Detailed working notes on aeronautical satellite communications: the AMS(R)S framework, legacy and current safety SATCOM systems, and the ESA/Inmarsat Iris programme. This folder expands the summary in topics/satcom_iris.md into per-aspect files so each can be read independently.

Files in this folder#

• overview.md — what AMS(R)S is, where it sits in the ICAO/ATM framework, and how safety SATCOM differs from commercial services.
• components.md — the space, ground, and airborne segments; service classes; the AES/GES/satellite architecture.
• blocks.md — SATCOM generations mapped to ASBU blocks: Classic Aero (B0), SB-S/Iridium (B0/B1), Iris/IPS-ready (B2).
• threads.md — functional axes: AMS(R)S SARPs compliance, safety-service provision, oceanic/remote operations, Iris and continental ATM, ATN/IPS integration, PBCS performance.
• modules.md — anatomy of one unit: Iris continental datalink supporting i4D, and an oceanic ADS-C/CPDLC worked example.
• enablers.md — spectrum, certification, ATN/IPS ground network, avionics, procedures, training, and institutional bodies.
• performance_objectives.md — KPA matrix, RCP 240/RSP 180, numeric performance targets.
• timeline.md — historical evolution from Classic Aero (1992) through SB-S, Iris Precursor, to Iris Service Evolution.
• references.md — consolidated ICAO and external references.

Reading order#

Start with overview.md to understand the regulatory and operational context. Then read components.md for the segment architecture and blocks.md for the generational progression. threads.md maps the functional axes. modules.md provides worked examples. enablers.md, performance_objectives.md, and timeline.md give supporting depth. Use references.md for citations.

Source basis#

Content is grounded in:

• ICAO Annex 10, Volume III (Aeronautical Telecommunications — Communication Systems), Chapter 4 (AMS(R)S SARPs) and Chapter 2, Section 2.5 (SATVOICE).
• Doc 9925 (Manual on the AMS(R)S), First Edition 2010, Amdt 1.
• Doc 9869 (PBCS Manual) — RCP 240 / RSP 180 specifications.
• Doc 4444 (PANS-ATM) — flight plan equipment codes and oceanic ADS-C/CPDLC procedures.
• ESA Iris programme documentation: https://www.esa.int/Applications/Telecommunications_Integrated_Applications/Iris
• EUROCONTROL satellite communications service information: https://www.eurocontrol.int/service/satellite-based-communication
• SESAR 3 JU Digital European Sky programme: https://www.sesarju.eu/projects/digital-european-sky

What AMS(R)S is#

The Aeronautical Mobile-Satellite (Route) Service (AMS(R)S) is the ICAO-regulated safety communications service provided by satellite systems to and from aircraft on international routes. "Route" in the designation distinguishes this service — used for the safety and regularity of flight — from the Aeronautical Mobile-Satellite (Off-Route) Service used for other purposes.

AMS(R)S is not a specific satellite system. It is a set of performance and interface requirements that any conformant satellite system may satisfy. Annex 10, Volume III, Chapter 4 is the normative ICAO framework: its SARPs cover the RF characteristics, dynamic performance, packet data and voice service performance, ATN integration, and addressing requirements that a system must meet. The manual on AMS(R)S (Doc 9925) then provides system- specific compliance guidance for the principal in-service systems.

Where SATCOM sits in the ICAO/ATM framework#

ICAO's Communications, Navigation, and Surveillance (CNS) triad places aeronautical communications in the C leg. Within communications, Annex 10 Vol III distinguishes:

• Air-ground voice — VHF DSB-AM (primary, continental/domestic), HF SSB (oceanic, backup), and SATVOICE (oceanic, remote, backup to HF in new operations).
• Air-ground datalink — VDL Mode 2 (ATN B1, continental), HFDL (oceanic, legacy), and AMS(R)S (oceanic/remote primary; Iris extends to continental).
• Ground-ground communications — AMHS, ATN/IPS voice-over-IP, and AFTN.

SATCOM specifically addresses the gap where VHF does not reach: oceanic and remote area, polar routes above VHF range, low- altitude continental blind spots (addressed by Iris), and areas where HF propagation is unreliable. The ATN recognizes AMS(R)S as a constituent mobile subnetwork (Annex 10 Vol III §4.6.4.1.1), meaning SATCOM-carried packets are indistinguishable at the ATN network layer from those carried over VDL or Mode S.

AMS(R)S vs. commercial satellite connectivity#

A critical distinction separates AMS(R)S (safety service) from commercial satellite connectivity (cabin wi-fi, passenger broadband, airline operational control using non-safety protocols):

• An AMS(R)S system must conform to Annex 10 Vol III Chapter 4 SARPs and carry certified avionics (RTCA DO-210D for Classic Aero/GEO; RTCA DO-262 for Iridium; RTCA SBB MASPS/MOPS for SwiftBroadband).
• Non-safety systems share spectrum but are not required by ITU Radio Regulations to offer safety services (AN10 V3 §4.3.1.1 Note).
• Priority and pre-emption within the satellite subnetwork must protect safety traffic; commercial traffic may be suspended when safety traffic demands all available channel resources.
• Only AMS(R)S-certified links may be used for CPDLC and ADS-C operations under PBCS (RCP 240, RSP 180).

The Iris programme in context#

The ESA/Inmarsat Iris programme sits at the intersection of two ATM modernization drives:

1. The ICAO/GANP push for ATN/IPS transition — Annex 10 Vol III Amendment 93 (applicable 27 November 2025) consolidates IPS requirements across multiple air-ground media, including satellite. Iris is designed from the outset as an ATN/IPS subnetwork.

2. The SESAR / ASBU push for TBO — ASBU COMI-B2 (communications infrastructure, Block 2, from 2025) calls for ATN/IPS data link migration and multi-frequency/satellite data link in oceanic and remote regions. Iris is the delivery vehicle for the continental Europe portion and the NAT oceanic extension.

Iris is thus not just a new satellite product: it is the intended SATCOM enabler for i4D (initial 4D) operations, the TBO precursor where CPDLC delivers Required Time of Arrival (RTA) constraints to the FMS at metering fixes.

Related topics (avoid duplication)#

• fci — the Future Communications Infrastructure thread, within which SATCOM/Iris appears as one link medium alongside VDL Mode 2, LDACS, and AeroMACS.
• datalink — CPDLC application layer; Iris is a transport, not the application.
• gnss_resilience — GNSS is navigation, not communications; space-based ADS-B (e.g., Aireon) is surveillance, not comms.
• tbo — the operational concept that Iris i4D supports.

