ISO/IEC TR 22560:2017

ISO/IEC TR 22560
Edition 1.0 2017-10
TECHNICAL
REPORT
colour
inside
Information technology – Sensor network – Guidelines for design in the
aeronautics industry: active air-flow control

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ISO/IEC TR 22560
Edition 1.0 2017-10
TECHNICAL
REPORT
colour
inside
Information technology – Sensor network – Guidelines for design in the

aeronautics industry: active air-flow control

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 35.110; 49.060 ISBN 978-2-8322-4920-8

– 2 – ISO/IEC TR 22560:2017 © ISO/IEC 2017
CONTENTS
FOREWORD . 5
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Symbols (and abbreviated terms) . 9
5 Motivations for active air-flow control (AFC). 11
5.1 Skin drag . 11
5.2 Approaches for Aircraft Skin Drag Reduction . 12
6 Objectives . 13
6.1 General . 13
6.2 Fuel efficiency . 13
6.3 Hybrid dense wired-wireless sensor and actuator networks . 13
6.4 Standardized and service oriented wireless sensor architecture . 13
6.5 Re/auto/self- configuration . 13
6.6 Communication protocols and scalability . 13
6.7 Smart actuation profiles and policies . 14
6.8 High rate sensor measurement, synchronous operation and data
compression . 14
6.9 Troubleshooting and fail safe operation . 14
6.10 Enabling of wireless communication technologies in aeronautics industry . 14
6.11 Integration of wireless technologies with the internal aeronautical
communication systems . 14
6.12 Design of bidirectional wireless transmission protocols for relaying of
aeronautical bus communication traffic . 14
6.13 Matching of criticality levels of aeronautics industry . 14
6.14 Internetworking and protocol translation between wireless and wireline
aeronautical networks . 14
7 System description . 15
7.1 Overview of system operation . 15
7.2 Patch design . 16
7.3 Internal aeronautics network . 17
8 Micro-sensors and actuators . 18
8.1 Micro-sensors . 18
8.2 Actuators . 19
9 High level architecture for aeronautical WSANs . 21
9.1 Bubble concept . 21
9.2 Layered model . 21
9.3 Mapping to ISO/IEC 29182 Sensor Networks Reference Architecture (SNRA) . 23
10 Requirements for AFC design . 28
10.1 Sensing and actuation . 28
10.1.1 BL position detection and space-time resolution . 28
10.1.2 Efficient flow control actuation . 28
10.1.3 Patch intra and inter-communication . 29
10.1.4 Patch sensor data pre-processing, fusion, management and storage. . 29
10.1.5 Patch configuration, redundancy, and organization . 29
10.1.6 Sensors synchronicity . 30

10.1.7 Low power sensor-actuator (patch) consumption . 30
10.1.8 Patch data rate and traffic constraints . 30
10.1.9 Patch low complexity . 30
10.2 Sensor Network Communications . 31
10.2.1 Interference . 31
10.2.2 Wireless range and connectivity . 31
10.3 Aeronautical Network and On-Board Systems . 31
10.3.1 Full-duplex communications . 31
10.3.2 Compatibility with avionics internal network (ARINC 664) . 31
10.3.3 AFC interface . 32
10.3.4 GS interface . 32
11 Testing platform and prototype development . 32
12 Scalability . 33
Annex A (informative) System level simulation . 36
A.1 Architecture of the simulator and module description . 36
A.1.1 Fluid modelling domain . 36
A.1.2 Sensor and actuators configuration: patches . 36
A.1.3 Wing design, aircraft configuration, and propagation modelling . 36
A.1.4 Radio resource management . 37
A.2 Simulation metrics . 38
A.2.1 AFC metrics . 38
A.2.2 WSN metrics. 39
Annex B (informative) Turbulent flow modeling . 40
Bibliography . 44

Figure 1 – Drag breakdown in commercial aircraft . 11
Figure 2 – Boundary layer (BL) transition exemplified with a wing profile . 12
Figure 3 – Operation mode of the AFC system . 15
Figure 4 – Architecture of the AFC system . 16
Figure 5 – Array(s) of patches of sensors/actuators . 17
Figure 6 – Interaction with internal avionics networks . 18
Figure 7 – Flow control actuators classified by function [22] . 20
Figure 8 – Flow control actuators: a) SJA; b) Fliperon . 21
Figure 9 – HLA mapping AFC system. 22
Figure 10 – Mapping AFC system to the ISO domain reference architecture view . 24
Figure 11 – Mapping AFC system to the ISO layered reference architecture view . 25
Figure 12 – Mapping AFC system to the ISO sensor node reference architecture . 25
Figure 13 – Mapping AFC system to the ISO physical reference architecture . 26
Figure 14 – Prototype implementation AFC system . 33
Figure 15 – Data rate vs patch size. . 35
Figure A.1 – Simulator architecture . 38
Figure B.1 – Characteristics of turbulent flow with different Reynolds numbers
(reproduced from [31]) . 41

