International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / As aircraft become more complex and require more resources over larger areas, the challenge of the test ranges is to provide economical solutions to move telemetry data from the test article to the data processing facility. Edwards AFB is in the process of upgrading the ground transmission facilities to transport data including telemetry using Asynchronous Transfer Mode (ATM). This paper documents the challenge of supporting telemetry over ATM, different approaches that are available, the benefits of using ATM, and discussion of candidate hardware options. The effort at Edwards include the linking of the major range facilities over a fiber optic backbone and links to other major test ranges in the Southwest Range Complex via microwave. The fiber optic backbone is expected to be OC-12c (622 Mbps) ATM supporting new capabilities as well as all of the legacy systems. The backbone system will be designed so that migration to OC-48 is possible without service disruption. The microwave links are multiple DS-3 capable. Some of these DS-3s may support legacy systems, but the ability to link ranges using ATM is expected simultaneously.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / As the flight test community moves into the 21st century, the ever increasing demand for higher telemetry data rates and the need to transport additional data types is becoming the challenge of every flight test range. The evolution of the flight test range has grown from low telemetry data rates and a few 2400 baud tracking sources into high-speed telemetry, GPS based tracking, networking, digital video, and more. Recognizing the need to change the way data is managed has resulted in an effort to redefine the work centers at the Air Force Flight Test Center (AFFTC) at Edwards AFB. The Technical Control Center (TCC) within the Ridley Mission Control Center at Edwards AFB is currently being relocated with the intent of achieving tomorrow’s vision, while supporting the missions of today. One major goal of this redefinition is the elimination of as much analog transmission equipment as possible in favor of digital transmission. The new digital range requires management of data and allocation of that management in different ways than the past. Moving to an all-digital range has advantages that are just now being realized. This paper outlines the current and future design, configuration, maintenance, and operation of the TCC and touches on how some of the other range functions are impacted. In addition, the challenges and benefits of implementing the next generation in range communications will be discussed.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / During the cold war, undersea warfare (USW) was perceived as a large-area, deep-water operation. The need for USW has recently shifted to the shallow water, littoral environment. Consequently, US naval forces must train to operate in these littoral environments where regional conflicts are most likely to occur. In light of these requirements the Shallow Water Training Range (SWTR) has been initiated. Telemetry is used in the following areas of SWTR: fiber optic, microwave, RF and underwater. Only phase 1 of 8 phases of the program is executing therefore SWTR is a good opportunity for telemetry industry involvement.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Asynchronous Transfer Mode (ATM) is a technology that is experiencing tremendous growth in the commercial telecommunications sector. Leveraging commercial investment and introducing ATM into today’s flight test range, while ensuring that all requirements are satisfied, are paying large dividends in capability and efficiency. The flight test community imposes unique requirements specifically with regards to telemetry that are not the norm of the commercial telecommunications industry. Efforts are underway at the Air Force Flight Test Center (AFFTC), Edwards Air Force Base (AFB) to implement an ATM system for all range communications. This paper addresses the unique requirements imposed by the flight test community, a revolutionary breakthrough from a commercial ATM vendor, and other challenges experienced while implementing this system. The system being implemented at Edwards will carry all types of range data over SONET/ATM hybrid equipment and interface to other flight test ranges and facilities over a mix of commercial leased lines and dedicated microwaves.

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Asynchronous Transfer Mode (ATM) Conversion Device (ACD) System is based on state-of-the-art ATM technology. The system interfaces between high-rate ECL/RS-422 raw data bitstreams and Synchronous Optical Network (SONET) OC-3 fiber. The SONET OC-3 interface uses ATM Adaptation Layer Type Five (AAL5) format. The system exceeds its 50 Mbps raw data, single stream requirement and provides single stream raw data throughput at rates up to 75 Mbps. With ATM and SONET packaging overhead, this translates into 90 Mbps on the OC-3 fiber. In addition to high-rate throughput, the system provides multiplexing and demultiplexing of multiple stream throughput based on the ATM cell header Virtual Path and Virtual Channel Identifier (VPI/VCI) values. The system is designed with the flexibility to provide between three and six throughput channels. All of which are multiplexed/demultiplexed to and from the same OC-3 interface. Multiple stream cumulative raw data throughput rates of up to 80 Mbps, or 96 Mbps on the fiber, have successfully run.

