Xem 1-20 trên 22 kết quả Terrestrial networks
  • This chapter aims to introduce the basic concepts of satellite networking including appli- cations and services, circuit and packet switching, broadband networks, network protocols and reference models, characteristics of satellite networks, internetworking between satellite and terrestrial networks and convergence of network technologies and protocols. When you have completed this chapter, you should be able to:

    pdf0p beobobeo 01-08-2012 33 7   Download

  • Trongtruyềnhìnhvàcácthiếtbịđiệntửdândụng: DVB-T/DVB-C/DVB-S (Digital Video Broadcastsing-Terrestrial/Cable/Satellite _ Truyềnhìnhsốmặtđất/cáp/vệtinh) - biểudiễnMPEG-2 chấtlượngcaohơnhẳntruyềnhìnhtươngtựtruyềnthống. Truyềnhìnhtươngtác- Cácứngdụnginternet trêntruyềnhình(Mail,Web, E-commerce_thươngmạiđiệntử) - khôngcầnđợiPC đểkhởiđộng, tắtmáy. CácđầuđọcCD/VCD/DVD/Mp3

    pdf171p son248 06-08-2011 84 32   Download

  • Reliable and accurate positioning and navigation is critical for a diverse set of emerging applications calling for advanced signal-processing techniques. This book provides an overview of some of the most recent research results in the field of signal processing for positioning and navigation, addressing many challenging open problems. The book stems from the European Network of Excellence in Wireless Communications NEWCOM++, in which I was privileged to be involved as both an external observer and a contributor.

    pdf446p namde04 03-05-2013 43 12   Download

  • The state of a normal or diseased cell is determined by external signals and by its intrinsic gene expression pat- tern. Transcription factors (TFs) are major regulators of gene expression, typically controlling more than one gene and acting in concert. Such TF-gene interactions can be described as networks, which are crucial to understand hierarchies of gene expression regulation. The identifica- tion of TF binding sites (TFBSs) in genomic DNA sequences has played an important role in predicting tran- scriptional networks.

    pdf17p yasuyidol 02-04-2013 15 4   Download

  • Event-driven programming is a popular model for writing programs for tiny embedded systems and sensor network nodes. While event-driven programming can keep the memory overhead down, it enforces a state machine programming style which makes many programs difcult to write, maintain, and debug. We present a novel programming abstraction called protothreads that makes it possible to write eventdriven programs in a thread-like style, with a memory overhead of only two bytes per protothread.

    pdf14p giamdocamnhac 06-04-2013 28 4   Download

  • The paper provides insights into a large and growing sector of the economy, as well as an area where, due to teaching responsibilities, finance scholars have a relatively large impact. Several prior papers on areaswithin the broader invest- ment banking community hint at possible reasons for the strong persistence in finance careers that I demonstrate below.

    pdf6p thieubaotrang 16-04-2013 21 4   Download

  • Securing and operating today’s complex systems is challenging and demanding. Mission and operational requirements to deliver services and applications swiftly and securely have never been greater. Organizations, having invested precious resources and scarce skills in various necessary security efforts such as risk analysis, certification, accreditation, security architectures, policy development, and other security efforts, can be tempted to neglect or insufficiently develop a cohesive, well-though out operational security testing program. ...

    pdf292p cao_can 02-01-2013 22 3   Download

  • Network scanning involves using a port scanner to identify all hosts potentially connected to an organization's network, the network services operating on those hosts, such as the file transfer protocol (FTP) and hypertext transfer protocol (HTTP), and the specific application running the identified service, such as WU-FTPD, Internet Information Server (IIS) and Apache for the HTTP service. The result of the scan is a comprehensive list of all active hosts and services, printers, switches, and routers operating in the address space scanned by the port-scanning tool, i.e.

    pdf31p cao_can 02-01-2013 16 3   Download

  • Many youth in the United States have fully integrated the Internet into their daily lives. For them, the Internet is a positive and powerful space for socializing, learning, and engaging in public life. Along with the positive aspects of Internet use come risks to safety, including the dangers of sexual solicitation, online harassment, and bullying, and exposure to problematic and illegal content.

    pdf0p bin_pham 05-02-2013 18 3   Download

  • Overview Code Division Multiple Access (CDMA) has been widely accepted and used for wireless access in terrestrial and satellite applications. These applications often require switching of the CDMA traffic channels in order to establish connectivity between end users. In existing terrestrial wireless networks, while CDMA is used for access, connectivity and routing is achieved via the Public Switched Telephone Network (PSTN). It is often desirable, however, that access and switching is performed within the same network in many applications.

    pdf25p doroxon 16-08-2010 95 38   Download

  • PACKET ACCESS IN UTRA FDD AND UTRA TDD In this chapter, first a brief introduction to UMTS Terrestrial Radio Access (UTRA) matters is provided, such as fundamental radio access network concepts, basics of, for example, the physical and the MAC layer, and the types of channels defined (namely logical, transport and physical channels). This is followed by a discussion of certain UTRA FDD features, such as soft handover, fast power control and compressed mode operation.

