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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

VEHICLE NETWORK TECHNOLOGY DEMONSTRATION

Grace, Thomas, Hodack, Dave 10 1900 (has links)
ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / iNET is a project tasked to foster advances in networking and telemetry technology to meet emerging needs. This paper describes one objective of the project, which is standardization and interoperability. It begins to explore issues for achieving a level of interoperability among differing vendor’s hardware such as data acquisition units, data recorders, video systems, transceivers, and network encryption. Specifically, this paper addresses the expansion of the current demonstration system with the addition of multiple vendor data acquisition units. It will also attempt to address the level of standardization necessary for achieving interoperability while still enabling vendors to add their value added contributions into their products.
122

The Challenges of Data Acquisition in Harsh Remote Places

Buckley, Dave 10 1900 (has links)
ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / In modern flight test installations there is a continuing trend to move the data acquisition closer to the sensors. As a consequence the data acquisition chassis needs to be mounted in locations that are small, inaccessible and subject to harsh environmental conditions. On top of this there are an increasing number of measurements required for each new flight test campaign. This paper discusses the challenges of designing a small lightweight data acquisition chassis which can provide hundreds of channels of measurement capability while operating in tight spaces which are exposed to fluids, high vibration and extremes of temperature. The paper suggests ways of designing and installing the data acquisition chassis in order to optimize the available installation space while mitigating the effects of the harsh environmental conditions.
123

Wireless Local Area Network for Data Telemetry from Fast Moving Nodes

Bamberger, Robert J., Barrett, George R., Nichols, Robert A., Burbank, Jack L., Lauss, Mark H. 10 1900 (has links)
International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / A Wireless Local Area Network (WLAN) based system called 2-Way Robust Acquisition of Data (2-RAD) is being developed to telemeter data from a number of fast moving airborne platforms to ground collection points distributed over a large test range. The Johns Hopkins University Applied Physics Laboratory (JHU/APL) is analyzing a 2-RAD prototype currently in operation at the U.S. Army Yuma Proving Ground (YPG) that uses an IEEE 802.11b WLAN infrastructure. Preliminary analysis efforts at JHU/APL indicate that the Doppler shift from fast movers, and the system radio link margin, do not preclude IEEE 802.11b from being used for 2 -RAD.
124

APPLYING IEEE 1451 STANDARD TO AATIS

Sinclair, Robert, Jones, Charles H. 10 1900 (has links)
International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Current legacy acquisition systems such as the Advanced Airborne Test Instrumentation System (AATIS) are custom-built to each individual application with unique sensors and data modules. Replacing, adding, or subtracting sensors requires the system to be removed from service for days, weeks, or even months. This is a result of having to route special wires to each sensor and reprogramming the system with sensor information, calibration data, etc. AR sensor information must be contained in the main system since these systems do not have intelligence at the sensor level. If sensors were to contain information in their own IEEE 1451-compliant transducer electronic data sheet (TEDS), the main system would no longer have to be reprogrammed with this information. This information could then be obtained directly from the sensors when they are inserted into the system. A plug-n-play capability is being added to the system with the development of a standard interface to the system control unit (SCU). This interface, called a Multi-Network Capable Applications Processor (Multi-NCAP), will interface IEEE 1451-compliant smart transducer interface modules (STIMs) to the SCU in the AATIS as well as other legacy systems. With this development, maintenance and new configuration times for the AATIS and other legacy systems will be significantly reduced.
125

Διερεύνηση τεχνικών παραμέτρων για τη βέλτιστη διαχείριση πόρων και τη βέλτιστη ραδιοκάλυψη στα σύγχρονα ασύρματα ευρυζωνικά δίκτυα

