Wolfgang Kampichler

A D-MILS console subsystem for advanced ATM communication services

Air Traffic Management (ATM) in the FAAs NEXTGEN as well as the European SESAR has embraced the concept of System Wide Information Management (SWIM) as the means to improve data exchange between various applications in different domains such as flight data management, weather and aeronautical information management. Enabling SWIM is a challenging change for ATM. Although many building blocks are already available, a full SWIM deployment has yet to emerge. Current SWIM functionality is based on historical grown technical restrictions. A performance-based and efficient approach will require new paradigms to organize the commonly shared information and develop and deploy the associated changes in the different user systems and applications as ATM services are developing towards a global and seamless airspace. The continuously increasing bandwidth in wide area networks has allowed new technologies to emerge such as Cloud Computing and Web based integrated user interfaces. The safety critical nature of ATM requires secure and timely sharing of information between separate platforms and diverse user groups. ATM data producers, consumers as well as the information elements themselves reside in multiple domains and will require seamless integration at the user interface level. This paper introduces a concept for Multiple Independent Layers of a Security (MILS) Console Subsystem (MCS) for a dependable information and communication infrastructure for ATM voice and data services. Safety and security requirements intrinsic to ATM networks present an ideal application for Distributed MILS architectures. This paper focuses on the console subsystem that manages the interactions between a human user and one or more separation kernel (SK) partitions. The MCS, itself, runs on a separation kernel. Its clients are partitions on the same SK nodes in an enclave that are capable of communicating with the MCS in a trustworthy fashion. The MCS communicates with its clients (client application back-end) via SK information channels (e.g. IP communication configured on a single node). The human interface provided by the MCS consists of input/output devices exemplified by a display screen, keyboard, mouse, microphone and speaker that can be shared among partitions for voice and data applications at the same time. MCS use cases are derived from Communication Services representing a unique class of communications equipment serving special purposes in safety-of-life-critical and security sensitive areas. Distributed MILS methodologies are used to achieve the required system availability. Distributed MILS (D-MILS) allows selected information elements to reside in all instantiated structures while completely prohibiting the propagation of faults from one side to the other and as such providing for a valid business continuity design. In the case of separated user domains the solution must not only ensure separation but also the integrity of voice and data streams on an end-to-end basis. Hardware virtualization techniques provide a new way of designing business continuity solutions for ATM solutions. They reduce cost and simplify system designs through the separation of data and information elements from the underlying hardware. The hardware degrades to a commodity exchangeable and replaceable in size, and scales separated from the hosted applications via an abstraction layer. Typical virtualization characteristics include partitioning, isolation, immediate multi-instantiation, and hardware independence. A discussion of the technical challenges arising from the use of an MCS based on a distributed MILS approach in a safety-critical environment concludes this contribution.

Implementing System Wide Information Management (swim) for ATM systems using a distributed MILS architecture

System Wide Information Management (SWIM) is attracting more and more interest as a design concept for Air Traffic Management (ATM). It improves data exchange between various applications in different domains such as flight data management, weather, and aeronautical information management and thereby enables new and improved services. Driven by emerging technologies, such as cloud computing and high-speed wide area networks, advanced system integration, like voice and data integration, becomes technically feasible. However, as ATM is a safety-critical technology great care must be taken, such that the information exchange remains secure and timely. This is a non-trivial design challenge, given that the producers and consumers of information, as well as the information itself, frequently reside in different domains, necessitating some form of cross domain solution.

LISP: A novel approach towards a future communication infrastructure multilink service

Future Communication Infrastructure (FCI) air ground data link services can use various technologies (radio links) to achieve the end to end data exchange objectives. Such functionality has been developed and standardized by ICAO under the Aeronautical Telecommunication Network (ATN) activities and is also available in the Internet Protocol Suite (IPS) world, but is currently not yet operationally deployed for ATM purposes. Work comprised in SESAR P15.2.4 project provides an initial perspective of the “Multi Link Operational Concept”, i.e. the notion of using multiple data links to support the communication exchanges in the context of the future SESAR concept of operations. In the context of this task the perimeter of the FCI is limited to just the three future technologies (LDACS, AeroMACS, and SATCOM) and the ATN/IPS-based network layer. This contribution introduces LISP (Locator/Identifier Separation Protocol) as novel approach in order to enhance the ATN/IPS-based network layer. LISP is an open IETF RFC [5] describing a solution for the scalability problem of the Internet routing caused mainly by provider independent addresses and multi-homing of customer networks to different Internet service providers. The concept is based on the separation of the device identity from the physical device location in an IP network. The current approach in the IP world is overloading of IP semantics. Who and where are both represented by the same IP address. Change of location leads to a different IP address and hence changes identity causing existing sessions to be interrupted. LISP is a network-based solution supporting seamless communication while allowing roaming between different locations. LISP is an incrementally deployable architectural upgrade to anexisting infrastructure. An interesting application is the seamless migration from IPv4 to IPv6 due to its address family agnostic behavior. Early adopters will be able to use their existing infrastructure and applications and immediately benefit from LISP. This paper focuses on usage of LISP technology in aeronautical networks in order to achieve mobility, high availability and security for safety critical communication between aircraft and ground infrastructures. Fast convergence, make-before break in multilink environments, easy deployment and operation, manageable security, avoidance of scalability limits and independence of service provider infrastructure are the main topics of interest. Typical use cases demonstrate the network power of LISP support both, future aeronautical data, and voice applications. This makes LISP an interesting candidate technology to handle the mobility of the aircraft while maintaining communications when moving between different ground stations. We show how the LISP mobility system can be enhanced to include application type or QoS specific information into the data link selection. This allows path preference selection for individual data transactions transparent to the application and implementation of outgoing traffic engineering whilst utilizing the basic LISP mechanisms. Finally we discuss make-before break handover in order to improve required communication performance (RCP) figures such as availability of use or continuity.

