NASA Scientific and Technical Aerospace Reports

safety, and real time performance of software and systems in such a way that the behavior of the system is always predictable.
In the last few years, avionics systems have evolved in a significant way as it may be observed at the two major aeronautics
manufacturer Boeing and Airbus: the trend is to replace classical approaches to avionics by Integrated Modular Avionics
(IMA). This evolution may be schematically described as follows: 1) In classical avionics, embedded systems are made of one
computer for each embedded function (e.g., flight command system, autopilot, or flight management system). Whenever two
functions had to communicate with each other, a physical connection is drawn between their support computers. 2) In IMA,
a set of computers provides generic resources to a set of functions. They are linked to each other by means of an avionics
embedded network. In this context, functions now share computer resources (e.g., computational or memory) and
communication resources. This new orientation gives rise to a set of new complex problems which were solved de facto by
the architectural choice of classical avionics: 1) Two functions sharing a given resource must be isolated from each other,
especially if these two functions do not have the same level of criticality. 2) End-to-end performance of function connection
must be predictable; this has consequences both on the use of shared computer resources and on the communication medium.
So major problems in the area of Verification and Validation of embedded systems are concerned with: 1) Middleware, the
central point being that the operating system allow functions to share the resources. 2) Application software, which are to be
run on a specific computer resource. 3) Communication systems. 4) Man-Machine Interfaces, which have specific concerns.
Indeed, the use of digital display, and the complexity and variety of information the pilot is to be provided with, demand
special care. Finally IMA opens the path toward modular verification and validation and the way to take it into account in a
certification process.
Derived from text
Avionics; Flight Management Systems; Software Engineering; Applications Programs (Computers); Embedded Computer
Systems; Automatic Pilots; Real Time Operation
20060001848 Army Research Lab., Adelphi, MD USA
Selective Routing for the Mobile IP LAN Protocol
Luu, Brian B.; Gopaul, Richard D.; Sep. 1, 2005; 18 pp.; In English
Report No.(s): AD-A440378; ARL-TR-3661; No Copyright; Avail.: Defense Technical Information Center (DTIC)
Mobile Internet Protocol (IP) Local Area Network (LAN) is a technique developed by the U.S. Army Research Laboratory
which allows a LAN to be IP mobile when it attaches to a foreign IP-based network and uses this network as a means to retain
connectivity to its home network. This technique is a form of virtual private networking which enables a LAN to roam on the
Internet. In this report, we describe implementation of selective routing for the Mobile IP LAN technique in order to improve
network communications for a mobile LAN. The selective routing implementation performs network address translation to
route selected network application packets based on IP address (layer 3 address) or transport identifier (layer 4 port) through
the foreign network. All other traffic is tunneled to the home network for routing, as in the conventional implementation of
Mobile IP LAN. This improves the network latency for those applications that do not specifically require the IP and transport
layers to be intact. To evaluate the performance of the Mobile IP LAN with selective routing technique, we have implemented
the following three different scenarios in which we vary the Internet connection of Mobile LAN: direct LAN-to-LAN
connection at the home network, connection at a foreign network using the secure mobile IP LAN technique, and connection
at a foreign network using the secure Mobile IP LAN with selective routing technique. We compare the data rates of file
transfers between a node on the mobile LAN and a node on the Internet in these three cases.
DTIC
Internets; Local Area Networks; Protocol (Computers)
20060001860 Air Force History Support Office, Bolling AFB, Washington, DC USA
The USA Air Force and the Culture of Innovation, 1945-1965
Johnson, Stephen B.; Jan. 1, 2002; 300 pp.; In English
Report No.(s): AD-A440395; No Copyright; Avail.: Defense Technical Information Center (DTIC)
This monograph shows how the application of systems management by the U.S. Air Force to its ballistic missiles and
computer programs not only produced critical new weapons, but also benefited U.S. industry. Systems management
harmonized the disparate goals of four interest groups. For the military it brought rapid technological progress; for scientists,
new products; for engineers, dependability; and for managers, predictable cost. The process evolved, beginning shortly after
the end of World War II, when Gen. Henry H. ‘Hap’ Arnold directed that the Army Air Forces continue its wartime
collaboration with the scientific community. This started as a voluntary association, with the establishment of the Scientific
Advisory Board and Project RAND. In the early 1950s, the Air Force reorganized its research and development function with
the creation of Air Research and Development Command (ARDC) and the Air Staff’s office of deputy chief of staff for
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