|IEEE L band|
|1 – 2 GHz|
|30 – 15 cm|
In Europe, the Electronic Communications Committee (ECC) of the European Conference of Postal and Telecommunications Administrations (CEPT) has harmonized part of the L band (1452–1492 MHz), allowing individual countries to adopt this spectrum for terrestrial mobile/fixed communications networks supplemental downlink (MFCN SDL). By means of carrier aggregation, an LTE-Advanced or UMTS/HSDPA base station could use this spectrum to provide additional bandwidth for communications from the base station to the mobile device; i.e., in the downlink direction.
The Global Positioning System carriers are in the L band, centered at 1176.45 MHz (L5), 1227.60 MHz (L2), 1381.05 MHz (L3), and 1575.42 MHz (L1) frequencies.
Mobile phones operate at 800–900 and 1700–2100 MHz. Iridium Communications satellite phones use frequencies between 1616 and 1626.5 MHz to communicate with the satellites. Inmarsat and LightSquared terminals use frequencies between 1525 and 1646.5 MHz. Thuraya satellite phones use frequencies between 1525 and 1661 MHz.
The aircraft L-band ranges from 962–1213 MHz. Aircraft can use Automatic dependent surveillance-broadcast (ADS-B) equipment at 1090 MHz to communicate position information to the ground as well as between them for traffic information and avoidance. The 1090 MHz frequency (paired with 1030 MHz) is also used by Mode S transponders, which ADS-B augments when operated at this frequency. The TCAS system also utilizes the 1030/1090 MHz paired frequencies. ADS-B information can also be broadcast on the L band frequency of 978 MHz. DME and TACAN systems are also in this frequency band.
The Radio Regulations of the International Telecommunication Union allow amateur radio operations in the frequency range 1,240–1,300 MHz, and amateur satellite up-links are allowed in the range 1,260–1,270 MHz. This is known as the 23-centimeter band by radio amateurs and as the L-band by AMSAT.
In the United States and overseas territories, the L band is held by the military for telemetry, thereby forcing digital radio to in-band on-channel (IBOC) solutions. Digital Audio Broadcasting (DAB) in Europe primarily uses Band III, but may also be carried in the 1452–1492 MHz range in some countries.
The band also contains the hyperfine transition of neutral hydrogen (the hydrogen line, 1420 MHz), which is of great astronomical interest as a means of imaging the normally invisible neutral atomic hydrogen in interstellar space. Consequently, parts of the L-band are protected radio astronomy allocations worldwide.
Frequency bands for 5G NR are being separated into two different frequency ranges. First there is Frequency Range 1 (FR1) that includes sub-6GHz frequency bands, some of which are bands traditionally used by previous standards. The other is Frequency Range 2 (FR2) that includes frequency bands above 24 GHz and into the millimeter wave range, that has shorter range but higher available bandwidth than bands in the FR1.ALOS-2
Advanced Land Observing Satellite 2 (ALOS 2), also called Daichi 2, is a 2-ton Japanese satellite launched in 2014. Although the predecessor ALOS satellite had featured 2 optical cameras in addition to 1.2 GHz (L-band) radar, ALOS-2 had optical cameras removed to simplify construction and reduce costs. The PALSAR-2 radar is a significant upgrade of the PALSAR radar, allowing higher-resolution (1x3m per pixel) spotlight modes in addition to the 10m resolution survey mode inherited from the ALOS spacecraft. Also, the SPAISE2 automatic ship identification system and the Compact Infra Red Camera (CIRC) will provide supplementary data about sea-going ships and provide early warnings of missile launches.B.A.L.L.
B.A.L.L. (pronounced "ball") were an American alternative rock band from New York City, formed in 1987. The band was formed by Don Fleming, Kramer, David Licht and Jay Spiegel. The band disintegrated in 1990, its members pursuing separate projects.Digital audio broadcasting
Digital audio broadcasting (DAB) is a digital radio standard for broadcasting digital audio radio services, used in many countries around the world, though not North America.
The DAB standard was initiated as a European research project in the 1980s. The Norwegian Broadcasting Corporation (NRK) launched the first DAB channel in the world on 1 June 1995 (NRK Klassisk), and the BBC and Swedish Radio (SR) launched their first DAB digital radio broadcasts in September 1995. DAB receivers have been available in many countries since the end of the 1990s.