References#

• Annex 10 Vol III (Aeronautical Telecommunications — Communication Systems), Chapter 4, §4.2.1 — AMS(R)S conformance requirement; technology-neutral, performance-oriented SARPs.
• Annex 10 Vol III, Chapter 4, §4.3.1.1 Note — ITU Radio Regulations allow non-safety MSS in AMS(R)S spectrum; States must manage spectrum protection.
• Annex 10 Vol III, Chapter 4, §4.6.4.1.1 — AMS(R)S packet data service shall operate as constituent ATN mobile subnetwork.
• Annex 10 Vol III, Chapter 2, §2.5 — SATVOICE system characteristics; Note references Doc 9925 and Doc 9869.
• Annex 10 Vol III, Amendment 93 (applicable 27 November 2025) — Updated ATN/IPS requirements across multiple media including satellite.
• Doc 9925 (Manual on the AMS(R)S), Foreword — Statement of purpose: AMS(R)S as global satellite subnetwork of ATN for safety and regularity of flight (authoritative source — not in local library for full text).
• Doc 9869 (PBCS Manual) — RCP 240 and RSP 180 performance requirements applicable to satellite-carried CPDLC and ADS-C (authoritative source — not in local library for full text).

The three-segment architecture#

Every AMS(R)S system shares the same three-segment architecture: space segment, ground segment, and airborne segment. The Annex 10 Vol III SARPs apply to the system as a whole (AES, satellite, and GES together) and specify the performance at the service boundary between the AMS(R)S subnetwork and the ATN or SATVOICE user.

Space segment#

GEO systems (Inmarsat Classic Aero, SwiftBroadband, Iris): geostationary satellites at approximately 35 786 km altitude. The Inmarsat Classic Aero constellation uses I-3 and I-4 satellites. Inmarsat I-4 and I-6 support SwiftBroadband; I-6 (GX payload) supports Iris Ka-band capacity. GEO provides continuous regional coverage but does not reach above approximately 75 degrees latitude (polar gap).

LEO/MEO systems (Iridium): 66 operational satellites in six polar orbital planes at 780 km altitude, providing true global coverage including the poles. Inter-satellite links relay traffic across the constellation without needing a ground station in coverage.

Ground segment — ground earth stations#

Ground earth stations (GES) provide the feeder link to the satellite and connect to the terrestrial ATN. The ICAO definition: "an earth station in the fixed satellite service, or in the aeronautical mobile-satellite service, located at a specified fixed point on land to provide a feeder link for the aeronautical mobile-satellite service" (AN10 V3 §1 defs).

For Classic Aero and SBB: Inmarsat Land Earth Stations (LES) and Satellite Access Stations (SAS) at multiple sites worldwide. ACARS gateways at SAS connect to SITA/AVITECH networks that ANSPs access via Communications Network Providers (CNPs).

For Iris: purpose-built ground infrastructure integrated with the EUROCONTROL Network Manager and national ANSP ATC systems, delivering ATN/IPS-compliant routing.

For Iridium: Iridium Gateway at Tempe, Arizona (primary), plus satellite-to-satellite relay means that a single ground station can serve the entire LEO constellation.

Airborne segment — aircraft earth stations#

The aircraft earth station (AES) consists of antenna, satellite data unit (SDU), and avionics interfaces. AES classes under SwiftBroadband (Doc 9925 Part IV §2.2.5):

• Class 4: enhanced low gain antenna (ELGA) — smallest, lowest cost, lower data rates.
• Class 7: intermediate gain antenna (IGA) — mid-range.
• Class 6: high gain antenna (HGA) — highest data rates; may include Classic Aero reversion for dual-service.

For Classic Aero: dedicated SDU per ARINC 741; antenna on fuselage. For Iridium: smaller low-profile antenna. For Iris (SB-S with IPS extension): existing SBB AES updated via software and gateway-side upgrades; no new airframe antenna required for initial service.

Service classes — safety and non-safety#

The AMS(R)S SARPs require priority and pre-emption to protect safety services. The four categories (SATVOICE call priorities, AN10 V3 §2.5 Table 2-1):

• Priority 1 (Distress/Urgency) — highest; flight crew emergency use.
• Priority 2 (Flight Safety — ANSP calls) — second highest; routine ATC SATVOICE and CPDLC transactions.
• Priority 3 (Regularity of flight — AOC) — airline operational control; below ANSP calls.
• Priority 4 (Public correspondence) — passenger connectivity; non-safety; may be pre-empted.

For packet data, the SARPs specify that all AMS(R)S data packets and voice calls shall be identified as to their associated priority (§4.4.2), and that voice channel blockage probability shall not exceed 10^-2 under peak loading (§4.6.5.1.3.1).

The AMS(R)S subnetwork and the ATN#

The interface between AMS(R)S and the ATN is specified at the subnetwork layer. Requirements:

• The AES shall support the subnetwork access protocol (SNAcP) for the ATN (or the ATN/IPS equivalent).
• The GES shall provide an interface to the ATN (§4.7.2.1).
• The system shall provide a connectivity notification (CN) function so the ATN can know when an aircraft's subnetwork connection is available or unavailable (§4.7.2.2).
• The aircraft is addressable by its ICAO 24-bit aircraft address (§4.7.1).

For ATN/IPS (Iris and future systems): the satellite link acts as a multi-link IP bearer. Annex 10 Vol III Chapter 3 §3.4.1 and §3.4.10 require the ATN/IPS to support multilink — allowing seamless failover between VDL Mode 2 and satellite.

The Iris service components#

The Iris service adds an IP-capable layer to the existing SBB infrastructure:

• I-6 Ka-band satellites (GX payload) for high-throughput European coverage.
• Iris Service Evolution ground network: integrated with EUROCONTROL Network Manager B2B services and national ANSP systems.
• Avionics: SBB AES with ARINC 781 connectivity; initial Iris deployment leverages existing SBB avionics with ground-side gateway changes and eventual IPS stack updates.
• Applications supported: CPDLC ATN B2 (FANS 1/A and ATN/OSI transition to IPS); ADS-C; i4D RTA delivery; AOC.

References#

• Annex 10 Vol III, Chapter 4, §4.2.1 — General AMS(R)S conformance requirement; whole system (AES, satellite, GES) must comply.
• Annex 10 Vol III, Chapter 4, §4.4.2 — All AMS(R)S packets and voice calls shall be identified by priority.
• Annex 10 Vol III, Chapter 4, §4.6.5.1.3.1 — Voice channel blockage probability not greater than 10^-2 under peak loading.
• Annex 10 Vol III, Chapter 4, §4.7.1 — ICAO 24-bit aircraft address for AMS(R)S routing.
• Annex 10 Vol III, Chapter 4, §4.7.2.1 and §4.7.2.2 — GES ATN interface and connectivity notification function requirements.
• Annex 10 Vol III, Chapter 2, §2.5 and Table 2-1 — SATVOICE call priority levels.
• Doc 9925 Part IV, §2.2.5 — SwiftBroadband AES antenna classes (Class 4/6/7).
• Doc 9925 Part IV, §2.2.3 — SBB 30/30 NM oceanic separation capability; RCP240/RSP180 compliance (authoritative source — not in local library for full text).
• ESA Iris programme — https://www.esa.int/Applications/Telecommunications_Integrated_Applications/Iris (authoritative source — not in local library).