– 4 – ISO/IEC TR 22560:2017 © ISO/IEC 2017
Table 1 – Mapping of AFC system to the HLA layered model . 23
Table 2 – Mapping of AFC architecture to ISO architecture entity and functional models. 27
Table 3 – Mapping of AFC system to ISO architecture interface model . 28

INFORMATION TECHNOLOGY – SENSOR NETWORK –
GUIDELINES FOR DESIGN IN THE AERONAUTICS
INDUSTRY: ACTIVE AIR-FLOW CONTROL
FOREWORD
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ISO/IEC TR 22560, which is a Technical Report, has been prepared by subcommittee 41:
Internet of Things and related technologies, of ISO/IEC joint technical committee 1:
Information technology.
This Technical Report has been approved by vote of the member bodies, and the voting
results may be obtained from the address given on the second title page.
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– 6 – ISO/IEC TR 22560:2017 © ISO/IEC 2017
INTRODUCTION
The number of wireless connections is growing exponentially around the world. Wireless
communications are expanding to areas previously reluctant to use this type of technology. In
the field of aeronautics, wireless intra-avionics applications are just recently gaining
acceptance both in industrial and academic arenas. This late adoption is mainly because
wireless transmissions have been conventionally associated with reliability and interference
issues. Aeronautics applications on board aircraft are highly critical and therefore the inherent
randomness of wireless technologies created lots of skepticism, particularly for sensing,
monitoring and control of critical aeronautical subsystems. In addition, uncontrolled wireless
transmissions can potentially create interference to other aeronautical subsystems, thus
leading to malfunctions and unsafe operation. However, recent interference and reliability
studies with state-of-the-art wireless standards suggest safe operation and thus the feasibility
of a relatively new research area called wireless avionics intra-communications (WAICs). In
the last few years, wireless technology has started to be used on board for systems that
conventionally used only wire-line infrastructure (i.e., as replacement of cables). It is also
being used for applications which are now only possible thanks to the wireless component
(e.g., indoor localization, tracking and wireless power transfer). Examples of potential
applications of wireless avionics intra-communications are the following: structure health
monitoring, avionics bus communications, smoke sensors, interference monitoring, logistics,
identification, replacing of cables, fuel tank sensors, automatic route control based on
optimized fuel consumption and weather monitoring, automatic turbulence reduction or active
air-flow control, EMI (electromagnetic interference) monitoring, and flexible wiring redundancy
design.
The avionics industry will experience a wireless revolution in the years to come. The concept
of “fly-by-wireless” opens several issues in design, configuration, security, spectrum
management, and interference control. There are several advantages in the use of wireless
technologies for the aeronautics industry. They permit reduction of cables in aircraft design,
thus reducing weight. Reduction of weight also leads to increased payload capacity, longer
ranges, faster speeds, and mainly savings in fuel consumption. The reduction of cables can
also improve the flexibility of aircraft design (less manpower for designing complex cabling
infrastructure). Additionally, wireless technologies can reach places of aircraft that are difficult
to reach by cables, while being relatively immune to electrical cable malfunctions. Wireless
technology also provides improved configuration and troubleshooting with over-the-air
functionalities of modern radio standards.
This document presents the application of wireless sensor and actuator networks for the
dynamic tracking and compensation of turbulent flows across the surface of aircraft. Turbulent
flow formation and the associated skin drag effect are responsible for the inefficiency of
airplane design and thus act as major factors in increased fuel consumption. The area of
active air-flow control represents the convergence of several scientific fields such as: fluid
mechanics, sensor networks, control theory, computational fluid dynamics, and actuator
design. Due to the high speeds experienced by modern commercial aircraft, dense networks
of sensors and actuators are necessary to accurately track the formation of turbulent flows
and for counteracting their effects by convenient actuation policies. The use of wireless
technologies in this field aims to facilitate the management of the information generated by
the large number of sensors, and reduce the need for cables to interconnect all the nodes or
groups of nodes (patches) in the network. Additionally, the use of the wireless components
opens new issues in joint propagation and turbulence flow modelling. This document presents
the design principles of active air-flow control systems using dense wireless/wired sensor
networks compliant with the ISO sensor network reference architecture (SNRA). Standardized
interfaces will help developers create smart cloud avionics applications that will improve fleet
management, optimized route traffic, and computation of actuation profiles for different
moments of an aircraft mission. This also lies within the context of future technological
concepts such as Internet of things, Big Data, and cloud computing.

