• VEHICLE MONITORING SYSTEM VIA GPS, GIS AND GPRS

      Lei, Huang; Qishan, Zhang; Xingjian, Huang; Beihang University (International Foundation for Telemetering, 2003-10)
      Vehicle Monitoring System (VMS) has being introduced into the world marketplace with the hope that it will help alleviate traffic congestion and the associated environmental pollution. In this paper we give an overview of system composition and principle of the VMS and several communications link solutions in China. We review technologies and focus on the key technological issues about the integration of VMS with the GPRS wireless mobile network and the Internet.
    • FLIGHT TEST MONITORING OF AVIONIC FIBRE CHANNEL NETWORKS FOR RECORDING AND TELEMETRY

      Zettwoch, Robert N.; The Boeing Company (International Foundation for Telemetering, 2003-10)
      The F/A-18E/F Super Hornet fighter aircraft program is currently flight testing a Fibre Channel Network (FCN), which will initially replace certain Avionics Systems’ MIL-STD-1553 communications. The Advanced Mission Computers and Displays (AMC&D) and the Active Electronically Scanned Array (AESA) RADAR are replacing their MIL-STD-1553 counterparts to fulfill performance enhancements and growing data requirements. The maximum amount of data that can be transferred between these systems is significantly increasing. Each remote terminal on a MIL-STD-1553 bus can transmit or receive approximately 1Mbps. Each node on a FCN can simultaneously transmit and receive 1Gbps. With a Fibre Channel Network Switch (FCNS), multiple systems can communicate concurrently, thus increasing overall system throughput even further. Several other systems will be replaced in the near future utilizing the FCNS. The Fibre Channel Interface Unit (FCIU) was designed for the F/A-18E/F AESA program as a nonintrusive way to monitor multiple nodes, extract node specific information, and record this information using conventional on-board recorders. In order to reduce the risks associated with developing hardware and software concurrently with the Avionic System’s protocol, the FCIU was developed as an upper-level-protocol (ULP) (layer FC-4) independent device. Two big advantages of ULP independence are the avoidance of complex protocol programming for each different type of monitored network system and the non-intrusive nature of the FCIU connection to the FCN. This facilitates the quick installation of the FCIU to monitor any FC network and the FCIU IRIG-106 PCM type output lends itself to be integrated quickly into a typical Flight Test data recording or telemetry system.
    • Performance of the IEEE 802.11b WLAN Standards for Fast-Moving Platforms

      Kasch, William T.; Burbank, Jack L.; Andrusenko, Julia; Lauss, Mark H.; Johns Hopkins University; Yuma Test Center (International Foundation for Telemetering, 2003-10)
      This paper addresses the physical and MAC layer performance of the IEEE 802.11b wireless local area networking (WLAN) standard in range-extended outdoor applications for high speed network platforms. Physical layer performance is quantified by bit error rate (BER) and packet error rate (PER) vs. range performance as well as acquisition and tracking performance considering Doppler effects caused by such high-speed platforms. This performance assessment is ascertained through the use of modeling and simulation and hardware-in-the-loop testing.
    • TCP EXTENSIONS FOR A SATELLITE CHANNEL

      Hu, Xuenan; Zhou, Tingxian; Harbin Institute of Technology (International Foundation for Telemetering, 2003-10)
      The usage of Internet is explosively growing. Satellite has become a choice solution breaking through the bandwidth bottleneck and the terrain limit. TCP, which is well suited to terrestrial networks, performs poorly on a satellite channel. The reduced efficiency and QoS(Quality of Service) mainly result from three characteristics of a satellite link: higher bit error rate, the high latency, asymmetry. For this issue, the paper presents connection-subsection network architecture, and brings forward S-TCP based on the architecture.
    • AN INTEGRATED DESIGN, TEST AND EVALUATION SYSTEM FOR GPS RECEIVER

      Yanhong, Kou; Dongkai, Yang; Qishan, Zhang; Beihang University (International Foundation for Telemetering, 2003-10)
      An integrated design, Test and Evaluation (T&E) system for GPS receiver is proposed in the paper, which can perform T&E early in R&D cycle, and combine new designs into a conceptual GPS receiver directly. The flowchart of its development mode is given. The architectures of the system, especially of the signal-computing software are described with frame diagrams. The mathematical models of three reference points are derived, with the impact of oscillator errors modeled. Future plans and further developments are also discussed.
    • ACHIEVING DATA TRANSFER AND SERVICE MANAGEMENT INTEROPERABILITY IN SATELLITE CONTROL NETWORKS

