L band
Encyclopedia
L band refers to four different bands of the electromagnetic spectrum
: 40 to 60 G
Hz
(NATO), 1 to 2 GHz
(IEEE), 1565 nm to 1625 nm (optical), and around 3.5 micrometres (infrared astronomy).
Hz
(5–7.5 mm).
and overseas territories
, the L band is held by the military
for telemetry
, thereby forcing digital radio
to in-band on-channel
(IBOC) solutions. DAB
is typically done in the 1452–1492-MHz range as in most of the world, but other countries also use VHF
and UHF
bands.
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 phone
s operate at 800–900 and 1800–1900 MHz. Iridium Satellite LLC phones use frequencies between 1616 and 1626.5 MHz to communicate with the satellites. Inmarsat
terminals use frequencies between 1525 and 1646.5 MHz to communicate with the satellites.
allow amateur radio
operations in the frequency range 1,240 to 1,300 MHz, and amateur satellite up-links are allowed in the range 1,260 to 1,270 MHz. This is known as the 23-centimeter band by amateurs and the L-band by AMSAT
.
satellite radio
broadcasts in the 1467–1492 MHz L sub-band.
The following blocks are used for S-DAB (satellite) broadcasts:
Note: Canada uses slightly different central frequencies for L-band DAB while in many European countries DAB is limited part of Band III due to television and mobile two way radio using the rest.
, 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.
In infrared astronomy
, the L band refers to an atmospheric transmission window centred on 3.5 micrometres (in the mid-infrared).
(RSGB), are shown in the table below:
Footnote: P band is sometimes incorrectly used for Ku Band. "P" for "previous" was a radar band used in the UK ranging from 250 to 500 MHz and now obsolete per IEEE Std 521, see http://www.radioing.com/eengineer/bands.html and http://www.microwaves101.com/encyclopedia/letterbands.cfm. For other definitions see Letter Designations of Microwave Bands
Electromagnetic spectrum
The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object....
: 40 to 60 G
Giga
Giga is a unit prefix in the metric system denoting a factor of billion . It has the symbol G.Giga is derived from the Greek γίγας, meaning 'giant'...
Hz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
(NATO), 1 to 2 GHz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
(IEEE), 1565 nm to 1625 nm (optical), and around 3.5 micrometres (infrared astronomy).
NATO L band
The NATO L band is defined as the frequency band between 40 and 60 GGiga
Giga is a unit prefix in the metric system denoting a factor of billion . It has the symbol G.Giga is derived from the Greek γίγας, meaning 'giant'...
Hz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
(5–7.5 mm).
Military use
In the United StatesUnited States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and overseas territories
United States territory
United States territory is any extent of region under the jurisdiction of the federal government of the United States, including all waters including all U.S. Naval carriers. The United States has traditionally proclaimed the sovereign rights for exploring, exploiting, conserving, and managing its...
, the L band is held by the military
Military of the United States
The United States Armed Forces are the military forces of the United States. They consist of the Army, Navy, Marine Corps, Air Force, and Coast Guard.The United States has a strong tradition of civilian control of the military...
for telemetry
Telemetry
Telemetry is a technology that allows measurements to be made at a distance, usually via radio wave transmission and reception of the information. The word is derived from Greek roots: tele = remote, and metron = measure...
, thereby forcing digital radio
Digital radio
Digital radio has several meanings:1. Today the most common meaning is digital radio broadcasting technologies, such as the digital audio broadcasting system, also known as Eureka 147. In these systems, the analog audio signal is digitized into zeros and ones, compressed using formats such as...
to in-band on-channel
In-band on-channel
In-band on-channel is a hybrid method of transmitting digital radio and analog radio broadcast signals simultaneously on the same frequency....
(IBOC) solutions. DAB
Digital audio broadcasting
Digital Audio Broadcasting is a digital radio technology for broadcasting radio stations, used in several countries, particularly in Europe. As of 2006, approximately 1,000 stations worldwide broadcast in the DAB format....
is typically done in the 1452–1492-MHz range as in most of the world, but other countries also use VHF
Very high frequency
Very high frequency is the radio frequency range from 30 MHz to 300 MHz. Frequencies immediately below VHF are denoted High frequency , and the next higher frequencies are known as Ultra high frequency...
and UHF
Ultra high frequency
Ultra-High Frequency designates the ITU Radio frequency range of electromagnetic waves between 300 MHz and 3 GHz , also known as the decimetre band or decimetre wave as the wavelengths range from one to ten decimetres...
bands.
