Extended Operational and Trade Vocabulary

Maritime Satcom and Telecommunications glossary (page 2)

The satellite-communications vocabulary: accounting authority identification codes, antenna acquisition and beam handover, active phased arrays and stabilized above-decks equipment, adjacent-satellite interference, and the VSAT, Inmarsat Fleet, Iridium, and Starlink LEO terms. Grounds each term in the satcom system, the airtime service, or the antenna technology it belongs to.

453 defined terms.

Showing 203 on this page (page 2 of 2).

K

Kymeta: American antenna manufacturer producing electronically steered, metamaterial-based flat panel antennas, including the u8 series.
Kymeta u8: Flat panel metamaterial antenna designed for mobility and offered with maritime configurations.

L

L-band: Satellite frequency band around 1.5 to 1.6 GHz used by Inmarsat and Iridium maritime services.
LAN Port: Ethernet interface on a satellite terminal connecting to vessel networks.
Land Earth Station: Earlier Inmarsat term for a gateway connecting the satellite network to terrestrial networks.
Latency: One-way delay across a satellite link, typically around 250 milliseconds for a GEO hop.
LEO: Low Earth Orbit, generally below 2,000 km altitude, used by Iridium and Starlink constellations.
LES: Large Eddy Simulation, scale-resolving turbulence approach available in STAR-CCM+, Fluent, and OpenFOAM.
Link Aggregation: Combining multiple WAN links such as VSAT and L-band into a single logical pipe.
Link Budget: Calculation of expected signal-to-noise margin across a satellite link.
LNB: Low Noise Block downconverter at the antenna that amplifies and shifts the received signal to an intermediate frequency.
Load Balancing: Distribution of traffic across multiple links based on policy and conditions.
Lockheed Martin A2100: Satellite bus used for some maritime-relevant geostationary platforms.
Look Angle: Combination of azimuth and elevation pointing a vessel antenna at the satellite.
Low Noise Block: See LNB.
LRIT: Long-Range Identification and Tracking, required by SOLAS V/19-1 since 31 December 2008.

M

Managed Service: Maritime connectivity offering in which the provider operates and supports the network on behalf of the shipowner.
MARISAT: Original maritime satellite constellation launched in the 1970s that preceded Inmarsat services.
Maritime Cybersecurity: Disciplines and tools, often delivered as part of services such as Fleet Secure, that protect vessel networks.
Maritime LTE: Coastal LTE networks deployed by some carriers and used by ships within range.
Marlink: Maritime satellite communications and IT services provider supporting many merchant and offshore operators.
Marlink Sealink: Marlink VSAT service brand covering Ku-band and Ka-band offerings.
Marlink XChange: Marlink onboard service delivery platform managing crew calling, internet, and content.
Master Reference Terminal: VSAT hub component providing precise timing references.
MEO: Medium Earth Orbit, generally between 2,000 and 35,786 km, used by some emerging maritime services.
Mesh Network (satellite): Configuration in which terminals communicate directly via satellite without routing all traffic through a hub.
Microwave Backhaul: Terrestrial line-of-sight link used to connect a teleport to upstream networks.
MIM (Mobility IP Modem): Generic term for VSAT modems optimized for moving platforms.
mini-C: Inmarsat Mini-C terminal class providing low-data-rate messaging and GMDSS functions.
mini-VSAT Broadband: KVH global maritime VSAT network using Ku-band HTS capacity.
MIR (Maximum Information Rate): Peak data rate permitted to a terminal under its service plan.
Mob (Man Overboard): MOB drill/COB procedure.
Modem (satellite): Equipment performing modulation, demodulation, framing, and error correction for a satellite link.
Modulation: Technique used to impress information onto a carrier, such as QPSK, 8PSK, 16APSK, or 32APSK.
Mountain Top Gateway: Common term for elevated teleport sites used to host satellite ground systems.
mPCM: Maritime modem family used in some VSAT installations.
MPLS Backbone: Multi-Protocol Label Switching backbone behind satellite teleports used to deliver private networks to shipowners.
MRCC: Maritime Rescue Coordination Centre established under SOLAS Chapter V Regulation 7.
MSC.434(98): IMO performance standard relevant to certain GMDSS satellite equipment.
MSS: Mobile Satellite Service, the ITU service category covering Inmarsat and Iridium.
MSV: Main steam valve, the boiler outlet stop valve.
MTU Tuning: Adjustment of maximum transmission unit on satellite links to optimize throughput.

