Airborne Networking
Encyclopedia
An Airborne Network is defined to be the infrastructure that provides communication transport services through at least one node that is on a platform capable of flight.
's Airborne Network is to expand the Global Information Grid
(GIG) to connect the three major domains of warfare: Air, Space, and Terrestrial. The Transformational Satellite Communications System
(TSAT) network currently provides connectivity for all communication through space assets. The Combat Information Transport System and Theater Deployable Communications provide terrestrial connectivity for theatre based operations. The Airborne Network is engineered to utilize all airborne assets to connect with space and surface networks building a seamless communications platform across all domains.
(LoS) communications infrastructure that can be packed up and moved in and out of the designated battlespace, enabling the military to have a reliable and secure communications network that extends globally. The network is designed to be flexible enough to provide the right communication and network packages for a specific region, mission, or technology.
Operationally, The AN is designed to be self-forming, self-organizing, and self-generating, with nodes joining and leaving the network as they enter and exit a specific region. The network consists of dedicated tactical links, wideband air-to-air links, and ad-hoc networks constructed by the Joint Tactical Radio System
(JTRS) networking services. [2] JTRS is a software-defined radio
that will work with many existing military and civilian radios. It includes integrated encryption and Wideband Networking Software to create mobile ad-hoc networks. [3] It also provides system performance analysis and fault diagnostics automatically, reducing the demand for human intervention and network maintenance.
, Surveillance
, and Reconnaissance
(ISR) aircraft may connect via a LOS link directly to a network ground entry point. Each of these tethered alternatives works exactly like a hub or switch that has an entry point to a larger network and allows their connected users access to that network. The figure outlines each of the three discussed examples of a tethered network.
(QoS) routing protocol.
(IP) based network. Gateways and proxies are essential in the operation of this network because so many different technologies are used to communicate in each domain. These systems will facilitate the transition of the legacy on-board infrastructure, transmission systems, tactical data link systems (TDLs), and user applications to the objective airborne network systems. Therefore, they are only temporary until all platforms utilize a standardized IP-radio for transmission.
• Compression: Data compression or header compression can be used to minimize the number of bits sent over the network.
• Data bundling: Smaller data packets can be combined (bundled) into a single large packet for transmission over the network.
• Caching: A local cache can be used to save and provide data objects that are requested multiple times, reducing transmissions over the network (and improving response times).
• Store-and-forward: Message queuing can be used to ensure message delivery to users who become disconnected from the network or are unable to connect to the network for a period of time. Once the platform connects, the stored messages are sent.
• Pipelining: Rather than opening several separate network connections pipelining can be used to share a single network connection for multiple data transfers.
• Protocol streamlining: The number of transmissions to set up and take down connections and acknowledge receipt of data can be minimized through a combination of caching, spoofing, and batching.
• Translation: A translation can be performed to replace particular protocols or data formats with more efficient versions developed for wireless environments.
• Embedded acknowledgments: Acknowledgements can be embedded in the header of larger information carrying packets to reduce the number of packets traversing the network.
(CAP). The strike package or CAP will have supporting airborne C2 and ISR platform(s), tanker (refueling) platform(s), and ground C2 platform(s). Each airborne fighter platform requires connectivity to all other strike package or CAP and supporting platforms; however, a majority of information will be exchanged between airborne fighter platforms. This is driven in large part because of the need for frequent situational awareness and target sorting updates in a highly mobile environment. Pilots will be provided services such as real-time data
, digital voice, and interactive data sharing.
Airborne fighter platforms will participate in both tethered and flat ad-hoc network topologies. A tethered topology would primarily be used for reachback and forwarding between the airborne fighter platform and supporting elements. A flat ad-hoc topology would be used between airborne fighter platforms in a strike package or CAP for the more frequent information exchanges. The figure outlines the minimum equipment requirements to support a fighter platform.
platform flight profile includes periods of en route flying and repeated, stable flight patterns. The relatively large size enables space available for mounting antennas and installing significant communications equipment to accommodate
multiple mission crew functions. It will host up to three dozen mission crew members, including a communications operator. A C4ISR platform’s mission applications and sensors will support multiple capabilities and mission types. Mission durations for any single aircraft and crew could range up to 12 hours; with aerial refueling it could be extended to 24 hours. These platforms often operate beyond line-of-sight of ground infrastructure and could be employed as a stand-alone or as part of a strike package or CAP in support of a strike package. C4ISR aircraft require a broad range of connection capability to connect peer-to-peer with other C4ISR aircraft or serve as a hub to connect fighter platform aircraft. The services provided by C4ISR aircraft include real-time data
, voice, video, bulk data transfer, and interactive data.