DAB is generally more efficient in its use of spectrum than analogue FM radio, and thus can offer more radio services for the same given bandwidth. However the sound quality can be noticeably inferior if the bit-rate allocated to each audio program is not sufficient. DAB is more robust with regard to noise and multipath fading for mobile listening, although DAB reception quality degrades rapidly when the signal strength falls below a critical threshold, whereas FM reception quality degrades slowly with the decreasing signal, providing effective coverage over a larger area.
The original version of DAB used the MP2 audio codec. An upgraded version of the system was released in February 2007, called DAB+, which uses the HE-AAC v2 audio codec. DAB is not forward compatible with DAB+, which means that DAB-only receivers are not able to receive DAB+ broadcasts. However, broadcasters can mix DAB and DAB+ programs inside the same transmission and so make a progressive transition to DAB+. DAB+ is approximately twice as efficient as DAB, and more robust.
In spectrum management, the bands that are allocated for public DAB services, are abbreviated with T-DAB, where the "T" stands for terrestrial.
As of 2018, 41 countries are running DAB services. The majority of these services are using DAB+, with only Ireland, UK, New Zealand, Romania and Brunei still using a significant number of DAB services. See Countries using DAB/DMB. In many countries, it is expected that existing FM services will switch over to DAB+. Norway is the first country to implement a national FM radio analog switchoff, in 2017, however that only applied to national broadcasters, not local ones.Ekspress AM5
Ekspress-AM5 (Russian: Экспресс АМ5) is a Russian communications satellite which was launched in 2013. Part of the Ekspress series of geostationary communications satellites, it is owned and operated by the Russian State Company for Satellite Communications.It provides digital television and radio broadcasting, telephone, video conferencing, data transmission and Internet services. The satellite is also used for mobile communications among between the Russian president and other government leaders. Express AM5 carries 40 Ku-band, 30 C-band, 12 Ka-band and two L-band transponders. The satellite is designed for a 15-year lifetime and will be positioned in geostationary orbit at 140 degrees east longitude, covering Russia's Far East, Southeast Asia and Australia. Such an orbit allows the spacecraft to remain in a fixed location in the sky for users on the ground.Ekspress AM6
Ekspress-AM6 (Russian: Экспресс АМ6) is a Russian communications satellite which was launched in 2014. The satellite has replaced the older Ekspress-AM22, at 53° East. Part of the Ekspress series of geostationary communications satellites, it is owned and operated by the Russian State Company for Satellite Communications.
The satellite has 30 C-band, 40 Ku-band, 12 Ka-band and 2 L-band transponders.Fox-1D
Fox-1D, AO-92 or AMSAT OSCAR 92 is an American amateur radio satellite. Fox-1D is a 1U CubeSat developed and built by AMSAT-NA. Fox-1D carries a single-channel transponder for mode U/V in FM. Fox-1D has an L-band converter (the AMSAT L-band downshifter experiment), which allows the FM transponder to be switched on an uplink in the 23 centimetres (9.1 in) band.
To enable it to launch under NASA's ELaNa (Educational Launch of Nanosatellites) program, the satellite continues to carry the following scientific and technical payloads:
High Energy Radiation CubeSat (HERCI);
MEMS GYRO Experiment.The satellite has a single whip antenna for the 70cm and 23cm bands (uplink), as well as an antenna for the 2m band (downlink).G.R.L.
G.R.L. is an American-British-Canadian girl group formed by Robin Antin. The group consists of members Lauren Bennett, Natasha Slayton and Jazzy Mejia. Past members included Simone Battle, Emmalyn Estrada, and Paula van Oppen.
The original line-up consisted of Slayton, Bennett, Estrada, Van Oppen, and Simone Battle. They made their debut appearance on the Smurfs 2 soundtrack with "Vacation". They would go on to appear on Pitbull's internationally successful track "Wild Wild Love" which peaked in the top-40 in the United States, top-10 in the United Kingdom, and was certified platinum by Recording Industry Association of America (RIAA). Their second single "Ugly Heart" gained international success shortly after the suicide of member Simone Battle. Leaving the group as a quartet, this inspired the group to release their next single "Lighthouse" in memory of Battle. The group disbanded shortly after its release, on June 2, 2015.
G.R.L. officially reformed on August 5, 2016, with the addition of new member Jazzy Mejia alongside original members Bennett and Slayton, making the group a trio.Inmarsat-6 F1
Inmarsat-6 F1 is a communications satellite to be operated by the British satellite operator Inmarsat and designed and manufactured by Airbus Defence and Space on the Eurostar 3000EOR platform. Part of the I-6 satellite fleet, it will be Inmarsat's first dual-payload satellite, with capabilities in both L-band and Ka band.