Overview#

SATCOM modernization follows a generational progression that maps onto the ASBU COMI (Communications Infrastructure) and COMS (Surface Communications) threads. The COMI thread governs air- ground data link; the relevant ASBU blocks for SATCOM are:

• COMI-B0: current-generation CNS including VHF, HF, and existing satellite data link (Classic Aero in oceanic use).
• COMI-B1: expanding data link reach; regional ATN/IPS pilots.
• COMI-B2 (from 2025): ATN/IPS data link migration; multi- frequency/satellite data link in oceanic and remote regions.

The four SATCOM generations below map to these blocks, primarily by domain (oceanic/remote vs. continental).

Generation 1 — Classic Aero (from ~1992)#

ASBU mapping: COMI-B0 (oceanic and remote segment).

Systems: Inmarsat Classic Aero (Aero-H, Aero-H+, Aero-I); MTSAT Classic Aero in the APAC region (JCAB, integrated into Inmarsat network 2006).

Space segment: Inmarsat I-3 and I-4 GEO satellites; up to seven Inmarsat satellites and one MTSAT satellite globally.

Services:

• CPDLC and ADS-C via FANS 1/A over ACARS (AEEC 622).
• D-ATIS and oceanic clearance delivery (OCD) via AEEC 623.
• SATVOICE (Priority 1/2 — distress and ATC safety calls).

Performance: Supports RCP 240 (CPDLC data) and RSP 180 (ADS-C) per Doc 9869. Enables 30/30 NM longitudinal/lateral separation in oceanic airspace. Long-range aircraft (oceanic operators) equipped with Classic Aero SDU and ARINC 741 antenna.

Limitations: L-band capacity shared by all services. No true polar coverage. Moderate data rates (lower than SBB). ACARS protocol (not ATN/IPS). No continental coverage design.

Status (2026): Still in service. Primary oceanic datalink for FANS 1/A equipped aircraft on NAT, Pacific, and Indian Ocean routes. Inmarsat I-3 satellites end-of-life; I-4 provides primary Classic Aero plus SBB capacity.

Generation 2 — SwiftBroadband-Safety / Iridium Certus (from ~2006)#

ASBU mapping: COMI-B0/B1 (enhanced oceanic; some remote).

Systems:

• Inmarsat SwiftBroadband (SBB): I-4 / I-6 broadband; safety- of-flight subset SB-S carries FANS over IP gateway.
• Iridium RUDICS / Short Burst Data (legacy) and Iridium Certus (next generation): LEO, true global coverage including poles.

Services (SBB):

• ACARS data over IP gateway: FANS 1/A CPDLC and ADS-C compliant with RCP 240 / RSP 180.
• Two channels cockpit voice (VoIP via IP bearer).
• Position reporting service.
• Higher-throughput AOC IP service.

Services (Iridium):

• AMS(R)S data and voice; FANS 1/A over SBD/RUDICS (legacy) or Certus bearer (next-generation).
• True polar coverage: only system providing AMS(R)S above 75 degrees latitude.

Key improvement over Gen 1: Higher data rates (SBB up to 432 kbps IP to aircraft); simultaneous safety and AOC services on separate priorities; reversion to Classic Aero possible for SBB Class 6 HGA equipped aircraft.

Limitations: SBB still uses ACARS protocol over IP gateway — not natively ATN/IPS. Iridium proportion of oceanic traffic small (approx. 1 per cent in NAT; remainder Inmarsat) but critical for polar operators.

Generation 3 — Iris Precursor (2018–2022)#

ASBU mapping: COMI-B1 (ATN/IPS pilot, continental validation).

Background: ESA initiated the Iris Precursor service as a proof-of-concept using Inmarsat I-4 capacity and a purpose-built ATN/IPS gateway. SESAR R&D validation trials demonstrated i4D RTA delivery via satellite CPDLC over the Iris Precursor network in European continental airspace.

Key milestones:

• First i4D operational trials over Iris satellite link in SESAR validation exercises.
• Demonstrated that satellite CPDLC can deliver RTA constraints at metering fixes with performance meeting ASBU COMI-B2 requirements.
• Established baseline compliance with Annex 10 Vol III ATN/IPS provisions introduced under Amendments 88-A and subsequent updates.

Limitations: Limited coverage; not a production service; small number of equipped aircraft; ground network not integrated with full Network Manager B2B environment.

Generation 4 — Iris Service Evolution (from 2022)#

ASBU mapping: COMI-B2 (ATN/IPS data link migration; satellite as multi-link bearer for continental and oceanic).

Space segment: Inmarsat I-6 GX (Ka-band) satellites providing European and Atlantic coverage; targeted L-band reserve for priority traffic.

Ground network: Integrated with EUROCONTROL Network Manager B2B services and national ANSP ATC systems via standardized ATN/IPS interfaces. Coverage spans continental Europe, NAT oceanic, and extensions.

Applications:

• CPDLC ATN B2 (supporting transition from ATN/OSI FANS 1/A).
• ADS-C (RSP 180 performance class).
• i4D RTA delivery: the key TBO enabler — satellite delivers the same CPDLC message to the FMS that VDL Mode 2 carries in VHF-coverage areas.
• AOC (Airline Operational Control) data services.

ATN/IPS alignment: Designed to the provisions of Annex 10 Vol III Amendment 93 (applicable 27 November 2025) for IPS mobility, multi-media access, security, and QoS. Iris is thus the first production AMS(R)S system built natively for ATN/IPS rather than retrofitted from ATN/OSI.

Certifications: Iris Service Evolution has been validated for use in European airspace. Aircraft avionics certification follows the EASA type approval process for avionics changes.

Domain matrix#

References#

• Annex 10 Vol III, Amendment 93 (applicable 27 November 2025) — ATN/IPS requirements for satellite and multi-media access; defines the regulatory baseline for Iris Gen 4.
• Doc 9925 (Manual on the AMS(R)S), Part III — Classic Aero history and system overview; Inmarsat as foundation of initial AMSS SARPs.
• Doc 9925, Part IV, §2.2.3 — SBB 30/30 NM oceanic separation capability; RCP240/RSP180 (authoritative source — not in local library for full text).
• ESA Iris programme — https://www.esa.int/Applications/Telecommunications_Integrated_Applications/Iris (authoritative source — not in local library).
• SESAR 3 JU Digital European Sky — https://www.sesarju.eu/projects/digital-european-sky — i4D validation over satellite (authoritative source — not in local library).
• EUROCONTROL satellite communications — https://www.eurocontrol.int/service/satellite-based-communication (authoritative source — not in local library).

How threads are used here#

The term "thread" is borrowed from the ASBU framework, where each thread is a functional subject area grouping related improvements. For SATCOM, six functional axes structure the material:

1. AMS(R)S SARPs compliance — the normative foundation
2. Safety service provision — priority, pre-emption, SATVOICE
3. Oceanic and remote operations — the primary use domain
4. Iris and continental ATM — the emerging domain
5. ATN/IPS integration — the technology evolution path
6. PBCS performance — RCP/RSP, RCP 240, RSP 180

These threads are not independent: the Iris thread draws on the SARPs thread, the ATN/IPS thread, and the PBCS thread simultaneously. The oceanic thread remains primary by fleet numbers and traffic volume.