C4ISR platforms will participate in both tethered and tiered ad-hoc network topologies. A tethered topology would primarily be used for reachback and forwarding between the C4ISR platform, GTACS, and strike package or CAP aircraft. A tiered ad-hoc topology would be used between the C4ISR platform and airborne fighter platforms in a strike package or CAP. The figure outlines the minimum equipment requirements to implement the operations of a C4ISR platform.
Airborne communications relay platforms will participate in both tethered and tiered ad-hoc network topologies. A tethered topology would primarily be used for reachback and forwarding between the C4ISR platform, GTACS, and strike package or CAP aircraft. A tiered ad-hoc topology would be used between the C4ISR platform and airborne fighter platforms in a strike package or CAP. The figure outlines the minimum equipment requirements to implement the operations of a communications relay platform.
Security of this network is another huge obstacle. The goal is to give the system a low probability of jamming and interception. Many ideas of how to protect the system are being investigated and tested. Traditional methods of authentication and authorization are being used, to include Biometrics
, cryptographic tokens, and integrated Public Key Infrastructure
.
(COTS) creates extreme engineering challenges. While it offers flexibility in application and saves money in production it is incredibly difficult to adapt to various application. Getting COTS to install in applications it was not designed for continues to be a vast engineering challenge as military researchers work to integrate civilian L-3 radio and FPGA technology into reconnaissance aircraft designed in the 60s.
Definition
The intent of the United States Air ForceUnited States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
's Airborne Network is to expand the Global Information Grid
Global Information Grid
The Global Information Grid is an all-encompassing communications project of the United States Department of Defense.It is defined as a "globally interconnected, end-to-end set of information capabilities for collecting, processing, storing, disseminating, and managing information on demand to...
(GIG) to connect the three major domains of warfare: Air, Space, and Terrestrial. The Transformational Satellite Communications System
Transformational Satellite Communications System
The Transformational Satellite Communications System program was a United States Department of Defense program sponsored by the U.S. Air Force for a secure, high-capacity global communications network serving the Department of Defense, NASA and the U.S. Intelligence Community...
(TSAT) network currently provides connectivity for all communication through space assets. The Combat Information Transport System and Theater Deployable Communications provide terrestrial connectivity for theatre based operations. The Airborne Network is engineered to utilize all airborne assets to connect with space and surface networks building a seamless communications platform across all domains.
Capabilities
The capabilities identified by this type of system are vastly beyond that of our current military. This system will enable the Air Force to provide a transportable network, flexible enough to communicate with any air, space, or ground asset in the area. The network will provide a beyond line-of-sightLine-of-sight propagation
Line-of-sight propagation refers to electro-magnetic radiation or acoustic wave propagation. Electromagnetic transmission includes light emissions traveling in a straight line...
(LoS) communications infrastructure that can be packed up and moved in and out of the designated battlespace, enabling the military to have a reliable and secure communications network that extends globally. The network is designed to be flexible enough to provide the right communication and network packages for a specific region, mission, or technology.
Operationally, The AN is designed to be self-forming, self-organizing, and self-generating, with nodes joining and leaving the network as they enter and exit a specific region. The network consists of dedicated tactical links, wideband air-to-air links, and ad-hoc networks constructed by the Joint Tactical Radio System
Joint Tactical Radio System
The Joint Tactical Radio System is planned to be the next-generation voice-and-data radio used by the U.S. military in field operations after 2010...
(JTRS) networking services. [2] JTRS is a software-defined radio
Software-defined radio
A software-defined radio system, or SDR, is a radio communication system where components that have been typically implemented in hardware are instead implemented by means of software on a personal computer or embedded computing devices...
that will work with many existing military and civilian radios. It includes integrated encryption and Wideband Networking Software to create mobile ad-hoc networks. [3] It also provides system performance analysis and fault diagnostics automatically, reducing the demand for human intervention and network maintenance.