GNSS
The Global Positioning SystemGlobal Positioning System
The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...
carriers
Carrier wave
In telecommunications, a carrier wave or carrier is a waveform that is modulated with an input signal for the purpose of conveying information. This carrier wave is usually a much higher frequency than the input signal...
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.
- The Galileo Navigation System uses the L-band similarly to GPS.
- The GLONASSGLONASSGLONASS , acronym for Globalnaya navigatsionnaya sputnikovaya sistema or Global Navigation Satellite System, is a radio-based satellite navigation system operated for the Russian government by the Russian Space Forces...
System uses the L-band similarly to GPS.
Telecommunications use
GSMGlobal System for Mobile Communications
GSM , is a standard set developed by the European Telecommunications Standards Institute to describe technologies for second generation digital cellular networks...
mobile phone
Mobile phone
A mobile phone is a device which can make and receive telephone calls over a radio link whilst moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile network operator...
s operate at 800–900 and 1800–1900 MHz. Iridium Satellite LLC phones use frequencies between 1616 and 1626.5 MHz to communicate with the satellites. Inmarsat
Inmarsat
Inmarsat plc is a British satellite telecommunications company, offering global, mobile services. It provides telephony and data services to users worldwide, via portable or mobile terminals which communicate to ground stations through eleven geostationary telecommunications satellites...
terminals use frequencies between 1525 and 1646.5 MHz to communicate with the satellites.
Amateur radio
The Radio Regulations of the International Telecommunication UnionInternational Telecommunication Union
The International Telecommunication Union is the specialized agency of the United Nations which is responsible for information and communication technologies...
allow amateur radio
Amateur radio
Amateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...
operations in the frequency range 1,240 to 1,300 MHz, and amateur satellite up-links are allowed in the range 1,260 to 1,270 MHz. This is known as the 23-centimeter band by amateurs and the L-band by AMSAT
AMSAT
AMSAT is a name for amateur radio satellite organizations worldwide, but in particular the Radio Amateur Satellite Corporation with headquarters at Silver Spring, Maryland, near Washington DC. AMSAT organizations design, build, arrange launches for, and then operate satellites carrying amateur...
.
Digital Audio Broadcasting (Earth Orbital)
WorldSpaceWorldSpace
1worldspace, formerly known as 'WorldSpace', is a currently defunct satellite radio network that provided service to over 170,000 subscribers in eastern and southern Africa, the Middle East, and much of Asia with 96% coming from India...
satellite radio
Satellite radio
Satellite radio is an analogue or digital radio signal that is relayed through one or more satellites and thus can be received in a much wider geographical area than terrestrial FM radio stations...
broadcasts in the 1467–1492 MHz L sub-band.
DAB L band usage
The following blocks are used for T-DAB (terrestrial) broadcasts:| Block | Center Frequency |
|---|---|
| LA | 1452.960 MHz |
| LB | 1454.672 MHz |
| LC | 1456.384 MHz |
| LD | 1458.096 MHz |
| LE | 1459.808 MHz |
| LF | 1461.520 MHz |
| LG | 1463.232 MHz |
| LH | 1464.944 MHz |
| LI | 1466.656 MHz |
| LJ | 1468.368 MHz |
| LK | 1470.080 MHz |
| LL | 1471.792 MHz |
| LM | 1473.504 MHz |
| LN | 1475.216 MHz |
| LO | 1476.928 MHz |
| LP | 1478.640 MHz |
The following blocks are used for S-DAB (satellite) broadcasts:
| Block | Center Frequency |
|---|---|
| LQ | 1480.352 MHz |
| LR | 1482.064 MHz |
| LS | 1483.776 MHz |
| LT | 1485.488 MHz |
| LU | 1487.200 MHz |
| LV | 1488.912 MHz |
| LW | 1490.624 MHz |
Note: Canada uses slightly different central frequencies for L-band DAB while in many European countries DAB is limited part of Band III due to television and mobile two way radio using the rest.
Physics issues relating to band use
The band also contains the hyperfine transition of neutral hydrogen (the hydrogen lineHydrogen line
The hydrogen line, 21 centimeter line or HI line refers to the electromagnetic radiation spectral line that is created by a change in the energy state of neutral hydrogen atoms. This electromagnetic radiation is at the precise frequency of 1420.40575177 MHz, which is equivalent to the vacuum...
, 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
Radio astronomy
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The initial detection of radio waves from an astronomical object was made in the 1930s, when Karl Jansky observed radiation coming from the Milky Way. Subsequent observations have identified a number of...
allocations worldwide.
