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Cellular Radiotelephone Service
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The 869-894 MHz band (base transmit/mobile receive), paired with the 824-849 MHz band (mobile transmit/base receive) is the original band in which first-generation cellular phone service was first widely deployed in the U.S. It is still used for 2G and 3G cellular services.
The paired band is subdivided into two smaller bands of 2x12.5 MHz each, referred to as the A block and the B block. When cell phone service was first authorized, the A block was assigned to the local exchange carrier, and the B block was assigned to a competitive local exchange carrier.
The cellular service in the United States is governed by Part 22 of the FCC's rules.
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Paired Frequency Bands |
Paired Bands | Use | Service | Table |
824 - 835 MHz | Cellular A block, mobile transmit/base receive | Land Mobile | N |
869 - 880 MHz | Cellular A block, base transmit/mobile receive | Land Mobile | N |
835 - 845 MHz | Cellular B block, mobile transmit/base receive | Land Mobile | N |
880 - 890 MHz | Cellular B block, base transmit/mobile receive | Land Mobile | N |
845 - 846.5 MHz | Cellular A' block, mobile transmit/base receive | Land Mobile | N |
890 - 891.5 MHz | Cellular A' block, base transmit/mobile receive | Land Mobile | N |
846.5 - 849 MHz | Cellular B' block, mobile transmit/base receive | Land Mobile | N |
891.5 - 894 MHz | Cellular B' block, base transmit/mobile receive | Land Mobile | N |
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Commercial Air-to-Ground Telephone Service
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The bands 849 - 851 and 894 - 896 MHz are allocated to the aeronautical mobile service and are used to provide air-to-ground telephone service for commercial airlines. Most people will recognize the Verizon Airfone service, which is installed in the seatbacks of many commercial airlines and which uses this band for its service. The lower band (849 - 851 MHz) is used by the base stations located on the ground to transmit to the planes; transmissions from the planes back to the ground use the upper band, 894 - 896 MHz.
In its original incarnation, the commercial air-to-ground telephone service was to support up to six licensees in this band, where all of the licensees would share the band for traffic channels, and each licensee would have dedicated control channels to manage its own traffic. In the end, Verizon Airfone (originally operated under GTE) was the only operator to remain commercially viable, and even they are estimated to handle, on average, only about three calls per flight. Due to channel bandwidth limitations, the only services that could be offered were voice phone calls and very slow dial-up-quality data connections.
By 2005, the FCC realized that the spectrum was not being used efficiently and instigated a rule making proceeding leading to the auction of new licenses for this band. The exact band plan for this spectrum was left as one of the bidding parameters, and the final result was a plan that provided a 3 MHz license (the bottom 1.5 MHz of each of the two bands), and a 1 MHz license (the top 0.5 MHz of each band). Auction 65, completed in June 2006, generated $38,339,000 for the U.S. treasury, with ACBidCo winning the 3 MHz license and LiveTV winning the 1 MHz license.
Although Verizon Airfone participated in the auction, they did not win, and the FCC banished their operations to the spectrum occupied by the 1 MHz license, and allowed them to continue service until 2010 on a shared basis with the new licensee. On May 13th, 2010, Verizon's Airfone license, KNKG804, expired for good. In June 2008, LiveTV, the winning bidder for Airfone's spectrum, announced that it was purchasing the Verizon Airfone network.
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Paired Frequency Bands |
Paired Bands | Use | Service | Table |
849 - 851 MHz | Ground-to-air | Aeronautical Mobile | - |
894 - 896 MHz | Air-to-ground | Aeronautical Mobile | - |
External Links:
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Unlicensed bands
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Although these bands are allocated for ISM use, e.g. microwave ovens and industrial equipment, a major use has been unlicensed (Part 15) systems such as Wi-Fi, Bluetooth, and ZigBee. In the period 1995-2005, most of the cordless phones marketed in the US were in the 902-928 MHz band, but conflicts with the other uses and availability of DECT equipment has greatly decreased sales of 902-928 MHz cordless phones.