Complex UAS operations using algorithms based on the LOST protocol

Soon, our National Airspace will be flooded with unmanned aircraft systems (UAS) from fixed-wing drones with aircraft-similar flight characteristics to multi-rotor UAS capable of 3-dimensional flight with ultra-small turn radius. Further down the road, single drones will make way for fleets of drones generating so-called drone swarms.

Location based communication services for UAS in the NAS

Unmanned aerial systems (UAS) are soon to cloud our skies in all areas of the national airspace, uncontrolled as well as controlled. Allowing UAS operation in controlled airspace is the responsibility of the National Navigation Service Providers (ANSP), such as the Federal Aviation Administration (FAA). Being able to locate UAS and thus associate it with its respective ground control station(s) is a prerequisite for seamless integration into the National Airspace (NAS). This contribution describes the concept of using the GPS capability of the UAS to provide location-based services to the air traffic control systems, to automate the association with appropriate air traffic control (ATC) communications channels and data links. It is a common expectation now that UAS will soon operate not as individual devices, but as part of a highly networked UAS infrastructure. Small to large UASs will need to be properly addressable from the ANSPs ground control systems such as tower, TRACON, or en-route center. As defined in RTCA DO-320 all UAS pilot-in-control (PIC) are subject to the same regulations as pilots flying aircraft while physically residing on the aircraft, thus need to adhere to commands and directives by air traffic control personnel located in these facilities. Communications links to ATC facilities include data and voice links between air traffic control and the PIC in the UAS ground station. In addition, voice commands need to be broadcasted to all other users (i.e. aircraft, and other UAS — PIC) operating in the same ATC sector. When a UAS transitions the boundary of two sectors the corresponding responsibility changes from one controller to another residing within the same or different ATC facilities. The described Location Based Services (LBS) may be used to dynamically associate the communication service to its responsible ATC facility without PIC intervention. Current communications links between UAS ground control stations (GCS) and ATC are relayed via the UAS itself resulting in the need for a special transceiver on the UAS in addition to the control link transceiver. Especially in the case of small UAS (sUAS) this transceiver constitutes a significant reduction in maximum vehicle payload capacity. This paper proposes a solution that operates without the need for a retransmission transceiver on board the UAS. All communications links between UAS GCS and ATC utilize solely ground based communications assets, networks, and protocols. The LBS concept allows calls to automatically find their way to the correct ATC center, respectively the ATC controller in charge for the associated airspace block. Such a mapping between the user location and the service boundary can be implemented using a Location-to-Service Translation (LoST) system. The LoST system fetches the geographic data representing the boundaries of the airspace sector from its authoritative AIXM database and looks up the unique identifier of the responsible sector, and ATC center. This information is then used to identify the corresponding radio frequency, represented by its EUROCAE ED-137 based identifier, which in turn is used to establish the communications association/link between the PIC and the ATC controller using available Ground communication facilities. We further discuss the dynamic communications link establishment from the ATC controller to the UAS PIC using the LBS. In the UAS network we propose the LBS to be setup as a subscribe/notify service allowing the sharing of additional metadata ahead of a sector handoff. The paper ends with an outlook into the option of a make-before-break automatic link establishment, which may enhanced operational safety and security and could further reduce complexity in the UAS coordination effort for air traffic controllers in the NAS.

A novel approach to advanced ATM communication services

Presents a collection of slides covering the following topics: advanced ATM communication services; ATM data and voice communication; SWIM deployment; voice and data integration; distributed multiple independent layers of security; system decomposition; spanning nodes; time-triggered Ethernet; D-MILS verification; communication relations; signaling delay and voice latency; data integrity.

LISP: A novel approach towards an FCI multilink service

Presents a collection of slides covering the following topics: LISP technology; network routing; network security; multihoming; mobility; ATM; data link communication; FCI multilink service and locator identifier separation protocol.

