Swallow Reef, also known as Pulau Layang-Layang, is an oceanic atoll of the Spratly Islands
administered by Malaysia, which is situated approximately 300 kilometres northwest of Kota Kinabalu,
Sabah. The atoll is about 7 km long and 2 km wide. There is a lighthouse on the atoll that sends weather
and security conditions periodically to the mainland. Due to the long distance and atmospheric
surroundings which are not conducive to modern telecommunications, the only means of
communication is by using Morse Code over a low powered radio transceiver.
Morse code is a method used in telecommunication to encode text characters as standardized sequences
of two different signal durations, called dots and dashes or dits and dahs. Morse code is named
after Samuel Morse, an inventor of the telegraph. The International Morse Code encodes the 26 English
letters A through Z, some non-English letters, the Arabic numerals (ten digits: 0, 1, 2, 3, 4, 5, 6, 7, 8
and 9 ) and small set of punctuation and procedural signals (prosigns). There is no distinction between
upper and lower case letters. The following figure shows a list of Morse codes for characters, symbols
and Arabic numerals.