Χαριτούδης, Ιωάννης 04 September 2013 (has links)
Αντικείμενο της παρούσας διπλωματικής εργασίας είναι η ολοκληρωμένη παρουσίαση του προτύπου IEEE 802.16, που χρησιμοποιείται από το σύγχρονο ασύρματο ευρυζωνικό δίκτυο με την εμπορική ονομασία WiMAX και η εκπόνηση μίας μελέτης ράδιο-κάλυψης για τον προσδιορισμό των τεχνικών παραμέτρων, ώστε η εφαρμογή ενός τέτοιου δικτύου να προσφέρει τη βέλτιστη ράδιο-κάλυψη. Αρχικά γίνεται μια εισαγωγική παρουσίαση των ασύρματων τεχνολογιών, που χρησιμοποιούνται στην Ελλάδα για την πρόσβαση στις ευρυζωνικές υπηρεσίες και παρατίθενται στατιστικά στοιχεία, που απεικονίζουν την κατάσταση που επικρατή στον ελλαδικό χώρο. Στη συνέχεια καταγράφεται η ανάπτυξη και η εξέλιξη του προτύπου IEEE 802.16 και γίνεται αναφορά στο ρόλο που διαδραματίζουν το WiMAX Forum και οι επίσημοι κατασκευαστές. Προχωρώντας, εμβαθύνουμε περισσότερο με την παρουσίαση της αρχιτεκτονικής των δικτύων WiMAX, αλλά και των τεχνικών χαρακτηριστικών και των προδιαγραφών, που αυτά προσφέρουν και τα έχουν καταστήσει πρωτοπόρα στην εμπορική αγορά των ασύρματων επικοινωνιών. Τέλος, εκπονούμε μία λεπτομερή μελέτη για τη βέλτιστη ράδιο-κάλυψη σε μία συγκεκριμένη γεωγραφική περιοχή, σύμφωνα με τις προδιαγραφές της τεχνολογίας WiMAX και προσδιορίζουμε την ποιότητα των υπηρεσιών που θα μπορεί να προσφέρει το δικτύου WiMAX, στηριζόμενοι στα αποτελέσματα της μελέτης. / The subject of this thesis is the complete presentation of the standard IEEE 802.16, which is used by the modern wireless broadband network under the trade name WiMAX and the conduction of a radio coverage study to determine the technical parameters, so that the implementation of such a network can offer the optimal radio coverage. First, we make an introduction of wireless technologies used for access to broadband services and we present statistics that reflect the real market condition in Greece. Then we record the development and the progress of the IEEE 802.16 standard and we also make a small reference to the role of the WiMAX Forum and the official manufacturers. In depth, we analyze the architecture of WiMAX networks and all the technical features and specifications, which make the WiMAX technology a pioneer and have consolidate it in the market of wireless communications. Finally, we work out a detailed study on the optimal radio coverage in a specific geographic area, in accordance with the requirements of WiMAX technology and furthermore we estimate the quality of services that can be provided by the WiMAX network, relying on the results of the simulation.
126

An Adaptive IEEE 802.11 MAC in Multihop Wireless Ad Hoc Networks Considering Large Interference Range / 多跳接IEEE 802.11無線網路中考慮大干擾範圍之可調媒介存取控制協定

涂建明, Chien-Ming Tu Unknown Date (has links)
在無線區域網路的範疇,IEEE 802.11是一個主要的媒介存取控制協定。然而在隨意式多跳接的網路中,IEEE 802.11面臨更嚴重的hidden terminal和exposed terminal problems,而這些問題主因都源自於過大的訊號干擾範圍與過大的訊號感應範圍。在這篇論文裡,我們提出一個可調式的媒介存取控制協定,針對IEEE 802.11 RTS/CTS handshake機制做簡單地修改,使得IEEE 802.11 devices可以依據週遭的傳收狀態動態調整自身的傳送和接收行為。實驗結果顯示我們的方法使原來的 802.11 減少了互相干擾的情形並且提升了系統的效能。 / The IEEE 802.11 standard is the most popular Medium Access Control (MAC) protocol for wireless local area networks. However, in multihop wireless ad hoc networks, the IEEE 802.11 MAC protocol will suffer from more serious hidden terminal and exposed terminal problems than those in single hop WLANs. More specifically, it is due to the large interference range and the large carrier sensing range. In this thesis, we propose an adaptive IEEE 802.11 MAC (AMAC) that makes two simple modifications of IEEE 802.11 RTS/CTS handshake to dynamically adjust the transmission and reception according to the shared medium status near transmitter and receiver, respectively. Simulation results show that our method can lessen interferences and increase system throughput as compared with IEEE 802.11 MAC.
127

在IEEE 802.11p網路中以偵測網路狀況為基礎動態調整競爭視窗的機制 / Network status detection-based dynamic adaptation of contention window in IEEE 802.11p

馮文捷, Feng, Wen Chieh Unknown Date (has links)
近年來,無線網路發展的成熟、行車安全問題的重視、全球定位系統的普及,以及車用網路(Vehicular Ad Hoc Networks, VANET)在研究上的前瞻性與未來的高應用價值,使得車用網路的發展也愈來愈受到各方的探討。然而,車用網路的拓撲變動性相當高且規模大,且屬於點對點(Ad-Hoc)的網路架構,因此,對於吞吐量(throughput)和碰撞率(collision)以及延遲時間(delay)皆有一定的需求。此外,由於車輛在道路上的分布容易造成訊號之間的碰撞和干擾,所以我們藉由修改RTS/CTS機制提出一個Detection-Based MAC,其機制可透過封包之間的訊息傳遞,偵測出網路的壅塞狀態,預測網路中鄰近節點的競爭情形,並依此來動態調整競爭視窗大小。最後,將此方法實作在IEEE 802.11p的媒體存取控制層(MAC)中,以解決車用網路節點互相干擾所造成的過多碰撞,並提升整體吞吐量。 / In recent years, the research on Vehicular Ad Hoc Networks (VANET) has been paid much attention due to the development of wireless network becoming mature, people think highly of traffic safety issues, the popularity of Global Positioning System (GPS), promising applications of VANET being exploited. However, VANET has the essential property of rapid change of large scale network topology. Besides, vehicles randomly distributed over the road usually causes serious signal collisions and interferences. Thus, it calls for special concerns to deal with the performances of throughput, collision, and delay. In this paper we propose a Detection-Based MAC mechanism by modifying RTS/CTS to detect network congestions through message exchange, and predict number of competing nodes. Both these information is used to dynamically adjust contention window sizes. Simulations are implemented on the MAC layer of IEEE 802.11p. The results show that the proposed method is able to effectively reduce collisions and increase overall throughput.
128

