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Fixed-satellite service
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Fixed-satellite service (FSS, or fixed-satellite radiocommunication service) is – according to article 1.21 of the International Telecommunication Union's (ITU) Radio Regulations (RR)[1] – defined as A radiocommunication service between earth stations at given positions, when one or more satellites are used; the given position may be a specified fixed point or any fixed point within specified areas; in some cases this service includes satellite-to-satellite links, which may also be operated in the inter-satellite service; the fixed-satellite service may also include feeder links for other space radiocommunication services.
Classification
[edit]This radiocommunication service is classified in accordance with ITU Radio Regulations (article 1) as follows:
Fixed service (article 1.20)
- Fixed-satellite service (article 1.21)
- Inter-satellite service (article 1.22)
- Earth exploration-satellite service (article 1.51)
- Meteorological-satellite service (article 1.52)
Frequency allocation
[edit]The allocation of radio frequencies is provided according to Article 5 of the ITU Radio Regulations (most recent version, Edition of 2020).[2]
In order to improve harmonisation in spectrum utilisation, the majority of service-allocations stipulated in this document were incorporated in national Tables of Frequency Allocations and Utilisations which is within the responsibility of the appropriate national administration. The allocation might be primary, secondary, exclusive, and shared.
- primary allocation: is indicated by writing in capital letters (see example below)
- secondary allocation: is indicated by small letters
- exclusive or shared utilization: is within the responsibility of administrations
- Example of frequency allocation
| Allocation to services | ||
| Region 1 | Region 2 | Region 3 |
14–14.25 GHz
| ||
14.25–14.3
| ||
Use in North America
[edit]FSS – is as well the official classification (used chiefly in North America) for geostationary communications satellites that provide broadcast feeds to television stations, radio stations and broadcast networks. FSSs also transmit information for telephony, telecommunications, and data communications.[3]
References
[edit]- ^ ITU Radio Regulations, Section IV. Radio Stations and Systems – Article 1.21, definition: fixed-satellite service / fixed-satellite radiocommunication service
- ^ ITU Radio Regulations, CHAPTER II – Frequencies, ARTICLE 5 Frequency allocations, Section IV – Table of Frequency Allocations
- ^ Chartrand, Mark R. (2003). Satellite communications for the nonspecialist. Bellingham, WA: SPIE Press. p. 31. ISBN 978-0-8194-5185-9.
Fixed-satellite service
View on GrokipediaDefinition and Scope
Definition
The fixed-satellite service (FSS) is defined in the International Telecommunication Union (ITU) Radio Regulations as "a radiocommunication service between earth stations at given positions, when one or more satellites are used; the given position may be a specified fixed point or any fixed point within specified areas; in some cases this service includes satellite-to-satellite links, which may also be operated in the inter-satellite service; the fixed-satellite service may also include feeder links for other space radiocommunication services."[6] This definition establishes FSS as a distinct radiocommunication service under international regulatory frameworks, emphasizing the use of satellite technology to enable communications between stationary ground-based facilities. Key terms in this definition highlight the service's focus on non-mobile infrastructure. Earth stations refer to ground-based terminals or antennas located at predetermined, fixed positions, distinguishing FSS from services involving mobile endpoints.[6] These stations facilitate point-to-point communications relayed through geostationary or non-geostationary satellites, ensuring reliable connectivity over long distances without the need for terrestrial infrastructure in remote or challenging terrains. The fixed-satellite service represents a specialized subset of the broader fixed service, which encompasses radiocommunication between any specified fixed points, as outlined in ITU Radio Regulations Article 1.20.[6] The scope of FSS encompasses both uplink and downlink transmissions tailored to fixed endpoints. Uplink transmissions involve signals sent from an earth station to the satellite (Earth-to-space direction), while downlink transmissions relay signals from the satellite to another earth station (space-to-Earth direction).[7] Additionally, the service may incorporate satellite-to-satellite links for inter-orbit relay and feeder links that support other space-based services, such as broadcasting or mobile applications, by providing backhaul connectivity.[6] This structure ensures FSS operates as a foundational enabler for global fixed communications via space infrastructure.Distinctions from Other Satellite Services
