Satellite is an object launched into space to orbit the Earth, sun, moon or other celestial body. Nowadays there is one of the most important way to communications. Satellites are used for the purpose of scientific research, weather reports or military reconnaissance. We should consider two aspects of satellite communications, it means, their advantages and disadvantages. The first advantage of satellite communications can be a coverage. The Earth is covered by satellites in 42,4% and it is rising every year. This way of communications needs less infrastructure than a terrestrial system which makes it is more available. Secondly is a reliability. Although a satellite is about 40 000 km away from the earth, there are not significant disturbances whereas in a terrestrial system, long path lengths lead to a high reduction signal. Through insignificant signal interferences it is possible to obtain high level of a quality of service. Satellites are made of resistant materials of a high quality, in order to survive in a harsh environment. Besides, satellites are able to transmit a large amount of communications on a large range.
They can do it without using a land infrastructure such as submarine cables. Nowadays, more often communications are transmitted by land due to the increasing technological capabilities, such as higher bandwidth cables. On the other hand there is the other aspect that I would like to present. In my opinion the most important disadvantage of using satellites is their cost. This is required in order to satellites are made of high quality materials, but unfortunately it involves with huge costs. As well as there is not possible to repair it after launch. The another disadvantage is a delay of the signal. The signal from the satellite has to travel a long distance, thus this may cause delays in the receipt the signal e.g. voice and video communications. Satellites are very useful in a normal life and make life easier. However, we have to be aware that they have some disadvantages. Before the using only satellites we should also consider other means of data transmission.