The U.S. Secret Service utilises high-tech communication equipment to protect the president of the United States, his family, former presidents or other high-ranking officials Not all of the Secret Service's equipment is known to the civilian sector, but some pieces have been revealed.
Wireless Prompter Channels
Secret Service members can reach one another through radio communication, including walkie-talkies and other wireless radio devices, such as wireless microphone systems. These devices operate via wireless prompter channels, carrying voices across the area from one sector to another. These can also be used to capture information, unbeknown to other parties in the same vicinity, and transmit that information to a primary point of contact.
Wired/Wireless Mini In-Ear Receiver
In lieu of using larger devices like walkie-talkies, Secret Service agents may wear in-ear listening devices that allow them to communicate with one another, both talking and listening. An in-ear device can be wireless; more commonly, it has a wire that trails down inside the agent's jacket, where a receiver connects remotely to a central base point.
When the Secret Service believes that someone may tamper with or tap into its communications, it can use a digital encryption service to scramble the radio wavelengths to all outside listeners. It also prevents recordings of conversations that are not meant for the public to hear.