N

NAVTEX: GMDSS broadcast service under SOLAS IV.
Network Innovations: Maritime and remote site satellite integrator with operations in multiple regions.
Newtec Dialog: Multiservice VSAT platform from ST Engineering iDirect used in maritime networks.
NMEA 0183: Marine electronics serial data standard.
NMEA 2000: CAN-based marine data network.
No-Email-Tail Stripping: Onboard email gateway feature that removes signatures and disclaimers to reduce data over satellite.
NOC: Network Operations Center monitoring satellite services and customer terminals.
Non-Geostationary: Satellite orbit other than GEO, including LEO and MEO platforms.
NSS: SES legacy New Skies Satellites brand, with capacity used historically by maritime networks.

O

O3b: SES medium Earth orbit Ka-band constellation used in some maritime mobility services.
OmniAccess: Maritime VSAT and IT services provider acquired by Inmarsat in 2017 and focused on yacht and cruise customers.
Onboard Network: Vessel local area network connecting bridge, engine room, and crew areas to the satellite gateway.
One-Way Latency: Time required for a signal to travel from sender to receiver across the satellite link.
OneWeb: Low Earth orbit Ku-band constellation operated by Eutelsat OneWeb, with maritime offerings in development.
OpenAMIP: Open antenna-modem interface protocol used in some VSAT installations.
OpenPort: See Iridium OpenPort.
Operational Technology Network: Vessel network segment carrying control system traffic, kept logically separate from crew internet.
Orbit AL-7103: ORBIT Communication Systems stabilized maritime tracking antenna.
ORBIT Communication Systems: Israeli manufacturer of stabilized maritime and aeronautical antennas.
ORCHESTRA (Inmarsat): Inmarsat planned multi-orbit network combining GEO, LEO, and terrestrial 5G.
OSPF Over Satellite: Use of the OSPF routing protocol across satellite links with appropriate timer adjustments.
OTAR (Over The Air Rekey): Remote update of cryptographic keys on satellite terminals.

P

Packet Loss: Fraction of transmitted packets that fail to arrive, important for measuring satellite link quality.
Pan-Pan: Urgency call category that may be transmitted via GMDSS satellite channels.
Parabolic Antenna: Reflector antenna shape used by most stabilized maritime VSAT systems.
Pay-As-You-Go: Prepaid tariff model used for some satellite services such as IsatPhone airtime.
Pay-Per-Megabyte: Tariff model in which customers pay per unit of data transferred.
Pedestal (antenna): Stabilized mounting assembly that maintains pointing on a moving vessel.
Performance Enhancing Proxy: Network appliance that accelerates TCP and HTTP traffic across satellite links.
Perigee: Point in the Moon's orbit nearest Earth.
Phased Array: Antenna composed of many small radiating elements whose relative phase determines the beam direction.
Phasor Solutions: British developer of electronically steered antennas whose technology was acquired by Hanwha Phasor.
Pilot Phone (vessel): Dedicated satellite voice line typically routed for pilotage and port communications.
Pilot Tone: Reference signal transmitted on a satellite carrier to aid receiver locking.
Polarization: Orientation of the electric field of a radio wave, used for frequency reuse on satellites.
Pole Mount: Antenna mounting hardware that locates a maritime antenna above superstructure obstructions.
Port Access Plan: Service description for VSAT or cellular use while alongside in port.
Power Spectral Density: Measure of how signal power is distributed across frequency.
Prefix Code Plan: Numbering plan used for satellite voice services to route calls to specific networks.
Prepaid Card (Inmarsat): Subscription model offering blocks of airtime for handheld and small terminal services.
Primary GMDSS Service Provider: Designation under IMSO for organizations providing recognized GMDSS satellite services.
Priority Plan (Starlink): Starlink subscription tier offering preferential network access for maritime users.
Private Network: Customer-specific virtual network delivered across a satellite service.

Q

Q-band: Satellite frequency range above Ka-band, used for some feeder links and considered for future services.
QoS (Quality of Service): Traffic policy mechanisms that prioritize critical applications over satellite links.
QPSK: Quadrature Phase Shift Keying modulation widely used on satellite links.

R

Radome: Protective enclosure around a maritime antenna that shields it from weather while allowing signal passage.
Rain Fade: Signal attenuation caused by rain in the satellite path, especially significant at Ku and Ka bands.
Rate Plan: Service tier defining committed and burst data rates and monthly allowance.
RCST (Return Channel Satellite Terminal): DVB-RCS terminal class used in some maritime VSAT networks.
Receive Only Antenna: Satellite antenna used solely for television or data reception.
Recognized Mobile Satellite Service: IMSO term for an MSS approved to provide GMDSS functions, currently including Inmarsat and Iridium.
Reflector: Curved surface of a parabolic antenna that focuses signals onto the feed.
Regenerative Satellite: Satellite that demodulates and remodulates signals onboard rather than acting only as a bent pipe.
Remote Diagnostics: Vendor-side troubleshooting of shipboard machinery.
Remote Tuning Antenna: Antenna with frequency or polarization that can be reconfigured by network commands.
Return Channel: Direction of transmission from vessel terminal through satellite to network hub.
RF Cable Loss: Attenuation of radio frequency signals in cables between modem and antenna.
Ring Topology: Satellite network design in which traffic can flow through alternate hubs for resilience.
Roam Plan (Starlink): Starlink global mobility plan available for maritime users with the appropriate hardware.
Roaming Agreement: Commercial agreement permitting a satellite terminal to use another operator's network.
Router (vessel): Onboard device that routes traffic between vessel networks and one or more satellite or cellular links.
Routing Policy: Configured rules determining which traffic uses which available link.