The rules for these bands sprung from FCC Docket 81-413 which sought to end an implicit prohibition of spread spectrum/CDMA technology that resulted from a focus on FDMA spectrum uses. This resulted in rules adopted in 1985 that allow unlicensed spread spectrum systems to use these bands for almost any possible application subject to a 1W power limit and a power spectral density limit. Initial applications, however, were limited to frequency hopping and "direct sequence" modulations, the latter being subject to ill-defined spreading and processing gain requirements.
An FCC rulemaking in 2002, in ET Docket No. 99-231, dropped the spreading and processing gain requirements, and permitted any digital modulation that meets the power and power spectral density limits. The immediate effect was to authorize Wi-Fi products under standard IEEE 802.11g. Subsequent Wi-Fi standards, including n and ac, were eligible for certification with no further rule changes.
Bluetooth is authorized under the original 1985 frequency hopping provisions. The 2400 and 5800 MHz bands are used for Wi-Fi.
A good history is "The Innovation Journey of Wi-Fi: The Road To Global Success" by Wolter Lemstra, Vic Hayes, John Groenewegen; Cambridge University Press, 2010.
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Frequency Bands |
Band | Use | Service | Table |
902 - 928 MHz | 900 MHz unlicensed band | - | - |
2400 - 2483.5 MHz | Unlicensed band (commonly used by Wi-Fi) | - | - |
5725 - 5850 MHz | Unlicensed band (commonly used by Wi-Fi) | - | - |
External Links:
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Industrial, Scientific, and Medical Devices (ISM, FCC Part 18)
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Part 18 (section 18.301) of the FCC rules designate certain bands for high-power Industrial, Scientific, and Medical (ISM) devices. These devices generate significant radio energy, but not for telecommunications purposes. Examples includes microwave ovens, industrial heaters, medical diathermy, jewelry cleaners, and RFID tags.
ISM devices may be operated in most frequency bands subject to strict power limits, but are allowed unlimited power in these eleven specially-designated ISM bands.
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Multiple Address System (MAS)
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According to the FCC, MAS is defined as "a point-to-multipoint or point-to-point radio communications system used for either one-way or two-way transmissions that operates in the 928/952/956 MHz, the 928/959 MHz or the 932/941 MHz bands" in accordance with section 101.147 of the FCC's rules. Specific rules for MAS are in Subpart O of Part 101.
Limited mobile operations are permitted under MAS, per 101.1307.
According to frequency coordinator Micronet, MAS are "point-to multipoint microwave systems that provide corporations and other institutions with the ability to support their dedicated operations."
Details of the MAS service were established in a 1999 FCC Report and Order (FCC 99-415), which took the following actions:
- Designate the 928/952/956 MHz bands exclusively for private internal services, licensed on a site-by-site basis.
- License the 928/959 MHz bands on a geographic area basis.
- License twenty of the forty paired channels in the 932/941 MHz bands on a geographic area basis.
- Reserve twenty of the forty channel pairs in the 932/941 MHz bands for public safety/Federal Government and private internal services, licensed on a first-come, first-served, site-by-site basis. Designate five of the twenty channels in the 932/941 MHz bands' set-aside exclusively for public safety/Federal Government services.
- Grandfather existing operations on the MAS bands and restrict expansion in the 928/959 MHz bands.
- Establish service areas based on the Federal Communications Commission's definition of Economic Areas (EAs) and on the U.S. Department of Commerce's definition of EAs.
- Establish construction/coverage requirements for EA licensees -- specifically, coverage to at least one-fifth of the population in their service areas or substantial service within five years of the license grant -- and a showing of substantial service within ten years of being licensed.
- Introduce flexibility to the MAS technical rules.
- Allow licensees to provide mobile and fixed operations on a co-primary basis for point-to-point and point-to-multipoint operations.
- Adopt a flexible approach for defining the regulatory status of MAS licensees by allowing the licensee to indicate its regulatory status.
- Lift the suspension on the acceptance of applications for the 928/952/956 MHz bands and the twenty channels in the 932/941 MHz bands designated for public safety/Federal Government and/or private internal services upon the release of this Report and Order.
- Adopt Part 1 competitive bidding rules for MAS spectrum.
