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13-centimeter Band
The 13 centimeter, 2.3 GHz or 2.4 GHz band is a portion of the UHF (microwave) radio spectrum internationally allocated to amateur radio and amateur satellite use on a secondary basis. The amateur radio band is between 2300 MHz and 2450 MHz, and thereby inside the S-band. The amateur satellite band is between 2400 MHz and 2450 MHz, and its use by satellite operations is on a non-interference basis to other radio users (ITU footnote 5.282). The license privileges of amateur radio operators include the use of frequencies and a wide variety of modes within these ranges for telecommunication. The allocations are the same in all three ITU Regions. In the 2300-2400 MHz range the band is also allocated to the Mobile service on a Primary basis which in practice leads to some challenging sharing scenarios and inconsistent allocations to amateurs at national level. Above 2400 MHz the band overlaps with the 2.4 GHz ISM (industrial, scientific, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultra High Frequency
Ultra high frequency (UHF) is the ITU designation for radio frequency, radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter (one decimeter). Radio waves with frequencies above the UHF band fall into the super-high frequency (SHF) or microwave frequency range. Lower frequency signals fall into the VHF (very high frequency) or lower bands. UHF radio waves propagate mainly by Line-of-sight propagation, line of sight; they are blocked by hills and large buildings although the transmission through building walls is strong enough for indoor reception. They are used for UHF television broadcasting, television broadcasting, cell phones, satellite communication including GPS, personal radio services including Wi-Fi and Bluetooth, walkie-talkies, cordless phones, satellite phones, and numerous other applications. The Institute of Electrical and Electronics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Telecommunication Union Region
The International Telecommunication Union (ITU), in its International Radio Regulations, divides the world into three ITU regions for the purposes of managing the global radio Electromagnetic spectrum, spectrum. Each region has its own set of frequency allocations, the main reason for defining the regions. Boundaries *Region 1 comprises Europe, Africa, the Commonwealth of Independent States, Mongolia, and the Middle East west of the Persian Gulf, including Iraq. ** The western boundary is defined by Line B. *Region 2 covers the Americas including Greenland, and some of the eastern Pacific Islands. ** The eastern boundary is defined by Line B. *Region 3 contains most of non-former Soviet Union, FSU Asia east of and including Iran, and most of Oceania. Lines: * Line B is a line running from the North Pole along meridian 10° West of Greenwich to its intersection with parallel 72° North; thence by great circle arc to the intersection of meridian 50° West and parallel 40° North; t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amateur Radio Frequency Allocations
Amateur radio frequency allocation is done by national telecommunication authorities. Globally, the International Telecommunication Union (ITU) oversees how much radio spectrum is set aside for amateur radio transmissions. Individual amateur stations are free to use any frequency within authorized frequency ranges; authorized bands may vary by the class of the station license. Radio amateurs use a variety of transmission modes, including Morse code, radioteletype, data, and voice. Specific frequency allocations vary from country to country and between ITU regions as specified in the current ITU HF frequency allocations for amateur radio. The list of frequency ranges is called a ''band allocation'', which may be set by international agreements, and national regulations. The modes and types of allocations within each frequency band is called a bandplan; it may be determined by regulation, but most typically is set by agreements between amateur radio operators. National authorities ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Radio Relay League
The American Radio Relay League (ARRL) is the largest membership association of amateur radio enthusiasts in the United States. ARRL is a non-profit organization, and was co-founded on April 6, 1914, by Hiram Percy Maxim and Clarence D. Tuska of Hartford, Connecticut. The ARRL represents the interests of amateur radio operators before federal regulatory bodies, provides technical advice and assistance to amateur radio enthusiasts, supports a number of educational programs and sponsors emergency communications service throughout the country. The ARRL has approximately 161,000 members. In addition to members in the US, the organization claims over 7,000 members in other countries. The ARRL publishes many books and a monthly membership journal called ''QST''. The ARRL is the primary representative organization of amateur radio operators to the US government. It performs this function by lobbying the United States Congress, US Congress and the Federal Communications Commission. The AR ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bandplan
A frequency plan, bandplan, band plan or wavelength plan is a plan for using a particular band of radio frequencies, that are a portion of the electromagnetic spectrum. Each frequency plan defines the frequency range to be included, how channels are to be defined, and what will be carried on those channels. Typical definitions set forth in a frequency plan are: *numbering scheme – which channel numbers or letters (if any) will be assigned *center frequencies – how far apart the carrier wave for each channel will be *bandwidth and/or deviation – how wide each channel will be *spectral mask – how extraneous signals will be attenuated by frequency *modulation – what type will be used or are permissible *content – what types of information are allowed, such as audio or video, analog or digital *licensing – what the procedure will be to obtain a broadcast license The actual authorized frequency bands are defined by the ITU and the local regulating agencies like the US F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Federal Communications Commission