INFORMATION TECHNOLOGY – SENSOR NETWORK –
GUIDELINES FOR DESIGN IN THE AERONAUTICS
INDUSTRY: ACTIVE AIR-FLOW CONTROL

1 Scope
This document describes the concepts, issues, objectives, and requirements for the design of
an active air-flow control (AFC) system for commercial aircraft based on a dense deployment
of wired/wireless sensor and actuator networks. The objective of this AFC system is to track
gradients of pressure across the surface of the fuselage of aircraft. This collected information
will be used to activate a set of actuators that will attempt to reduce the skin drag effect
produced by the separation between laminar and turbulent flows. This will be translated into
increased lift-off forces, higher vehicle speeds, longer ranges, and reduced fuel consumption.
The document focuses on the architecture design, module definition, statement of objectives,
scalability analysis, system-level simulation, as well as networking and implementation issues
using standardized interfaces and service-oriented middleware architectures. This document
aims to serve as guideline on how to design wireless sensor and actuator networks compliant
with ISO/IEC 29182.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
ISO/IEC 29182-2:2013, Information technology – Sensor networks: Sensor Network
Reference Architecture (SNRA) – Part 2: Vocabulary and terminology
ISO/IEC 29182-3:2014, Information technology – Sensor networks: Sensor Network
Reference Architecture (SNRA) – Part 3: Reference architecture views
ISO/IEC 29182-4:2013, Information technology – Sensor networks: Sensor Network
Reference Architecture (SNRA) – Part 4: Entity models
ISO/IEC 29182-5:2013, Information technology – Sensor networks: Sensor Network
Reference Architecture (SNRA) – Part 5: Interface definitions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 29182-2:2013
and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org.obp

– 8 – ISO/IEC TR 22560:2017 © ISO/IEC 2017
3.1
active air-flow control
AFC
ability to manipulate a flow field to improve efficiency or performance adding energy to the
flow by an actuator and using a sensor or sensors to adjust, optimize, and turn on/off the
actuation policy
3.2
ARINC 664
A664
standard that defines the electrical and protocol specifications (IEEE 802.3 and ARINC 664,
Part 7) for the exchange of data between avionics subsystems [1]
3.3
boundary layer
BL
region in the immediate vicinity of a bounding surface in which the velocity of a flowing fluid
increases rapidly from zero and approaches the velocity of the main stream [2]
3.4
boundary layer separation
detachment of a boundary layer from the surface into a broader wake [3], [4]
3.5
bubble
higher level abstraction of a heterogeneous wireless sensor network with different underlying
technologies that enables semantic interoperability between them and with the external world
using standardized interfaces and flexible middleware application program interfaces
3.6
computational fluid dynamics
CFD
art of using a computer to predict how gases and liquids flow [5]
3.7
drag
force acting opposite to the relative motion of any object moving with respect to a surrounding
fluid [29]
3.8
fly-by-wireless
paradigm where avionics subsystems usually controlled or linked by means of cables will use
now a wireless connection
3.9
fuselage
aircraft's main body section that holds crew and passengers or cargo [6]
3.10
laminar flow
flow regime that typically occurs at the lower velocities where the particles of fluid move
entirely in straight lines even though the velocity with which the particles move along one line
is not necessarily the same as along another line [7]

Numbers in square brackets refer to the Bibliography.