Intended Use
The AN was designed as the cornerstone for the new military doctrine known as Network Centric Warfare. This doctrine was developed to use information superiority to equip warfighters with more precise information enabling commanders and shooters to make smarter decisions faster. The AN contributes to Network Centric Warfare by enabling commanders to provide real-time information to warfighters in the air and on the ground. Warfighters can then utilize more information and make more educated decisions about how to act in a particular situation. Once the act has been carried out commanders will have immediate information about the result and can make judgments on how to continue. All-in-all the AN was designed to reduce the time necessary to identify a target, make clear and educated decisions to pull/not pull the trigger, and assess battle damage.Topologies
There are four main topologies that will be deployed and vary based on the placement of backbone and subnet class networks.Space, Air, Ground Tether
Establishing a direct connection to another aircraft or ground node, via a point-to-point link for nodes within line-of-sight (LOS) or via a SATCOM link for nodes that are beyond line-of-sight (BLOS) is known as tethering. Satellite Communications (SATCOM) links provide connectivity to a network ground entry point. Strike aircraft that accompany Command and Control (C2) aircraft such as an AWACS are tethered via point-to-point links. Finally, C2 or IntelligenceIntelligence
Intelligence has been defined in different ways, including the abilities for abstract thought, understanding, communication, reasoning, learning, planning, emotional intelligence and problem solving....
, Surveillance
Surveillance
Surveillance is the monitoring of the behavior, activities, or other changing information, usually of people. It is sometimes done in a surreptitious manner...
, and Reconnaissance
Reconnaissance
Reconnaissance is the military term for exploring beyond the area occupied by friendly forces to gain information about enemy forces or features of the environment....
(ISR) aircraft may connect via a LOS link directly to a network ground entry point. Each of these tethered alternatives works exactly like a hub or switch that has an entry point to a larger network and allows their connected users access to that network. The figure outlines each of the three discussed examples of a tethered network.
Flat Ad-Hoc
A flat ad-hoc topology refers to establishing nonpersistent network connections as needed among AN nodes that are present at a given time. With this network the nodes dynamically “discover” other nodes to which they can interconnect and form the network. The specific interconnections between the nodes are not planned in advance, but are made as opportunities arise. The nodes join and leave the network at will, continually changing connections to neighbor nodes based upon their location and mobility characteristics. The figure outlines this concept.Tiered Ad-Hoc
Ad-hoc networks can be flat in the sense that all nodes are peers of each other in a single network, as discussed above, or they can dynamically organize themselves into hierarchical tiers such that higher tiers are used to move data between more localized subnets. The Figure depicts such a tiered ad-hoc topology. This network topology can be compared to any conventional deployed network that utilizes routers, switches, and hubs to temporarily connect users.Persistent Backbone
A network topology characterized by a persistent backbone is shown in the next Figure. The backbone is established using relatively persistent wideband connections among high-value platforms flying relatively stable orbits. It provides the connectivity between the tactical subnets which are considered edge networks relative to the backbone. This provides concentration points for connectivity to the space backbone as well as to terrestrial networks. This type of network topology is comparable to a conventional permanent network with established data trunks, routers, switches, and hubs to connect users.Network Management
The platform management system enables operators to manage all on-board network elements. It interfaces and interoperates with the Airborne Network management system to enable operators to manage remote network elements in the airborne network. The network management system monitors the health of the network by passively testing the network for faults and latency. The system will also actively troubleshoot faults with probes to identify and isolate faulty connections, and enables operators to apply network parameters and security changes to all systems based on the status of the network.Routing/Switching
Routing and switching enables data to be dynamically transmitted over the network to other nodes. Routing protocols must be able to identify nodes transmitted within their own platform and data to be sent to other platforms regardless of the current topology. The routing protocol must also provide seamless roaming by ensuring that no routed packets are lost when a node changes its point of attachment to the network. Maintaining scalability is important in routing as the network is constantly changing. The network must be able to function with numerous levels of platforms, varying numbers of fast moving platforms, and varying amounts of traffic per platform. Routers and switches will use metrics to determine the best paths to take when routing data. The routing protocol utilized for the AN will be an Adaptive Quality of ServiceAdaptive quality of service
In multi-hop networks, Adaptive Quality of Service routing protocols have become increasingly popular and have numerous applications. One application in which it may be useful is in Mobile ad hoc networking ....
