1.2. Background

Communicating over long distances has been a challenge throughout history. In ancient times, runners were used to carry important messages between rulers or other important people. Other forms of long-distance communication included smoke signals, chains of searchlights and flags to send a message from one tower to another, carrier pigeons, and horses. Modern telecommunications began in the 1800s with the discovery that electricity can be used to transmit a signal. For the first time, a signal could be sent faster than any other mode of transportation. The first practical telecommunications device to make use of this discovery was the telegraph.