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General Mobile Radio Service
The General Mobile Radio Service (GMRS) is a land-mobile FM UHF radio service designed for short-distance two-way communication and authorized under part 95 of 47 USC. It requires a license in the United States, but some GMRS compatible equipment can be used license-free in Canada. The US GMRS license is issued for a period of 10 years by the FCC. The United States permits use by adult individuals who possess a valid GMRS license, as well as their immediate family members.The FCC definition of “immediate family” includes the licensee’s spouse, children, stepchildren, parents, stepparents, siblings, grandparents, aunts, uncles, nephews, nieces, and in-laws. See . Immediate relatives of the GMRS system licensee are entitled to communicate among themselves for personal or business purposes, but employees of the licensee who are not family members are not covered by the license. Non-family members must be licensed separately. GMRS radios are typically handheld portable d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Effective Radiated Power
Effective radiated power (ERP), synonymous with equivalent radiated power, is an IEEE standardized definition of directional radio frequency (RF) power, such as that emitted by a radio transmitter. It is the total power in watts that would have to be radiated by a half-wave dipole antenna to give the same radiation intensity (signal strength or power flux density in watts per square meter) as the actual source antenna at a distant receiver located in the direction of the antenna's strongest beam (main lobe). ERP measures the combination of the power emitted by the transmitter and the ability of the antenna to direct that power in a given direction. It is equal to the input power to the antenna multiplied by the gain of the antenna. It is used in electronics and telecommunications, particularly in broadcasting to quantify the apparent power of a broadcasting station experienced by listeners in its reception area. An alternate parameter that measures the same thing is effec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unlicensed Personal Communications Services
Unlicensed Personal Communications Services or UPCS band is the 1920–1930 MHz frequency band allocated by the United States Federal Communications Commission (FCC) for short range Personal Communications Services (PCS) applications in the United States, such as the Digital Enhanced Cordless Telecommunications (DECT) wireless protocol. History Prior to an FCC rules change in April 2005, the band also included the frequencies 1910-1920 MHz and 2390–2400 MHz. These were used for a variety of short range communications, including point-to-point microwave links. Allocation These allocation rules are described in Title 47Part 15of the Code of Federal Regulations. ''Licensed'' PCS, although not necessarily distinguished as such from UPCS, is used for digital mobile phone services. DECT devices designed to operate in this band in the US use the marketing term DECT 6.0. See also *Amateur radio (Licence Required) *Citizens band radio *Family Radio Service *General Mobile Radi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public Radio Service
Public Radio Service (PRS) is a walkie-talkie personal radio service in the People's Republic of China, including Hong Kong and Macau, but excluding Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the nort .... It can be used without a license. It uses 409 MHz. It is also known as PRS409.423 号文件） (trans-title:Technical requirements for micropower (short range) radio transmitting equipment) page 8 ] It is similar to the American Family Radio Service (FRS) and PMR446 in the European Union. Technical information The PRS radios use narrow-band frequency modulation (NBFM) with a maximum deviation of 2.5 kHz. The channels are spaced at 12.5 kHz intervals. They are limited to 500 milliwatts effective radiated power. See also * 70-centimeter band * CDCSS * Continuous Tone-Coded Squ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multi-Use Radio Service
In the United States, the Multi-Use Radio Service (MURS) is a licensed by rule (i.e. under part 95, subpart J, of title 47, Code of Federal Regulations) two-way radio service similar to the Citizens band (CB). Established by the U.S. Federal Communications Commission in the fall of 2000, MURS created a radio service allowing for licensed by rule (Part 95) operation in a narrow selection of the VHF band, with a power limit of 2 watts. The FCC formally defines MURS as "a private, two-way, short-distance voice or data communications service for personal or business activities of the general public." MURS stations may not be connected to the public telephone network, may not be used for store and forward operations, and radio repeaters are not permitted. In 2009, Industry Canada (IC) established a five-year transition plan, which would have permitted the use of MURS in Canada starting June 2014. In August 2014 IC announced a deferral of MURS introduction, as "the Department does not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISM Band
The ISM radio bands are portions of the radio spectrum reserved internationally for industrial, scientific and medical (ISM) purposes, excluding applications in telecommunications. Examples of applications for the use of radio frequency (RF) energy in these bands include radio-frequency process heating, microwave ovens, and medical diathermy machines. The powerful emissions of these devices can create electromagnetic interference and disrupt radio communication using the same frequency, so these devices are limited to certain bands of frequencies. In general, communications equipment operating in ISM bands must tolerate any interference generated by ISM applications, and users have no regulatory protection from ISM device operation in these bands. Despite the intent of the original allocations, in recent years the fastest-growing use of these bands has been for short-range, low power wireless communications systems, since these bands are often approved for such devices, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LPD433