      Sunshine, Carl; Williams, Lance; The Aerospace Corporation; Northrop Grumman (International Foundation for Telemetering, 2003-10)
      A critical area for achieving interoperability between satellite control networks is the means chosen to interconnect Satellite Operations Centers and remote antenna systems. The CCSDS Space Link Extension (SLE) services are good candidates for this purpose, but national security space activities have demanding requirements for accuracy of data transfer, controlled delay, and security, which may not be fully achievable with the existing recommendations. The US Air Force developed a test bed to evaluate the SLE protocols during live satellite contacts, for both data transfer and management functions such as scheduling, configuring ground resources, and status reporting. Performance was generally satisfactory, but several extensions were found to be necessary. The SLE services provide a promising basis for use in ground stations to support both legacy Air Force interfaces and newer standards based satellite control services.
    • PEER-TO-PEER NETWORKING WITH TELEMETRY RECORDERS

      Kortick, David N.; Astro-Med, Inc. (International Foundation for Telemetering, 2003-10)
      Telemetry recorders have historically been used as standalone systems with each user responsible for operation and data interpretation on that system. Utilizing the latest peerto- peer networking technologies, telemetry recorders can now be linked to provide instantaneous communication between systems. This fully distributed, network-based architecture can be used for command and control of multiple recorders, as well as message passing between them. A centralized server is no longer required, resulting in considerable logistical and cost savings. The peer-to-peer communication topology can efficiently connect telemetry recorder “islands of information”.
    • AN INTRODUCTION TO LOW-DENSITY PARITY-CHECK CODES

      Moon, Todd K.; Gunther, Jacob H.; Utah State University (International Foundation for Telemetering, 2003-10)
      Low-Density Parity-Check (LDPC) codes are powerful codes capable of nearly achieving the Shannon channel capacity. This paper presents a tutorial introduction to LDPC codes, with a detailed description of the decoding algorithm. The algorithm propagates information about bit and check probabilities through a tree obtained from the Tanner graph for the code. This paper may be useful as a supplement in a course on error-control coding or digital communication.
    • IMPROVING REAL-TIME LATENCY PERFORMANCE ON COTS ARCHITECTURES

      Bono, John; Hauck, Preston; NetAcquire Corporation (International Foundation for Telemetering, 2003-10)
      Telemetry systems designed to support the current needs of mission-critical applications often have stringent real-time requirements. These systems must guarantee a maximum worst-case processing and response time when incoming data is received. These real-time tolerances continue to tighten as data rates increase. At the same time, end user requirements for COTS pricing efficiencies have forced many telemetry systems to now run on desktop operating systems like Windows or Unix. While these desktop operating systems offer advanced user interface capabilities, they cannot meet the realtime requirements of the many mission-critical telemetry applications. Furthermore, attempts to enhance desktop operating systems to support real-time constraints have met with only limited success. This paper presents a telemetry system architecture that offers real-time guarantees while at the same time extensively leveraging inexpensive COTS hardware and software components. This is accomplished by partitioning the telemetry system onto two processors. The first processor is a NetAcquire subsystem running a real-time operating system (RTOS). The second processor runs a desktop operating system running the user interface. The two processors are connected together with a high-speed Ethernet IP internetwork. This architecture affords an improvement of two orders of magnitude over the real-time performance of a standalone desktop operating system.
    • DESIGN OF A GIGABIT DATA ACQUISITION AND MULTIPLEXER SYSTEM

      Berdugo, Albert; Teletronics Technology Corporation (International Foundation for Telemetering, 2003-10)
      Gigabits and hundreds of megabit communication buses are starting to appear as the avionic buses of choice for new or upgraded airborne systems. This trend presents new challenges for instrumentation engineers in the areas of high speed data multiplexing, data recording, and data transmission of flight safety information. This paper describes the approach currently under development to acquire data from several types of high-speed avionic buses using distributed multiplexer and acquisition units. Additional input data may include PCM, wideband analog data, discrete, real-time video and others. The system is capable of multiplexing and recording all incoming data channels, while at the same time providing data selection down to the parameter level from input channels for transmission of flight safety information. Additionally, an extensive set of data capture trigger/filter/truncation mechanisms are supported.
    • SMALL VOLUME, FEHER-PATENTED QUADRATURE PHASE SHIFT KEYING, JR VERSION, TELEMETRY TRANSMITTER

      Bottenfield, Joe; Moore, Vern; Herley Lancaster (International Foundation for Telemetering, 2003-10)
      This paper describes the implementation of a Feher-Patented Quadrature Phase Shift Keying (FQPSK) waveform variant that reduces overall design complexity, which in turn results in a telemetry transmitter that provides all the benefits of the existing FQPSK-B waveform, in a 3.0 x 2.0 x 1.0 volume. This variant is referred to the as the FQPSK-JR version. This waveform differs from the “near constant” envelop response of the qualified Herley airborne FQPSK-B telemetry transmitter in terms of the time domain wavelet transition functions and the amplitude scaling term associated with those functions. The end result is a “constant envelop” design, which employs simplified antialias filtering and more efficient digital design techniques.
    • CCSDS FILE DELIVERY PROTOCOL (CFDP) – WHY IT’S USEFUL AND HOW IT WORKS

