate of 500 kbps (kilo bits per second) and operates in the 2.4 GHz ISM band. It will support interface with computers, VOIP phones for search and rescue operations, IP cameras for monitoring dangerous and remote locations, search and rescue robots, robotic surgeons like da Vinci and Sofie that can provide expert medical support at remote locations from anywhere in the world through a network etc.
A high altitude platform is chosen because it combines the best features of satellites and fixed wireless access services. It is much cheaper than satellite based solutions and can be set up much faster. It can provide a line of sight transmission range of hundreds of kilometers. This implies that rescue workers need not carry powerful transceivers and heavy,high capacity batteries with them. The radio signals from the high altitude platform can reach easily in between mountain folds which would be difficult with terrestrial radio systems. It also features less propagation loss than a satellite link. In addition to this the the delay occurring in satellite communication makes it a bad choice for real time communications. A Low Earth Orbit Satellite at a height of 1390 Km will cause a delay of about 5 ms while a high altitude platform will cause a delay of about 0.083ms only. The high altitude platform can be powered using solar panels and a high speed optical fiber based Internet backbone,if needed, can be provided through the tether.
In addition to disaster management, this system can also be used for military applications. It is possible to establish a high speed data network at a war-front. Also since it is at much lower altitude than satellites, it will be much difficult for the neighboring country to intercept the signals
In short we believe that this system will bring the latest communication techniques to disaster management and will equip search and rescue operators with the latest communication gear rather than a pair of the ham radio and help to save lives..