Satellite based voice communication for air traffic management and airline operation

Satellite based voice communication services today are typically provided by communication centers interconnecting ground based communication facilities with suitably equipped aircrafts. These communication services are either based on a radio operator relaying the radio calls or by connecting the call automatically to phone lines through a telephone gateway. Calls from ground parties to aircraft typically use telephone numbers on a private telephone network in order to reach the appropriate air-to-ground relay station, which in turn patches the call into the radio call to the aircraft, or v ia a dispatcher in a communication center. Common for these satellite based services is the fact that only a single aircraft is addressed. Further, there is no relation between boundaries controlled by Air Navigation Service Providers (ANSPs), or any other responsible agency and the coverage of a satellite beam. This is a clear disadvantage over conventional Air Traffic Management (ATM) voice communications performed via VHF radio. Situational awareness is key for the decision making process of controllers and pilots in the next generation airspace system (NEXTGEN). In VHF radio communications this awareness is automatically provided by the shared-media nature of the air waves, thus allowing commands from controllers and the corresponding read-back from pilots to be received by all listeners on a particular frequency simultaneously (propagation delay of the radio signal not considered). In addition, todays sector boundaries (horizontal and vertical) are based on traffic patterns and thus are in accordance with the major air traffic routes, where it never happens, that a single sector requires a handover between two different radio channels (i.e. different physical frequencies). We describe mechanisms that allow combining aircrafts to virtual sector groups independent of satellite beam coverage and introduce communication services by considering technical issues of satellite based communications. Aspects of NEXTGEN are addressed such as capacity, performance, and global coverage. ANSPs, FAA, Eurocontrol, and industry are working together to define IP as the next generation common network layer for voice and data communications. EUROCAE Working Group 67 (WG-67) has recently completed its recommendation documents [1], which are now ready to become ICAO recommendations. To ensure interoperability at the application layer, open standards, a center piece of the internet protocol suite, have been agreed upon by consensus. In addition we elaborate an optimization concept for satellite communication that is in the context of the WG-67 definitions. It takes into account the available data-rate, channel access methods, different end-to-end delay, and more. A translation and optimization entity between the different technologies is introduced providing the WG-67 interface definitions on the ground side and an optimized air-to-ground interface as Link Gateway (LGW). The LGW provides the key communication capabilities to both ends, the ground based voice communications network and the aircraft and handles the interface to the data-link layer (L2) capabilities provided by the data-link via the Ground Earth Station (GES). This allows designing voice communication application services independent of the underlying transport technology. For instance changing or extending the interface at the GES would not affect the Voice Communication System (VCS) or aircraft application, only changes at the LGW are necessary. Another service entity, the Sector Floor Control (SFC) performs floor control and if applicable requests appropriate resources from the GES via the LGW. Finally, we discuss the benefits of future ATM data-link concepts as well as the benefits of integration in a multi-link environment.

Eurocae WG-67 standards for voice-over-IP in ATM for advanced NEXTGEN conops

EUROCAE working group (WG) 67 was founded over six years ago. Following the path to a converged telecommunications network carrying IP-only traffic for data as well as voice communications emerged the reality of an international standard for Voice over IP for the ATC environment. The EUROCAE WG-67 born in a coordinated effort among RTCA and EUROCAE mastered its first milestone in 2004 in the Vienna agreement, where international ANSPs, under the auspices of FAA and Eurocontrol agreed on a first set of terminologies and interface control document to be generated. In 2009 the standards for radio communications, ground-ground communications among ATC centers, as well as requirements for the underlying telecommunications infrastructure have been agreed upon by Air Navigation Service Providers (ANSPs) in Europe, the Federal Aviation Administration (FAA), and industry and were issued as a series of ED recommendation documents ED 136 to ED 139. Starting in 2008 interoperability tests as well as international field trials were performed and substantiated the maturity and validity of the standards. The paper addresses the applicability of the WG-67 standards to the National Air Space (NAS). It further addresses the impact on the next generation ATC programs NEXTGEN and SESAR, the potential for cost savings, and implementation of advanced NEXTGEN concept of operations such as Dynamic Resectorization. Finally an outlook is given at the roadmap for the WG-67 VoIP standards to be adopted by ICAO.

VOIP in ATC communications — Where are we today

Under the auspices of Eurocae WG-67 industry and global Air Traffic Navigation Service Providers have collectively developed a set of standards, which look promising for global implementation in ATC. This paper provides a compact description of the main notions of the recommendations developed in Eurocae WG-67. Results of interoperability testing and field trials within operational environments conducted in the first half of 2009 are discussed demonstrating the applicability of SIP and RTP protocols to ATC communications. Industry (radio and voice communication systems) and major air traffic navigation service providers (ANSPs) agreed on field trial testing of IP based equipment with the aim to allow for a seamless airspace that is managed flexibly within dynamic airspace blocks. The paper describes selected radio practices and outlines associated requirements for absolute and relative delay as well as minimal end-to-end data rates of ground-to-air transmission compared to results from those field-trials.