(QoS) routing protocol.
Gateways/Proxies
Gateways and proxies enable the connection numerous technology types regardless of age to communicate across the Internet ProtocolInternet Protocol
The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
(IP) based network. Gateways and proxies are essential in the operation of this network because so many different technologies are used to communicate in each domain. These systems will facilitate the transition of the legacy on-board infrastructure, transmission systems, tactical data link systems (TDLs), and user applications to the objective airborne network systems. Therefore, they are only temporary until all platforms utilize a standardized IP-radio for transmission.
Performance Enhancing Proxies
Performance Enhancing Proxies (PEPs) improve the performance of user applications running across the Airborne Network by countering wireless network impairments, such as limited bandwidth, long delays, high loss rates, and disruptions in network connections. Proxy systems are implemented between the user application and the network and can be used to improve performance at the application and transport functional layers of the OSI model. Some techniques that can be employed include:• Compression: Data compression or header compression can be used to minimize the number of bits sent over the network.
• Data bundling: Smaller data packets can be combined (bundled) into a single large packet for transmission over the network.
• Caching: A local cache can be used to save and provide data objects that are requested multiple times, reducing transmissions over the network (and improving response times).
• Store-and-forward: Message queuing can be used to ensure message delivery to users who become disconnected from the network or are unable to connect to the network for a period of time. Once the platform connects, the stored messages are sent.
• Pipelining: Rather than opening several separate network connections pipelining can be used to share a single network connection for multiple data transfers.
• Protocol streamlining: The number of transmissions to set up and take down connections and acknowledge receipt of data can be minimized through a combination of caching, spoofing, and batching.
• Translation: A translation can be performed to replace particular protocols or data formats with more efficient versions developed for wireless environments.
• Embedded acknowledgments: Acknowledgements can be embedded in the header of larger information carrying packets to reduce the number of packets traversing the network.
Platform Categories
To categorize a specific airborne asset or class communications equipment all aircraft are divided into three main categories. These categories are determined by the types of missions the aircraft typically performs. The aircraft also fit into each category based on the type of equipment they can equip the airframe with. Each of the following sections outlines these three main categories.Fighter Platforms
An airborne fighter platform flight profile includes periods of stable flight patterns and dynamic maneuvers at high speeds. Its relatively small size limits the amount of space available for mounting antennas and installing equipment. It will be employed as part of a strike package or combat air patrolCombat air patrol
Combat air patrol is a type of flying mission for fighter aircraft.A combat air patrol is an aircraft patrol provided over an objective area, over the force protected, over the critical area of a combat zone, or over an air defense area, for the purpose of intercepting and destroying hostile...
(CAP). The strike package or CAP will have supporting airborne C2 and ISR platform(s), tanker (refueling) platform(s), and ground C2 platform(s). Each airborne fighter platform requires connectivity to all other strike package or CAP and supporting platforms; however, a majority of information will be exchanged between airborne fighter platforms. This is driven in large part because of the need for frequent situational awareness and target sorting updates in a highly mobile environment. Pilots will be provided services such as real-time data
Real-time data
Real-time data denotes information that is delivered immediately after collection. There is no delay in the timeliness of the information provided. Real-time data is often used for navigation or tracking....
, digital voice, and interactive data sharing.
Airborne fighter platforms will participate in both tethered and flat ad-hoc network topologies. A tethered topology would primarily be used for reachback and forwarding between the airborne fighter platform and supporting elements. A flat ad-hoc topology would be used between airborne fighter platforms in a strike package or CAP for the more frequent information exchanges. The figure outlines the minimum equipment requirements to support a fighter platform.
