ITU Radio Band Numbers 4 5 6 7 8 9 10 11 12

ITU Radio Band Symbols VLF LF MF HF VHF UHF SHF EHF

NATO Radio bands A B C D E F G H I J K L M

IEEE Radar bands HF VHF UHF L S C X Ku K Ka V W edit

The K_u band (pronounced "kay-yoo") is a portion of the electromagnetic spectrum in the microwave range of frequencies. English phonology is the study of the Phonology (ie the sound system of the English language. The electromagnetic (EM spectrum is the range of all possible Electromagnetic radiation frequencies Microwaves are electromagnetic waves with Wavelengths ranging from 1 mm to 1 m or frequencies between 0 This symbol refers to "K-under" — in other words, the band directly below the K-band. NATO K band The NATO K band is defined as a frequency band between 20 and 40 GHz (7 In radar applications, it ranges from 12 to 18  GHz according to the formal definition of radar frequency band nomenclature in IEEE Standard 521-2002. The hertz (symbol Hz) is a measure of Frequency, informally defined as the number of events occurring per Second. ^[1][2]

K_u band is primarily used for satellite communications, most notably NASA's Tracking Data Relay Satellite used for both space shuttles, and ISS communications. A communications satellite (sometimes abbreviated to comsat) is an artificial Satellite stationed in space for the purposes of Telecommunications. The National Aeronautics and Space Administration ( NASA, ˈnæsə is an agency of the United States government, responsible for the nation's public space program A Tracking and Data Relay Satellite ( TDRS) is one of a network of Communications satellites of the Tracking and Data Relay Satellite System (TDRSS used NASA 's Space Shuttle, officially called the Space Transportation System ( STS) is the Spacecraft currently used by the United States K_u band satellites are also used for backhauls and particularly for satellite from remote locations back to a television network's studio for editing and broadcasting. Television ( TV) is a widely used Telecommunication medium for sending ( Broadcasting) and receiving moving Images, either monochromatic For the band see Broadcast (band Broadcasting is the distribution of audio and/or Video signals which transmit The band is split into multiple segments that vary by geographical region by the International Telecommunication Union (ITU). NBC was the first television network to uplink a majority of its affiliate feeds via K_u band in 1983. The National Broadcasting Company ( NBC) is an American Television network headquartered in the GE Building in New York City's Year 1983 ( MCMLXXXIII) was a Common year starting on Saturday (link displays the 1983 Gregorian calendar)

Contents 1 Segments and regions 1.1 The Americas 1.2 Europe and Africa 1.3 Australia 1.4 Others 1.5 Indonesia 2 Advantages 3 Disadvantages 4 References 5 External links

Segments and regions

The Americas

Segments in most of the Americas are represented by (ITU Region 2) and they are, the 11. The International Telecommunication Union (ITU in its International Radio Regulations, divides the world into three ITU regions for the purposes of managing the 7 to 12. 2 GHz (Local Oscillator Frequency (LOF) 10. 750 GHz) band is allocated to the FSS (fixed service satellite, uplink 14. Fixed Service Satellite (or FSS) is the official classification (used chiefly in North America for Geostationary Communications satellites used for broadcast Uplink An uplink (UL or U/L is the portion of a communications link used for the transmission of signals from an Earth terminal 0 to 14. 5 GHz). There are more than 22 FSS K_u-band satellites orbiting over North America, each carrying 12 to 24 transponders, 20 to 120 watts per transponder, and requiring a 0. In Telecommunication, the term transponder (short-for Trans mitter-res ponder and sometimes abbreviated to XPDR XPNDR TPDR or TP has the following meanings The watt (symbol W) is the SI derived unit of power, equal to one Joule of energy per Second. 8-m to 1. 5-m antenna for clear reception.

The 12. 2 to 12. 7 GHz (LOF 11. 250 GHz) segment is allocated to the BSS (broadcasting satellite service). Direct broadcast satellite (DBS is a term used to refer to Satellite television broadcasts intended for home reception also referred to more broadly as direct-to-home BSS/DBS direct broadcast satellites normally carry 16 to 32 transponders of 27 MHz bandwidth running at 100 to 240 watts of power, allowing the use of receiver antennas as small as 18 inches (450 mm). Direct broadcast satellite (DBS is a term used to refer to Satellite television broadcasts intended for home reception also referred to more broadly as direct-to-home The hertz (symbol Hz) is a measure of Frequency, informally defined as the number of events occurring per Second.

Europe and Africa

Segments in those regions are represented by ITU Region 1 and they are, the 11. 45 to 11. 7 and 12. 5 to 12. 75 GHz bands are allocated to the FSS (fixed satellite service, uplink 14. Fixed Service Satellite (or FSS) is the official classification (used chiefly in North America for Geostationary Communications satellites used for broadcast Uplink An uplink (UL or U/L is the portion of a communications link used for the transmission of signals from an Earth terminal 0 to 14. 5 GHz).

In Europe K_u band is used from 10. 7 to 12. 75 GHz (LOF Low 9. 750 GHz, LOF High 10. 600 GHz) for direct broadcast satellite services like SES Astra. Direct broadcast satellite (DBS is a term used to refer to Satellite television broadcasts intended for home reception also referred to more broadly as direct-to-home SES Astra SA, is a corporate Subsidiary of SES, based in Betzdorf, in eastern Luxembourg, that owns and operates the Astra

The 11. 7 to 12. 5 GHz segment is allocated to the BSS (broadcasting satellite service). Direct broadcast satellite (DBS is a term used to refer to Satellite television broadcasts intended for home reception also referred to more broadly as direct-to-home

Australia

Australia is part of ITU Region 3 and the Australian regulatory environment provides a class license that covers downlinking from 12. 25GHz to 12. 75GHz and uplinking from 14. 0GHz to 14. 5GHz.