Thread 1 — AMS(R)S SARPs compliance#

The regulatory foundation for all aeronautical SATCOM. Annex 10 Vol III Chapter 4 defines the requirements any conformant system must meet, regardless of technology:

• Section 4.2 — General: system conformance; technology neutrality; regional agreement basis for mandatory carriage.
• Section 4.3 — RF characteristics: frequency band protection in ITU-allocated AMS(R)S spectrum (1 545-1 555 MHz and 1 646.5-1 656.5 MHz for user links); emissions control.
• Section 4.4 — Operational and message priorities: priority and pre-emption rules protecting safety traffic.
• Section 4.5 — Dynamic performance: acquisition and tracking up to 800 knots ground speed and 0.6 g acceleration.
• Section 4.6 — Continuity, availability, and service performance: packet data delays; voice transfer delays.
• Section 4.7 — Interoperability: ICAO 24-bit address; ATN interface; connectivity notification (CN) function.

Systems operating under this thread: Classic Aero (compliance matrix in Doc 9925 Part III Appendix), SBB (compliance matrix in Doc 9925 Part IV), Iridium (compliance matrix in Doc 9925 Part II), Iris (ATN/IPS extension per Amdt 93).

The Aeronautical Communications Panel (ACP) of ICAO maintains and amends these SARPs. Recent evolution: Amendment 88-A (2013) added ATN/IPS provisions; Amendment 90 (2016) introduced the SATVOICE section (§2.5); Amendment 93 (2025) consolidated IPS requirements across multiple air-ground media.

Thread 2 — Safety service provision#

Safety service provision encompasses the end-to-end processes by which AMS(R)S delivers certified, prioritized communications for ATS functions.

Key elements:

• Priority and pre-emption: AMS(R)S must support the four priority levels (distress, flight safety, regularity, public) and must pre-empt lower-priority traffic when safety calls or CPDLC transactions need resources.
• SATVOICE certification: ground-based calling systems must be able to locate the aircraft regardless of GES/satellite (AN10 V3 §2.5.2). This is the operational backstop when CPDLC or VHF fails.
• Communications service providers (CSPs): ANSPs do not operate GES directly; they contract CSPs who have agreements with GES operators. Service level agreements (SLAs) with CSPs must satisfy the RCP/RSP allocations in Doc 9869.
• Post-implementation monitoring: Doc 9869 requires ANSPs to monitor CPDLC performance and report outages to agencies such as the North Atlantic Data Link Monitoring Agency (DLMA). The Doc 10063 (PBCS monitoring manual) provides methodology.

Thread 3 — Oceanic and remote operations#

The primary SATCOM use domain by traffic volume and regulatory maturity. CPDLC and ADS-C over Classic Aero or SBB underpin oceanic procedural separation globally.

Main applications:

• CPDLC (Controller-Pilot Data Link Communications): structured message exchange replacing HF voice for routine ATC instructions — level changes, track assignments, speed constraints, contact instructions. FANS 1/A protocol over ACARS; message set per PANS-ATM and Doc 9694.
• ADS-C (Automatic Dependent Surveillance - Contract): periodic and event-driven position reports including the Extended Projected Profile (EPP) with downstream trajectory intent. Supports longitudinal conformance monitoring and reduces radar surveillance dependency in oceanic airspace.
• SATVOICE: backup voice channel; used when CPDLC unavailable and HF quality insufficient.

Major oceanic regions using SATCOM:

• NAT (North Atlantic Track System): SATCOM primary for CPDLC/ADS-C; NAT Data Link Monitoring Agency oversees performance.
• Pacific (FUKUOKA, OAKLAND, AUCKLAND FIRs): SATCOM primary for long-haul trans-Pacific routes.
• Indian Ocean / EURASIA oceanic FIRs: mixed SATCOM and HF.
• Polar routes: Iridium required; Classic Aero and SBB insufficient above 75 degrees latitude.

Thread 4 — Iris and continental ATM#

The emerging domain, driven by the ASBU COMI-B2 requirement for satellite data link to extend ATN/IPS coverage to areas VHF does not reliably cover.

Operational need:

• Low-altitude flying (climb/descent below VHF/VDL coverage): aircraft lose VDL Mode 2 connectivity at low altitudes in remote continental areas; Iris fills this gap.
• Pre-departure TBO planning: i4D metering over Iris allows an aircraft to receive an RTA constraint during oceanic pre-departure or in remote continental sectors where VDL is unavailable.
• Network Manager integration: Iris ground network connects directly to EUROCONTROL Network Manager B2B services, enabling Iris-delivered CPDLC messages to be part of the same ATM automation chain as VDL.

i4D over Iris — operational concept:

The aircraft is equipped with SBB/Iris AES and an FMS capable of RTA compliance. The ANSP ATC system issues an RTA clearance at a metering fix (e.g., entry point to a congested sector or oceanic crossing). The clearance travels via the ATN/IPS network and, if VDL is unavailable, is routed over the Iris satellite link to the aircraft. The FMS computes the required speed schedule to arrive at the fix at exactly the specified time. The aircraft subsequently sends ADS-C conformance reports back over the same Iris link. This closed-loop cycle is the definition of initial 4D (i4D) and the entry point to TBO.

Thread 5 — ATN/IPS integration#

The technical evolution path that allows satellite links to participate in the next-generation ATM information environment.

Key elements:

• Multilink operation: Annex 10 Vol III §3.4.10 requires ATN/IPS to support multilink. An aircraft simultaneously maintains connections over VDL Mode 2 and satellite; if VDL drops out, the ATN/IPS layer routes traffic over satellite without interrupting the application (CPDLC session).
• IPS security: Amendment 93 adds security provisions for IPS links, addressing the integrity and authenticity of CPDLC and ADS-C messages carried over satellite.
• Naming and addressing: the ATN/IPS framework uses IP addressing above the subnetwork layer; the ICAO 24-bit aircraft address remains the identifier at the subnetwork layer (§4.7.1).
• Interoperability with ATN/OSI: the existing FANS 1/A fleet uses ATN/OSI; the Iris generation operates ATN/IPS. Annex 10 Vol III §3.3.2 requires implementation to be based on regional agreements specifying which standard applies. Both are supported Standards.

Thread 6 — PBCS performance (RCP/RSP)#

The performance thread links SATCOM system performance to the separation minima that ANSPs apply. Required Communication Performance (RCP) and Required Surveillance Performance (RSP) are the quantitative measures:

RCP 240: the communication transaction time must not exceed 240 seconds in 95th percentile; continuity 0.999; integrity 10^-5 per flight hour; availability 0.999 (safety) and 0.9999 (efficiency). Applicable to CPDLC-based separation.