3.11
patch
array of sensors and actuators wired together with a central or distributed control scheme
3.12
Reynolds number
number that characterizes the relative importance of inertial and viscous forces in a flow
Note 1 to entry: It is important in determining the state of the flow, whether it is laminar or turbulent [7].
3.13
shear force
force acting on a substance in a direction perpendicular to the extension of the substance,
acting in a direction to a planar cross section of a body [8]
3.14
skin friction drag
effect that arises from the friction of the fluid against the "skin" of the object that is moving
through it [30]
3.15
synthetic jet actuator
type of actuator whose main effect is produced by the interactions of a train of vortices that
are typically formed by alternating momentary ejection and suction of fluid across an orifice
such that the net mass flux is zero [8]
3.16
turbulence
type of flow where the paths of individual particles of fluid are no longer everywhere straight
(as in laminar flow) but are sinuous, intertwining and crossing one another in a disorderly
manner so that a thorough mixing of fluid takes place [2]
3.17
viscosity
resistance of a fluid to a change in shape, or to the movement of neighbouring portions
relative to one another [9]
3.18
wireless avionics intra-communications
type of wireless communications within an aircraft [10]
4 Symbols and abbreviated terms
4.1 Abbreviated terms
AFC Active air-Flow Control
A664 ARINC 664
AGP Accelerated Graphics Port
AOC Airline Operation Control
ARINC Aeronautical Radio INC.
BL Boundary Layer
CAD Computer Aided Design
CFD Computational Fluid Dynamics
GS Ground Systems
HLA High-Level Architecture
– 10 – ISO/IEC TR 22560:2017 © ISO/IEC 2017
L0 Level 0 of the aeronautical high-level architecture. Used to transport sensor reading
via wireless/wireline infrastructure.
L1 Level 1 of the aeronautical high-level architecture. Used to interconnect several L0
WSNs.
L2 Level 2 of the aeronautical high-level architecture. Used to provide external access
to the aeronautical WSN or bubble.
LNSE Linear Navier-Stokes Equation
LSLI Link-to-System Level Interface
MCDU Multifunction Control Display Unit
MEMS Micro-Electro-Mechanical Systems
SDBD Single Dielectric Barrier Discharge
SFC Specific Fuel Consumption
SJA Synthetic Jet Actuator
UDP User Datagram Protocol
VL Virtual Link
WAIC Wireless Avionics Intra Communications
ZNMF Zero Net Mass Flux
4.2 Symbols
d size of a patch
D drag force
∆ spacing between sensors (spatial sampling spacing)
s
f sampling rate
g gravitational constant
l characteristic linear dimension of a fluid
L lift force
L
lift-to-drag ratio
D
µ dynamic viscosity of the fluid
N number of actuators per patch
a
N number of sensors per patch
s
N number of patches per wireless sensor network gateway
p
p pressure
ρ density of the fluid
R range
R wireline nominal data rate
b
R wireless nominal data rate
c
r rate per sensor
s
Re Reynolds number
u flow velocity vector
V speed of the aircraft
ψ kinematic viscosity of the fluid
W initial weight of the aircraft
initial
W final weight of the aircraft
final
ξ data compression ratio inside a patch of sensors and actuators

5 Motivations for active air-flow control (AFC)
5.1 Skin drag
The environmental impact (CO footprint) of the ever-increasing number of flights needs to be
reduced. This can be achieved by means of new fuel sources, novel engine technologies and
structures, advanced concepts of aircraft morphing (smart materials), improved aerodynamics,
and improved air traffic management [34].
The reduction of fuel consumption is important for environmental protection purposes
(reduced emissions) as well as for cost reduction. The potential for a 50 % reduction in fuel
consumption within the next 15 years can be attained by using a combination of aerodynamic,
engine, and structural improvements [11], as expressed by the well-known Breguet range
equation:
 
V L W
initial
 
R= × × ln
(1)
 
g× SFC D W
final
 
where V is the velocity of the vehicle, L is the lift force, D is the drag force, SFC is the specific
fuel consumption, ln(·) is the natural logarithm function, g is the gravitational constant, W
initial
is the final weight of the aircraft. By inspecting the
is the initial weight of the aircraft and W
final
expression in Formula (1) it becomes evident that technologies that reduce aircraft drag and
the weight of an empty aircraft are crucial regardless of physical configuration. Aerodynamic
drag is known to be one of the main factors contributing to increased aircraft fuel consumption.
In [12], a study shows that for a long haul commercial aircraft (325 passengers) a combined
reduction of 10 % in both skin friction and induced drag (i.e., the components that roughly
contribute around 80 % to the total aerodynamic drag in such type of aircraft) may lead to a
15 % fuel consumption reduction. The drag breakdown of a commercial aircraft shows that
skin friction drag and lift-induced drag constitute the two main sources of drag, approximately
one half and one third, respectively, of the total drag for a typical long range aircraft in cruise
conditions [12][13] (see Figure 1).
IEC
Figure 1 – Drag breakdown in commercial aircraft
Skin friction drag is therefore the main component of the aerodynamic drag. Skin friction
arises from the friction of air against the skin of an aircraft in motion. The primary source of
skin friction drag during a flight is the boundary layer separation. The boundary layer (BL) is
the layer of air moving smoothly in the immediate vicinity of the aircraft (wing, fuselage, tail)

