ARINC 792-2 PDF

Purpose to this Characteristic

This standard sets forth the desired characteristics of a second-generation aviation Ku-band and Ka-band satellite communication (satcom) system intended for installation in all types of aircraft. The system described in this document represents the next step from the systems defined by ARINC Characteristic 791, Part 1, including:

• Flat-panel phased-array, antenna

o Scalable to very large aperture (42″)

o Modular support for one or more apertures

o Integrated beam steering and Radio Frequency (RF) electronics

o Fault-tolerant High-Power Amplifier (HPA)

• Multi-beam receiver

• Expandability to multiple modem usage or switching

• Support for emerging Non-Geostationary Orbit (NGSO) satellite networks

• Provisions for multiple apertures of varying size

o Six fitting positions

• Three variable positions for the forward set of fitting positions

• Three variable positions for the rear set of fitting positions

o Fixed connector penetration zone

• Fewer/simpler components and wiring

o Removal of Ku/Ka band Radio Frequency Unit (KRFU) and associated interwiring

o Autonomous position, attitude, and heading reference

o Relocation of motor drive electronics (if used) and removal of interwiring o Virtual APM

o Fixed, low loss, Intermediate Frequency (IF) coax cabling

• Single, standard provisions with no optional wiring

• Accommodation of gate-to-gate operations

This document provides guidance on the physical interfaces, and the form and fit of small form factor Ku/Ka-band satcom system. The reader of this document is advised that ARINC Characteristic 791, Part 2, provides a common functional definition for both ARINC 791, Part 1 and ARINC 792 satcom systems.

The desired operational capability of the satcom equipment is to provide a broadband Internet link that can be used for data, video, and voice communications. Service is primarily for passenger communications and/or entertainment but is also available for aircraft information systems and airplane health monitoring systems.

At the time of this writing, Ku/Ka-band satcom frequencies are licensed for aviation non-safety functions only. The International Telecommunication Union (ITU) identifies specific radio frequency spectrum that is assigned for Aeronautical Mobile Satellite Route Service (AMS(R)S). Ku-band and Ka-band frequencies are not authorized or licensed for AMS(R)S. However, many services and applications have no time-criticality, no safety impact, and are therefore good candidates for Ku-band and Ka-band satcom systems. Refer to ARINC Characteristic 791, Part 2.

The key goal of this document is to promote interchangeability at a number of levels, as shown below, with the aim of minimizing airline life cycle costs:

• Aircraft Manufacturer Interchangeability: The same equipment can be fitted to aircraft built by different aircraft manufacturers.

• Aircraft Type Interchangeability: The same equipment can be fitted to a large number of different aircraft types.

• Equipment Manufacturer Interchangeability: Equipment from different manufacturers can be fitted to standardized aircraft provisions.

• Frequency Band Interchangeability: The same aircraft provisions can be used for either Ku-band or Ka-band equipment.

• Satellite System Interchangeability: The same Ku-band antenna subsystem could be used for different Ku-band satellite networks. Likewise, the same Ka-band antenna subsystem could be used for different Ka satellite networks. Therefore, in principle, an airline could change their satellite service provider (provided the frequency band is not changed and polarization is compatible) and could reuse their antenna subsystem, although they may need a new Modem and Manager (MODMAN), or the use of an Auxiliary Modem Unit (AMU) to switch between satellite networks.

Note: Outside Antenna Equipment (OAE) and the Ku/Ka-band Power Supply Unit (KPSU) (collectively known as the antenna subsystem), the MODMAN and the AMU, are described in Sections 3.0 to 5.0 and also Section 11.0.

• Antenna Subsystem and MODMAN Interchangeability: A consequence of satellite system Interchangeability is that the antenna subsystem can be sourced from one supplier and the MODMAN can be sourced from a different supplier.

• AMU (Optional) and MODMAN Interchangeability: The AMU and the MODMAN may also be provided by different suppliers. It will be the responsibility of the system integrator to ensure the functionality of AMU and MODMAN combinations.

• MODMAN and Airplane Personality Module (APM) Interchangeability: The MODMAN and the APM (when installed) are defined to be a functional doublet. This means that the interwiring between these units and their installation details are defined in this document. However, due to unique electrical signaling, protocol implementations and memory size/architecture/content, the supply and acquisition of these units are manufacturer-specific. Functional doublets are different from matched pairs in that each unit of the functional doublet may fail and be changed independently, whereas in matched pairs, both units must be changed regardless of which unit has failed.

• Each LRU must be designed to be autonomous for installation purposes. The airlines will not accept “matched pairs” of units or similar unbreakable bonds that necessitate changing more than the LRU whose failure actually causes a subsystem malfunction.