RSP 180: the surveillance data delivery time must not exceed 180 seconds; continuity and availability values per Doc 9869 Table 2-2. Applicable to ADS-C-based surveillance.

Both specifications are satisfied by Classic Aero and SBB operating FANS 1/A over ACARS (Doc 9925 Part IV §2.2.3). Iris is designed to the same or better specifications.

The PBCS thread connects to operational separation in oceanic airspace:

• 30/30 NM longitudinal and lateral separation is predicated on RCP 240 CPDLC and RSP 180 ADS-C being available.
• If SATCOM performance degrades below the RCP 240 threshold, the ANSP must revert to a separation minimum not based on CPDLC performance.
• Post-implementation monitoring per Doc 10063 detects degradation and triggers corrective action.

References#

• Annex 10 Vol III, Chapter 4, §4.2–§4.7 — AMS(R)S SARPs; all six threads anchor here.
• Annex 10 Vol III, Chapter 2, §2.5 — SATVOICE; Thread 2 basis.
• Annex 10 Vol III, Chapter 3, §3.4.1 and §3.4.10 — ATN/IPS requirements including multilink; Thread 5.
• Annex 10 Vol III, Amendment 93 (2025) — IPS mobility, security, QoS; Thread 5.
• Doc 9869 (PBCS Manual), §2.2.1 (RCP 240) and §2.4.1 (RSP 180) — Thread 6 performance specifications (authoritative source — not in local library for full text).
• Doc 9925 (Manual on AMS(R)S), Part IV §2.2.3 — SBB RCP240/RSP180 compliance; Thread 6.
• ESA Iris programme — https://www.esa.int/Applications/Telecommunications_Integrated_Applications/Iris — Thread 4 source (authoritative source — not in local library).

This file works through two complete operational examples to make the SATCOM architecture concrete: (A) Iris continental i4D, and (B) oceanic ADS-C/CPDLC over Classic Aero. Both are drawn from the ASBU COMI thread at the intersection of the blocks and threads described in blocks.md and threads.md.

Module A — Iris continental i4D (COMI-B2 exemplar)#

Operational scenario#

An aircraft departs an airport in the EUR region on an oceanic route. During the climb phase the aircraft is below the reliable VDL Mode 2 coverage threshold. The ANSP needs to deliver an RTA constraint at the oceanic entry point (a metering fix) to sequence the aircraft into the North Atlantic track system.

How the transaction works#

Step 1 — ANSP initiates the RTA clearance. The ATC system computes the Required Time of Arrival at the oceanic entry fix. It generates a CPDLC message: AT [fix] CROSS AT [time]. The message enters the ATN/IPS ground network.

Step 2 — Routing decision. The ATN/IPS multilink layer checks which subnetwork is available to the aircraft. VDL Mode 2 is unavailable (aircraft below coverage altitude). The ground router selects the Iris satellite link as the active subnetwork.

Step 3 — Satellite transmission. The CPDLC message travels via the ATN/IPS network to the Iris ground station, up to the Inmarsat I-6 GX satellite over the Ka-band feeder link, and down to the aircraft AES on the Ka-band user link. The message is presented to the CMU.

Step 4 — Flight deck receipt and FMS load. The crew (or the CMU autoflight interface) loads the RTA into the FMS. The FMS computes the required speed schedule to arrive at the fix at exactly the specified time, adjusting thrust and flight level as necessary.

Step 5 — CPDLC WILCO response. The crew sends WILCO. The response travels back over Iris to the ANSP ATC system within the RCP 240 transaction time (240 seconds in the 95th percentile).

Step 6 — ADS-C conformance monitoring. Separately, the aircraft is under an ADS-C contract. Periodic position reports including the Extended Projected Profile (EPP) with downstream intent are sent via Iris. The ANSP monitors that the aircraft's projected time at the entry fix matches the agreed RTA. If the aircraft deviates beyond tolerance, an event report triggers a controller alert or a re-negotiation cycle.

Step 7 — Transition at VHF coverage entry. As the aircraft climbs above the VDL coverage threshold, the ATN/IPS multilink layer routes subsequent traffic over VDL Mode 2. The CPDLC session is maintained without interruption from the pilot's perspective.

What this demonstrates#

This module is the operational definition of initial 4D (i4D) delivered over satellite. It closes the loop between ground metering constraints and FMS trajectory execution without requiring the aircraft to be in VHF coverage. For operations planning, it means the ASBU COMI-B2 RTA-delivery benefit applies in any airspace where the aircraft has an Iris or SBB link, including oceanic and remote sectors.

Module B — Oceanic ADS-C/CPDLC over Classic Aero (COMI-B0 exemplar)#

Operational scenario#

A long-haul aircraft on a trans-Pacific route is in FUKUOKA Oceanic FIR at FL380, 1 200 NM from the nearest land. The crew is operating under a 30/30 NM lateral/longitudinal separation standard. VHF and Mode S are out of range. The only air-ground link is Classic Aero L-band SATCOM.

ADS-C contract#

At entry into oceanic airspace the ANSP established an ADS-C periodic contract with the aircraft: the aircraft sends position reports every 14 minutes and event reports on lateral deviation (0.5 NM threshold) and altitude change. Each report includes latitude, longitude, altitude, actual time over fix, and the EPP with the projected trajectory for the next segment.

The ANSP's oceanic automation system uses these reports to maintain a surveillance picture. If the EPP shows a projected deviation beyond the protected zone, a controller alert fires. The separation assurance tool compares the EPP with adjacent tracks to detect conflicts 15 to 30 minutes ahead.

CPDLC exchange#

The ANSP needs to issue a speed restriction to maintain longitudinal separation behind a preceding aircraft. The controller composes a CPDLC message: MAINTAIN MACH 0.84. The transaction:

• Ground ATC system to SITA/AVITECH ACARS ground network.
• ACARS network to Inmarsat Land Earth Station.
• LES to Inmarsat I-4 satellite (L-band uplink).
• Satellite to aircraft AES (L-band downlink; less than 12 seconds one-way delay at geostationary altitude).
• CMU to MCDU; crew sees message on DCDU screen.
• Crew reviews, sends WILCO.
• Return path reverses: aircraft to satellite to LES to ground.
• Total CPDLC transaction time well within RCP 240 (240 seconds).

SATVOICE backup#

If the ACARS data link fails (CPDLC degraded), the controller can place a SATVOICE call to the aircraft using the ICAO 24-bit address expressed as an 8-digit octal SATVOICE number. The Inmarsat GES locates the aircraft regardless of which satellite or LES it is logged on to, and rings the cockpit audio. This is the final safety backstop before HF voice.

Performance monitoring#

The North Atlantic Data Link Monitoring Agency (DLMA) collects ADS-C and CPDLC transaction performance data from all oceanic ANSPs in the NAT region. If the Inmarsat system has an outage, the DLMA tracks its duration and the proportion of traffic affected. Doc 10063 (monitoring manual) prescribes the methodology. If availability falls below 0.999 (the RCP 240 safety threshold), ANSPs revert to 50/50 NM separation.

