12 Feb Net-Centric Air Traffic Management System Explained
Net-centric, in its most common definition, refers to “participation as a part of a continuously evolving, complex community of people, devices, information and services interconnected by a communications network to optimise resource management and provide superior information on events and conditions needed to empower decision makers.” It will be clear from the definition that “net-centric” does not refer to a network as such. It is a term that covers all elements constituting the environment referred to as “net-centric”.
Exchanges between members of the community are based not on cumbersome individual interfaces and point to point connections but a flexible network paradigm that is never a hindrance to the evolution of the net-centric community. Net-centricity promotes a “many-to-many” exchange of data, enabling a multiplicity of users and applications to make use of the same data which in itself extends way beyond the traditional, predefined and package oriented data set while still being standardised sufficiently to ensure global interoperability. The aim of a net-centric system is to make all data visible, available and usable, when needed and where needed, to accelerate and improve the decision making process.
In a net-centric environment, unanticipated but authorised users can find and use data more quickly. The net-centric environment is populated with all data on a “post and share before processing” basis enabling authorised users and applications to access data without wait time for processing, exploitation and dissemination. This approach also enables vendors to develop value added services, tailored to specific needs but still based on the shared data.
In the context of Air Traffic Management (ATM), the data to be provided is that concerning the state (past, present and future) of the ATM Network. Participants in this complex community created by the net-centric concept can make use of a vastly enlarged scope of acceptable data sources and data types (aircraft platforms, airspace user systems, etc.) while their own data also reaches the community on a level never previously achieved.
How are decisions different in a net-centric environment?
Information sharing and the end-user applications it enables is the most beneficial enabler of collaborative decision making. The more complete the information that is being shared and the more thorough its accessibility to the community involved, the higher the benefit potential. In a traditional environment, decisions are often arbitrary and the effects of the decisions are not completely transparent to the partners involved. Information sharing on a limited scale (as is the case in the mainly local information sharing hitherto implemented) results in a substantial improvement in the quality of decisions but this is mainly local and improvements in the overall ATM Network are consequential rather than direct.
If the ATM Network is built using the net-centric approach, decisions are empowered on the basis of information available in the totality of the net-centric environment and interaction among members of the community, irrespective of their role or location, can be based on need rather than feasibility.
Since awareness of the state (past, present or future) of the ATM Network is not limited by lack of involvement of any part as such, finding out the likely or actual consequences of decisions is facilitated, providing an important feed-back loop that further improves the quality of decisions on all levels.
Looking at things from the collaborative decision making (CDM) perspective, it is important to realise that net-centricity is not something created for the sole purpose of making CDM better. Net-centricity is a feature of the complete ATM system design, providing different benefits to different aspects of air traffic management operations. It is when collaboration in decision making exploits also the facilities made possible by the overall net-centric ATM Network, that the superior quality of decisions becomes truly visible.
The concept of services
In traditional system design, information technology (IT) was often driving developments and the functionality being provided in some cases became a limitation on the business it was meant to support. Service orientation is the necessary step to separate the business processes from the IT processes and to enable business considerations to drive the underlying IT requirements. Aligning IT to the business rather than the other way round improves business agility and efficiency.
“Service” in this context is defined as “the delivery of a capability in line with published characteristics, including policies.” This refers to the ATM services required and not the underlying (technical) supporting services and physical assets that need to be deployed. In other words, service refers to the business services and not the information technology services.
Well designed business services must exhibit a number of characteristics that describe the service being offered sufficiently well for the service consumer(s) to clearly understand the service and hence to want to make use them.
On the business level, contracts and service level agreements that put the service in the proper context are very important as they cover not only the function(s) that will be performed but also the non-functional terms and conditions to which the consumer and provider have agreed.
There are several business processes that can be identified in the context of air traffic management. Some are related to the aircraft themselves (e.g. turn-round), others concern the passengers and their baggage. These and all other business processes require specific services to progress and complete in accordance with the business objectives of the process owner. Cleaning and refuelling of the aircraft, passenger check-in, security checking, etc. are just a few examples of the business services that need to be provided in order to achieve the objective, in this case a timely and safe departure.
When viewed on an enterprise level, a given service once defined is often reusable across the enterprise where identical or similar processes are found, resulting in a major potential for cost saving.
The services so defined will then set the requirements for the underlying IT support.
The effects of net-centric integration
The term “integration” is often associated with “centralisation” and the elimination/rationalisation of facilities. While from an economic perspective integration may indeed mean all of the above, net-centric integration is about empowering better decision making through the creation of the complex, networked community of people, devices, information and services that generate benefits to all members of the community without necessarily changing the mapping (nature, number and location) of the community members.
At the same time, net-centric integration enables superior business agility and flexibility so that community members may evolve and change (drop out or new ones come in) in response to the changing needs of the users of the system concerned.
