The great thing was Samuel Morse and Alfred Vail thought of a brilliant way on how these pulses could be turned into a decipherable message which is, you got it, the Morse code— a system of sending messages through a series of on and off beeps, lights, or clicks. The main concept was to use dashes and dots to represent numbers and letters, whereas a dash is thrice the length of a dot. Perhaps the most universally-known one was … — … (or is it — — –.)

During the war, these telegraphs were used on both sides to communicate from the front line of the trenches back to the officers and farther from one nation to another by using telegraph lines across Europe and the Atlantic. These enabled them to instantly receive information regarding troop movements, battle outcomes, and all sorts of crucial information and quickly make appropriate actions and decisions.

Telephone

Thanks to Alexander Graham Bell, who made the first patent of the telephone in 1876. The electric telegraph was developed, and telephones could convert sound into electronic signals transmitted through cables over long distances, replaying those signals at once so we could hear them in real-time.

In WWI, telephones were used by the Western Front to communicate between the marines and soldiers and their respective commanders. Although portable, it wasn’t as easy as they had to construct 2,000 miles of these telegraph and telephone poles by using 28,000 miles long combat lines. They also established 134 permanent telegraph offices and 273 telephone exchanges. The primary responsibility was given to the Signal Corps.

Heavy artillery bombardment and German interception were some of the problems they often encountered, as these were far from sophisticated telegraph sets. Despite that, its speed in relaying messages and information was the fastest they could have, so it’s a risk worth taking.

Radio

Before the war, radios were often used by ships to transmit messages. In fact, the Titanic used radio to communicate with other ships and radio stations in 1912. However, before 1910, these radios could only send a telegraph, thus why it was always referred to as “wireless telegraph.” As The National Archives UK wrote:

This improved telecommunications equipment made it easier for troops and officers to get information up and down the chain of command; from forces headquarters to the front line and back. One important piece of apparatus for sending intelligence and operational updates was the portable morse code machine, used by the British army throughout the conflict and often in trench holes at the heart of the battle.

Improvements were further made, and things like oscillators, amplifiers, and electron tubes were added to create a more reliable channel for voice communication. These were proven valuable when radio operators with portable transmitters could warn soldiers of an attack of poisonous gas, for instance, or when the troops had to call for backup.