1. Modular, Cost-Effective, Extensible Avionics Architecture for Secure, Mobile Communications over Aeronautical Data Links
2006 IEEE Aerospace Conference
Big Sky, Montana
Will Ivancic
NASA Glenn Research Center

2. NASA’s Request for Comments on the Global Air Space System Requirements

3. Current View of the Global Airspace System
Current Global and National Airspace System
Stove-piped communication systems
Disjoint set of networks
Currently not globally network centric
Evolved over time with limited concern for network security
Security by obscurity
Closed systems
Insufficient bandwidth to support security measures
Safe and Secure
Air Traffic Control methods have evolved in reaction to changes in technology, capacity and use
Current methods are reaching limit of scalability
FAA - Bringing Safety to America’s Skies
Mission is to provide the safest, most efficient aerospace system in the world.
Responsible National Airspace System, not funded to address global issues.
Movement toward Network Centric Operations
Cross network security
Authentication, Authorization, Accounting and Encryption
Required changes in Policy!

4. Global Airspace System Requirements
Must be value added
Cannot add cost without a return on investment that meets or exceeds those costs.
Must be capable of seamless global operation.
Must be capable of operating independently of available communications link. Must support critical Air Traffic Management (ATM) functions over low-bandwidth links with required performance.
Must use same security mechanisms for Air Mobile and Ground Infrastructure (surface, terminal, en router, oceanic and space)
Critical ATM messages must be authenticated.
Must be capable of encryption when deemed necessary
Security mechanisms must be usable globally
Must not violate International Traffic in Arms Regulations
Must operate across networks owned and operated by various entities
Must be able to share network infrastructure
Must make maximum use of standard commercial technologies (i.e. core networking hardware and protocols)
Must enable sharing of information with proper security, authentication, and authorization
Situational Awareness
Passenger Lists
Aircraft Maintenance
Same network must accommodate both commercial, military and general aviation.

5. Design Concepts Must be IPv6 based.
Must be capable of a prioritized mixing of traffic over a single RF link (e.g. ATM, maintenance, onboard security, weather and entertainment).
Must utilize IPsec-based security with Security Associations (SAs) bound to permanent host identities (e.g. certificates) and not ephemeral host locators (e.g. IP addresses).
Must be capable of accommodating mobile networks.
Must be capable of multicasting
Must be scalable to tens of thousands of aircraft

6. Consensus on Six Major Points
It is critical that any new technologies being deployed provide a positive return on investment (ROI).
Network Centric Operations (NCO) will be a major technology in future airspace systems and the next generation Internet Protocol, IPv6 will be the protocol of choice.
Links should be shared, and the system should be provider-independent. This makes QoS a requirement.
A common global security structure must be developed and IPsec is probably the best choice. Some work still needs to be done regarding IPsec multicast, envisioning a certificate-based security architecture, and figuring out how exactly to do QoS with respect to wireless links and encryption.
The system must be able to share network infrastructure.
The system must be extensible to meet future needs.

7. Aircraft Communications Addressing and Reporting System (ACARS) and the Aeronautical Telecommunication Network (ATN)

8. Current Avionics Architecture
ACARS is based upon an all-in-one communications management unit.
Origin can be traced back to global teleprinter network, telex, established in the 1920s!
Point-to-point telex network where all messages come to a central processing location
Today ACARS is widely deployed in commercial airlines.
ATN network is an attempt to modernize ACARS, using most of the existing radio technologies with limited modifications.
Deployed in a closed, aeronautics-only network
Limited flexibility
Cannot adapt easily to new technologies, new communication protocols, and new communication links
Security currently is extremely limited at best; however, specifications have been updated in an attempt to rectify this
Limited bandwidth makes security difficult

9. Typical ACARS Onboard Network
ARINC 741
SATCOM AERO-1 System
GateLink
ARINC 761
SATCOM AERO-H/H+ System
Ethernet
(Optional)
Communication Management Unit (CMU)
File Server Subsystem
ARINC 716
ARINC 750
VHF Voice/DATA System
Terminal
HF Voice/DATA System
Printer
ARINC 719
ARINC 753
ARINC 740/744