International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper presents a progress report on Global Air Traffic Management (GATM) avionic system test activities at the Air Force Flight Test Center. In many parts of the world today the continuing growth of commercial air traffic is running up against limits brought on by overuse of aviation resources. Air corridors in Europe and on transoceanic air routes are operating at maximum capacity. Civil Aviation Authorities (CAAs) are working these challenges on two levels—near-term incremental improvements and long-term visionary changes. Each country has a CAA; ours being the Federal Aviation Administration (FAA). Near-term solutions focus on better utilization of resources such as air space and frequency spectrum and improved performance of air traffic control facilities. Long-term visionary changes, such as free flight, could fundamentally change the current civil aviation business process model. CAA policies and standards are driving near-term improvements and migration toward long-term objectives. This initiative is referred as Communication Navigation Surveillance/Air Traffic Management (CNS/ATM). Implementation of the U.S. military’s vision, Global Reach/Global Power, requires the ability to rapidly deploy armed forces to major regional conflicts anywhere in the world, and to sustain these forces for as long as it takes to resolve these conflicts. To achieve this goal and accomplish rapid deployments while at the same time minimizing costs, the Air Force has adopted a solution that makes extensive use of CNS/ATM. The Air Force calls its initiative Global Air Traffic Management (GATM). Air Force aircraft equipped with GATM avionics will be able to use CNS/ATM capabilities such as reduced vertical separation minimum (RVSM), 8.33 kHz data links, automatic dependent surveillance - broadcast (ADS-B), and global communication networks. These capabilities make possible improved flight safety, lower fuel costs, and quicker turn times. The Air Force Flight Test Center supports the GATM initiative by providing Air Traffic Control (ATC) Communications Test Facilities and Avionic System Test (ACTFAST) capabilities to support aircraft modification programs.

The immune system recognizes and eliminates an enormous array of pathogens due to the diverse antigen receptor repertoire of T and B lymphocytes. However, the development of lymphocytes bearing receptors with unique specificities requires the generation of programmed double strand breaks (DSB) coupled with bursts of proliferation, rendering lymphocytes susceptible to mutations and oncogenic transformation. Thus, mechanisms responsible for monitoring global genomic integrity, such as those coordinated by the ATM (ataxia-telangiectasia mutated) kinase, must be activated during lymphocyte development to limit the oncogenic potential of antigen receptor locus recombination. I show that ATM deficiency compromises TCRα recombination and the post-mitotic survival of T-cell receptor αβ (TCRαβ+) CD4+CD8+ (DP) thymocytes, providing a molecular and developmental basis for the immunodeficiency characteristic of ATM loss. Moreover, I show that in early thymocyte progenitors undergoing TCRβ recombination, ATM loss leads to cell cycle defects and developmental arrest, likely facilitating the acquisition of mutations that contribute to leukemogenesis. Using ATM deficiency as a murine model of T cell precursor acute lymphoblastic leukemia (T-ALL), I demonstrate that IL-7 signaling, a critical survival and proliferation signal during early stages of normal thymocyte development, is also required for leukemic maintenance. Moreover, we show for the first time that in normal and leukemic thymocyte precursors, interleukin 7 receptor (IL-7R) expression and function are controlled by Notch signaling, a key determinant of T cell fate. Collectively, these findings provide insight into the mechanisms by which ATM promotes normal lymphocyte development and protects from neoplastic transformation, while establishing the groundwork for assessing the molecular events that lead to the initiation and stepwise progression of T cell leukemogenesis.