IEEE 802.16 Commercial Off The Shelf (COTS) technologies as a compliment to Ship To Objective Maneuver (STOM) communications

Munoz, Ramon J., Guice, Robert J. 09 1900 (has links)
Approved for public release; distribution is unlimited. / This research evaluates the IEEE 802.16 standards and technologies that are currently being developed in the commercial sector. The robust capability of this standard lends itself potentially to numerous military applications. This research explores how this technology might address the shortcomings of existing military radio and data systems; specifically, with respect to the issues surrounding the Ship to Objective Maneuver (STOM) communications. The intent of this research is to provide recommendations on the necessary 'adapt from COTS' changes for this technology to address STOM networking requirements. This research includes discussions on the military requirements for an IEEE 802.16 adapted waveform. The requirements are for the IEEE 802.16 'adapt from COTS' are derived from researched on the Concept of Employment for STOM operations and the specification of the Joint Tactical Radio Systems (JTRS) Wideband Networking Waveform (WNW). These discussions offer an illustration of the complex networking demands the COTS adapted systems would need to address. Through detailed exploration of the current IEEE 802.16 standards and implementation testing with pre-standard IEEE 802.16a equipment, we were able to make recommendations on the COTS adaptations necessary to make IEEE 802.16 suitable as a complimentary technology within the STOM scenario. / Captain, United States Marine Corps
129

Denial of service attacks on 802.1X security protocol

Ozan, Orhan 03 1900 (has links)
Approved for public release, distribution unlimited / Wireless Local Area Networks (WLANs) are quickly becoming popular in daily life. Users are adopting the latest technology to save time and costs. In addition, WLANs are providing high-speed network access to the users. There are security concerns with WLANs that must be considered when deploying them over critical infrastructure, such as military and administrative government LANs. The IEEE 802.11 wireless standard specifies both an authentication service and encryption protocol, but research has demonstrated that these protocols are severely flawed. The IEEE has established a new workgroup, the IEEE 802.11i, to address all the security vulnerabilities of the 802.11 security protocol. The workgroup proposed using the IEEE 802.1X Port-Based Network Access Control Standard as an interim measure to meet the security requirements of the WLANs and to maintain the confidentiality, authenticity, and availability of the data until the workgroup is finished with the new specifications. Using an open-source test-bed for evaluating DoS attacks on WLANs, this research demonstrates four different DoS attacks that verify the weaknesses of the IEEE 802.1X protocol. Solutions are provided to mitigate the effects of such DoS attacks. / Lieutenant Junior Grade, Turkish Navy
130

Developing a Fly-Away-Kit (FLAK) to support Hastily Formed Networks (HFN) for Humanitarian Assistance and Disaster Relief)

Lancaster, David D. 06 1900 (has links)
This research discusses developing a FLy-Away-Kit (FLAK) to support the forming of Hastily Formed Networks (HFNs) in remote areas in support of Humanitarian Assistance and Disaster Relief (HA/DR) operations. The initial focus will be on the requirements, situation, area of operations and mission. Different definitions and perspectives emerge when an individual mentions HFNs, HA/DR and Complex Humanitarian Disasters (CHDs). It is the author's intention to define and describe both a HFN and a CHD, in order to justify the need for the FLAK. This process will also define the requirements for the FLAK as well as facilitate processes for ensuring those requirements are met. The personnel responding to the attacks of September 11, 2001 and the December 26, 2004 Southeast Asia Tsunami suffered Command and Control (C2) and information challenges. Even more challenges are being currently addressed by Homeland Defense, Maritime Domain Awareness, and Non-Governmental Organizations (NGOs) abroad. From the top down, levels of administration are developing new plans, procedures, and organizations that will improve the security and communication processes of our nation. A global, broadband, rapidly deployable network node complete with Internet reachback, voice, data, and video capability is of the utmost importance to enable C2 and Network Centric Operations (NCO). Undoubtedly, commercial and military organizations, traditional or new, will greatly benefit from this capability. The U.S. DoD is particularly interested in improving interaction, coordination, communications, and operations when DoD and other entities respond simultaneously to natural or man-made CHD's.

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