In the net-centric context it is not integration as such that changes the enterprise landscape. Such changes, if any, are the result of the economic imperatives that need to be met and which can now be met based on the improved business agility.
The end-user aspects of net-centric operations
One of the less understood aspects of traditional decision making is that it is not really possible to realise when decisions are based on less then full and/or correct information. The garbage in/garbage out principle applies also to the decision making process. At the same time, the effects of less than good decisions may not be immediately visible. In many cases, poor decisions will affect the efficiency of the overall operation without the negative effects even being traceable to individual decisions. So, while everyone may be doing their very best, the result may still be far short of the quality that would be otherwise achievable.
When the scope and quality of data upon which decisions are based is expanded and improved, the quality of decisions improves almost automatically. The decision makers will notice the expanded possibilities and ultimately the success of the enterprise will also improve in a visible way.
When net-centric operations are introduced, the potential for improvement and the options for achieving the improvement multiply considerably. In the more restricted environment, end-users will have been asking for more information and tools to make using data easier. More often than not, their wish went unfulfilled due to lack of data and/or poor quality and the consequent poor performance of the tools that may have been created. The shared environment under net-centric operations brings all the data anyone may ever wish to have. The services are defined on the basis of the business needs and will also support the tools end-users need to properly interact with net-centric environment, integrating into a coherent whole their individual decision making processes.
In a way a well implemented net-centric system is transparent to the end-users. In particular, they do not need to concern themselves with the location of data they require or the quality thereof. Information management, that is part of the net-centric environment, takes care of finding the information needed and also its quality assurance.
End-user applications are the most visible part of net-centric operations and they can be built to satisfy end-user needs in respect of any process that needs to be handled.
In the ATM context, vastly improved controller decision making tools, safety nets and trajectory calculation are only a few examples of the possible benefits.
The institutional implications of net-centric operations
International air navigation is by definition a highly regulated environment and regulations provide some of the most important pillars of both safety and interoperability. The net-centric and service oriented future ATM environment possesses a number of aspects which by themselves provide powerful drivers for proper regulation. It is important to note that the institutional issues associated with net-centric operations are wider than just CDM and hence early efforts to address the CDM related aspects will benefit the whole of the ATM enterprise. The items of particular relevance are summarised below:
o Wide scope of information contributors – The information needs of the future ATM Network, including the scope of that information, will result in a multitude of new information sources/contributors and/or new types of information being obtained from various information sources.
o Air and ground integration – In the traditional ATM set-up, the coupling between ground and airborne systems are normally very loose or non-existent. Once the net-centric ATM Network is realised and aircraft become nodes on the network, a completely new regulatory-target regime is created in the form of the integrated air/ground ATM elements.
o Information sharing – The value of using shared information is one of the main reasons why System Wide Information Management (SWIM) for the future net-centric ATM environment is being defined. There are however legitimate requirements for protecting some information in one or more of several ways, including de-identification of the source, limiting access, etc.
o Integration of diverse airspace use activities – Airspace is used for various purposes and civil aviation is just one of those. Specific military usage (not all of which involves aircraft operations) as well as various civilian projects and missions employ information that is even more sensitive than the normal business or security sensitive information categories. Their proper protection is essential if the military and other operators generating such sensitive information are to be integrated into the overall ATM process. This aspect poses a specific challenge since not only is the information possibly in a military/State security domain but the regulatory domains may also be nested in different organisations that need to be brought together for and under the SWIM umbrella.
o Disappearance of the difference between voice and data – In the mid- to longer time frames, the expected traffic levels will make the move to almost exclusive use of digital link communications inevitable. This does not mean the disappearance of voice communications on the end-user level. However, a reliable communications system that can serve the voice and data needs of the future ATM environment is by definition digital and hence even voice messages will be transferred via digital means. Hence a convergence of the regulatory regimes for voice and data communications will be inevitable.
o Global interoperability – Aeronautical information has always been global in nature but the strongly limited access and product oriented philosophy has contained the issues of global interoperability. The net-centric approach of the new ATM environment will create large islands of shared information which must however be able to interoperate between each other as well as with legacy environments, constituting a new, global need for proper regulatory regimes.
o Common information pipes for passenger and operational communications – In the traditional analogue environment, aviation has enjoyed dedicated communications means and this tradition was carried over to a certain extent also into the new digital communications technologies. The dedicated “pipe” in air/ground communications is certainly a reality today but the same cannot be said of the ground-ground communications links. The early point to point connections have been replaced in most applications by leased lines which, for substantial segments, are in fact shared with other, often not aviation, users. The drivers behind this change are obviously cost effectiveness considerations. Although early attempts to provide in-flight passenger connectivity have not proved the commercial success many had forecast, it is already visible that in the not too distant future, personal communications needs will evolve to the point where people will demand uninterrupted connectivity even on relatively short flights. Since such demands will always fetch a premium price, it stands to reason that combining the operational and passenger connectivity needs onto a single air/ground pipe could be commercially attractive. While the technology to do this safely will certainly be available, the regulatory aspects will have to be explored in time to ensure that the actual solutions used meet all the safety and other requirements.
