5.388 The frequency bands 1 885-2 025 MHz and 2 110-2 200 MHz are intended for use, on a worldwide basis, by administrations wishing to implement International Mobile Telecommunications (IMT). Such use does not preclude the use of these frequency bands by other services to which they are allocated. The frequency bands should be made available for IMT in accordance with Resolution 212 (Rev.WRC 15)* (see also Resolution 223 (Rev.WRC 15)*). (WRC 15)
5.388A In Regions 1 and 3, the bands 1 885-1 980 MHz, 2 010-2 025 MHz and 2 110-2 170 MHz and, in Region 2, the bands 1 885-1 980 MHz and 2 110-2 160 MHz may be used by high altitude platform stations as base stations to provide International Mobile Telecommunications (IMT), in accordance with Resolution 221 (Rev.WRC 07). Their use by IMT applications using high altitude platform stations as base stations does not preclude the use of these bands by any station in the services to which they are allocated and does not establish priority in the Radio Regulations. (WRC-12)
5.388B In Algeria, Saudi Arabia, Bahrain, Benin, Burkina Faso, Cameroon, Comoros, Côte d’Ivoire, China, Cuba, Djibouti, Egypt, United Arab Emirates, Eritrea, Ethiopia, Gabon, Ghana, India, Iran (Islamic Republic of), Israel, Jordan, Kenya, Kuwait, Lebanon, Libya, Mali, Morocco, Mauritania, Nigeria, Oman, Uganda, Pakistan, Qatar, the Syrian Arab Republic, Senegal, Singapore, Sudan, South Sudan, Tanzania, Chad, Togo, Tunisia, Yemen, Zambia and Zimbabwe, for the purpose of protecting fixed and mobile services, including IMT mobile stations, in their territories from co channel interference, a high altitude platform station (HAPS) operating as an IMT base station in neighbouring countries, in the frequency bands referred to in No. 5.388A, shall not exceed a co-channel power flux-density of −127 dB(W/(m² · MHz)) at the Earth’s surface outside a country’s borders unless explicit agreement of the affected administration is provided at the time of the notification of HAPS. (WRC 19)
US252 The band 2110-2120 MHz is also allocated to the space research service (deep space) (Earth-to-space) on a primary basis at Goldstone, CA (35° 20' N, 116° 53' W).

Wiki entries

NASA Tracking and Data Relay Satellite System (TDRSS)

Current Use 2025.8–2117.9 MHz S-band Single Access (TDRS transmit)

According to NASA:

The Tracking and Data Relay Satellites (TDRS) comprise the communication satellite component of the Tracking and Data Relay Satellite System (TDRSS). TDRSS is a communication signal relay system which provides tracking and data aquisition services between low-earth orbiting spacecraft and control and/or data processing facilities. The system is capable of transmitting to and receiving data from spacecraft over at least 85% of the spacecraft's orbit.

The TDRSS space segment consists of six on-orbit Tracking and Data Relay Satellites located in geosynchronous orbit. Three TDRSs are available for operational support at any given time. The operational spacecraft are located at 41°, 174° and 275° West longitude. The other TDRSs in the constellation provide ready backup in the event of a failure to an operational spacecraft and, in some specialized cases, resources for target of opportunity activities.

The TDRSS ground segment is located near Las Cruces, New Mexico, known as the White Sands Complex. Forward data is uplinked from the ground segment to the TDRS and from the TDRS to the spacecraft. Return data is downlinked from the spacecraft via the TDRS to the ground segment and then on to the designated data collection location.

The Tracking and Data Relay Satellite (TDRS) Project is providing follow-on and replacement spacecraft necessary to maintain and expand the Space Network. The contract to build three additional TDRS spacecraft, known as TDRS K, L, and M, was awarded to Boeing Space Systems in December 2007. TDRS K launched January 30, 2013, and TDRS L launched January 23, 2014. TDRS M's launch readiness date is scheduled for 2015. The contract also has options for one additional spacecraft, TDRS N. In addition to building the TDRS K, L, and M spacecraft, the contract also includes the modifications to the White Sands Complex (WSC) ground system required to support these new spacecraft.

The TDRS Project, established in 1973, is responsible for the development, launch, and on-orbit test and calibration of TDRS spacecraft. There have been four procurements of TDRS spacecraft, which include the Basic Program (TDRS F1-F6), the Replacement Program (TDRS F7), the TDRS H,I,J Program, and the TDRS K,L,M Program. TDRS Flight 7 was a replacement for Flight 2, which was lost aboard Challenger in 1986. The first seven spacecraft (TDRS F1-F7) are referred to as the First Generation, the H,I,J series are called the Second Generation, and the K,L,M series are known as the Third Generation. TDRS F1-7 spacecraft were built by TRW (now Northrop Grumman) in Redondo Beach, CA. The TDRS F8-10 (H,I,J) spacecraft were built by Hughes (now Boeing) in El Segundo, CA.

The NASA Space Network consists of the on-orbit telecommunications TDRS satellites, placed in geosynchronous orbit, and the associated TDRS ground stations, located in White Sands, New Mexico and Guam. The TDRS constellation is capable of providing nearly continuous high bandwidth (S, Ku, and Ka band) telecommunications services for expandable launch vehicles and user spacecraft in low Earth orbit. Examples include: the Hubble Space Telescope, the Earth Observig Fleet and the International Space Station. The TDRS System is a basic agency capability and a critical national resource.