      Ray, Tim; National Aeronautics and Space Administration; Goddard Space Flight Center (International Foundation for Telemetering, 2003-10)
      Reliable delivery of data products is often required across space links. For example, a NASA mission will require reliable delivery of images produced by an on-board detector. Many missions have their own (unique) way of accomplishing this, requiring custom software. Many missions also require manual operations (e.g. the telemetry receiver software keeps track of what data is missing, and a person manually inputs the appropriate commands to request retransmissions). The Consultative Committee for Space Data Systems (CCSDS) developed the CCSDS File Delivery Protocol (CFDP) specifically for this situation. CFDP is an international standard communication protocol that provides reliable delivery of data products. It is designed for use across space links. It will work well if run over the widely used CCSDS Telemetry and Telecommand protocols. However, it can be run over any protocol, and will work well as long as the underlying protocol delivers a reasonable portion of the data. The CFDP receiver will autonomously determine what data is missing, and request retransmissions as needed. The CFDP sender will autonomously perform the requested transmissions. When the entire data product is delivered, the CFDP receiver will let the CFDP sender know that the transaction has completed successfully. The result is that custom software becomes standard, and manual operations become autonomous. This paper will consider various ways of achieving reliable file delivery, explain why CFDP is the optimal choice for use over space links, explain how the core protocol works, and give some guidance on how to best utilize CFDP within various mission scenarios. It will also touch on additional features of CFDP, as well as other uses for CFDP (e.g. the loading of on-board memory and tables).
    • RIPCom – A REMOTE INTERNET PROTOCOL COMMUNICATION SYSTEM

      Lawson, Shawn; Brentzel, Kelvin; Harris, Carol; Coronado, Patrick; Pasciuto, Michael; Greenfield, Paul; Zajkowski, Thomas; Global Science and Technology; National Aeronautical Space Administration; United States Forest Service (International Foundation for Telemetering, 2003-10)
      NASA Goddard Space Flight Center (GSFC) is developing the Remote Internet Protocol Communication (RIPCom) system, which is a wireless communication system that makes an aircraft look like a network node in the sky. RIPCom provides an Ethernet to Radio Frequency (RF) connection solution for real-time data transmission, and its design allows the end points of the communication system to become nodes on a network with assigned IP addresses. RIPCom’s design is especially suitable for Unmanned Aerial Vehicle (UAV) applications, and its versatility makes it valuable for many systems that require a high speed, digital wireless network.
    • INTEROPERABILITY TESTING OF THE CCSDS FILE DELIVERY PROTOCOL

      Carper, Richard D.; Space Data Systems (International Foundation for Telemetering, 2003-10)
      The CCSDS recently developed the CCSDS File Delivery Protocol which can operate in configurations from simple point-to-point space/ground systems to complex arrangements of orbiters, landers, relaying spacecraft, and multiple ground facilities. An international interoperability test program has been developed in support of the development and fielding of the protocol. The first phase was successfully completed in the Fall of 2002. The second phase is to be completed about the time of the presentation of this paper. First phase testing involved five independent implementations of the Core Procedures of the protocol. Since these Procedures are for point-to-point file transfers, only two protocol “entities” were involved in each executed test. The second phase tests other Procedures, which involve multi-hop transferring of files. This phase will involve two separate, independent implementations, with one implementation being hosted on multiple hardware/OS platforms. Each test will involve three or more entities.
    • A LINEAR PAM-BASED RECEIVER FOR MULTI-H CPM

      Rice, Michael; Perrins, Erik; Brigham Young University (International Foundation for Telemetering, 2003-10)
      A linear pulse-amplitude modulation (PAM) receiver for the ARTM Tier II multi-h waveform is presented. The receiver is optimal and can be implemented using maximum likelihood sequence estimation (MLSE). The linear signal model also allows many attractive complexity reductions. The performance of these reduced-complexity receivers is evaluated via computer simulation. One simplified receiver consists of three matched filters and a 32-state Viterbi trellis and is shown to perform with a 1:5 dB degradation relative to the optimal receiver.
    • EXPERIMENTAL RESULTS FOR PCM/FM, TIER 1 SOQPSK, AND TIER II MULTI-H CPM WITH TURBO PRODUCT CODES