References#

• Annex 10 Vol III, Chapter 4, §4.6.4.1.2.3 and §4.6.4.1.2.4 — Data transit delay standards for AMS(R)S packet data (from-aircraft and to-aircraft, highest priority).
• Annex 10 Vol III, Chapter 2, §2.5.2 — SATVOICE: system must locate aircraft regardless of GES/satellite logged on.
• Doc 9925 Part IV, §2.2.1-§2.2.3 — SBB ACARS gateway, FANS 1/A support, RCP240/RSP180 compliance for oceanic separation (authoritative source — not in local library for full text).
• Doc 9869 (PBCS Manual), §2.2.1 — RCP 240 specification: 240-second 95th-percentile transaction time; continuity, integrity, availability values.
• Doc 4444 (PANS-ATM), Chapter 13 — ADS-C procedures including periodic and event contract types, EPP reports.
• ESA Iris programme — https://www.esa.int/Applications/Telecommunications_Integrated_Applications/Iris — i4D over satellite basis (authoritative source — not in local library).
• SESAR 3 JU Digital European Sky — https://www.sesarju.eu/projects/digital-european-sky — i4D demonstrations over Iris (authoritative source — not in local library).

Overview#

SATCOM/Iris deployment depends on a web of interdependent enablers spanning spectrum governance, avionics certification, ground network infrastructure, ATM procedures, crew training, and regulatory coordination. Missing any single enabler creates a bottleneck that blocks the operational benefit even when the satellite hardware is in place.

Spectrum governance#

AMS(R)S operates in ITU-allocated spectrum: L-band (1 545-1 555 MHz and 1 646.5-1 656.5 MHz for protected AMS(R)S user links) and Ka-band (Iris GX payload). Annex 10 Vol III §4.3.1.1 Note flags that ITU Radio Regulations permit non-safety mobile satellite services (commercial broadband) to use the same spectrum without offering safety services. This creates the risk of AMS(R)S spectrum congestion.

Enabler actions:

• States must coordinate with national frequency authorities to ensure AMS(R)S spectrum is protected in national frequency plans (§4.2.4 Recommendation).
• ITU World Radiocommunication Conference decisions affecting L-band allocation must be monitored.
• Regional air navigation agreements specify implementation timescales and carriage requirements (§4.2.2 and §4.2.3 — at least two years' notice required before mandatory carriage).

Avionics certification#

Safety SATCOM requires certified avionics (AES):

• Classic Aero / GEO: RTCA DO-210D (Minimum Operational Performance Standards for Geosynchronous Orbit Aeronautical Mobile Satellite Services Avionics).
• Iridium: RTCA DO-262 (MOPS for avionics supporting next- generation satellite systems, including Iridium).
• SwiftBroadband: RTCA SBB MASPS (Minimum Aviation System Performance Specifications) and SBB MOPS (Minimum Operational Performance Standards).
• Iris: SBB avionics are the initial baseline; ATN/IPS stack updates to SBB avionics or new avionics per updated MOPS aligned with Annex 10 Vol III Amendment 93.

Installation requires ARINC 741 (antenna) and ARINC 781 (cockpit interface) compliance. Aircraft type certification or STC (Supplemental Type Certificate) needed for each aircraft variant.

Ground network and communications service providers#

ANSPs do not operate satellite infrastructure directly. The ground network enabler chain:

• Satellite operator (Inmarsat, Iridium): provides space and GES infrastructure; must hold ICAO-recognized AMS(R)S capability.
• Communications Network Provider (CNP): SITA, AVITECH, or equivalent; operates the ACARS ground network connecting GES to ANSPs.
• ANSP data link management: CPDLC and ADS-C sessions managed by the ANSP's ATC automation (e.g., Aireon, NATS EXCDS, NAV CANADA CAATS for oceanic; EUROCONTROL NM for Iris continental).
• Service Level Agreements: Doc 9869 requires that SLAs with CSPs specify the RCP/RSP allocation. Failure to meet SLA triggers corrective action per Doc 10063.

For Iris specifically: EUROCONTROL acts as the integrator of the Iris Service Evolution, connecting the Iris ground network to Network Manager B2B and to national ANSP ATC systems. EASA oversight applies to the European airspace operations.

ATM procedures#

SATCOM-specific procedures that must be in place before operational use:

• Oceanic pre-entry: aircraft operators must verify SATCOM operational status before entering ADS-C/CPDLC oceanic airspace. Flight plan equipment codes (M1, M3, J7) must correctly reflect installed and serviceable equipment.
• PBCS eligibility: operators must hold PBCS approval from their national authority, demonstrating aircraft compliance with RCP 240 / RSP 180 per Doc 9869 Chapter 4.
• Contingency procedures: if CPDLC is lost, crew must revert to HF voice or SATVOICE procedures; ANSP must revert to larger separation. PANS-ATM Chapter 13 specifies the CPDLC failure modes and controller actions.
• i4D RTA procedures: specific procedures for RTA receipt, FMS loading, and WILCO/UNABLE response per PANS-ATM Appendix 5 (CPDLC message set) and emerging i4D guidance from SESAR/Eurocontrol for Iris operations.

Training and human performance#

• Air traffic controllers (oceanic): trained in CPDLC and ADS-C procedures, PBCS monitoring, EPP interpretation, and SATVOICE use as a backup. Regional oceanic training organizations (e.g., ICAO APAC and EUR) provide courses.
• Flight crew: trained in FANS 1/A or ATN B2 CPDLC, ADS-C operation, RTA input via FMS, and SATVOICE priority calls. Operator training approved under AOC.
• i4D / Iris: specific training needed for RTA-based operations in continental airspace via satellite. SESAR- developed training materials for initial Iris roll-out.

Regulatory and institutional enablers#

• Regional air navigation agreement: mandatory carriage of AES requires a regional agreement under §4.2.2. In the NAT region this is the NAT Doc; in APAC the ICAO APAC regional supplement to PANS-ATM.
• PBCS approval: national aviation authority issues PBCS approval to aircraft operators. Approval is based on avionics certification, demonstrated RCP/RSP compliance, and operator procedures.
• Data link service provider designation: some States or regions formally designate approved data link service providers for use in their airspace.
• Monitoring agencies: North Atlantic Data Link Monitoring Agency (DLMA); similar function in Pacific (ISPACG CRA). Reporting requirements per Doc 9869 and Doc 10063.
• ESA / EASA coordination for Iris: ESA funds and develops the satellite segment; EASA certifies the avionics and airspace application; EUROCONTROL integrates with the network management layer. This three-party coordination is an institutional enabler unique to Iris in Europe.