Others

Other ITU allocations have been made within the K_u band to the fixed service (microwave towers), radio astronomy service, space research service, mobile service, mobile satellite service, radiolocation service (radar), amateur radio service, and radionavigation. Amateur radio, often called ham radio, is both a Hobby and a service in which participants called "hams" use various types of Radio communications However, not all of these services are actually operating in this band and others are only minor users.

Indonesia

The ITU has categorized Indonesia as Region P, countries with very high rain precipitation. The Republic of Indonesia ( (Republik Indonesia is a Country in Southeast Asia. This statement has made many people unsure about using Ku-band (11 – 18 GHz) in Indonesia. If frequencies higher than 10 GHz are used in a heavy rain area, a decrease in communication availability results. This problem can be solved by using an appropriate link budget when designing the wireless communication link. A link budget is the accounting of all of the gains and losses from the transmitter through the medium (free space cable waveguide fiber etc Higher power can overcome the loss to rain fade. Rain fade refers primarily to the absorption of a Microwave Radio Frequency (RF signal by atmospheric rain snow or ice and losses are especially prevalent

Measurements of rain attenuation in Indonesia have been done for satellite communication links in Padang, Cibinong, Surabaya and Bandung. The DAH Model for rain attenuation prediction is valid for Indonesia, in addition to the ITU model. The DAH model has become an ITU recommendation since 2001 (Recommendation No. ITU-R P. 618-7). This model can create a 99. 7% available link so that Ku-band can be applied in Indonesia.

The use of the Ku-band for satellite communications in tropical regions like Indonesia is becoming more frequent. Several satellites above Indonesia have Ku-band transponders, and even Ka-band transponders. In Telecommunication, the term transponder (short-for Trans mitter-res ponder and sometimes abbreviated to XPDR XPNDR TPDR or TP has the following meanings The Ka band (Pronounced "Kay-A Band" covers the frequencies of 26 Newskies (NSS 6), launched in December 2002 and positioned at 95° East, contains only Ku-band transponders with a footprint on Indonesia (Sumatra, Java, Borneo, Celebes, Bali, Nusa Tenggara, Moluccas). Sumatra (also spelled Sumatera) is the sixth largest island in the world (approximately 470000 km² and is the largest island entirely in Indonesia (two Java (Jawa is an Island of Indonesia and the site of its Capital city Jakarta. Borneo is the third largest island in the world and is located at the centre of Maritime Southeast Asia. Sulawesi (formerly known as Celebes, ˈsɛlɛbiz is one of the four larger Sunda Islands of Indonesia and is situated between Borneo and the Bali is an Indonesian Island located at, the westernmost of the Lesser Sunda Islands, lying between Java to the west and Lombok to The Nusa Tenggara (lit Southeast Islands or Lesser Sunda Islands, are a group of Islands in the middle-south part of the Malay Archipelago. The Maluku Islands (also known as the Moluccas, Moluccan Islands, the Spice Islands or simply Maluku) are an Archipelago The iPSTAR satellite, launched in 2004 also uses Ku band footprints. Spot Beam Technology Traditional satellite technology utilizes a broad single beam to cover entire continents and regions Measat has named the Ku-band footprint directed towards Indonesia Ku-band for Indonesi. Measat 4 plans to cover the whole of Indonesia from West to East. This satellite will be launched by Malaysia in 2007. For the biogeographical region see Malesia Malaysia (məˈleɪʒə or /məˈleɪziə/ is a country that consists of thirteen states and

Advantages

Compared with C-band, K_u band is not similarly restricted in power to avoid interference with terrestrial microwave systems, and the power of its uplinks and downlinks can be increased. C band is a name given to certain portions of the Electromagnetic spectrum, as well as a range of Wavelengths of Light, used for communications This higher power also translates into smaller receiving dishes and points out a generalization between a satellite’s transmission and a dish’s size. As the power increases, the dish’s size can decrease. ^[3]

The K_u band also offers a user more flexibility. A dish smaller size and a K_u band system’s freedom from terrestrial operations simplifies finding a suitable dish site. K_u band is generally cheaper and enables smaller antennas (both because of the higher frequency and a more focused beam). ^[4] K_uband is also less vulnerable to rain fade than the K_a-band frequency spectrum.

Disadvantages

There are, however, some disadvantages of K_u band system. Especially at frequencies higher than 10 GHz in heavy rain fall areas, a noticeable degradation occurs, due to the problems caused by and proportional to the amount of rainfall (commonly known as "rain fade"). Rain fade refers primarily to the absorption of a Microwave Radio Frequency (RF signal by atmospheric rain snow or ice and losses are especially prevalent ^[5] This problem can be mitigated, however, by deploying an appropriate link budget strategy when designing the satellite network, and allocating a higher power consumption to reduce rain fade loss. The K_u band is not only used for television transmission, which some sources imply, but also very much for digital data transmission via satellites, and for voice/audio transmissions.

The higher frequency spectrum of the K_u band is particularly susceptible to signal degradation, considerably more so than C-band satellite frequency spectrum. A similar phenomenon, called "snow fade" (where snow or ice accumulation significantly alters the focal point of a dish) can also occur during winter precipitation. Also, the K_uband satellites typically require considerably more power to transmit than the C-band satellites. Under both "rain fade" and "snow fade" conditions, Ka and Ku band losses can be marginally (but significantly) reduced using super-hydrophobic Lotus effect coatings. Rain fade refers primarily to the absorption of a Microwave Radio Frequency (RF signal by atmospheric rain snow or ice and losses are especially prevalent The leaves of the sacred lotus flower ( Nelumbo) are characterized by a very high water repellency ( superhydrophobicity)

References

External links

• Spectrum allocation chart

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