– 12 – ISO/IEC TR 22560:2017 © ISO/IEC 2017
where the flow velocity is lower than that of the free air stream. The proposal of the concept of
boundary layer by Prandtl in [28] represented a turning point in the understanding of fluids
flowing along the surface of solid objects and the conditions for turbulence formation
(boundary layer separation). Inside the BL, viscosity effects are relevant and thus viscous
forces dominate. As the flow develops along the surface, the smooth laminar flow is disturbed
by the phenomenon of turbulence, which largely increases drag force (Figure 2). In a turbulent
flow, viscous and shear forces attempt to counteract each other in a chaotic manner. In this
transition, flow separation occurs due to a reversed flow at the surface, increasing drag
(particularly pressure drag).
IEC
Figure 2 – Boundary layer (BL) transition exemplified with a wing profile
Both BL transition and separation can be controlled in order to reduce drag. Skin friction can
be reduced by keeping the flow in the laminar regime, thus reducing the extent of turbulent
flow over the air-foil. Preventing flow separation will improve lifting and reduce pressure drag.
5.2 Approaches for aircraft skin drag reduction
The position of the BL transition is affected by local flow disturbances that can be caused by
several factors, such as: surface roughness, vibration, heat, air-stream turbulence, etc. There
are various approaches to reduce turbulent skin friction, involving different mechanisms, such
as:
• reducing turbulent friction drag through riblets;
• deformable active skin using smart materials (compliant walls), or by
• locally delaying the boundary layer transition using vortex generators, such as dimples,
holes or synthetic jet actuators (SJAs).
In the case of SJAs, suction from the surface of the wing can be used to remove the low-
energy air directly from the BL. Additional momentum (high-energy air) can be achieved in
SJA solutions by generating stream wise vortices near the edge of the BL that re-energize the
BL flow.
A recent research work in [14] uses SJAs located at key positions on the wing to continuously
energize the BL and delay its separation. However, this approach does not use sensors to
detect and trace the flow separation point, and is therefore static and proactive in nature. The
efficiency of passive flow control is compromised and energy resources are wasted when

there is no boundary layer separation or when it lies outside the optimal control field. For this
reason, active air-flow control (AFC) approaches have been proposed that allow for a dynamic
tracking of the BL via a network of sensors. By definition, AFC uses extra energy to control
and manipulate flow conditions.
AFC is a multidisciplinary research field that integrates knowledge and exploits interactions
on fluid mechanics, instability analysis, sensor and actuator design, and control systems, with
the goal of improving aerodynamic performance. AFC has already been targeted by a number
of research efforts (e.g., [11]–[14]). These works studied different aspects of AFC, including:
energy consumption, efficiency, feedback control, delay, adjoint optimization, linear control,
instability analysis, etc.
6 Objectives
6.1 General
Clause 6 provides a detailed explanation of the objectives of the AFC system based on dense
wireless sensor and actuator networks.
6.2 Fuel efficiency
The proposed AFC system will increase fuel efficiency by reducing aircraft skin drag. It is
expected that up to 25 % reduction of fuel consumption will be achieved in the next five years
in the aeronautics industry. Fuel efficiency can be deduced from improvements of lift-to-drag
ratio or simply lift-off forces.
6.3 Hybrid dense wired-wireless sensor and actuator networks
There is a need to design a dense network of patches of sensors/actuators wired together on
the surface of fuselage of aircraft. Each patch represents a node in the architecture,
communicating wirelessly with gateways located in different positions of the aircraft. This will
be a hybrid network with wired and wireless features. Different types of sensor data with
different statistics will be managed at different levels of the architecture, depending on latency
and capacity restrictions.
6.4 Standardized and service oriented wireless sensor architecture
A standardized and service oriented architecture will be constructed for the AFC system,
where the internal user lies in the command control unit of the aircraft and the external user is
ground control operator. Standardized interfaces and architecture will help external users to
create flexible smart avionics applications to improve fleet management and air traffic control.
In this same line, service oriented architecture will enable the use of flexible middleware
applications to develop high-level cloud avionics applications.
6.5 Re-/auto-/self-configuration
Develop advanced sensor and actuator nodes with re-/auto-/self-configuration features. The
network of patches will be thus able to adapt to changing conditions based in different flight
profiles, turbulence conditions, air traffic patterns, and both to internal and outer patch failures
or incorrect measurements.
6.6 Communication protocols and scalability
Employ a wireless sensor and communication network for suppression of the turbulent flow.
The dense wireless sensor network should be able to be used for different types of aircraft,
and to increase the number of elements to allow for a full fuselage coverage in future
deployments. A full scalability study should be conducted for the capacity, delay and other
requirements of the intra-patch and inter-patch communication framework. This involves