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Frequency Bands |
Band | Use | Service | Table |
928 - 929 MHz | Multiple Address System | Fixed | N |
932 - 932.5 MHz | Multiple Address System | Fixed | N |
941 - 941.5 MHz | Multiple Address System | Fixed | N |
952 - 960 MHz | Multiple Address System | Fixed | N |
External Links:
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Amateur Radio (33 cm)
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According to the ITU, "the 902 MHz band is allocated to the amateur service only in Region 2, where it is also used for industrial, scientific and medical applications, and low-power devices."
In the United States, the ARRL has adopted the following band plan. The band plan may apply in other countries as well:
Frequency (MHz): Use
902-903: Narrow-bandwidth, weak-signal communications
902-902.8: SSTV, FAX, ACSSB, experimental
902.1: Weak-signal calling frequency
902.8-903: Reserved for Earth-Moon-Earth, CW expansion
903.1: Alternate calling frequency
903-906: Digital communications
906-909: FM repeater inputs
909-915: ATV
915-918: Digital communications
918-921: FM repeater outputs
921-927: ATV
927-928: FM simplex and links
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Frequency Bands |
Band | Use | Service | Table |
902 - 928 MHz | Amateur radio 33 cm band (Region 2) | AM | N |
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Location and Monitoring Service (LMS)
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The Location and Monitoring Service (LMS) is a locationing technology optimized for use in urban environments and in buildings, where other technologies, such as GPS, may not work well or at all.
Two different types of LMS are defined: Multilateration LMS (M-LMS) and non-multilateration LMS. The respective FCC definitions are:
Multilateration LMS system: A system that is designed to locate vehicles or other objects by measuring the difference of time of arrival, or difference in phase, of signals transmitted from a unit to a number of fixed points or from a number of fixed points to the unit to be located.
Non-multilateration LMS System. A system that employs any of a number of non-multilateration technologies to transmit information to and/or from vehicular units.
LMS shares the band with a variety of users. Most prominently, the band is used by a multitude of unlicensed devices such as many models of cordless phones, baby monitors, and wireless speakers.
LMS licenses were first auctioned in 1999, in FCC auction 21, and in a follow-up auction (39) in 2001. Since then, much effort has been spent creating frameworks and operational constraints that allow LMS, unlicensed devices, and other services to share the band. (See the CommLawBlog link for more details). The FCC has created a chart that shows the hierarchy of rights in this band. The chart has been uploaded under the "FCC Proceedings" heading below.
The majority of licenses in the LMS auctions were won by Progeny LLC. Some of the other winners have since defaulted on their bid payments. Progeny received a waiver of the FCC rules to allow its multilateration system to locate objects other than vehicles. It also received a waiver to provide locationing service by using one-way transmissions from a low density of powerful sites, rather than by using two-way technology that was originally envisioned for LMS.
The 902-928 MHz band has been divided into LMS blocks, which are then authorized for M-LMS or non-multilateration LMS, or shared between the two. LMS operates under Subpart M of Part 90 of the FCC rules, and is considered part of the Intelligent Transportation Systems Radio Service.
In the range 902-927.25 MHz, LMS systems are limited to 30 W ERP. In the range 927.25-928 MHz, the power limit is 300 W ERP [47 CFR 90.205(l)].
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Frequency Bands |
Band | Use | Service | Table |
902 - 904 MHz | Non-multilateration LMS | - | N |
904 - 909.75 MHz | Multilateration LMS Block A | - | N |
909.75 - 921.75 MHz | Non-multilateration LMS (919.75-921.75 shared with multilateration LMS) | - | N |
919.75 - 921.75 MHz | Multilateration LMS Block B (shared with non-multilateration LMS) | - | N |
921.75 - 927.75 MHz | Multilateration LMS Block C | - | N |
927.25 - 927.5 MHz | Multilateration LMS Block C (forward link) | - | N |
927.5 - 927.75 MHz | Multilateration LMS Block B (forward link) | - | N |
927.75 - 928 MHz | Multilateration LMS Block A (forward link) | - | N |
External Links:
Associated Files:
Hierarchy of rights in the 902-928 MHz band (from FCC 13-78).
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