    pdf41p huggoo 20-08-2010 39 9   Download

  • DATA NETWORK TYPES A ROUGH SORT OF TWO-WAY SYSTEMS In North America terrestrial, two-way wireless data networks can initially be sorted into private versus public systems. Private system examples include a few very large users, such as .ederal Express, and many smaller systems for public safety (police and fire departments), taxi/limo dispatch, and utilities. In private systems the infrastructure is owned, and the spectrum is licensed, by the user. Public systems are “for hire.

    pdf9p tienvovan 16-09-2010 50 8   Download

  • The rapid development of both terrestrial and undersea optical fibre networks has paved the way for a global communication network. Highly efficient semiconductor injection lasers have played a leading role in facing the challenges of the information era. In this chapter, before discussing the operating principle of the semiconductor distributed feedback (DFB) laser diode (LD), general concepts with regard to the principles of lasers will first be presented.

    pdf48p doroxon 18-08-2010 49 7   Download

  • Mobile Satellite Communication∗ In principle communications satellites provide the same connectivity as terrestrial (wireless and wireline) networks. The advantages of satellites, such as fast wide-area coverage, flexible transmission parameters and cost independence due to distance, are compared with the disadvantages, such as restricted channel capacity because of the frequencies available, orbital positions, need for line-of-sight connectivity and high initial investment besides relatively long signal propagation times.

    pdf57p huggoo 20-08-2010 39 7   Download

  • PUBLIC TERRESTRIAL CIRCUIT SWITCHED NETWORKS REPRESENTATIVE NATIONWIDE NETWORKS Nationwide circuit switched networks exist in vehicular, mobile applications; the successful ones use the existing voice cellular network as a “last mile” solution. One well-known system is that of United Parcel Service (UPS), which has no voice capability in its devices. During 1998 UPS began its move to a packet switched approach via a public network: ARDIS. Other circuit switched systems are also beginning to experiment with packet alternatives, from hybrid CS-CDPD through Cellemetry.

    pdf13p tienvovan 16-09-2010 40 6   Download

  • HYBRID NETWORKS TERRESTRIAL PACKET/SATELLITE Trucking company Boyle Transport makes it crystal clear: “you should be able to pick a radio or cellular based system for regional service and satellite for long haul, but be able to use the same provider.”1 This is the goal of most hybrid offerings, though satellite may well be avoided in favor of an alternative technique such as circuit switched cellular. 7.1.1 AMSC/ARDIS Multimode System In March 1990 Rockwell announced that it was developing a satellite-based vehicle location and two-way data system.

    pdf5p tienvovan 16-09-2010 47 6   Download

  • FITTING APPLICATIONS TO PUBLIC OFFERINGS NETWORK PRICE POSITIONING We are always interested in simple ways to classify complex choices. An initial “application fit” technique for terrestrial, two-way wireless data networks is shown in .igure 8-1. If traffic activity is brisk but message lengths are short, public packet switched networks are a reasonable business choice. If traffic activity is modest but message lengths are long, data over cellular channels are a better fit. This category includes “pure” (image) facsimile....

    pdf26p tienvovan 16-09-2010 45 6   Download

  • Switched CDMA Networks Overview Code Division Multiple Access (CDMA) has been widely accepted and used for wireless access in terrestrial and satellite applications. These applications often require switching of the CDMA traffic channels in order to establish connectivity between end users. In existing terrestrial wireless networks, while CDMA is used for access, connectivity and routing is achieved via the Public Switched Telephone Network (PSTN). It is often desirable, however, that access and switching is performed within the same network in many applications.

    pdf25p goixanh 22-09-2010 59 6   Download

  • PUBLIC TERRESTRIAL PACKET SWITCHED NETWORKS MESSAGING/DISPATCH ORIENTATION Amateur packet radio has been active in the 2- and 20-meter bands since the early 1980s. But recognizable pay-for-service packet switched offerings began in Chicago in 1986 with Motorola’s DRN. With coverage in only three cities and weak marketing, DRN struggled for three years. In 1990 it was folded into a joint venture that also embraced IBM’s .ield Service System. The result was ARDIS, a truly nationwide public packet data network.

    pdf32p tienvovan 16-09-2010 48 5   Download

  • Signaling traffic in wireless ATM networks Handoff algorithms in terrestrial wireless networks focus on the connection rerouting problem. Basically, there are three connection rerouting approaches: full connection establishment, partial connection reestablishment, and multicast connection reestablishment. Full connection establishment algorithms calculate a new optimum route for the call as for a new call request. The resulting route is always optimal; however, the call rerouting delay and the signaling overheads are high....

    pdf15p doroxon 16-08-2010 37 3   Download

Đồng bộ tài khoản