AIR FORCE LAUNCHES WIDE RANGE OF INITIATIVES
AIMED AT DEPLOYING AIRBORNE NETWORKS.
As they look ahead to potential future missions, defense officials know that they may have to deploy hundreds of aircraft, ground vehicles, ships and satellites to an area that contains little or no existing network infrastructure. A major challenge in such situations is building and securing an ad hoc, mobile network capable of integrating the multifaceted participants in order to achieve seamless decision-making, greater speed and greater precision in the targeting process.
A key enabler for achieving this type of network-centric capability is moving to Internet Protocol-based routing. This enables platforms such as aircraft to access more sources of information and greater volumes of it, faster.
But while ground-based IP networking exists, Air Force leaders have been concerned that there is no airborne IP network to speak of. The vast majority of air platforms currently rely on a Link 16 line-ofsight capability.
Many platforms are not even connected via a data link of any kind. Moreover, current networks are not conducive to adding new nodes and platforms easily, at a time when the number of deployed sensors and platforms is increasing greatly, with an associated increase in bandwidth needs.
At transmission speeds of 118 kbps, Link 16 has limited capability. Transmitting the amount of data equivalent to an unabridged dictionary would take two minutes. IPbased networking using the common data link (CDL), by contrast, enables speeds of 274 mbps, or more than 2,000 times faster. Transmitting the same dictionary would take just 5 milliseconds.
The Office of the Secretary of the Air Force envisions establishing a “self-forming, self-healing” Global Information Grid, in which IP-addressable aircraft can dynamically enter and leave a network, and where more there are more entry and exit points for data to pass between the ground and airborne GIG. IP-based protocols would automatically find and connect with a network within an RF range.
A goal is to upgrade information-sharing capabilities of aircraft from voice-only or data link-only, to a network-centric LOS and beyond line-of-site (BLOS) connectivity. Instead of broadcasting, information could be routed to only those platforms that need it. And airborne platforms could act as routers, dynamically choosing the best path to send information.
In response to these concerns, the Air Force has launched a wide range of initiatives aimed at deploying airborne networks. The Air Force Communications Agency (AFCA) and Air Force Research Laboratory (AFRL) recently sponsored a conference to review progress on airborne networking, which they defined as “an infrastructure that provides communication transport services through at least one node that is a platform capable of flight.”
STRATEGY SHIFT
From an architectural point of view, the goal is to move beyond stovepiped tactical data links, or point-to-point communication systems, and toward more network-oriented IP-based communications, and to obtain tactical data link formatting and link it to an IP structure. The Battlefield Airborne Communications Node (BACN) is an example of that. “It tackles point-to-point radio communications—data or voice—and integrates them using an IP packet routing architecture to better integrate in, and be interoperable with, the Global Information Grid,” said Colonel Robert Steele, commander of the AFCA. “It enables moving toward a netcentric IP-based platform. That in itself isn’t a capability, but rather an architectural or technological construct.” AFCA is the lead command for the Airborne Network Integration initiative within the Air Force.
As recently as a year ago, the Air Force approached the challenge of Airborne Network Integration through the framework of the C4ISR Roadmap. Moving away from a “platform-centric” way of looking at airborne communications that were essentially stovepiped, the C4ISR Roadmap indicated where the programs and platforms specifically should be at a given point in time, and what each platform would yield, and what could be done to better integrate them into a net-centric environment.
That approach has been improved. Today it is much more capability oriented. “What we do now is leverage things like the Integrated Capability Review and Risk Assessment [I-CRRA], and look at the missions that we would be required to fly. Things like time-sensitive targeting, close air support, homeland defense and humanitarian relief operations—critical missions that we do every day. Then we look at the capabilities needed to effectively carry out those missions, and go from there.”
The approach now, explained Steele, is developing an overall strategy for airborne networking that’s more closely aligned with those risk assessments and the shortfalls and gaps in existing programs the risk assessments uncover. For example, there are challenges with BLOS connectivity for tactical data links. An F-16 Block 50/52 may be data-link enabled, but it could be flying outside of the connectivity footprint of another Link16-enabled aircraft or gateway.
“Rather than just chasing a technology,” pointed out Steele, “the new approach involves running scenarios based on experience from past missions, and from that, deriving the requirements that will in turn drive the systems required for airborne networking,”
In reporting on progress in Airborne Networking Integration, traditionally the Air Force would give briefings on the family of data links, encompassing areas such as narrowband and wideband satellite systems, individual weapon system data links. “It was very program centric, such as ‘here’s what this thing, by itself, will do for you, and here’s what it will yield,” said Steele. The new approach is reflective of DoD direction—to look at capability-based planning and effects-based programming. “Before, we were driven by the programs,” he added. “Now we’re at the point where we’re trying to drive the programs to be integrated, interoperable, more cost-effective and more netcentric.”
Funding issues prompted much of the shift in approach. Iraq and Afghanistan, as well as higher-than-expected costs of the Joint Tactical Radio System program, have been consuming dollars that would have gone into many airborne network integration programs, according to Colonel James Henderson, chief of the expeditionary network operations division within the Secretary of the Air Force Office of Warfighting Integration and Chief Information Officer. “We lost a lot of money, so we stepped back and looked at our missions, and which platforms are really helping us in those missions,” he said.