– 14 – ISO/IEC TR 22560:2017 © ISO/IEC 2017
capacity calculation considering turbulence stability models, compression algorithms, intra-
patch communication protocols, etc.
6.7 Smart actuation profiles and policies
Enable the use of actuation profiles optimized and managed by ground control in response to
the collected sensor measurements. This implies the use of communication services to obtain
data gathered by a fleet of airplanes and based on statistical analysis using cloud computing,
to optimize actuation policies for different instants of a mission in different commercial routes.
6.8 High rate sensor measurement, synchronous operation and data compression
Obtain sensor measurements at high frequency and in synchronicity with each other, to be
able to correlate sensor readings, especially from adjacent or closely located patches of
sensors.
6.9 Troubleshooting and fail safe operation
The WSN also needs to deal with failures of sensors, and this can be approached by
employing reliable data transmission, data delivery mechanisms, and also by employing data
processing strategies that can deal with sensor failures or inaccuracies. Data redundancy can
be used to estimate the position of the BL and recover potential errors across patches and
across sensors. A malfunctioning sensor can detect erroneously the position of the BL, but
using context and the feedback of adjacent sensors or patches, the measurement can be
corrected or eliminated from the data aggregation process.
6.10 Enabling of wireless communication technologies in aeronautics industry
It is important to potentiate the use of wireless communication systems on board aircraft to
enable the deployment, as soon as possible, of technologies like structural monitoring and
AFC. This will reduce the time to market for commercial fly-by-wireless smart applications.
6.11 Integration of wireless technologies with the internal aeronautical communication
systems
Wireless networks and sensor systems need to communicate and interact with the main data
buses of the aircraft. This creates the challenge of protocol translation, gateway definition, etc.
6.12 Design of bidirectional wireless transmission protocols for relaying of
aeronautical bus communication traffic
Design bidirectional bridges between different types of technologies. This is still the case if
wireless technologies are used as the main data bus of the aircraft. Bidirectional transmission
is necessary in modern aircraft communication systems. Therefore, the wireless transmission
should support an abstraction of bidirectional traffic relaying, even if the underlying wireless
technology is one-directional. This can be achieved by convenient scheduling design.
6.13 Matching of criticality levels of aeronautics industry
Ensure that different wireless networks, with different criticalities and different underlying
technologies, will operate together without possibility of unreliable data delivery, reduced
interference, and with adequate quality of service support.
6.14 Internetworking and protocol translation between wireless and wireline
aeronautical networks
Bridge protocols and interfaces should be specified which respect the constraints of the
different networks in the wireless and in the airline world. More specifically, the wireless
network should support the operation of the internal aeronautics communication bus. In the

case of ARINC 664 (A664), gateway definition should map the virtual links (VLs) of the A664
standard to the wireless sensor network.
7 System description
7.1 Overview of system operation
The main goal of the AFC system is to employ a dense wireless sensor-actuator and
communication network for suppression of the turbulent flow and delaying the BL transition.
The sensor network will detect the low-pressure region on the upper wing surface. The
position of BL transition zone will be defined, selecting the appropriate actuators to be
activated. At the same time, and based on the sensor values, the set of conditions for
operation of the actuators (e.g., frequency, amplitude) will be calculated based on existing
data (pre-set data). The selected actuators are activated to manage the turbulent flow on the
wing surface. The data is stored. A new sensor reading is collected and the cycle is repeated.
The stored data can be analysed to assess system operation during, for example, different
flight profiles or moments (e.g., take-off, landing, and cruise) (see Figure 3).
IEC
Figure 3 – Operation mode of the AFC system
Ground systems can interact with the sensor-actuator and communication network to get the
data recorded during the flight and process thi
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