Avionics Full DupleX Switched Ethernet AFDX is a standard that defines the electrical and protocol specifications (IEEE 802.3 and ARINC 664, Part 7) for the exchange of data between Avionics Subsystems. One thousand times faster than its predecessor, ARINC 429, it builds upon the original AFDX concepts introduced by Airbus.
Initiated by Airbus in the evolution of its A380 Aircraft, they coined the term, AFDX, for Avionics Full-DupleX, switched Ethernet. AFDX brings a number of improvements such as higher-speed data transfer and with regard to the host airframe significantly less wiring, thereby reducing wire runs and the attendant weight.
Avionics Subsystem: The traditional Avionics Subsystems on board an aircraft, such as the flight control computer, global positioning system, tire pressure monitoring system, etc. An Avionics Computer System provides a computational environment for the Avionics Subsystems. Each Avionics Computer System contains an embedded End System that connects the Avionics Subsystems to an AFDX Interconnect.
AFDX End System : Provides an “interface” between the Avionics Subsystems and the AFDX Interconnect. Each Avionics Subsystem the End System interface to guarantee a secure and reliable data interchange with other Avionics Subsystems. This interface exports an application program interface (API) to the various Avionics Subsystems, enabling them to communicate with each other through a simple message interface.
AFDX Interconnect: A full-duplex, switched Ethernet interconnect. It generally consists of a network of switches that forward Ethernet frames to their appropriate destinations. This switched Ethernet technology is a departure from the traditional ARINC 429 unidirectional, point-to-point technology and the MIL-STD-1553 bus technology.
AFDX bus: Avionics Full-Duplex switched ethernet
"The development of the Airbus A380 increased the need to
move toward the scale of communication mechanisms
between systems. This resulted in the introduction of the
Avionics Full-Duplex switched Ethernet
The AFDX is a network protocol at the data link
level (layer 2 “data link” of the Open Systems Interconnection
[OSI] model), based on the reliable and redundant Ethernet
protocol which enables the generic transmission of data
between emitter and receiver systems. AFDX systems are
therefore connected by a standardized Ethernet interface.
Data are contained in the Internet Protocol (IP) packets,
which are transmitted into the Ethernet frames. AFDX
switches ensure the direction of the frames within the AFDX
network.
However, the size of the topology of an AFDX network is
limited by technology. The current closed network of the
A380 contains a hundred or so terminal nodes which
represent large amounts of work in terms of administration
and certification. In addition, specific research is required to
optimize the performance of this avionic network. Opening
up this network to external data increases the number
of potential nodes in the network. At a higher protocol
level than that of the AFDX, the IP protocol (level 3
“network” of the OSI model) offers the opportunity to
increase the size of virtual networks by maintaining
acceptable-sized physical networks at the lower layers. The
IP protocol is linked to routing functionalities: while
“physical routing” (the switching of frames) is realized at
level 2 by AFDX switches, “virtual” routing (packet routing)
is possible at level 3 using a network component known as
the “IP router”. ."
