Institute for Systems Research Technical Reports

Permanent URI for this collectionhttp://hdl.handle.net/1903/4376

This archive contains a collection of reports generated by the faculty and students of the Institute for Systems Research (ISR), a permanent, interdisciplinary research unit in the A. James Clark School of Engineering at the University of Maryland. ISR-based projects are conducted through partnerships with industry and government, bringing together faculty and students from multiple academic departments and colleges across the university.

Browse

Subject: search.filters.subject.satellite communications

Search Results

Now showing 1 - 5 of 5
  • Thumbnail Image
    Item
    Broadband Access via Satellite
    (1999) Hadjitheodosiou, Michael H.; Ephremides, Anthony; Friedman, Daniel E.; Ephremides, A.; ISR; CSHCN
    Satellites are well suited for broadband communications. In this paperwe consider the special features of satellite systems, some of thebroadband applications that are well-suited for satellites and someof the technologies which make possible broadband satellitecommunications, as well as the research programs that led to theirdevelopment. We describe how such technologies, and other factors,have contributed to the evolution of broadband satellite systems,and discuss some of the challenges in establishing such systems.We finish by offering some concluding remarks on the role ofsatellites for broadband access.

    The research and scientific content in this material hasbeen published in Computer Networks, vol. 31, pp. 353-378, 1999.
  • Thumbnail Image
    Item
    Large Deviations for Partial Sum Processes on Infinite Time Intervals with Applications to Single-Server Queues and Effective Bandwidths
    (1996) Banege, Lionel; Makowski, Armand M.; ISR; CSHCN
    In this dissertation, we establish large deviations results for partial sum processes on infinite time intervals, and apply them to the characterization of the large deviations behavior of the stationary and transient output processes of a single-server queue with time-varying capacities. We first show that the extension of a partial sum process on the infinite time interval [0, infinity) satisfies the Large Deviations Principle (LDP) in the function space D [0, infinity), provided the partial sum process itself satisfies the LDP in the space D [0,1]. Furthermore, for a stationary random sequence whose associated partial sum process satisfies the LDP in D [0,1], we establish LDP jointly for a partial sum process based on the entire past and future of sequence, a result especially useful in queueing theory. Through a functional approach at the sample path level, the Contraction Principle then enables us to derive the sample path LDP for processes of interest in the study of single-server queues, from that of the inputs. Finally, using our results, we refine the newly introduced notion of effective bandwidths.
  • Thumbnail Image
    Item
    Advanced Orbiting Systems Data Generator/Simulator: A Functional Description of the Software (Version 3)
    (1994) Baras, John S.; Atallah, George C.; Fuja, Tom E.; Murad, A.; Jang, Kap D.; ISR; CSHCN
    The Advanced Orbiting System (AOS) Data Generator/Simulator is a software implementation of the transmitter (data generation) section of the CCSDS Recommendation 701.0-B-2 for Advanced Orbiting Systems: Networks and Data Links. An object-oriented approach to the simulation of a complex, high-performance communication protocol, it makes full use of the concepts of data-encapsulation and inheritance to ease implementation. The backbone of the software is a general-purpose packet description and generation module that may be used as part of any packet- based simulation software. The user-interface to the program is in the form of a command-language, designed to ease the process of generation of large, multiple data-streams. The output of the program may be configured for interpretation by a graphical user interface (for visual inspection of the data), or as a bit-stream suitable for further processing. This paper consists of three sections. The first two sections provide a brief, yet comprehensive description of the above CCSDS Recommendation. The various kinds and qualities of user-services, data units involved, and data-paths defined by the protocol are discussed. The different qualities of service (in terms or data reliability) available to the user (and the error-control schemes used to provide them) are also discussed. The last section describes the structure and user-interfaces of the AOS Data Generator/Simulator.
  • Thumbnail Image
    Item
    Admission Control Schemes for Spot-Beam Satellite Networks
    (1993) Ramseier, S.; Ephremides, Anthony; ISR; CSHCN
    In this report, we consider communication networks with a satellite with multiple spot beams. We describe the structure and features of these networks, and we consider admission control schemes which optimize the network revenue if several services types with different revenues are present. We show that in some cases the blocking of some calls even if capacity is available can considerably increase the network revenue. We will point out, however, that complete sharing, i.e., accepting calls on a first- come, first-served basis, is optimum for systems with similar traffic types.
  • Thumbnail Image
    Item
    LAN Interconnection by Satellite --- A Literature Review
    (1993) Ramseier, S.; ISR; CSHCN
    In this report we give an overview on experiments interconnecting LANs by satellite, which are reported in the technical literature. Most reported scientific experiments have been performed in Europe and Japan, whereas in the USA a more application oriented, commercial approach seems to have been taken. In this report, we briefly describe several projects, such as the French NADIR, the European STELLA, UNIVERSE and SATINE-2, some experiments performed by the European Space Agency ESA, such as PRODAT and CODE as well as a special internetworking experiment. We also mention some Japanese and a Canadian project.