The fixed-satellite service (FSS) is distinguished from the mobile-satellite service (MSS) primarily by the nature of its earth stations and operational focus. In FSS, communications occur between earth stations located at specified fixed positions or within designated areas, enabling reliable point-to-point or point-to-multipoint links for targeted data exchange.[1] In contrast, MSS involves radiocommunication between mobile earth stations—such as those on vehicles, ships, or aircraft—and space stations, supporting connectivity for users in motion or at unspecified locations.[1] This fixed versus mobile distinction, as outlined in the ITU Radio Regulations, ensures FSS prioritizes stationary infrastructure for high-capacity, stable connections, while MSS accommodates dynamic, on-the-move applications.[1] FSS also differs from the broadcasting-satellite service (BSS) in its reception model and audience targeting. FSS delivers signals to specific fixed receivers at predetermined sites, facilitating directed services like backhaul or enterprise networks rather than mass dissemination.[1] BSS, however, transmits signals from space stations for direct reception by the general public via individual or community earth stations, emphasizing wide-area broadcasting to numerous simultaneous users without individual addressing.[1] These boundaries prevent overlap, with FSS suited for selective, controlled access and BSS designed for open, one-to-many distribution. A key relational aspect of FSS is its role in supporting feeder links for other satellite services, including BSS and MSS, without encompassing their primary operations. Feeder links in FSS connect earth stations to satellite uplinks or downlinks to enable the core functions of BSS or MSS, such as aggregating content for broadcast or relaying mobile signals, but FSS itself does not include the end-user delivery in those services.[1] For instance, FSS enables dedicated telecommunication links for point-to-point data transmission in remote areas, such as broadband backhaul for internet service providers across continents.[2] In comparison, BSS supports direct-to-home television broadcasting, where signals are received by fixed consumer antennas for public viewing without targeted routing.[2]Regulatory Framework
ITU Classification
The fixed-satellite service (FSS) is formally classified within the International Telecommunication Union's (ITU) regulatory framework as a subset of the fixed service, as defined in Article 1.20 of the ITU Radio Regulations, which describes the fixed service as a radiocommunication service between specified fixed points. Satellite-specific provisions for FSS are outlined in Article 1.21, establishing it as a radiocommunication service between earth stations at specified fixed points using one or more satellites, potentially including satellite-to-satellite links and feeder links for other space services. World Radiocommunication Conferences (WRCs), held every three to four years, play a central role in governing FSS by addressing dedicated agenda items focused on service protection, spectrum allocation adjustments, and international coordination to ensure equitable access and minimize interference. For instance, recent WRCs have prioritized studies on technical and regulatory measures for FSS systems, including protections for earth stations in motion and harmonization of frequency bands to support evolving satellite technologies while accommodating the needs of developing countries.[8] International coordination of FSS frequency assignments is mandated under ITU procedures to prevent harmful interference, requiring administrations to notify proposed networks for examination and, if compatible, recording in the ITU's Master International Frequency Register (MIFR).[9] The MIFR serves as the authoritative global database for recognized FSS assignments, providing legal protection and facilitating dispute resolution through detailed particulars of each entry, such as orbital parameters and technical characteristics.[10] Protection criteria for FSS earth stations emphasize interference mitigation through established ITU-R recommendations, including power flux-density limits, equivalent power flux-density thresholds, and coordination distances to safeguard against unwanted emissions from adjacent services.[11] Specific rules, such as those in Recommendation ITU-R M.2161, guide administrations in applying mitigation techniques like site diversity, antenna discrimination, and operational constraints to maintain acceptable interference levels at FSS receiving earth stations.[12]Frequency Allocations
The frequency allocations for the fixed-satellite service (FSS) are defined in Article 5 of the ITU Radio Regulations, which outlines the Table of Frequency Allocations assigning spectrum bands to radiocommunication services on a primary or secondary basis, with distinctions across ITU Regions 1 (Europe, Africa, former Soviet Union, Middle East), 2 (Americas), and 3 (Asia-Pacific, Australasia). These allocations ensure coordinated use of the radio-frequency spectrum for FSS operations, primarily involving geostationary (GSO) and non-geostationary (NGSO) satellite systems for point-to-point communications.[13][14] Primary FSS allocations focus on several key bands, with space-to-Earth (downlink) and Earth-to-space (uplink) directions specified to support high-capacity data transmission. The following table summarizes representative primary FSS bands, which are allocated globally unless otherwise noted:| Band Designation | Downlink Frequency Range (GHz) | Uplink Frequency Range (GHz) | Notes on Allocation |
|---|---|---|---|
| C-band | 3.7–4.2 | 5.925–6.425 | Primary allocation worldwide for FSS (space-to-Earth and Earth-to-space); used for international trunk telephony and TV distribution.[15][16] |
| Ku-band | 11–12.75 | 13.75–14.5 | Primary allocation with regional variations; supports direct-to-home broadcasting and VSAT networks.[17][18] |
| Ka-band | 17.7–21.2 | 27.5–30 | Primary allocation for high-throughput satellites; enables broadband and backhaul services.[19][20] |
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