Scientists transferred 700 TB of data between the two cities by laser beam
A team of scientists from Project X (a subsidiary of Alphabet) has successfully implemented a high-speed data transmission technology between two African cities using a laser beam. Such laser-optical communication will be able to connect settlements to which it is impossible to conduct underground lines of fiber-optic cables, and radio and satellite Internet are unstable, or roads. The cities of Brazzaville (Republic of the Congo) and Kinshasa (Democratic Republic of the Congo) participated in the test. And although the shortest distance between them is 4,800 meters, the length of the existing fiber-optic cable is more than 400 kilometers, since it took to bypass the bed of the Congo River to lay it. For this reason, the cost of Internet access in the capital of the DRC is much higher than in the neighboring country.
During the three weeks of the experiment, about 700 terabytes of data were transmitted using a laser beam with an average speed of 20 Gbit / s and a reliability of 99.9 %. Of course, the transmission of an optical beam through the air does not have absolute reliability due to interference in the form of birds, fog and rain, but the experiment proved the possibility of organizing a stable connection. The laser beam cannot be seen with the naked eye, but it can hit a receiver measuring only 5 cm from a distance of up to 10 kilometers. The receiving device is synchronized, automatically adjusting the mirror in case of beam fluctuations. And although the weather does not allow for wireless optical communication in all regions of the planet, in most parts of the world it is possible to transmit information with at least 90 percent reliability.