o The value of information – Information is a valuable commodity and in the competitive environment of aviation this commodity is of course sought after by many partners, including others than only aircraft operators or airports. The essential safety contribution of information in air traffic management creates an especially complicated web of relationships, some commercial some not, some State obligations some voluntary, and so on that need to be properly regulated with a view to ensuring cost recovery while not discouraging information use.
o Cost effectiveness – Although not always thought of as a driver for regulation, a proper regulatory environment will favour cost-effective, user oriented solutions.
o Training and personnel licensing – The information sharing environment of SWIM will require experts who are conversant not only with the requirements of air traffic management and aircraft operations but also the information technology aspects of the new approach to managing information. This has implications in the construction and approval of training syllabuses, examination fulfilment criteria as well as the qualification requirements. The need for refresher/recurrent training also grows and needs to be part of the overall regulatory regime.
o Standardisation – System wide sharing of information in a net-centric environment requires that the data be the subject of proper standardisation on all levels. This is the key to achieving global interoperability in the technical as well as the service/operational sense. The development and use of the necessary standards can only be realised under a proper regulatory regime.
All the above aspects imply the creation of a regulatory regime that is aligned with the specific needs of a net-centric operation and which is able to regulate for safety and proper performance, including economic performance, appropriate for the new digital environment. Trying to apply traditional methods of regulation without taking the new realities into account is counter productive and must be avoided. This is an important message for both the regulators and the regulated.
The aspects of regulation to be considered include:
o Information interoperability
o Service level interoperability
o Physical interoperability
In terms of who should be regulated, thought should be given to at least:
o The State as data provider
o Licensed providers of services, including network services
o Licensed data sources
o Licensed providers of end-user applications
o User credentials and trusted users
It is important to answer also the question: who should be the regulator? This must be agreed in terms of:
o International rules and global oversight
o Licensing rules and global oversight
The types of regulatory activities that need to be put in place concern mainly compliance verification and certification; quality maintenance; and enforcement and penalties.
As mentioned already, the above institutional aspects concern more than just CDM, however, for CDM and in particular information sharing to work in the net-centric environment, they need to be addressed as a prerequisite of implementation.
The technical implications of net-centric operations
On the conceptual level, net-centric operations mean the sharing of superior quality information as part of a community and acting on that information to improve decisions for the benefit of the individual as well as for the network (the networked community). Obviously, this type of operation must be enabled by a proper technical infrastructure.
This technical infrastructure is often thought of as a network with the required band-width and reliability; it is true that the replacement of the one-to-one connections that characterise legacy systems with the many-to-many relationships of the net-centric environment does require a powerful network that fully meets all the quality requirements, but there is much more to net-centricity than this.
The management of the shared data pool, including currency, access rights, quality control, etc. brings in a layer of technical requirements that sit higher than the network as such.
If we then define ‘information’ as ‘data put in context’ it is easy to see that creating the information from the shared data constitutes yet another layer of required technical solutions. These are often referred to as intelligent end-user applications. Tools which end-users can call upon to perform tasks they need for successfully completing their missions. End-users may be pilots, air traffic controllers, flight dispatchers, handling agents or any other person or system with a need for the shared information. In all cases, the end-user applications collect and collate the data needed to create the information required. This then may be a synthetic display of the airport on an EFB, a trajectory on a what-if tool display or a list of arrivals for the taxi company and so on.
End-user applications are scalable to fit, both in functionality and cost, the specific needs of the end-user for whom they are created. This scalability enables the end-user applications to run on different networked devices from simple PDAs through airlines systems to on-board equipment.
It shall be noted that one of the most important characteristics of a net-centric environment that technical solutions must support is that the requirements against equipment are driven by the services/functionality they must provide and NOT by their actual location in the network. As an example, the integrity of the data used to build a trajectory and the quality of the application used to manipulate/interact with the trajectory will depend on the use that will be made of the trajectory and not per se on whether the application is running on the ground or in an aircraft.
This adaptability of the technical solutions to the actual needs (rather than location in the network) leads to important cost saving opportunities.
Net-centricity – the essence of the future
The net-centric approach to system design is not a silver bullet. It is just the environment that enables properly managed information to be exploited to the full and provide the enterprise with the agility it needs to constantly adapt to the changing world for the benefit of the customers and the enterprise itself.
It is the end-user applications built to work in the net-centric environment that come closest to being the silver bullets…