Amateur Radio, otherwise known as Ham Radio, is a field of electrical engineering that pertains to the transmission and reception of radio signals made through certain assigned bands in the radio frequency spectrum by private individuals for non-commercial and two-way purposes. Millions of people around the world are involved in amateur radio and many commit time to serve the public during times of emergency.
Amateur radio is primarily self-regulating with a degree of government regulation and licensing performed by agencies such as the Federal Communications Commission (FCC) to prevent interference with or by other users of the RF spectrum. Amateur radio is also regulated by the International Telecommunications Union (ITU). Organizations such as the (ARRL) Amateur Radio Relay League in the United States, and the (RAC) Radio Amateurs of Canada in Canada are responsible for the efficient use of the bandwidth provided through their respective telecommunications regulation agencies. Amateurs use a wide variety of modes to communicate to other amateurs across the globe. Modes are typically divided into three categories, Phone, Digital, and Image. Phone modes are those where voice is the primary means of communicating, such as (SSB) Single Sideband, or (FM) Frequency Modulation. Digital modes are much like (CW) morse code, where the primary mode of communication is the pattern and arrangement of discrete audio tones such as with (RTTY) Radio Teletype, or more advanced modes such as Packet Radio. Image modes involve the transmission of pictures by means of either a digital or analog method. (SSTV) Slow Scan Television is a popular way of transmitting images over lower frequency bands, in higher bands (ATV) Amateur Television is becoming a more sophisticated alternative allowing for real time video to be transmitted over UHF and VHF bands.