10. Future Air Navigation System (FANS)
In 1983, FANS originated as study of the current air traffic infrastructure and recommend changes to support the anticipated growth in air traffic over the next 25 years
The FANS committee identified these needs:
Replacement of the current analog radios with digital air/ground communications;
Use of satellite and HF communication systems to provide communication where deployment of line-of-sight systems is not practical such as in the oceanic domain;
Global Interoperability;
Network-enabled systems to support automation in the airplanes and on the ground;
Transition to a Global Positioning System (GPS)-based navigation and landing systems; and,
Installation of flight service automation to enable pilots to plan and file flight plans without reliance on flight service specialists.
Widely Deployed over ACARS as FANS-1/A
It is now 2005 – 22 years later, and only an extremely small portion of FANS has been deployed using ATN

11. ATN and Mobility Uses the Inter-Domain Routing Protocol (IDRP)
Using a routing protocol to handle mobility effectively requires one to own the entire infrastructure because one generally is not permitted to inject routes into another’s infrastructure.
If the radio access is not secure and ATN secure routing is not implemented, the system is extremely vulnerable
A distributed IDRP directory using Boundary Intermediate Systems (BISs) is implemented along with a two level directory approach
Uses an ATN Island concept consisting of backbone BISs and a home BISs concept
This is done to limit the convergence time or route updates.
If the routing structure were to become to large, convergence times would become unacceptable.

12. ATN Island Routing Domain Confederation
Mobile RD
Mobile RD
Another
ATN Island
ATN Backbone RDC
ATN TRD
ATN TRD
Mobile RD
ATN TRD
ATN ERD
ATN ERD
ATN Island RDC
ERD – End Routing Domain
RD – Routing Domain
RDC – Routing Domain Confederation
TRD – Transit Routing Domain

13. Typical ATN Onboard Network
Similar to CMU in ACARS Network

14. Mobile-IP Based Architecture

15. Features of Mobile-IP Based Mobile Networking
Commercial-Off-The-Shelf technology
IETF NEtwork MObility (nemo)
Base functionality is standardized
Currently working on route optimization
Rapid Convergence Time
Link independent (Multihoming)
Does not inject routes into the infrastructure
Allows for use of shared infrastructure.
One does not have to own the infrastructure
Allows for insertion of new link technologies as they mature.
Enables competition which should reduce cost
Policy-based Routing (Currently in development)
IETF Mobile Nodes and Multiple Interfaces in IPv6 (monami6)

16. Cryptography and Firewall
SATCOM AERO-1
Traditional Avionics
SATCOM AERO-HH
Communication Management Unit (CMU)
Cryptography and Firewall
VHF Voice/DATA
Mobile Router
HF Voice/DATA
Display
INMARSAT Swift 64
Connexion by Boeing
Passenger Services
WiFi Max
GateLink
IP-Based Transitional Architecture
Cellular
Future Links

17. Air Traffic Management LAN
SATCOM AERO-1
Communication and Display
SATCOM AERO-HH
Air Traffic Management LAN
Cryptography and Firewall
VHF Voice/DATA
Mobile Router
HF Voice/DATA
Operations LAN (Avionics)
Cryptography and Firewall
INMARSAT Swift 64
Connexion by Boeing
Sensor Controller (Optional Display)
WiFi Max
GateLink
Passenger Services
Cellular
Future Links
IP-Based Architecture with ATC and AOC Separate

18. IP-Based Architecture with ATC and AOC Combined
Air Traffic Management LAN
Radio Link 1
Mobile Router
Radio Link 2
Operations LAN (Avionics)
Cryptography and Firewall
Radio Link 3
Radio Link 4
Communications Sensor Controller and Display
Radio Link N
Passenger Services
IP-Based Architecture with ATC and AOC Combined