LPD433 (low power device 433 MHz) is a UHF band in which license free communication devices are allowed to operate in some regions. The frequencies correspond with the ITU region 1 ISM band of 433.050 MHz to 434.790 MHz, and operation is limited to CEPT countries. The frequencies used are within the 70-centimeter band, which is currently reserved for government and amateur radio operations in the United States and most nations worldwide. LPD hand-held radios are authorized for licence-free voice communications use in most of Europe using analog frequency modulation (FM) as part of short range device regulations, CEPT/ERCbr> REC 70-03 (22 August 2011) with 25 kHz channel spacing, for a total of 69 channels. In some countries, LPD devices may only be used with an integral and non-removable antenna with a maximum legal power output of 10 mW. Voice communication in the LPD band was introduced to reduce the burden on the eight (now sixteen) PMR446 channels over shorter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PMR446
PMR446 (Private Mobile Radio, 446 MHz) is a licence exempt service in the UHF radio frequency band and is available for business and personal use in most countries throughout the European Union. PMR446 is typically used for small-site, same-building and line of sight outdoor activities. Equipment used ranges from consumer-grade to professional quality walkie-talkies (similar to those used for FRS/GMRS in the United States and Canada). Depending on surrounding terrain range can vary from a few hundred metres (in a city) to a few kilometres (flat countryside) to many kilometres from high ground. Historically, analogue FM is used but a digital voice mode has been available in radios conforming to digital private mobile radio (dPMR446) and digital mobile radio (DMR Tier 1) standards designed by ETSI. Originally 8 channels were available in analogue mode but this has now been increased to 16 channels. Typically PMR446 is used for both recreational and business use, addition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Repeater
A radio repeater is a combination of a radio receiver and a radio transmitter that receives a signal and retransmits it, so that two-way radio signals can cover longer distances. A repeater sited at a high elevation can allow two mobile stations, otherwise out of line-of-sight propagation range of each other, to communicate. Repeaters are found in professional, commercial, and government mobile radio systems and also in amateur radio. Repeater systems use two different radio frequencies; the mobiles transmit on one frequency, and the repeater station receives those transmission and transmits on a second frequency. Since the repeater must transmit at the same time as the signal is being received, and may even use the same antenna for both transmitting and receiving, frequency-selective filters are required to prevent the receiver from being overloaded by the transmitted signal. Some repeaters use two different frequency bands to provide isolation between input and output or as a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Business Band
In the United States, the business band is the colloquial name used by radio users who utilize, and scanner hobbyists who listen to, the Federal Communications Commission (FCC) Industrial/Business pool frequencies. The regulations listing frequencies in this pool are contained in Subpart C of Part 90, Title 47 of the CFR. Overview The pool describes a series of frequencies on the VHF and UHF two-way radio bands. They are reserved for use by companies and individuals operating commercial activities; educational, philanthropic, or ecclesiastical institutions; clergy activities or hospitals, clinics, or medical associations. In the United States, use of these frequencies requires a license issued by the U.S. FCC. The exceptions to this are five specific frequencies that are also part of the Multi-Use Radio Service (MURS), which permits unlicensed operation on these frequencies, provided the output power does not exceed 2 watts. Other frequency bands, such as citizens band r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metropolitan Statistical Area
In the United States, a metropolitan statistical area (MSA) is a geographical region with a relatively high population density at its core and close economic ties throughout the area. Such regions are neither legally Incorporated town, incorporated as a city or town would be, nor are they legal administrative divisions like County (United States), counties or separate entities such as U.S. state, states; because of this, the precise definition of any given metropolitan area can vary with the source. The statistical criteria for a standard metropolitan area were defined in 1949 and redefined as metropolitan statistical area in 1983. A typical metropolitan area is centered on a single large city that wields substantial influence over the region (e.g., New York City or Chicago). However, some metropolitan areas contain more than one large city with no single municipality holding a substantially dominant position (e.g., Dallas–Fort Worth metroplex, Hampton Roads, Virginia B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
