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28-558: There are two types in the WSR-74 series, which are almost identical except for operating frequency. The WSR-74C (used for local warnings) operates in the C band , and the WSR-74S (used in the national network) operates in the S band (like the WSR-57 and the current WSR-88D ). S band frequencies are better suited because they are not attenuated significantly in heavy rain while the C Band

56-594: A WSR-57 at Washington, DC. WSR-74S providing local coverage WSR-74S providing local coverage. Became part of the national network after the WSR-57 at Miami was destroyed in Hurricane Andrew . C band (IEEE) The C band is a designation by the Institute of Electrical and Electronics Engineers (IEEE) for a portion of the electromagnetic spectrum in the microwave range of frequencies ranging from 4.0 to 8.0  gigahertz (GHz). However,

84-671: A WSR-3. Now the ARMOR radar, still used by Local Media/NWS. On top of the Federal Building in Westwood to this day. At Madison Airport. Replaced a WSR-3 (Doppler capability after 1982 ) At the Paducah Airport. WSR-74S providing local coverage Replaced a WSR-57 . (Doppler capability) Replaced a WSR-57 at Chicago. At East Memphis/Agricenter site Replaced a WSR-57 . At Patuxent River NAS Replaced

112-426: Is by the high frequency (5.2 GHz) band of Wi-Fi ( IEEE 802.11a ) wireless computer networks. These are the most widely used computer networks in the world, used to allow laptops , smartphones , printers and TVs to connect to the internet through a wireless router in home and small office networks, and access points in hotels, libraries, and coffee shops. The communications C band was the first frequency band that

140-476: Is reserved exclusively for radar altimeter installed on board aircraft and for the associated transponders on the ground. In February 2020, the U.S. Federal Communications Commission adopted rules for the C ;band at 3.7–4.2 GHz that allocated the lower 280 megahertz of the band, at 3.7–3.98 GHz, for terrestrial wireless use. Existing satellite operators will have to repack their operations into

168-476: Is strongly attenuated, and has a generally shorter maximum effective range. The WSR-74C uses a wavelength of 5.4 cm. It also has a dish diameter of 8 feet, and a maximum range of 579 km (313 nm) as it was used only for reflectivities (see Doppler dilemma ). The WSR-57 network was very spread out, with 66 radars to cover the entire country. There was little to no overlap in case one of these vacuum-tube radars went down for maintenance. The WSR-74

196-407: The 5.8 GHz ISM band between 5.725 and 5.875 GHz, which is used for medical and industrial heating applications and many unlicensed short-range microwave communication systems, such as cordless phones , baby monitors , and keyless entry systems for vehicles. The C-band frequencies of 5.4 GHz band [5.15 to 5.35 GHz, 5.47 to 5.725 GHz, or 5.725 to 5.875 GHz, depending on

224-421: The C band is highly associated with television receive-only satellite reception systems, commonly called "big dish" systems, since small receiving antennas are not optimal for C band. Typical antenna sizes on C-band-capable systems range from 6 to 12 feet (1.8 to 3.5 meters) on consumer satellite dishes, although larger ones also can be used. For satellite communications, the microwave frequencies of

252-430: The C band perform better under adverse weather conditions in comparison with the K u  band (11.2–14.5  GHz ), microwave frequencies used by other communication satellites . Rain fade  – the collective name for the negative effects of adverse weather conditions on transmission – is mostly a consequence of precipitation and moisture in the air . The C band also includes

280-643: The C-Band Alliance (CBA) was established in September 2018 by the four satellite operators— Intelsat , SES , Eutelsat and Telesat —that provide the majority of C-band satellite services in the US, including media distribution reaching 100 million US households. The consortium made a proposal to the FCC to act as a facilitator for the clearing and repurposing of a 200 MHz portion of C-band spectrum to accelerate

308-514: The C-Band Alliance was dead. Among other claims, Intelsat argued that it was obvious that the FCC was already treating each satellite operator individually and that it therefore made business sense for each company to respond to the FCC from its own commercial perspective. One of the major members of the C-Band Alliance, Intelsat, filed for bankruptcy on 14 May 2020, just before the new 5G spectrum auctions were to take place, with over US$ 15 billion in total debt. Public information showed that

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336-476: The IEEE S band for radars. The C-band communication satellites typically have 24 radio transponders spaced 20 MHz apart, but with the adjacent transponders on opposite polarizations such that transponders on the same polarization are always 40 MHz apart. Of this 40 MHz, each transponder utilizes about 36 MHz. The unused 4.0 MHz between the pairs of transponders act as guard bands for

364-465: The U.S. Federal Communications Commission C band proceeding and auction, designated 3.7–4.2 GHz as C band. The C band is used for many satellite communications transmissions, some cordless telephones , as well as some radar and weather radar systems . The C band contains the 5.725 - 5.875 GHz ISM band allowing unlicensed use by low power devices, such as garage door openers , wireless doorbells , and baby monitors . A very large use

392-514: The WSR-88D, but some of these radars are in commercial use. WSR-74 sites include the following two categories: Was atop the WSFO building at 3420 Norman Berry Drive Replaced a WSR-3. Replaced a WSR-3. Replaced a WSR-1. Replaced a WSR-3. Replaced a WSR-3. Replaced a WSR-3. Replaced a WSR-3. Replaced a WSR-3. Atop the Federal Building (Doppler capability after July 1991) Replaced

