A signaller, signalman, colloquially referred to as a radioman or signaleer in the armed forces is a specialist soldier, sailor or airman responsible for military communications. Signallers, a.k.a. Combat Signallers or signalmen or women, are commonly employed as radio or telephone operators, relaying messages for field commanders at the front line (Army units, Ships or Aircraft), through a chain of command which includes field headquarters. Messages are transmitted and received via a communications infrastructure comprising fixed and mobile installations. Duties In the past, signalling skills have included the use of: Heliograph, Aldis lamp, semaphore flags, "Don R" (Dispatch Riders) and even carrier pigeons. Modern signallers are responsible for the battlefield voice and data communication and information technology infrastructure or in common English terms, they may carry a backpack radio transceiver used to communicate to forward operating bases (large and small outposts for the military), using a variety of media. All types of wire (line), satellite and ionospheric radio communication are employed. These include common radio systems such as HF/VHF radio and UHF/SHF radio (operated in line of sight, for example). Cellular radio and telephone systems such as TETRA are also becoming common. In addition to day-to-day soldiering, the signaller is required to be competent at a number of skill levels in the following topics: Maintaining Power Supplies (Batteries and Charging for example) Radio sets; storage and logistics; installation and operation; maintenance and repair at unit level. Station Organisation; Managing Radio Nets and Maintaining Net Discipline for example, map marking, log keeping etc. Voice and wireless telegraphy procedure (using Morse code or RATT (Radio assisted Teletype) for example). Formal message procedure, electronic mail. Electronic Warfare (EW); Communications Security (COMSEC) - including the encryption and deciphering of coded messages using paper/voice and electronic codes for example. Telephone and Line Information and Communication Technology Antennae selection and design Air Forces In an air force, a signaller, an aircrew member, is a person trained to communicate between the aircraft, its base and units in the area of operation, by means of radio or other digital communications. Navy Forces In the navy, a signaller is usually a seaman trained to communicate between the fleet forces and naval bases in the area of operation, by means of radio or other digital communications. Armies Australia In the Australian Army, a signaller is often referred to as a Chook (Australian Slang for Chicken) by soldiers outside the Signal