The L band is the

Institute of Electrical and Electronics Engineers The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operation ...

(IEEE) designation for the range of

frequencies Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ...

in the radio spectrum from 1 to 2 gigahertz (GHz). This is at the top end of the ultra high frequency (UHF) band, at the lower end of the microwave range.

Applications

Mobile service

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 LTE Advanced (LTE+) is a mobile communication standard and a major enhancement of the Long Term Evolution (LTE) standard. It was formally submitted as a candidate 4G to ITU-T in late 2009 as meeting the requirements of the IMT-Advanced standard ...

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. In the Americas, mobile services are operated between the 1.7 GHz to 2.1 GHz range in the

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and

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bands.

Satellite navigation

The

Global Positioning System The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite sy ...

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. L band waves are used for GPS units because they are able to penetrate clouds, fog, rain, storms, and vegetation. Only dense environments such as heavy forest canopies or concrete buildings can cause GPS units to receive data inaccurately. The Galileo Navigation System, the GLONASS System, and the BeiDou systems use the L band similar to GPS, although the frequency ranges are named differently. Modern receivers, such as those found in smartphones, are able to take advantage of multiple systems (usually only around the oldest L1 band) at the same time.

Telecommunications use

Mobile phones operate at 600–900 and 1700–2100 MHz. Iridium Communications satellite phones use frequencies between 1616 and 1626.5 MHz to communicate with the satellites. Iridium Communications 2-way messaging service Snapdragon Satellite will utilize frequencies in the L Band as well. Inmarsat and Ligado Networks (formerly LightSquared) terminals use frequencies between 1525 and 1646.5 MHz. Thuraya satellite phones use frequencies between 1525 and 1661 MHz.

Aircraft surveillance

The aircraft L-band ranges from 960–1215MHz. 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 1030/1090MHz 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.

Amateur radio

The Radio Regulations of the International Telecommunication Union allow

amateur radio Amateur radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communic ...

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 The 23 centimeter, 1200 MHz or 1.2 GHz band is a portion of the UHF (microwave) radio spectrum internationally allocated to amateur radio and amateur satellite use on a secondary basis. The amateur radio band is between 1240 MHz and ...

by radio amateurs and as the L-band by AMSAT.

Digital audio broadcasting

In the United States and

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, the L band is held by the military for telemetry, thereby forcing

digital radio Digital radio is the use of digital technology to transmit or receive across the radio spectrum. Digital transmission by radio waves includes digital broadcasting, and especially digital audio radio services. Types In digital broadcasting syst ...

in-band on-channel In-band on-channel (IBOC) is a hybrid method of transmitting digital radio and analog radio broadcast signals simultaneously on the same frequency. The name refers to the new digital signals being broadcast in the same AM or FM band (in-band), a ...

(IBOC) solutions. Digital Audio Broadcasting (DAB) in Europe primarily uses

Band III Band III is the name of the range of radio frequencies within the very high frequency (VHF) part of the electromagnetic spectrum from 174 to 240 megahertz (MHz). It is primarily used for radio and television broadcasting. It is also called high-b ...

, but may also be carried in the 1452–1492MHz range in some countries. WorldSpace

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 ter ...

used to broadcast in the 1467–1492 MHz L sub-band.

Digital video broadcasting

DVB-H DVB-H (Digital Video Broadcasting - Handheld) is one of three prevalent mobile TV formats. It is a technical specification for bringing broadcast services to mobile handsets. DVB-H was formally adopted as ETSI standard EN 302 304 in November 20 ...

, DVB-SH, and DVB-T2 can operate in the L band.

Digital multimedia broadcasting

T-DMB can operate in the L band.

Astronomy

The band 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. The band also contains hydroxyl radical transition lines at 1665 and 1667 MHz. Consequently, parts of the L band are protected radio astronomy allocations worldwide. Specifically, the 1400–1427 MHz and 1660.6–1670.0 MHz regions are protected.

References

{{Audio broadcasting Microwave bands Satellite broadcasting