      Geoghegan, Mark; Nova Engineering Inc. (International Foundation for Telemetering, 2003-10)
      Improving the spectral-efficiency of aeronautical telemetry has been a principal area of research over the last several years due to the increasing demand for more data and the limitation of available spectrum. These efforts have lead to the development of the ARTM Tier 1 SOQPSK and Tier II Multi-h CPM waveforms which improve the spectral efficiency by two and three times, as compared to legacy PCM/FM, while maintaining similar detection efficiency. Now that more spectrally efficient waveform options are becoming available, another challenge is to further increase the detection performance. Better detection efficiency translates into additional link margin that can be used to extend the operating range, support higher data throughput, or significantly improve the quality of the received data. It is well known that Forward Error Correction (FEC) is one means of achieving this objective at the cost of additional overhead and increased receiver complexity. However, as mentioned above, spectral efficiency is also vitally important meaning that the FEC must also have a low amount of overhead. Unfortunately, low overhead and high coding gain are generally conflicting trades, although recent work has shown that Turbo Product Codes (TPC) are a particularly attractive candidate. Computer simulations predict that very impressive gains in detection performance are possible for a relatively small increase in bandwidth. The main drawbacks are the additional complexity of the decoding circuitry and an increase in receive side latency. This paper presents the latest simulation and hardware performance results of PCM/FM, SOQPSK, and Multi-h CPM with TPC.
    • RANGE AND SPACE NETWORKING - WHAT’S MISSING

      Rash, James; Hogie, Keith; Criscuolo, Ed; Parise, Ron; NASA; Computer Sciences Corporation (International Foundation for Telemetering, 2003-10)
      A large selection of hardware and software components are readily available for supporting Internet communication in the ground network environment. These components can be used to construct very powerful and flexible communication systems. The Operating Missions as Nodes on the Internet (OMNI) project at NASA/GSFC has been defining and demonstrating ways to use standard Internet technologies for future space communication. Theses concepts and technologies are also applicable to test range telemetry applications. This paper identifies the network equipment and protocols to support end-to-end IP communication from range sensors and spacecraft instruments to end users. After identifying the end-to-end network hardware and software components, the paper discusses which ones are currently available and lists specific examples of each. This includes examples of space missions currently using Internet technology for end-to-end communication. It also lists missing pieces and includes information on their current status. The goal of this paper is also to stimulate thought and discussion on what steps need to be taken to start filling in the remaining missing pieces for end-to-end range and space network connectivity.
    • ITS VEHICLE SUBSYSTEM BASED ON GPRS

      Zhang, Zhengxuan; Zhang, Qishan; Beihang University (International Foundation for Telemetering, 2003-10)
      The IMS(In-vehicle Monitoring Subsystem) of VMS(Vehicle Monitoring System) is the multifunctional and complex integrate embedded system, which sends the data of various in-vehicle devices to MC(Monitoring Center) and accepts commands and schedules from there. Using GPRS platform in this system make it possible for real-time and effective data transmission. This paper proposes some new insights on IMS applied to public traffic, including its software and hardware composition, and its realization method.
    • CCSDS SPACE LINK EXTENSION SERVICE MANAGEMENT STANDARDS AND PROTOTYPING ACTIVITIES

      Pietras, John; Global Science & Technology, Inc. (International Foundation for Telemetering, 2003-10)
      The Consultative Committee for Space Data Systems (CCSDS) is developing standards for the interface through which spaceflight mission managers request tracking, telemetry, and command (TT&C) and Space Link Extension (SLE) services from TT&C ground stations and networks. The standards are intended for use not just by the spaceflight projects and networks operated by the CCSDS member agencies, but also by commercial networks and networks operated by other governmental agencies. As part of the process of developing the standards, several prototypes are under development. This paper presents a summary status of both the emerging service request standards and the prototypes that implement them.
    • IEEE802.11 WIRELESS NETWORK UNDER AGGRESSIVE MOBILITY SCENARIOS

      Bergamo, Pierpaolo; Maniezzo, Daniela; Yao, Kung; Cesana, Matteo; Pau, Giovanni; Gerla, Mario; Whiteman, Don; University of California; NASA (International Foundation for Telemetering, 2003-10)
      Wireless LAN (WLAN) has been extensively deployed in commercial, scientific and home applications due to the availability of low-cost wireless Network lnterace Cards (NICs) based on the IEEE802.11 standard. The purpose of this work is to study experimentally the behavior of an IEEE802.11 wireless network when the nodes arc characterized by mobility up to the speed of 240 km/h. This study leads to the understanding of the survivability and the performance of a connection under various aggressive mobility conditions. These studies may be adapted for data telemetry from mobile airborne nodes to fixed networks or between airborne nodes.