The Federal Communications Commission (FCC) is an independent agency of the United States federal government that regulates communications by radio, television, wire, satellite, and cable across the United States. The FCC maintains jurisdiction over the areas of broadband access, fair competition, radio frequency use, media responsibility, public safety, and homeland security. The FCC was formed by the Communications Act of 1934 to replace the radio regulation functions of the Federal Radio Commission. The FCC took over wire communication regulation from the Interstate Commerce Commission. The FCC's mandated jurisdiction covers the 50 states, the District of Columbia, and the territories of the United States. The FCC also provides varied degrees of cooperation, oversight, and leadership for similar communications bodies in other countries of North America. The FCC is funded entirely by regulatory fees. It has an estimated fiscal-2022 budget of US $388 million. It has 1,482 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amateur Radio Licensing In The United States
In the United States, amateur radio licensing is governed by the Federal Communications Commission (FCC). Licenses to operate amateur stations for personal use are granted to individuals of any age once they demonstrate an understanding of both pertinent FCC regulations and knowledge of radio station operation and safety considerations. Applicants as young as five years old have passed examinations and were granted licenses. Operator licenses are divided into different classes, each of which corresponds to an increasing degree of knowledge and corresponding privileges. Over the years, the details of the classes have changed significantly, leading to the current system of three open classes and three grandfathered (but closed to new applicants) classes. Current license classes Amateur radio licenses in the United States are issued and renewed by the Federal Communications Commission. In 2022 the FCC began charging a Congressionally-mandated $35 administrative fee. Private indiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sirius XM Radio
Sirius XM Holdings Inc. is an American broadcasting company headquartered in Midtown Manhattan, New York City that provides satellite radio and online radio services operating in the United States. It was formed by the 2008 merger of Sirius Satellite Radio and XM Satellite Radio, merging them into SiriusXM Radio. The company also has a 70% equity interest in Sirius XM Canada, an Subsidiary, affiliate company that provides Sirius and XM service in Canada. On May 21, 2013, Sirius XM Holdings, Inc. was incorporated, and in January 2020, Sirius XM reorganized their corporate structure, which made Sirius XM Radio Inc. a direct, wholly owned subsidiary of Sirius XM Holdings, Inc. The U.S. Federal Communications Commission (FCC) approved the merger of XM Satellite Radio and Sirius Satellite Radio, Inc. on July 29, 2008, 17 months after the companies first proposed it. The merger created a company with 18.5 million subscribers, and the deal was valued at US$3.3 billion, not including de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct-sequence Spread Spectrum
In telecommunications, direct-sequence spread spectrum (DSSS) is a spread-spectrum modulation technique primarily used to reduce overall signal interference. The direct-sequence modulation makes the transmitted signal wider in bandwidth than the information bandwidth. After the despreading or removal of the direct-sequence modulation in the receiver, the information bandwidth is restored, while the unintentional and intentional interference is substantially reduced. The first known scheme for this technique was introduced by a Swiss inventor, Gustav Guanella. With DSSS, the message bits are modulated by a pseudorandom bit sequence known as a spreading sequence. Each spreading-sequence bit, which is known as a chip, has a much shorter duration (larger bandwidth) than the original message bits. The modulation of the message bits scrambles and spreads the pieces of data, and thereby results in a bandwidth size nearly identical to that of the spreading sequence. The smaller the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency-hopping Spread Spectrum
Frequency-hopping spread spectrum (FHSS) is a method of transmitting radio signals by rapidly changing the carrier frequency among many distinct frequencies occupying a large spectral band. The changes are controlled by a code known to both transmitter and receiver. FHSS is used to avoid interference, to prevent eavesdropping, and to enable code-division multiple access (CDMA) communications. The available frequency band is divided into smaller sub-bands. Signals rapidly change ("hop") their carrier frequencies among the center frequencies of these sub-bands in a predetermined order. Interference at a specific frequency will affect the signal only during a short interval. FHSS offers four main advantages over a fixed-frequency transmission: # FHSS signals are highly resistant to narrowband interference because the signal hops to a different frequency band. # Signals are difficult to intercept if the frequency-hopping pattern is not known. # Jamming is also difficult if the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio-controlled Aircraft
A radio-controlled aircraft (often called RC aircraft or RC plane) is a small flying machine that is controlled remotely by an operator on the ground using a hand-held radio transmitter. The transmitter continuously communicates with a receiver (radio), receiver within the craft that sends signals to servomechanisms (servos) which move the Flight control surfaces, control surfaces based on the position of joysticks on the transmitter. The control surfaces, in turn, directly affect the orientation of the plane. Flying RC aircraft as a hobby grew substantially from the 2000s with improvements in the cost, weight, performance, and capabilities of motors, battery (electricity), batteries and electronics. Scientific, government, and military organizations are also using RC aircraft for experiments, gathering weather readings, aerodynamics, aerodynamic modeling, and testing. A wide variety of models, parts, and styles is available for the DIY market. Nowadays, distinct from recreationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