C4ISR Platforms
A C4ISRC4ISR
C4ISR may refer to:* the C4ISR concept of Command, Control, Communications, Computers, Intelligence, Surveillance and Reconnaissance, the U.S. term for C4ISTAR* C4ISR Journal, a journal published by the Defense News Media Group...
platform flight profile includes periods of en route flying and repeated, stable flight patterns. The relatively large size enables space available for mounting antennas and installing significant communications equipment to accommodate
multiple mission crew functions. It will host up to three dozen mission crew members, including a communications operator. A C4ISR platform’s mission applications and sensors will support multiple capabilities and mission types. Mission durations for any single aircraft and crew could range up to 12 hours; with aerial refueling it could be extended to 24 hours. These platforms often operate beyond line-of-sight of ground infrastructure and could be employed as a stand-alone or as part of a strike package or CAP in support of a strike package. C4ISR aircraft require a broad range of connection capability to connect peer-to-peer with other C4ISR aircraft or serve as a hub to connect fighter platform aircraft. The services provided by C4ISR aircraft include real-time data
Real-time data
Real-time data denotes information that is delivered immediately after collection. There is no delay in the timeliness of the information provided. Real-time data is often used for navigation or tracking....
, voice, video, bulk data transfer, and interactive data.
C4ISR platforms will participate in both tethered and tiered ad-hoc network topologies. A tethered topology would primarily be used for reachback and forwarding between the C4ISR platform, GTACS, and strike package or CAP aircraft. A tiered ad-hoc topology would be used between the C4ISR platform and airborne fighter platforms in a strike package or CAP. The figure outlines the minimum equipment requirements to implement the operations of a C4ISR platform.
Airborne Communications Relay Platforms
Airborne communications relay platform flight profile includes periods of en route flying and repeated, stable flight patterns. The relatively large size of widebodies theoretically enables space available for mounting antennas and installing significant communications equipment. UAVs offer long endurance and high altitude, which give wide area air and surface coverage and good optical paths to satellites. The mission of an airborne communications relay platform is to be employed as part of and/or support to C4ISR constellation and/or strike package(s) or CAP. The communications relay platform provides connectivity between elements of a strike package, CAP aircraft, C4ISR platforms, and GTACS platforms that require range extension or internetworking and gateway functions between networks for information interoperability. The services necessary for communication relay platforms include real-time data transfer, voice, video, bulk data, and interactive data transfer.Airborne communications relay platforms will participate in both tethered and tiered ad-hoc network topologies. A tethered topology would primarily be used for reachback and forwarding between the C4ISR platform, GTACS, and strike package or CAP aircraft. A tiered ad-hoc topology would be used between the C4ISR platform and airborne fighter platforms in a strike package or CAP. The figure outlines the minimum equipment requirements to implement the operations of a communications relay platform.
Current Technology Restrictions
Many challenges lie ahead before the AN will exist as described in this document. Many of the challenges currently lie in the Legacy system avionics found on all aircraft. The biggest obstacle is a lack in bandwidth. Until more optics are integrated into aircraft systems, this system will lag in data transfer speeds and latency. One technology under research to resolve this problem is the Navy’s research into highly integrated photonics (HIP) to manage communication of the sensor suite on aircraft. The technique runs radio frequencies over fiber optics and is currently being integrated into the EA-6B Prowler electronic warfare jet. [4]Security of this network is another huge obstacle. The goal is to give the system a low probability of jamming and interception. Many ideas of how to protect the system are being investigated and tested. Traditional methods of authentication and authorization are being used, to include Biometrics
Biometrics
Biometrics As Jain & Ross point out, "the term biometric authentication is perhaps more appropriate than biometrics since the latter has been historically used in the field of statistics to refer to the analysis of biological data [36]" . consists of methods...
, cryptographic tokens, and integrated Public Key Infrastructure
Public key infrastructure
Public Key Infrastructure is a set of hardware, software, people, policies, and procedures needed to create, manage, distribute, use, store, and revoke digital certificates. In cryptography, a PKI is an arrangement that binds public keys with respective user identities by means of a certificate...
.
Commercial Off the Shelf
Commercial off-the-shelfCommercial off-the-shelf
In the United States, Commercially available Off-The-Shelf is a Federal Acquisition Regulation term defining a nondevelopmental item of supply that is both commercial and sold in substantial quantities in the commercial marketplace, and that can be procured or utilized under government contract...
(COTS) creates extreme engineering challenges. While it offers flexibility in application and saves money in production it is incredibly difficult to adapt to various application. Getting COTS to install in applications it was not designed for continues to be a vast engineering challenge as military researchers work to integrate civilian L-3 radio and FPGA technology into reconnaissance aircraft designed in the 60s.