Advanced Wireless Services (AWS-1) Band

Current Use 2110–2155 MHz AWS-1 (base transmit)

The band 1710-1755 MHz (mobile transmit) is paired with 2110-2155 MHz (base transmit) to create the first band dedicated specifically for what the FCC calls Advanced Wireless Services (AWS). According to the Commission, AWS refers to 3G systems and beyond (also referred to as International Mobile Telecommunications 2000, or IMT-2000, by the ITU).

The 1710-1755 MHz band was created out of spectrum that was previously reserved for the federal government only. In 1995, it was identified as feasible for shared government/non-government use. In accordance with footnote US378, some government operations, in particular fixed and tactical radio systems near Cherry Point, NC, and Yuma, AZ, will continue to operate in this band on a primary basis.

The band 2110-2155 MHz was created from spectrum that had previously been used for fixed microwave links (2110-2150 MHz) and for the Multipoint Distribution Service (MDS) (2150-2155 MHz). The FCC declared these bands for use by AWS in 2002.

As of mid-2012, some operators in the U.S., such as T-Mobile, are using AWS-1 spectrum to provide 4G service (HSPA+ in the case of T-Mobile).

European Union 3G & 4G (LTE) Band

Current Use 2110–2170 MHz European Union 3G & 4G band

In November, 2012, the European Commission adopted new rules clearing the way for the frequency band 1920-1980 MHz, paired with 2110-2170 MHz, to be used for 4G (LTE) services, in addition to its existing designated use for 3G services.

High Altitude Platform Station (HAPS)

Current Use 2110–2160 MHz HAPS service links for IMT in Regions 1, 2, & 3 (per 5.388A)

The ITU has identified various bands for use by High Altitude Platform Stations (HAPS), which are defined as "a station located on an object at an altitude of 20 to 50 km and at a specified, nominal, fixed point relative to the Earth."

One set of bands (47.2-47.5 and 47.9-48.2 GHz) is identified on a worldwide basis. The others apply regionally or in a subset of countries.

Although there was a flurry of activity related to HAPS beginning in the late 1990's, no HAPS systems were ever developed. As of 2015, there is renewed interest in HAPS for applications involving telecommunications from Unmanned Aerial Systems (UAS).

HAPS is declared as an application of the fixed service.

NASA Deep Space Network (DSN)

Current Use 2110–2120 MHz DSN S-Band Uplink (to spacecraft more than 2 million km from Earth)

According to NASA:

"The NASA Deep Space Network - or DSN - is an international network of antennas that supports interplanetary spacecraft missions and radio and radar astronomy observations for the exploration of the solar system and the universe. The network also supports selected Earth-orbiting missions.

"The DSN currently consists of three deep-space communications facilities placed approximately 120 degrees apart around the world: at Goldstone, in California's Mojave Desert; near Madrid, Spain; and near Canberra, Australia. This strategic placement permits constant observation of spacecraft as the Earth rotates, and helps to make the DSN the largest and most sensitive scientific telecommunications system in the world."

Pioneer 10 & 11 Spacecraft

Historical Use 2.11 GHz Pioneer 10 & 11 uplink transmissions

Pioneer 10 & 11 were launched in 1972 and 1973, respectively, to probe the asteroid belt, Jupiter, and Saturn. The spacecraft achieved sufficient speed to escape the gravitational pull of the solar system, and have now travelled to distances well beyond the orbits of Neptune and Pluto.

Some navigational information (the speed of the spacecraft along the line of sight) was obtained by measuring the Doppler shift of the downlink signal. The spacecraft did not have accurate frequency references onboard, so the downlink frequency was tuned by reference to the received uplink frequency.

The high gain antenna used by the spacecraft was 3 m in diameter, which provide a 3.3 deg beam at 2.3 GHz. The effective isotropic radiated power from the antenna was 70 dBm (about 10,000 W) from the 8 W transmitter (antenna forward gain of approximately 31 dBi). The downlink bit rate was between 16-2048 bps.

Due to the distance to the spacecraft and the declining power being created by their radioisotope thermoelectric generators, communications with Pioneer 10 & 11 (via NASA's Deep Space Network) has been lost since 2003 and 1995, respectively.

As of 2012, Pioneer 10 is moving at about 12,000 km/s with respect to the Sun, or about 4% of the speed of light. At that speed, its downlink signal at 2292 MHz would be Doppler shifted to 2200.0 MHz.

Standard LTE Bands

Current Use 2110–2170 MHz LTE band 10 FDD downlink 2110–2155 MHz LTE band 4 FDD downlink 2110–2170 MHz LTE band 1 FDD downlink

The following bands have been defined by 3GPP as standard LTE bands for Frequency Division Duplex (FDD, where mobile and base stations transmit in separate bands) and Time Division Duplex (TDD, where mobiles and bases transmit and receive on the same frequency). These bands are defined in 3GPP TS 36.101 (link below).

Note that bands 15 & 16 and 30-32 are not defined, and the FDD band 29 is used for downlink-only for carrier aggregation, so it has no corresponding uplink band.

Uplinks refer to the frequencies used for handsets and other user devices to transmit to the base station, and downlinks refer to frequencies used by base stations to transmit to the user devices.