420-1100: The auction. In December 2021, Boeing and Airbus called on the US government to delay the rollout of new 5G phone service that uses C band due to concern of the interference with some sensitive aircraft instruments, especially radio altimeters operating at 4.2–4.4 GHz. On January 18, 2022, Verizon and AT&T announced that they would delay their C-band 5G rollout near airports in response to those concerns. ELF 3 Hz/100 Mm 30 Hz/10 Mm SLF 30 Hz/10 Mm 300 Hz/1 Mm ULF 300 Hz/1 Mm 3 kHz/100 km VLF 3 kHz/100 km 30 kHz/10 km LF 30 kHz/10 km 300 kHz/1 km MF 300 kHz/1 km 3 MHz/100 m HF 3 MHz/100 m 30 MHz/10 m VHF 30 MHz/10 m 300 MHz/1 m UHF 300 MHz/1 m 3 GHz/100 mm SHF 3 GHz/100 mm 30 GHz/10 mm EHF 30 GHz/10 mm 300 GHz/1 mm THF 300 GHz/1 mm 3 THz/0.1 mm ISM band Too Many Requests If you report this error to

448-459: The company had been considering bankruptcy protection from at least as early as February 2020. Slight variations in the assignments of C-band frequencies have been approved for use in various parts of the world, depending on their locations in the three ITU radio regions. Note that one region includes all of Europe and Africa , plus all of Russia ; a second includes all of the Americas, and

476-675: The country as the National Weather Service's radar network until the 1990s. They were gradually replaced by the WSR-88D model (Weather Surveillance Radar - 1988, Doppler), constituting the NEXRAD network. The WSR-74 had served the NWS for two decades. The last WSR-74C used by the NWS was located in Williston, ND, before being decommissioned at the end of 2012. No WSR-74S's are in the NWS inventory today, having been replaced by

504-486: The deployment of next generation 5G services, while protecting incumbent users and their content distribution and data networks in the US from potential interference. The C-Band Alliance lobbied for a private sale, but the FCC and some members of Congress wanted an auction . In November 2019, the FCC announced that an auction was planned, which took place in December 2020. Cable operators wanted to be compensated for

532-501: The likely case of imperfections in the microwave electronics . One use of the C band is for satellite communication, whether for full-time satellite television networks or raw satellite feeds, although subscription programming also exists. This use contrasts with direct-broadcast satellite , which is a completely closed system used to deliver subscription programming to small satellite dishes that are connected with proprietary receiving equipment. The satellite communications portion of

560-461: The loss of 200 MHz, which would not include a guard band of 20 MHz to prevent interference. By late 2019, the commercial alliance had weakened. Eutelsat formally pulled out of the consortium in September 2019 over internal disagreements. By February 2020, it became even less of a factor in C-band spectrum reallocation as Intelsat pulled out of the alliance and communicated to the FCC that

588-446: The ranges 5.830 to 5.850 GHz for down-links and 5.650 to 5.670 GHz for up-links. This is known as the 5-centimeter band by amateurs and the C band by AMSAT . Particle accelerators may be powered by C-band RF sources. The frequencies are then standardized at 5.996 GHz (Europe) or 5.712 GHz (US), which is the second harmonic of S band . Several tokamak fusion reactors use high-power C-band RF sources to sustain

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616-541: The region of the world] are used for Wi-Fi wireless computer networks in the 5 GHz spectrum . The C-Band Alliance was an industry consortium of four large communications satellite operators in 2018–2020. In response to a Notice of Proposed Rulemaking of July 2018 from the US Federal Communications Commission (FCC) to make the 3.7 to 4.2 GHz spectrum available for next-generation terrestrial fixed and mobile broadband services,

644-512: The third region includes all of Asia outside of Russia, plus Australia and New Zealand . This latter region is the most populous one, since it includes China , India , Pakistan , Japan , and Southeast Asia . The Radio Regulations of the International Telecommunication Union allow amateur radio operations in the frequency range 5.650 to 5.925 GHz, and amateur satellite operations are allowed in

672-446: The toroidal plasma current. Common frequencies include 3.7 GHz ( Joint European Torus , WEST (formerly Tore Supra) ), 4.6 GHz (Alcator C, Alcator C-Mod , EAST , DIII-D ), 5 GHz ( KSTAR , ITER ) and 8 GHz ( Frascati Tokamak Upgrade ). The band 4.2–4.4 GHz is currently allocated to the aeronautical radionavigation service (ARNS) on a primary worldwide basis. RR No. 5.438 notes specifically that this band

700-402: The upper 200 megahertz of the band, from 4.0 to 4.2 GHz, and there is a 20-megahertz guard band at 3.98–4.0 GHz. Licenses to use the 3.7–3.98 GHz band were auctioned in December 2020. Verizon, AT&T and T-Mobile are main winners of the auction . Verizon, AT&T, and T-Mobile spent approximately $ 45 billion, $ 23 billion, and $ 9 billion respectively during

728-455: Was allocated for commercial telecommunications via satellites. The same frequencies were already in use for terrestrial microwave radio relay chains. Nearly all C-band communication satellites use the band of frequencies from 3.7  to 4.2 GHz for their downlinks , and the band of frequencies from 5.925 to 6.425 GHz for their uplinks . Note that by using the band from 3.7  to 4.0 GHz, this C band overlaps somewhat with

756-530: Was expected, while WSR-74S radars were generally used to replace WSR-57 radars in the national weather surveillance network. When a network radar went down, a nearby local radar might have to supply updates like a network radar. NWS Lubbock received the first WSR-74C in August 1973 following widespread attention from the F5 Lubbock tornado of 1970. 128 of the WSR-57 and WSR-74 model radars were spread across

784-421: Was introduced as a "gap filler", as well as an updated radar that, among other things, was transistor-based. In the early 1970s, Enterprise Electronics Corporation (EEC), based out of Enterprise, Alabama won the contract to design, manufacture, test, and deliver the entire WSR-74 radar network (both C and S-Band versions). WSR-74C radars were generally local-use radars that didn't operate unless severe weather

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