Optical communications L band
L band is also used in optical communications to refer to the wavelength range 1565 nm to 1625 nm.Infrared astronomy
Infrared astronomy
Infrared astronomy is the branch of astronomy and astrophysics that studies astronomical objects visible in infrared radiation. The wavelength of infrared light ranges from 0.75 to 300 micrometers...
, the L band refers to an atmospheric transmission window centred on 3.5 micrometres (in the mid-infrared).
Other microwave bands
The microwave spectrum is usually defined as electromagnetic energy ranging from approximately 1 GHz to 100 GHz in frequency, but older usage includes lower frequencies. Most common applications are within the 1 to 40 GHz range. Microwave frequency bands, as defined by the Radio Society of Great BritainRadio Society of Great Britain
First founded in 1913 as the London Wireless Club, the Radio Society of Great Britain is the United Kingdom's recognised national society for amateur radio operators. The society's patron is Prince Philip, Duke of Edinburgh and it represents the interests of the UK’s 60,000 licensed radio amateurs...
(RSGB), are shown in the table below:
| L band | 1 to 2 GHz |
| S band S band The S band is defined by an IEEE standard for radio waves with frequencies that range from 2 to 4 GHz, crossing the conventional boundary between UHF and SHF at 3.0 GHz. It is part of the microwave band of the electromagnetic spectrum... |
2 to 4 GHz |
| C band C band The C band is a name given to certain portions of the electromagnetic spectrum, including wavelengths of microwaves that are used for long-distance radio telecommunications. The IEEE C-band - and its slight variations - contains frequency ranges that are used for many satellite communications... |
4 to 8 GHz |
| X band X band The X band is a segment of the microwave radio region of the electromagnetic spectrum. In some cases, such as in communication engineering, the frequency range of X band is rather indefinitely set at approximately 7.0 to 11.2 gigahertz . In radar engineering, the frequency range is specified... |
8 to 12 GHz |
| Ku band Ku band The Kμ band is a portion of the electromagnetic spectrum in the microwave range of frequencies. This symbol refers to —in other words, the band directly below the K-band... |
12 to 18 GHz |
| K band K band K band designates certain portions of the electromagnetic spectrum, in either the microwave domain or in the infrared domain. The microwave K bands are used primarily for radar and satellite communications while the infrared K band is used for astronomical observations.-NATO K band:The NATO K band... |
18 to 26.5 GHz |
| Ka band Ka band The Ka band covers the frequencies of 26.5–40 GHz. The Ka band is part of the K band of the microwave band of the electromagnetic spectrum. This symbol refers to "K-above" — in other words, the band directly above the K-band... |
26.5 to 40 GHz |
| Q band Q band The Q band of the microwave part of the electromagnetic spectrum and ranges from 33 to 50 GHz. It sits above, and partly overlaps with, the U.S. IEEE designated Ka band . It sits below the U.S... |
30 to 50 GHz |
| U band | 40 to 60 GHz |
| V band V band The V band of the electromagnetic spectrum ranges from 50 to 75 GHz. The V band is not heavily used, except for millimeter wave radar research and other kinds of scientific research... |
50 to 75 GHz |
| E band E band The NATO E band is the range of radio frequencies from 2 GHz to 3 GHz in the electromagnetic spectrum. This is equal to wave lengths between 15 cm and 10 cm. The E band is in the upper UHF range of the radio spectrum... |
60 to 90 GHz |
| W band W band The W band of the microwave part of the electromagnetic spectrum ranges from 75 to 110 GHz. It sits above the U.S. IEEE designated V band in frequency, yet overlaps the NATO designated M band... |
75 to 110 GHz |
| F band F band The F band is the range of radio frequencies from 90 GHz to 140 GHz in the electromagnetic spectrum. This is equal to wave lengths between 2.1 mm and 3.3 mm... |
90 to 140 GHz |
| D band D band IEEE D band is the range of radio frequencies from 110 GHz to 170 GHz in the electromagnetic spectrum. This is equal to wave lengths between 1.8 mm and 2.7 mm... |
110 to 170 GHz |
Footnote: P band is sometimes incorrectly used for Ku Band. "P" for "previous" was a radar band used in the UK ranging from 250 to 500 MHz and now obsolete per IEEE Std 521, see http://www.radioing.com/eengineer/bands.html and http://www.microwaves101.com/encyclopedia/letterbands.cfm. For other definitions see Letter Designations of Microwave Bands
See also
- Earth observation satellites transmission frequenciesEarth observation satellites transmission frequenciesThe earth is constantly being monitored by a great number earth observation satellites. These artificial satellites have onboard sensors from which they gather data. The data is transmitted back to earth via radio frequency...