19. Policy-Based Routing, All Links Active
P-DATA
High speed link
P-DATA
P-DATA
P-DATA
P-DATA
AOC
HomeAgent
int1
P-DATA
Low latency link
ATC
AOC
AOC
AOC
P-DATA
int2
ATC
Reliable link
int3
ATC
ATC
ATC
AOC
Routing Policy
Routing Policy

20. Policy-Based Routing, Critical Link Active
P-DATA
High speed link
P-DATA
AOC
HomeAgent
int1
ATC
Low latency link
AOC
P-DATA
int2
ATC
Reliable link
int3
ATC
ATC
ATC
Routing Policy
Routing Policy

21. Policy-Based Routing, Passengers Link Active
P-DATA
High speed link
P-DATA
P-DATA
P-DATA
AOC
ATC
AOC
HomeAgent
int1
P-DATA
ATC
Low latency link
P-DATA
int2
AOC
Reliable link
int3
ATC
Routing Policy
Routing Policy

22. Achieving Positive Return on Investment

23. Internet Protocol Value Added Features
Lower Telecommunication Costs of IP-based networks as compared to dedicated point-to-point links
Competition among information providers
Economies of scale
Lower development costs for new applications and maintenance due to standardization of interfaces

24. Link Independence
Most important considerations for this is not technical, but related to cost, safety, and politics
Facilitates globalization and supports positive ROI
Requires change in policy
Change in use of spectrum
World Radio Conference to allow use of other frequencies for air traffic control messages
Air Traffic Controller is now networked.
These are some very different modes of  operation from what the aeronautics community is comfortable with.

25. Airplanes and Automobiles
Commercial airlines make up only 4% of the active civil aircraft
– approximately 15,000 out of a total of 215,000 aircraft
“Airbus forecasts that of this total, 16,600 new passenger aircraft of more than 100 seats will be needed in the coming 20-year period
Today, 700 million cars are globally deployed for a human population of 6 billion.
Toyota expects to produce 9.2 million vehicles in 2006.
General Motors produce approximately 9.1 million vehicles in 2005

26. Applications for Mobile Platforms
Car-to-car communication (plane-to-plane)
Driver assistance information
ITS taxi service where the taxi company runs a system to distribute the best taxi based on the locations, idle/operation information. (Air Operations)
Probe servers collects and distributes information gathered by various probes
Car inspection information and maintenance log Preventative maintenance (Air Operations)
Probe data analysis and synthesis where time/location data among various probe data can be integrated to create traffic information. (Air Traffic Management)
Vending machine networks where vending machines can become wireless LAN access points, to offer broadband wireless communication infrastructure. (Surface Area)
Large volume content distribution service (Electronic Flight Bag)
Encrypted data contents can be downloaded onto car-equipped devices and decryption key can be sent later to enable a new type of distribution, which lowers communication cost and makes download operation transparent.
Next-generation road service where computer-assisted road service automates the process of locating and failure of a broken-down car and towing it to a desired destination. (Air Operations)

27. Backup Slides

28. Car-to-Car Communications
Mission and Objectives
Create and establish an open European industry standard for Car2Car communication systems based on wireless LAN components
Guarantee European-wide inter-vehicle operability
Enable the development of active safety applications by specifying, prototyping and demonstrating the Car2Car system
Promote the allocation of a royalty free European wide exclusive frequency band for Car2Car applications
Push the harmonization of Car2Car Communication standards worldwide
Develop realistic deployment strategies and business models to speed-up the market penetration
Technical Approach
Use of IPv6
Utilize wireless LAN technology
Ad hoc routing capable of handling rapid changes in topology
Source: Car2Car Communication Consortium

29. Security Mechanisms
Encryption mechanisms should be limited to those that are free of ITAR restrictions
Other counties also have regulations restricting the exportation of cryptography technology
These regulations may limit the ability to realize cost and schedule advantages that could be gained by using a single set of proven security infrastructure software throughout the world.
Multicast and current IPSec implementations do not necessarily work well together.
Support for IPSec-base security with Security Associations bound to permanent host (multicast group) identities (e.g. certificates)
Location, control, and responsiveness of the authentication authority servers is critical.