low-frequency communication
1Low-power communication device — In telecommunication, a low power communication device, also Short Range Device (SRD) is a restricted radiation device, exclusive of those employing conducted or guided radio frequency techniques, used for the transmission of signs, signals… …
2Extremely low frequency — (ELF) is the band of radio frequencies from 3 to 30 Hz. ELF was used by the US Navy and Soviet/Russian Navy to communicate with submerged submarines.ExplanationBecause of the electrical conductivity of salt water, submarines are shielded from… …
3Very low frequency — or VLF refers to radio frequencies (RF) in the range of 3 kHz to 30 kHz. Since there is not much bandwidth in this band of the radio spectrum, only the very simplest signals are used, such as for radio navigation. Also known as the myriameter… …
4Super low frequency — (SLF) is the frequency range between 30 hertz and 300 hertz. This frequency range includes the frequencies of AC power grids (50 hertz and 60 hertz). The radio services Seafarer (USA) on 76 hertz and ZEVS (Russia) on 82 hertz operate in this… …
5Ultra low frequency — The Ultra Low Frequency (ULF) is the frequency range between 300 hertz and 3 kilohertz. Many types of waves in the ULF frequency band can be observed in the magnetosphere and on the ground. These waves represent important physical processes in… …
6Communication with submarines — is difficult because radio waves do not travel well through thick electrical conductors like salt water. The obvious solution is to surface and raise an antenna above the water, then use ordinary radio transmissions. Early submarines had to… …
7Communication Arts (magazine) — Communication Arts Communication Arts logo Frequency Bi monthly Circulation 63,043 [1] Publisher Patri …
8Frequency-division multiple access — or FDMA is an channel access method that is used by radio systems to share a certain radio spectrum between multiple users. The users are individually allocated one or several frequency bands, allowing them to access the radio system without… …
9Low-power broadcasting — Contents 1 United States 1.1 FM radio 1.1.1 LPFM classes 1.1.2 …
10Frequency synthesizer — A frequency synthesizer is an electronic system for generating any of a range of frequencies from a single fixed timebase or oscillator. They are found in many modern devices, including radio receivers, mobile telephones, radiotelephones, walkie… …