S

S-band: Satellite frequency band around 2 to 4 GHz used by some mobile satellite services.
SafetyNET: Inmarsat-C broadcast service for MSI to selected sea or NAVAREAs.
SAILOR: Cobham SATCOM maritime product family that includes the SAILOR 600, 900, and 100 GX terminals.
SAILOR 100 GX: Cobham Ka-band maritime VSAT terminal certified for Inmarsat Global Xpress.
SAILOR 600 VSAT Ku: Cobham Ku-band maritime VSAT terminal.
SAILOR 900 VSAT Ka: Cobham Ka-band maritime VSAT terminal.
SAR: Search and Rescue, governed by the 1979 SAR Convention and IAMSAR Manual.
SatCom Integration: Engineering work that ties satellite terminals into bridge, IT, and crew systems.
Satellite Bus: Common satellite platform on which different payloads are integrated.
Satellite Distress Alert: Priority alert transmitted via a recognized GMDSS satellite service.
SBD: Short Burst Data, Iridium short message service used widely for IoT and tracking.
SCN (Satellite Communications Network): Generic acronym for satellite-based corporate networks at sea.
SCPC: Single Channel Per Carrier transmission allocating a dedicated carrier to each link.
Scrambler: Component that randomizes data patterns to maintain bit transitions on satellite carriers.
SD-WAN (maritime): Software-defined wide area networking applied across multiple maritime links for application-aware routing.
Sealink: Marlink VSAT service brand.
SES: Luxembourg-headquartered satellite operator providing GEO and MEO capacity used in maritime services.
SesGEM: Marketing term for some SES maritime mobility offerings.
Shaped Beam: Satellite beam contoured to match a specific geographic region.
Shore-Side NOC: Operations center ashore that monitors and supports vessel satellite services.
Short Burst Data: See SBD.
Signal Strength Meter: Tool used during installation to verify antenna pointing.
SIM (Subscriber Identity Module): Smart card used in some satellite services such as IsatPhone for subscriber authentication.
Single Hop: Architecture where vessel traffic transits one satellite leg before reaching the terrestrial backbone.
Site Survey: A pre-installation inspection of an offshore field location covering bathymetry, geotechnics, and existing infrastructure.
SkyEdge: Gilat VSAT platform used in some maritime networks.
Skywave: Radio wave reflected by the ionosphere.
SOLAS: International Convention for the Safety of Life at Sea, 1974; the IMO treaty setting minimum construction, equipment, and operation standards for merchant ships.
SpaceX: American aerospace company that operates the Starlink constellation.
Spectrum Efficiency: Bits per second per Hertz delivered by a given modulation and coding scheme.
Speedcast: Maritime communications service provider whose Ku and Ka band networks support many merchant and offshore vessels.
Speedcast SIGMA Net: Speedcast hybrid network management platform for vessel WAN orchestration.
Spot Beam: Narrow satellite beam used to concentrate capacity on a specific region.
Stabilized Antenna: Maritime antenna whose pointing is maintained by a mechanical pedestal regardless of vessel motion.
Star Network: VSAT topology in which all terminals communicate through a central hub.
Starlink: SpaceX low Earth orbit Ku-band broadband constellation.
Starlink Flat High Performance: Starlink antenna model designed for harsh and mobile environments.
Starlink Maritime: SpaceX LEO maritime broadband service.
Starlink Mobility: Starlink service tier for moving platforms including vessels and aircraft.
Starlink Priority: Starlink service tier offering prioritized network access for business and maritime users.
Starlink Roam: Starlink global mobility plan suitable for many smaller vessels.
Static IP: IP address that remains constant on a vessel network, often required for VPN connectivity.
STN Atlas: Historical bridge electronics manufacturer whose lineage influenced modern integrated bridge and satcom integration.
Subscription Plan: Recurring tariff for maritime broadband services, typically defined by data and speed.
Sun Outage: Periodic interference event when the sun aligns behind a geostationary satellite.
Supplementary Services: Voice features such as call forwarding offered on Inmarsat and Iridium services.
Survey Vessel Connectivity: Specialized high-bandwidth satellite services used by hydrographic and seismic survey ships.
System Resource Manager: VSAT hub function that allocates carriers and capacity to terminals.