References#

• Annex 10 Vol III, Chapter 4, §4.2.2 and §4.2.3 — Regional air navigation agreement basis for mandatory carriage; two-year notice requirement.
• Annex 10 Vol III, Chapter 4, §4.2.4 Recommendation — CAAs to coordinate with national frequency authorities and service providers for worldwide interoperability.
• Annex 10 Vol III, Chapter 4, §4.3.1.1 Note — ITU spectrum protection issue; States must plan AMS(R)S spectrum protection.
• Doc 9869 (PBCS Manual), Chapter 4 — PBCS approval process; SLA requirements with CSPs; operator eligibility.
• Doc 9925 Part IV, §2.3 and §2.4 — SBB requirements and ANSP implementation guidance; SLA metrics, CSP contracting, post-implementation monitoring.
• Doc 4444 (PANS-ATM), Chapter 13 — ADS-C and CPDLC procedures; failure modes and contingency; oceanic pre-entry requirements.
• ESA Iris programme — https://www.esa.int/Applications/Telecommunications_Integrated_Applications/Iris (authoritative source — not in local library).
• EUROCONTROL satellite communications — https://www.eurocontrol.int/service/satellite-based-communication (authoritative source — not in local library).

The performance framework#

SATCOM performance is framed at two levels:

1. Technical performance: defined by the AMS(R)S SARPs (Annex 10 Vol III Chapter 4) and the PBCS specifications in Doc 9869. These are system-level requirements the satellite network must meet continuously.

2. ATM performance: the improvement in Key Performance Area (KPA) outcomes that SATCOM-enabled datalink operations deliver, measurable via ASBU-aligned KPIs.

The chain: SATCOM system meets SARPs → enables RCP/RSP compliance → enables reduced separation and TBO precursor operations → delivers ATM performance improvements in the KPAs.

Technical performance requirements (from SARPs)#

The following table summarizes the SATCOM-specific performance specifications from Annex 10 Vol III and Doc 9869.

KPA contribution by SATCOM generation (ASBU blocks)#

The matrix below scores each KPA by the principal benefit the SATCOM generation delivers. Scale: 1 = some benefit, 2 = clear benefit, 3 = primary driver. Consistent with ASBU KPA scoring methodology from Doc 9883 and the GANP Portal.

Performance objectives and KPIs#

PO 1 — Maintain safety of oceanic and remote operations#

Applicable KPAs: Safety (primary driver at all generations).

SATCOM enables the separation minima that protect against collision in procedurally controlled airspace. Without an AMS(R)S-compliant data link meeting RCP 240 / RSP 180, the 30/30 NM oceanic separation standard cannot be applied and ANSPs must revert to 50/50 NM or greater.

KPIs:

• SATCOM system availability per RCP 240 threshold (0.999 safety / 0.9999 efficiency).
• CPDLC transaction completion rate.
• ADS-C delivery success rate.
• Number of separation events attributable to data link failure.

PO 2 — Increase oceanic and remote airspace capacity#

Applicable KPAs: Capacity (clear benefit at SB-S/Iridium; primary driver at Iris).

Reduced separation from 50/50 NM to 30/30 NM roughly doubles the number of aircraft that can simultaneously occupy a given oceanic route sector. With Iris extending this performance to continental/oceanic boundary areas, the capacity benefit extends earlier in the flight.

KPIs:

• Declared track capacity in NAT/Pacific RNAV routes.
• ATFM delay attributable to oceanic route congestion.
• Number of aircraft able to use optimum FL on oceanic tracks.

PO 3 — Improve flight efficiency and TBO enablement#

Applicable KPAs: Flight efficiency, Predictability (primary drivers at Iris generation).

i4D over Iris delivers the RTA mechanism that allows ATFM metering to convert holding delays into speed adjustments and trajectory compression. Each flight operating under i4D uses its FMS more accurately, reducing off-track deviations and vertical inefficiency.

KPIs:

• KEP / KEA (flight efficiency: planned vs. actual great-circle extension) on Iris-enabled routes.
• Variance in actual vs. planned crossing time at metering fixes for i4D-equipped aircraft.
• Fuel per flight-hour savings vs. unmetered baseline.
• ATFM minutes delay converted to RTA compliance (avoided airborne holding).

PO 4 — Enable ATN/IPS transition and interoperability#

Applicable KPAs: Interoperability (primary driver at Iris).

Iris is the satellite enabler for the ATN/IPS migration mandated by ASBU COMI-B2. Without a certified ATN/IPS satellite subnetwork, the multilink ATN/IPS architecture cannot extend to oceanic and remote airspace, fragmenting the information environment between continental and oceanic segments.

KPIs:

• Number of ANSP pairs exchanging ATN B2 CPDLC messages (including via satellite).
• Proportion of oceanic CPDLC traffic using ATN/IPS vs. ACARS/FANS 1/A protocols.
• Iris ground network availability and mean time to restore.

PO 5 — Reduce environmental impact of oceanic operations#

Applicable KPAs: Environment (moderate benefit at Iris).

SATCOM-enabled 30/30 NM separation allows aircraft to fly optimum flight levels on oceanic tracks. Without separation reduction, track-limited FL occupancy forces suboptimal levels, increasing fuel burn. Iris extends the benefit to continental low-altitude operations via i4D metering.

KPIs:

• Fuel burn per oceanic flight-hour vs. 50/50 NM baseline.
• Optimum flight level access rate (actual vs. filed FL).
• CO2 per oceanic flight attributed to ATFM oceanic delay (direct + indirect from level sub-optimality).

How performance is monitored#

• NAT region: North Atlantic Data Link Monitoring Agency (DLMA); publishes performance reports per Doc 9869 and Doc 10063. Inmarsat system outage data feeds DLMA analysis.
• Pacific region: ISPACG Central Reporting Agency (CRA).
• EUROCONTROL area (Iris): EUROCONTROL Network Manager performance monitoring; SESAR validation data; national ANSP CPDLC performance reports per PBCS approval conditions.
• Globally: ICAO ASBU implementation monitoring under the GANP review cycle; COMI thread performance reported to ICAO Air Navigation Commission.

References#

• Annex 10 Vol III, Chapter 4, §4.5, §4.6.4, §4.6.5 — AMS(R)S SARPs performance specifications (acquisition, delay, voice, ATN).
• Doc 9869 (PBCS Manual), Table 2-1 (RCP 240) and Table 2-2 (RSP 180) — Complete performance specification tables (authoritative source — not in local library for full text).
• Doc 9883 (Manual on Global Performance of the Air Navigation System) — KPA framework and KPI methodology (authoritative source — not in local library).
• Doc 9925 Part IV, §2.2.3 — SBB 30/30 NM oceanic separation capability narrative; RCP240/RSP180 compliance.
• Doc 10063 (Manual on Monitoring the Application of Performance-based Horizontal Separation Minima) — PBCS monitoring methodology for oceanic SATCOM operations (authoritative source — not in local library).

Historical evolution#

The timeline below tracks key events in aeronautical SATCOM from Inmarsat's aeronautical service launch through the Iris Service Evolution. The "Year" column is auto-classified by the web app's timeline visualizer.

