High Frequency Data Link

Last updated

High Frequency Data Link (HFDL) is an ACARS communications medium used to exchange data such as Aeronautical Operational Control (AOC) messages, Controller Pilot Data Link Communications (CPDLC) messages and Automatic Dependent Surveillance (ADS) messages between aircraft end-systems and corresponding ground-based HFDL ground stations. Using the unique propagation characteristics of high-frequency radio waves, the ground stations provide data link communications to properly equipped aircraft operating anywhere in the world. As a result, pilots can always communicate with someone on the ground. [1]

Contents

Avionics supporting HFDL

To use the service, an aircraft only needs a Communications Management Unit (CMU), or equivalent and an HFDL data radio. The CMU is an airborne communications router that interfaces with many aircraft communications systems including SATCOM, VHF, HFDL, FMS and others.

Global coverage

Today, HFDL is an air/ground data link standard with coverage in virtually every corner of the globe, approximately 168,000,000 square miles (440,000,000 km2) where aircraft are never out of touch both in the air and on the ground. There are around 15 HF ground stations (HGS) available today, and, like a canopy within a jungle, the stations provide overlap and redundancy in the unlikely event of a HGS failure. These 15 stations provide nearly complete global coverage, including both poles, and system availability is 100 percent.

Evolving technology

The HFDL network and avionics are a continuing evolution. Recent innovations in avionics software developed by both Honeywell and Collins have enhanced performance and contribute to the service’s outstanding message success rates. There is continued investment in the HFDL infrastructure and there is a long term strategy in place to ensure its success.

ARINC have been quoted as saying that the system and its use have grown at rates above 20% for each of the past ten years and it now supports over sixty airlines with well over 1,200 aircraft sending more than 1 million messages a month. In 2009 eight new operating frequencies were added which brings the total number of frequencies to 167 worldwide.

Increased system use

The design of the system allows for 4 channels per ground station. Currently, 12 stations are only using ½ of the designed capacity. 3 others are using 3 of the 4 designed channels. Stations are actively monitored for traffic load and can determine when additional channels needs to be added by the service providers.

HFDL outperforms HF voice

Due to the digital nature of HFDL, it uses between 1/3 and 1/2 of the bandwidth that voice requires, so data can continue to be decoded when voice is unusable. This was proven during the 2003 Halloween Solar Storm when aircraft were still using HFDL on polar routes when voice was unusable.

Automatic frequency selection

HFDL does not require pilots to dial in specific frequencies, as with HF voice, the data radios constantly scan and select the most efficient frequency to use making operation seamless for flight crews.

Flight planning providers

Related Research Articles

<span class="mw-page-title-main">Avionics</span> Electronic systems used on aircraft

Avionics are the electronic systems used on aircraft. Avionic systems include communications, navigation, the display and management of multiple systems, and the hundreds of systems that are fitted to aircraft to perform individual functions. These can be as simple as a searchlight for a police helicopter or as complicated as the tactical system for an airborne early warning platform.

Automatic Link Establishment, commonly known as ALE, is the worldwide de facto standard for digitally initiating and sustaining HF radio communications. ALE is a feature in an HF communications radio transceiver system that enables the radio station to make contact, or initiate a circuit, between itself and another HF radio station or network of stations. The purpose is to provide a reliable rapid method of calling and connecting during constantly changing HF ionospheric propagation, reception interference, and shared spectrum use of busy or congested HF channels.

<span class="mw-page-title-main">Radiotelephone</span> Communications system for transmission of speech over radio

A radiotelephone, abbreviated RT, is a radio communication system for conducting a conversation; radiotelephony means telephony by radio. It is in contrast to radiotelegraphy, which is radio transmission of telegrams (messages), or television, transmission of moving pictures and sound. The term is related to radio broadcasting, which transmit audio one way to listeners. Radiotelephony refers specifically to two-way radio systems for bidirectional person-to-person voice communication between separated users, such as CB radio or marine radio. In spite of the name, radiotelephony systems are not necessarily connected to or have anything to do with the telephone network, and in some radio services, including GMRS, interconnection is prohibited.

<span class="mw-page-title-main">Rockwell Collins</span> Defunct US-based electronics company (2001-2018)

Rockwell Collins, Inc. was a multinational corporation headquartered in Cedar Rapids, Iowa, providing avionics and information technology systems and services to government agencies and aircraft manufacturers. It was formed when the Collins Radio Company, facing financial difficulties, was purchased by Rockwell International in 1973. In 2001, the avionics division of Rockwell International was spun off to form the current Rockwell Collins, Inc., retaining its name.

<span class="mw-page-title-main">Shanwick Oceanic Control</span> Area of International Airspace which lies above the northeast part of the North Atlantic

Shanwick is the air traffic control (ATC) name given to the area of international airspace which lies above the northeast part of the Atlantic Ocean.

Aeronautical Radio, Incorporated (ARINC), established in 1929, was a major provider of transport communications and systems engineering solutions for eight industries: aviation, airports, defense, government, healthcare, networks, security, and transportation. ARINC had installed computer data networks in police cars and railroad cars and also maintains the standards for line-replaceable units.

Airband or aircraft band is the name for a group of frequencies in the VHF radio spectrum allocated to radio communication in civil aviation, sometimes also referred to as VHF, or phonetically as "Victor". Different sections of the band are used for radionavigational aids and air traffic control.

<span class="mw-page-title-main">ACARS</span> Aircraft digital message communication system

In aviation, ACARS is a digital datalink system for transmission of short messages between aircraft and ground stations via airband radio or satellite. The protocol was designed by ARINC and deployed in 1978, using the Telex format. More ACARS radio stations were added subsequently by SITA.