The L-band payload will support a wide variety of purposes including very low cost mobile services and IoT applications, while the Ka band payload will augment the Global Xpress constellation.JERS-1
Japanese Earth Resources Satellite 1 (JERS-1) was a satellite launched in 1992 by the Japan Aerospace Exploration Agency (at that time also known as "NASDA", now "JAXA"). It carried three instruments:
An L-band (HH polarization) synthetic aperture radar (SAR);
A nadir-pointing optical camera (OPS);
A side-looking optical camera (AVNIR).The satellite operated until 1998 and re-entered the Earth's atmosphere in 2001.LTE frequency bands
Long Term Evolution (LTE) telecommunications networks use several frequency bands with associated bandwidths.L band (NATO)
The NATO L band is the obsolete designation given to the radio frequencies from 40 to 60 GHz (equivalent to wavelengths between 7.5 and 5 mm) during the cold war period. Since 1992 frequency allocations, allotment and assignments are in line to NATO Joint Civil/Military Frequency Agreement (NJFA).However, in order to identify military radio spectrum requirements, e.g. for crises management planning, training, Electronic warfare activities, or in military operations, this system is still in use.Microwave Imaging Radiometer with Aperture Synthesis
Microwave Imaging Radiometer with Aperture Synthesis (MIRAS) is the major instrument on the Soil Moisture and Ocean Salinity satellite (SMOS). MIRAS employs a planar antenna composed of a central body (the so-called hub) and three telescoping, deployable arms, in total 69 receivers on the Unit. Each receiver is composed of one LICEF module, which detects radiation in the microwave L-band, both in horizontal and vertical polarizations. The aperture on the LICEF detectors, planar in arrangement on MIRAS, point directly toward the Earth's surface as the satellite orbits. The arrangement and orientation of MIRAS makes the instrument a 2-D interferometric radiometer that generates brightness temperature images, from which both geophysical variables are computed. The salinity measurement requires demanding performance of the instrument in terms of calibration and stability. The MIRAS instrument's prime contractor was EADS CASA Espacio, manufacturing the payload of SMOS under ESA's contract.Mobile-satellite service
Mobile-satellite service (MSS, or mobile-satellite radiocommunication service) is – according to Article 1.25 of the International Telecommunication Union's Radio Regulations
– "A radiocommunication service
between mobile earth stations and one or more space stations, or between space stations used by this service; or
between mobile earth stations by means of one or more space stations.This service may also include feeder links necessary for its operation."
Most commercial voice and some data mobile satellite services are provided by systems operating in the L-band by Iridium, Inmarsat, Globalstar and Thuraya. The L-band spectrum allocated for MSS is between 1.5 and 2.5 GHz, with the upper portion often referred to as the S-band. Constellations of low earth orbiting (LEO) satellites are used by Iridium (66 satellites) and Globalstar (48 satellites). Inmarsat and Thuraya currently use 4 (i4) and 2 geostationary satellites respectively, their L-band services are similar but not interoperable and most terminals can only use one or the other service, although some data terminals provide a mechanical switch required due to the different polarization schemes used by both systems. Another MSS service is MSV / MSAT / LightSquared / Ligado with 2 geostationary satellites serving North America.China has shown an upcoming S-band satellite phone which will use its recently launched Tiantong-1 geostationary satellite. As of mid 2016 Iridium has experienced in-orbit failures which cannot be corrected with in-orbit spare satellites, thus only 64 of the 66 satellites required for seamless global coverage are in operation. As a result, service interruptions can be observed, especially around the equatorial region where the satellite footprints are most spread out and there is least overlap.Additionally to the four active Inmarsat 4 ('I4') satellites, Inmarsat also maintains some legacy L-band services on its previous generation satellites, although they are being gradually phased out and users are invited to upgrade to i4-based services, mostly based on variations of BGAN. Inmarsat also owns and operates a new fleet of three Ka-band satellites, known as the Inmarsat 5 constellation (usually abbreviated to 'I5'), providing high speed mobile satellite data services known as Global Express.