Two timelines to distinguish#

When reading SATCOM dates, distinguish:

1. SARPs amendment timeline — when ICAO changed the normative framework (Annex 10 Vol III amendments, listed above).

2. Service availability timeline — when a given satellite service became commercially or operationally available (Classic Aero 1992, SBB 2009, Iris Service Evolution 2022).

3. Fleet equipage timeline — when a sufficient fraction of the aircraft fleet is equipped to make a service operationally useful. Fleet equipage lags service availability by years. For Iris, the initial fleet is primarily long-haul FANS 1/A equipped aircraft that already have SBB AES.

Amendment history reference#

Annex 10 Vol III amendments relevant to SATCOM (from the amendment table in AN10 V3 lines 310-428):

References#

• Annex 10 Vol III, Amendment history table (lines 310-428 in local mds) — Source for all ICAO amendment dates above.
• Doc 9925 (Manual on the AMS(R)S), First Edition 2010, Foreword and Part III §1.3 — History of Classic Aero and Inmarsat AMSS development.
• Doc 9925 Part III §1.3.1-§1.3.4 — Inmarsat founding, AMSS basis, Classic Aero history to JCAB integration.
• ESA Iris programme — https://www.esa.int/Applications/Telecommunications_Integrated_Applications/Iris — Iris Precursor and Service Evolution dates (authoritative source — not in local library).
• EUROCONTROL satellite communications — https://www.eurocontrol.int/service/satellite-based-communication — Iris Service Evolution operational status (authoritative source — not in local library).

ICAO Annex 10#

• Annex 10 Vol III (Aeronautical Telecommunications — Communication Systems), Chapter 4 — AMS(R)S SARPs; the primary normative instrument for all aeronautical satellite communications. Technology-neutral, service-and-performance-oriented.
• Annex 10 Vol III, Chapter 4, §4.2 — General requirements; AMS(R)S conformance; technology neutrality; regional agreement basis for mandatory carriage (§4.2.2, §4.2.3).
• Annex 10 Vol III, Chapter 4, §4.3 — RF characteristics; frequency band allocation and protection; interference to GNSS and other AMS(R)S equipment.
• Annex 10 Vol III, Chapter 4, §4.4 — Message priorities and pre-emption.
• Annex 10 Vol III, Chapter 4, §4.5 — Dynamic performance: acquisition and tracking up to 800 kt and 0.6 g.
• Annex 10 Vol III, Chapter 4, §4.6.1-§4.6.3 — Continuity and availability; service outage notification.
• Annex 10 Vol III, Chapter 4, §4.6.4 — Packet data service performance for ATN; delay parameters; connectivity notification.
• Annex 10 Vol III, Chapter 4, §4.6.4.1.1 — AMS(R)S packet data service shall be capable of operating as a constituent mobile subnetwork of the ATN.
• Annex 10 Vol III, Chapter 4, §4.6.5 — SATVOICE performance; total voice transfer delay not greater than 0.485 seconds; blockage probability.
• Annex 10 Vol III, Chapter 4, §4.7.1 and §4.7.2 — ICAO 24-bit aircraft address; GES ATN interface; connectivity notification (CN) function.
• Annex 10 Vol III, Chapter 2, §2.5 — SATVOICE system characteristics; mandatory location capability; four-level call priority (Table 2-1).
• Annex 10 Vol III, Chapter 3, §3.1.2 — ATN subnetwork independence; ISO 8473 PDUs may transit AMSS, Mode S, or VDL.
• Annex 10 Vol III, Chapter 3, §3.4.1 and §3.4.10 — ATN/IPS requirements; multilink support requirement.
• Annex 10 Vol III, Amendment 88-A (2013) — Introduction of ATN/IPS alongside ATN/OSI as supported Standards.
• Annex 10 Vol III, Amendment 90 (2016) — SATVOICE section added normatively.
• Annex 10 Vol III, Amendment 93 (applicable 27 November 2025) — ATN/IPS update: IPS mobility, multi-media, naming/addressing, security, QoS; applicable to satellite subnetworks including Iris.

ICAO PANS#

• Doc 4444 (PANS-ATM), Appendix 2 to Chapter 4 (Equipment codes) — Flight plan codes M1 (ATC SATVOICE, Inmarsat), M3 (ATC SATVOICE, Iridium), J7 (CPDLC FANS 1/A SATCOM), identifying SATCOM capability in flight plans.
• Doc 4444 (PANS-ATM), Chapter 13 — ADS-C procedures: periodic and event contracts; EPP reports; CPDLC failure modes and controller contingency procedures.
• Doc 4444 (PANS-ATM), Appendix 5 — CPDLC message set including RTA (Required Time of Arrival) constraint messages; the operational mechanism for i4D over CPDLC/SATCOM.

ICAO Documents#

• Doc 9925 (Manual on the AMS(R)S), First Edition 2010, Amdt 1 — The primary system-specific guidance document. Part I: general AMS(R)S overview. Part II: Iridium. Part III: Inmarsat/MTSAT Classic Aero. Part IV: Inmarsat SwiftBroadband compliance matrix.
• Doc 9869 (PBCS Manual) — RCP 240 and RSP 180 performance specifications; PBCS approval process; SLA requirements with CSPs; monitoring obligations for oceanic CPDLC and ADS-C operations.
• Doc 10063 (Manual on Monitoring the Application of Performance-based Horizontal Separation Minima) — SATCOM performance monitoring methodology; outage reporting; corrective action thresholds.
• Doc 10037 (Global Operational Data Link Manual, GOLD) — Previous RCP/RSP reference; now superseded by Doc 9869 for RCP/RSP specifications.
• Doc 10038 (Satellite Voice Operations Manual, SVOM) — SATVOICE operational guidance supplementing Annex 10 Vol III §2.5.

External authoritative sources#

• https://www.esa.int/Applications/Telecommunications_Integrated_Applications/Iris - ESA Iris programme; Iris Precursor and Service Evolution; i4D-over-satellite design (authoritative source — not in local library).
• https://www.inmarsat.com/en/solutions/aviation/air-traffic-management.html - Inmarsat aviation ATM products: Classic Aero, SwiftBroadband-Safety, Iris (authoritative source — not in local library).
• https://www.eurocontrol.int/service/satellite-based-communication - EUROCONTROL satellite-based communications; Iris integration with Network Manager (authoritative source — not in local library).
• https://www.sesarju.eu/projects/digital-european-sky - SESAR 3 JU Digital European Sky; i4D over Iris validation results (authoritative source — not in local library).
• https://store.icao.int/en/manual-on-the-aeronautical-mobile-satellite-route-service-doc-9925 - ICAO store: Doc 9925 (Manual on the AMS(R)S).
• https://store.icao.int/en/performance-based-communication-and-surveillance-pbcs-manual-doc-9869 - ICAO store: Doc 9869 (PBCS Manual).
• https://www.iridium.com/solutions/aviation/ - Iridium aviation safety communications; Iridium Certus AMS(R)S; polar coverage (authoritative source — not in local library).