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Frequency Coordination
Frequency Coordination is a technical and regulatory process that removes or mitigates radio-frequency interference between different radio systems that operate on the same frequency. Normally frequency coordination is a function of an administration, such as a governmental spectrum regulator, as part of a formal regulatory process under the procedures of the Radio Regulations (an intergovernmental treaty text that regulates the radio frequency spectrum). Before an administrations lets an operator operate a new radio communications network, it must undergo coordination in the following steps: * Inform other operators about the plans * Receive comments if appropriate * Conduct technical discussions with priority networks * Agree on technical and operational parameters * Gain international recognition and protection on the Master International Frequency Register * Bring the network into use This coordination ensures that: * All administrations know the technical plans of othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio-frequency
Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the upper limit of audio frequencies that humans can hear (though these are not electromagnetic) and the lower limit of infrared frequencies, and also encompasses the microwave range. These are the frequencies at which energy from an oscillating current can radiate off a conductor into space as radio waves, so they are used in radio technology, among other uses. Different sources specify different upper and lower bounds for the frequency range. Electric current Electric currents that oscillate at radio frequencies (RF currents) have special properties not shared by direct current or lower audio frequency alternating current, such as the 50 or 60 Hz current used in electrical power distribution. * Energy from RF currents in con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Co-channel Interference
Co-channel interference or CCI is crosstalk from two different radio transmitters using the same channel. Co-channel interference can be caused by many factors from weather conditions to administrative and design issues. Co-channel interference may be controlled by various radio resource management schemes. Cellular mobile networks In cellular mobile communication (GSM & LTE Systems, for instance), frequency spectrum is a precious resource which is divided into non-overlapping spectrum bands which are assigned to different cells (In cellular communications, a cell refers to the hexagonal/circular area around the base station antenna). However, after certain geographical distance, these frequency bands are re-used, i.e. the same spectrum bands are reassigned to other distant cells. The co-channel interference arises in the cellular mobile networks owing to this phenomenon of frequency reuse. Thus, besides the intended signal from within the cell, signals at the same freque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency
Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light. The interval of time between events is called the period. It is the reciprocal of the frequency. For example, if a heart beats at a frequency of 120 times per minute (2 hertz), its period is one half of a second. Special definitions of frequency are used in certain contexts, such as the angular frequency in rotational or cyclical properties, when the rate of angular progress is measured. Spatial frequency is defined for properties that vary or cccur repeatedly in geometry or space. The unit of measurement of frequency in the International System of Units (SI) is the hertz, having the symbol Hz. Definitions and units For cyclical phenomena such as oscillations, waves, or for examp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Regulations
Radio regulation refers to the regulation and licensing of radio in international law, by individual governments, and by municipalities. International regulation The International Telecommunication Union (ITU) is a specialized agency of the United Nations (UN) that is responsible for issues that concern information and communication technologies. ''ITU Radio Regulations'' are the set of ITU's regulations governing electromagnetic spectrum from 9 kHz to 275 GHz. The reasons are that the radio waves spectrum is on the one hand considered to be a limited natural resource, on the other side some radio waves are able to propagate on considerable distances and interfere with radio services abroad. Government regulation United States In the United States, radio is regulated by the Federal Communications Commission The Federal Communications Commission (FCC) is an independent agency of the United States government that regulates communications by radio, television, wir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Frequency Spectrum
Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the upper limit of audio frequencies that humans can hear (though these are not electromagnetic) and the lower limit of infrared frequencies, and also encompasses the microwave range. These are the frequencies at which energy from an oscillating current can radiate off a conductor into space as radio waves, so they are used in radio technology, among other uses. Different sources specify different upper and lower bounds for the frequency range. Electric current Electric currents that oscillate at radio frequencies (RF currents) have special properties not shared by direct current or lower audio frequency alternating current, such as the 50 or 60 Hz current used in electrical power distribution. * Energy from RF currents in conductors can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AASHTO
The American Association of State Highway and Transportation Officials (AASHTO) is a standards setting body which publishes specifications, test quality control, protocols, and guidelines that are used in highway design and construction throughout the United States. Despite its name, the association represents not only highways but air, rail, water, and public transportation as well. Although AASHTO sets transportation standards and policy for the United States as a whole, AASHTO is not an agency of the federal government; rather it is an organization of the states themselves. Policies of AASHTO are not federal laws or policies, but rather are ways to coordinate state laws and policies in the field of transportation. Purpose The American Association of State Highway Officials (AASHO) was founded on December 12, 1914. Its name was changed to American Association of State Highway and Transportation Officials on November 13, 1973. The name change reflects a broadened scope to co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Automobile Association
American Automobile Association (AAA) is a federation of motor clubs throughout North America. AAA is a privately held not-for-profit national member association and service organization with over 60 million members in the United States and Canada. AAA provides services to its members, including roadside assistance and others. Its national headquarters are in Heathrow, Florida. History The American Automobile Association (AAA) was founded on March 4, 1902, in Chicago, Illinois, in response to a lack of roads and highways suitable for automobiles.Automobile Men Organize . ''Minneapolis Daily Times''. March 5, 1902. p. 6. At that time, nine motor clubs with a total of 1,500 members banded together to form the AAA. Those individual motor clubs included the Chicago Automobile Club, Automobile Club of America, Automobile Club of N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PCIA - The Wireless Infrastructure Association
The Wireless Infrastructure Association (WIA), formerly known as PCIA, is an American trade association for wireless providers and companies that build cell phone towers, rooftop wireless sites, and other facilities that transmit wireless communication signals. ''The Washington Post'' described the industry as "the people who build all those cell towers so you can actually make those calls, download that data." These technologies are collectively referred to as "wireless telecommunications infrastructure." Examples of companies that are members of WIA include American Tower Corporation, American Tower, Ericsson, Graybar, JMA Wireless, Qualcomm, and SBA Communications. In all, member companies own and run more than 125,000 towers and antennas in the U.S. WIA advocates for a variety of issues before the federal government, on topics such as broadband deployment (the act of building wireless broadband infrastructure in the United States), utility pole attachment (adding wireless sig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