T

TCP Acceleration: Performance enhancing proxy technique used to overcome long satellite latencies.
TDMA: Time Division Multiple Access, the basic medium-access scheme of AIS.
Telemetry, Tracking, and Command: Satellite operations subsystem used by the operator to manage the spacecraft.
Telenor Satellite Broadcasting: Norwegian satellite operator whose maritime distribution business contributed to Marlink.
Teleport: Earth station facility hosting satellite uplink and downlink equipment for one or more services.
Terminal Identifier: Unique address used by the satellite network to route traffic to a specific vessel terminal.
ThinKom: American manufacturer of phased array antennas used in some mobility applications including maritime trials.
Thrane and Thrane: Danish satellite terminal manufacturer now part of Cobham SATCOM.
Throughput: Effective data rate delivered to a customer across a satellite link.
Time Slot: Discrete transmission window used in TDMA satellite access.
Tracking Filter: Antenna control function used to maintain satellite lock during vessel maneuvers.
Tracking System: Combined hardware and software that keeps a maritime antenna pointed at the satellite.
Transponder: Satellite payload subsystem that receives, frequency-translates, amplifies, and retransmits signals.
Tropospheric Scintillation: Rapid signal fluctuations caused by turbulence in the lower atmosphere.
Trunk Carrier: High-capacity satellite carrier connecting major hub sites.
Trusted Source Routing: SD-WAN feature that selects routes based on policy and source authentication.

U

Uninterruptible Power Supply: Battery-backed power source used to keep critical satcom equipment online through power transitions.
Universal Customer Edge: Generic term for a multi-function gateway combining routing, firewall, and link management.
Uplink: Direction of transmission from the vessel terminal to the satellite.
Uplink Power Control: Adaptive technique that increases vessel transmit power during rain fade.
User Terminal: General term for the satellite equipment installed on the vessel.
UT (Inmarsat): User Terminal in Inmarsat documentation.

V

V-band: Satellite frequency band above Ka used for some feeder links and considered for future high-capacity systems.
VAR (Value Added Reseller): Channel partner that integrates and resells maritime satcom services.
VDR: Voyage Data Recorder, required under SOLAS V/20.
Velocity (iDirect): iDirect Velocity high-throughput VSAT platform used in maritime networks.
Vessel IT Network: Onboard local area network that supports navigation, operations, and crew systems.
Viasat: American satellite operator with maritime Ka-band offerings, including services formerly branded as Inmarsat Global Xpress after the 2023 Viasat acquisition of Inmarsat.
Viasat Maritime: Combined Viasat and Inmarsat maritime portfolio following the acquisition completed in 2023.
Video Conferencing at Sea: Use of FleetBroadband, Fleet Xpress, VSAT, or Starlink links to support video calls from vessels.
Virtual NOC: Cloud-hosted operations center used by some integrators to monitor vessel terminals.
Voice Over IP: Carriage of voice services as IP packets across a satellite link.
Voucher System: Crew Wi-Fi prepaid model in which seafarers purchase scratch cards or codes for internet access.
VPN at Sea: Use of virtual private network tunnels across a satellite link to connect to corporate networks.
VSAT: Very Small Aperture Terminal satellite system used for two-way broadband at sea.

W

WAN Optimization: Techniques to improve performance of wide area links, often deployed on satcom paths.
Watch Receiver: DSC receiver that monitors Channel 70, 2187.5 kHz and HF DSC frequencies.
Wavelength Conversion: Translation of signals between frequency bands at the satellite or ground.
Weather Routing Service: A commercial routing service whose use is sometimes documented under VIQ Chapter 4.
Web Filtering: Onboard content filtering applied to traffic before it crosses the satellite link.
White Listing: Network policy that permits only specified destinations or applications over the satellite link.
Wi-Fi Calling at Sea: Use of vessel Wi-Fi over a satellite link to support mobile phone calls when in port or coverage of a hotspot.

X

X-band: 8 to 12 GHz radar band (9.2 to 9.5 GHz for marine radar and Racons).
XChange (Marlink): Marlink onboard service delivery platform.
Xpress Link: Branding occasionally used for hybrid Ka and L-band maritime services predating Fleet Xpress.

Y

Yagi-Like Pattern: Informal description of certain compact antenna radiation patterns occasionally seen in maritime accessories.
Yield Management (capacity): Operator practice of pricing satellite capacity to maximize utilization across customer segments.

Z

Z-axis Stabilization: Vertical-axis stabilization component within a three-axis stabilized maritime antenna pedestal.
Zero-Touch Provisioning: Automatic configuration of vessel terminals upon power-up without on-site intervention.
Zone Beam: Satellite beam shaped to cover a defined operational zone rather than a complete hemisphere.