Other MSS systems currently inoperative were Ico / Pendrell, TerreStar and Ellipso.Several governments also operate and use MSS systems, although most make extensive use of the Iridium and Inmarsat systems. Mexico is currently developing an S-band system based on its own geostationary satellites and the United States uses MUOS and other systems. The US Government also runs its own gateway in Hawaii for direct access to the Iridium constellation under a contract lasting at least until 2018.Machine-to-machine:Orbcomm provides data-only M2M services using a constellation of LEO satellites in the VHF band and a partnership with Inmarsat for M2M services in the L-band. Iridium also has low bandwidth modes often used for M2M and Inmarsat offers an M2M version of BGAN called BGAN M2M.Interoperability:
Telephone calls to satellite terminals are often accomplished by dialing numbers assigned to the Global Mobile Satellite System, although most Globalstar users and some Iridium users are assigned country-based numbers. Thus, calls can be made to satellite phones from normal land-line and cellular terminals. However, pricing for terrestrial-satellite is often higher than pricing for satellite-terrestrial and satellite-satellite calls. Satellite-based Internet access is also fully interoperable with traditional land-based and mobile Internet and can access the same services, although cost is usually much higher and satellite link latency can affect some interactive services. Also, due to security concerns, the satellite segment and end-user can be (and in the case of BGAN often are) behind a NAT.
In most territories, access to mobile satellite service is managed by traditional telecom companies and specialized resellers which market hardware, software and network access to end users, although occasionally some constellation operators also market service directly to end users. This is a list of some companies providing commercial access:
Global Marine Networks,
iridium with nearly 1 million subscribers in December 2017, 368k with voice & Data services,
inmarsat purportedly the leading provider of global mobile satellite communications services,
The NASA-ISRO Synthetic Aperture Radar (NISAR) mission is a joint project between NASA and ISRO to co-develop and launch a dual-frequency synthetic aperture radar on an Earth observation satellite. The satellite will be the first radar imaging satellite to use dual frequencies. It will be used for remote sensing, to observe and understand natural processes on Earth. For example, its right-facing instruments will study the Antarctic cryosphere.With a total cost estimated at US$1.5 billion, NISAR is likely to be the world's most expensive Earth-imaging satellite.S band
The S band is a designation by the Institute of Electrical and Electronics Engineers (IEEE) for a part of the microwave band of the electromagnetic spectrum covering frequencies from 2 to 4 gigahertz (GHz). Thus it crosses the conventional boundary between the UHF and SHF bands at 3.0 GHz. The S band is used by airport surveillance radar for air traffic control, weather radar, surface ship radar, and some communications satellites, especially those used by NASA to communicate with the Space Shuttle and the International Space Station. The 10 cm radar short-band ranges roughly from 1.55 to 5.2 GHz. The S band also contains the 2.4–2.483 GHz ISM band, widely used for low power unlicensed microwave devices such as cordless phones, wireless headphones (Bluetooth), wireless networking (WiFi), garage door openers, keyless vehicle locks, baby monitors as well as for medical diathermy machines and microwave ovens (typically at 2.495 GHz). India’s regional satellite navigation network (IRNSS) broadcasts on 2.483778 to 2.500278 GHz.Satellite radio
Satellite radio is defined by the International Telecommunication Union (ITU)'s ITU Radio Regulations (RR) as a broadcasting-satellite service. The satellite's signals are broadcast nationwide, across a much wider geographical area than terrestrial radio stations, and the service is primarily intended for the occupants of motor vehicles. It is available by subscription, mostly commercial free, and offers subscribers more stations and a wider variety of programming options than terrestrial radio.Satellite radio technology was inducted into the Space Foundation Space Technology Hall of Fame in 2002. Satellite radio uses the 2.3 GHz S band in North America for nationwide digital radio broadcasting. In other parts of the world, satellite radio uses the 1.4 GHz L band allocated for DAB.Thuraya
Thuraya (Arabic: الثريا, Gulf Arabic pron.: [ɐθ.θʊˈrɑj.jɐ]; from the Arabic name for the constellation of the Pleiades, Thurayya) is a United Arab Emirates-based regional mobile-satellite service (MSS) provider. The company operates two geostationary satellites and provides telecommunications coverage in more than 161 countries in Europe, the Middle East, North, Central and East Africa, Asia and Australia. Thuraya’s L-band network delivers voice and data services
Thuraya, is the mobile satellite services subsidiary of Yahsat, a global satellite operator based in the United Arab Emirates, fully owned by Mubadala Investment Company.Ultra high frequency
Ultra high frequency (UHF) is the ITU designation for 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; they are blocked by hills and large buildings although the transmission through building walls is strong enough for indoor reception. They are used for television broadcasting, cell phones, satellite communication including GPS, personal radio services including Wi-Fi and Bluetooth, walkie-talkies, cordless phones, and numerous other applications.
The IEEE defines the UHF radar band as frequencies between 300 MHz and 1 GHz. Two other IEEE radar bands overlap the ITU UHF band: the L band between 1 and 2 GHz and the S band between 2 and 4 GHz.
Radio spectrum (ITU)