Ataxia telangiectasia mutated (ATM) is a serine-threonine protein kinase and major regulator of the DNA damage response (DDR). One critical ATM target is protein phosphatase 2A (PP2A) known to regulate diverse cellular processes such as mitosis and cell growth as well as dephosphorylation of many proteins during the recovery from the DDR while returning the cell to normalcy. Interestingly, ATM and PP2A are known to form an auto-regulatory yin-yang kinase-phosphatase relationship. Herein, we show that the phosphorylation of the PP2A-Aα structural subunit at S401 by ATM results in nuclear export, which regulates the DDR at multiple levels and affects genomic stability and cell growth. We generated PP2A-Aα conditional knockout mouse embryonic fibroblasts expressing PP2A-Aα-WT, S401A (cannot be phosphorylated), or S401D phosphomimetic) transgenes by floxing out the endogenous PP2A-Aα alleles with Cre. The S401D mutant cells displayed increased ERK and AKT signaling, resulting in an enhanced growth rate. Phosphorylation of PP2A-Aα at S401 caused the dissociation of ATM with the holoenzyme, an effect that could be recapitulated with S401D. Additionally, the S401A and S401D mutants exhibited significantly more chromosomal aberrations and underwent increased mitotic catastrophe after radiation. Both the S401A and the S401D cells showed impaired DSB repair (Non-homologous end joining and Homologous recombination repair) and exhibited delayed DNA damage recovery, which was reflected in reduced radiation survival. Time-lapse video and cellular localization experiments showed that the PP2A-Aα subunit was exported to the cytoplasm after radiation possibly by CRM1, a nuclear export protein, in line with the very rapid pleiotropic effects seen. In conclusion, our study demonstrates using a genetically defined system that ATM phosphorylation of a single, critical amino acid S401 is essential for regulating DDR. To study how the interplay between ATM and PP2A affects DDR in the brain, we are in the process of generating a brain specific PP2A-Aα conditional knockout mouse. Loss of many DDR related proteins like ATM and PP2A can lead to severe neuropathological effects. This model will be helpful in dissecting the PP2A-Aα/ATM regulatory circuit in the brain in response to DDR.

A garantia de qualidade de serviço (QoS) tem-se demonstrado muito importante em aplicações em tempo real. Este trabalho apresenta um estudo sobre Mecanismos de Policiamento na tecnologia A TM, mais especificamente, sobre o funcionamento do Mecanismo Dual Leaky Bucket, utilizado pela classe de serviço VBR em rede ATM. Para este estudo foi implementado um simulador por software do mecanismo Dual Leaky Bucket. Foram analisados dois tipos de tráfegos de vídeo com compressão MPEG-2, com pouca e muita movimentação. A partir da simulação pôde-se analisar como o erro na definição de parâmetros do contrato de QoS definidos pelo usuário no estabelecimento da conexão pode levar ao aumento na taxa de perda de informações e, conseqüentemente, a degradação da qualidade necessária pela aplicação / The guarantee of quality of service (QoS) has been demonstrating very important in real time applications. This work presents a study on Policing Mechanisms in the ATM technology, more specifically, on the operation of the Dual Leaky Bucket Mechanism, used by the class of service VBR in ATM networks. For this study a Dual Leaky Bucket mechanism simulator by software was implemented. Two kinds of MPEG-2 video traffics were analyzed with a little and a lot of movement. The simulation shows how a mistake in the definition of parameters in the QoS contract, defined by user, during of the connection establishment can leads to increase of information loss rate and, consequently, the degradation of the necessary quality for the application

Asynchronous Transfer Mode (ATM) can provide deterministic channels as required for real time signals, as well as statistical multiplexing. For this reason, ATM has been chosen as the underlying technology for providing a Broadband Integrated Services Digital Network (B-ISDN). Two main classes of services are expected to be supported over a B-ISDN. These classes are real-time services and data services. Data services include computer communications (Local Area Network (LAN) interconnections) and general non-real time traffic, such as file transfer and small transactions.The provision of data services over ATM are better served with statistical multiplexing, provided that the service is loss-free. For multiplexing to be loss-free and still statistical, while the maximum service rate is fixed, the multiplexer tributaries must be controlled in flow, to assure no overflow of the multiplexing buffer. Provision of a service over ATM is accomplished by an ATM layer. Transfer Capability (ATC).This thesis investigates and reports on the operating characteristics of an ATM layer Transfer Capability proposed to the International Telecommunications Union (ITU), and called Controlled Cell Transfer (CCT). CCT uses credit window based flow control on links and a quota based control in switches, and will give loss free statistical multiplexing for data. Other ITU defined ATCs are examined in regard to data service provision and compared with CCT. It is found that only CCT can provide a fast and at the same time efficient data service.The thesis also examines the impact that support of the CCT capability would have on an ATM switch, through determination of required functionality, and mapping of the required functions into a switch design. Finally, an architecture and implementation of an ATM switch is described that would support the CCT as well as the Deterministic Bit Rate (DBR) ++ / transfer capability, and would provide efficient data and real-time services.