Avionics Full-Duplex Switched Ethernet (AFDX), also ARINC 664, is a data network, patented by international aircraft manufacturer Airbus, for safety-critical applications that utilizes dedicated bandwidth while providing deterministic quality of service (QoS). AFDX is a worldwide registered trademark by Airbus. The AFDX data network is based on Ethernet technology using commercial off-the-shelf (COTS) components. The AFDX data network is a specific implementation of ARINC Specification 664 Part 7, a profiled version of an IEEE 802.3 network per parts 1 & 2, which defines how commercial off-the-shelf networking components will be used for future generation Aircraft Data Networks (ADN). The six primary aspects of an AFDX data network include full duplex, redundancy, determinism, high speed performance, switched and profiled network.

The Future Air Navigation System (FANS) is an avionics system which provides direct data link communication between the pilot and the air traffic controller. The communications include air traffic control clearances, pilot requests and position reporting. In the FANS-B equipped Airbus A320 family aircraft, an Air Traffic Services Unit (ATSU) and a VHF Data Link radio (VDR3) in the avionics rack and two data link control and display units (DCDUs) in the cockpit enable the flight crew to read and answer the controller–pilot data link communications (CPDLC) messages received from the ground.

Controller–pilot data link communications (CPDLC), also referred to as controller pilot data link (CPDL), is a method by which air traffic controllers can communicate with pilots over a datalink system.

<span class="mw-page-title-main">AN/ARC-190</span>

The AN/ARC-190 is an airborne HF communications system, found on C-130, C-20, KC-135, C-141, C-5, C-9, KC-10, B-1, B-52, C-17, E-3, E-4, E-8 JSTARS, F-15, F-16, H-53, H-60, S-2T, and Bell Boeing V-22 Osprey aircraft.

In international aviation, SELCAL or SelCal is a selective-calling radio system that can alert an aircraft's crew that a ground radio station wishes to communicate with the aircraft. SELCAL uses a ground-based encoder and radio transmitter to broadcast an audio signal that is picked up by a decoder and radio receiver on an aircraft. The use of SELCAL allows an aircraft crew to be notified of incoming communications even when the aircraft's radio has been muted. Thus, crewmembers need not devote their attention to continuous radio listening.

During World War II, the German Luftwaffe relied on an increasingly diverse array of electronic communications, IFF and RDF equipment as avionics in its aircraft and also on the ground. Most of this equipment received the generic prefix FuG for Funkgerät, meaning "radio equipment". Most of the aircraft-mounted Radar equipment also used the FuG prefix. This article is a list and a description of the radio, IFF and RDF equipment.

<span class="mw-page-title-main">Automatic Dependent Surveillance–Broadcast</span> Aircraft surveillance technology

Automatic Dependent Surveillance–Broadcast (ADS-B) is an aviation surveillance technology and form of electronic conspicuity in which an aircraft determines its position via satellite navigation or other sensors and periodically broadcasts its position and other related data, enabling it to be tracked. The information can be received by air traffic control ground-based or satellite-based receivers as a replacement for secondary surveillance radar (SSR). Unlike SSR, ADS-B does not require an interrogation signal from the ground or from other aircraft to activate its transmissions. ADS-B can also receive point-to-point by other nearby equipped "ADS-B In" equipped aircraft to provide traffic situational awareness and support self-separation. ADS-B is "automatic" in that it requires no pilot or external input to trigger its transmissions. It is "dependent" in that it depends on data from the aircraft's navigation system to provide the transmitted data.

The VHF Data Link or VHF Digital Link (VDL) is a means of sending information between aircraft and ground stations. Aeronautical VHF data links use the band 117.975–137 MHz assigned by the International Telecommunication Union to Aeronautical mobile (R) service. There are ARINC standards for ACARS on VHF and other data links installed on approximately 14,000 aircraft and a range of ICAO standards defined by the Aeronautical Mobile Communications Panel (AMCP) in the 1990s. Mode 2 is the only VDL mode being implemented operationally to support Controller Pilot Data Link Communications (CPDLC).

Next Generation (NextGen) Data Communications, an element of the Next Generation Air Transportation System, will significantly reduce controller-to-pilot communications and controller workload, whilst improving safety. NextGen comprises complex integrated and interlinked programs, portfolios, systems, policies, and procedures. NextGen has modernized air traffic infrastructure in communications, navigation, surveillance, automation, and information management.

FANS-1/A design is a range of Future Air Navigation System (FANS) products that allows aircraft to be seen by ATC in areas where radar is not practical so that aircraft separation can be maintained. FANS includes many components from human to avionics hardware and a dedicated network linking Air Traffic Control (ATC) to the flight crew via satellite and landlines. FANS 1/A consists of CPDLC and ADS-C. CPDLC allows communications between the pilot and ATC and ADS-C is an electronic contract, valid through the duration of time the aircraft is in FANS 1/A airspace, offered by ATC and accepted by the flight crew. ADS-C provides aircraft position information to ATC including heading, altitude, airspeed and position. The communications include air traffic control clearances, pilot requests, and position reporting. FANS-1 is Boeing's solution and FANS-A is the Airbus solution.

SwiftBroadband is an IP-based packet-switched communications network that provides a symmetric ‘always-on’ data connection of up to 650 kbit/s per channel for aircraft globally except for the polar regions, using the Inmarsat satellite constellation.

References

  1. Tony Anselmi. "HFDL Ground Stations (traffic to and from)" . Retrieved 2024-08-12.