As the services build their budgets, all airborne networking programs are being evaluated. “If you can specifically show the warfighting effect of a program and how it relates to a mission, you get better support for that than if you can’t link it to a mission,” Henderson said.
All ongoing airborne networking programs are still important, Henderson said, but they cannot be funded based on the timelines they have been on. Decisions are being made as to which can be cut back, although nothing has been finalized.
Continued Henderson, “A number of years ago we didn’t have huge war bills driving a lot of issues, and we didn’t have people out there in harm’s way on a daily basis. But we can’t just put all of our money towards that with no transformation funds. So finding that balance is what we’re trying to do.”
The process involves identifying gaps and shortfalls in existing systems, then investing in those systems in order to satisfy those gaps and short falls. For example, explained Steele, there are challenges with BLOS connectivity for tactical data links. An F-16 may be data-link enabled, but it could be flying outside of the footprint of another receiver.
“Rather than just chasing a technology, the new approach involves running scenarios based on experience from past missions, and from that, derive the requirements that will in turn drive the systems required for airborne networking,” Steele said.
SYSTEMS APPROACH
In addressing challenges in the airborne networking environment, traditionally the approach has focused on one particular aspect, such as a faster data link, a better routing protocol, a smarter application or a way to do quality service. Now it’s recognized that solving the problems requires a systems approach. All of the issues need to be fundamentally addressed.
AFRL has also been heavily involved in this area. In recent interviews, AFRL officials discussed programs they are working on that take that systems approach.
One such program is the Interim Capability for Airborne Networking (ICAN), an ongoing program to enable aircraft to communicate with participants on the ground. This program enables the creation of a network among disadvantaged links, which may suffer from low bandwidth, high error rates, long latency or non-connectivity. ICAN gives aircraft an unprecedented ability to participate in the planning and targeting process.
ICAN is essentially a smart router, said Dan Hague, senior scientist within the Information Grid Division at AFRL. It is aware of the system-level concerns and also fluent in tactical radios and other disadvantaged links. For instance, the ICAN box is placed in an aircraft and connects to the existing radio resources on the aircraft.
A ground infrastructure is put in as well, in the form of radio access points or ground entry sites. These are connected to the SIPRNet, and there is a distributed set of hardware that talks to the individual radios that are located throughout the SIPRnet infrastructure.
“ICAN determines the most effective link protocol in order to send IP data over highfrequency radios, and looks at how mobile IP can help and support this, and integrate better and smarter transport protocols. And, make performance-enhancing proxies that improve the performance of the system overall. And most importantly, how to put that all together,” said Hague.
The focus is routing, quality of service, cross-layer protocol work and interoperability.
“ICAN and JCAN [Joint Capability for Airborne Networking] are providing IT enabling,” said Hague. “A user, whether in an aircraft or on the ground, will be able to connect in either an local network or an individual computer on their end, and be able to communicate with other resources like they were sitting at their desk at work, with the ability to chat, e-mail, share information and use Web browsers, just as they do at their desk.”
AFRL has been working closely with AFCA in developing ICAN, as well as the Air Force’s Electronics System Center, Aeronautical System Center, C2ISR Center and others. AFRL is working on integrating ICAN with the Navy as well.
Another program aimed at integrating disadvantaged links to the GIG is the Battlefield Airfield Targeting Network (BATN). It consists of a high-data-rate, IP-capable radio that helps close the last tactical mile between disadvantaged users and other nodes.
“We’re putting in our requirements to create one radio for these disadvantaged users, in order to connect into the airborne networks, to make sure that the ground users have requirements [that] are fulfilled, and be able to communicate to the weapons, and if necessary take over control of their radio and guide that weapon into a target opportunity or talk to a UAV to be able to transfer data,” explained program manager Captain Robin Watts.
A disadvantaged user is someone who doesn’t have a backbone of support like a whole brigade would have, Watts said. It typically would be a foot soldier, particularly special operations personnel. Development of the radio is expected to begin at the end of 2008, and deployment a few years after that. Rockwell Collins is the lead contractor.
Intelligence Information Routing for Airborne Networks (I2RAN) is another systems-approach-oriented program, which is getting under way this fiscal year. It consits of creating a mission- and scenario-modeling capability for airborne networking.
Fred Hall, senior electronics engineer at AFRL and program manager for I2RAN, said it will enable users to more effectively design and construct ad-hoc networks and establish concepts of operations. Users could look at a mission from a top-down view, examining the type of missions, scenarios and platforms. It will also provide for a bottom-up view, such as types of radios, waveforms and other equipment needed. It will help plan out the enterprise management as well as the technologies to enable the connections between points.
“One of the big problems of applying enterprise management to the airborne network is that it’s so dynamic. You have nodes leaving and entering, whereas with groundbased networks nodes are more static. Sothat’s where we’re taking this program,” said Hall. ♦
