global system for mobile communications wikipedia

... which are discussed extensively in Chapter 4. For one 2G system called cdmaOne and most 3G systems, e.g. the Universal Mobile Telecommunications System (UMTS), DS/CDMA was chosen as a basic multiple ... Communication Systems 25 2.2.1 Analogue First Generation Cellular Systems 25 2.2.2 Digital Second Generation Systems 25 2.3 First 3G Systems 27 2.3.1 Requirements for 3G 27 2.3.2 Evolution of 2G Systems ... Models for the Physical Layer and for User Traffic Generation 221 5.1 How to Account for the Physical Layer? 221 5.1.1 What to Account For and How? 221 5.1.2 Using Approximations for Error Performance...

Ngày tải lên: 02/03/2013, 16:59

... Network OMC AUC HLR MSC EIRVLR BSC BTS MS External PSTN & PDN N/W SS BSS Switching System Base Station System MS Mobile Station BTS Base transceiver System BSC Base Station Controller MSC Mobile Switching Center HLR Home Location ... messages ã International Mobile Equipment Identifier (IMEI) 38 GSM Architecture HLR VLR EIR AUC MSC B S C B S C SMSC PSTN VMSC Mobile Station GSM Air interface OMCR TRAU Base Station System Network and ... Circuit Switched Data EDGE = Enhanced Data rate for GSM Evolution UMTS = Universal Mobile Telecommunication System 10 sec 1 min 10 min 1 hour0 UMTS E/GPRS ISDN PSTN GSM webe-mail photo web photo e-mail web...

Ngày tải lên: 19/10/2013, 15:15

... bibliographical references and index. ISBN 0-471-48697-3 1. Wireless Internet. 2. Global system for mobile communications. 3. TCP/IP (Computer network protocol) I. Eardley, Philip. II. Burness, ... paths for them are handled by the SGSN. 1.2.3 IP for 3G What is meant by IP for 3G? 3G systems will include IP multimedia allowing the user to browse the Internet, send e-mails, and so forth. ... being captured for malicious use and impersonation of users. One, final, level of security is performed on the mobile equipment itself, as opposed to the mobile subscriber (for example, putting...

Ngày tải lên: 27/10/2013, 17:15

... Center for Telecom- munications and Information Systems Laboratory, Stanford University, Stanford, CA, June 1994. [2] Second workshop on smart antennas in wireless mobile communications, Center for ... selection performance analysis of a switched multi-beamantenna systemin mobile communications environments, Stanford, CA,July 1995. Second workshop on Smart Antennas in Wireless Mobile Communications. [28] ... Telecom- munications and Information Systems Laboratory, Stanford University, Stanford, CA, July 20-21, 1995. [3] Third workshop on smart antennas in wireless mobile communications, Center for Telecom- munications...

Ngày tải lên: 16/12/2013, 04:15

... bandwidth and storage requirement. B. System performance vs. network resource We next evaluate the performance of our system. One major metric of the performance of our system is the message success rate, ... Sprite, a simple, cheat-proof, credit- based system for stimulating cooperation among selfish nodes in mobile ad hoc networks. Our system provides incentive for mobile nodes to cooperate and report actions ... discussed in Sec- tion III, although our system provides incentive for cooperation by giving more credit for forwarding a message, whether or not to forward a specific message will depend on the...

Ngày tải lên: 15/03/2014, 04:20

... to achieve better performance. 4 System Architecture In this section, we present our global D2W system, which solves the optimization problem in Eq. 3. We refer to the system as GLOW, for Global Wikifica- tion. ... but still enforces some degree of coherence among the disambiguations. 3 Related Work Wikipedia was first explored as an information source for named entity disambiguation and in- formation retrieval ... unambiguous entities the system relies on for disambiguation. 7 Conclusions We have formalized the Disambiguation to Wikipedia (D2W) task as an optimization problem with local and global variants, and...

Ngày tải lên: 17/03/2014, 00:20

... described in Chapter 4. 14 HSDPA/HSUPA for UMTS HSUPA HARQ for uplink Fast Node B scheduling for uplink Shorter TTI for uplink Figure 2.4 The techniques chosen for the HSUPA work item. Work items created Feasibility study started Impact ... Pedersen 7.1 General performance factors 123 7.1.1 Essential performance metrics 124 7.2 Single-user performance 125 7.2.1 Basic modulation and coding performance 126 7.2.2 HS-DSCH performance 128 7.2.3 ... responsible for physical layer aspects; . TSG RAN WG2: responsible for layer 2 and 3 aspects; . TSG RAN WG3: responsible for RAN internal interfaces; . TSG RAN WG4: responsible for performance and...

Ngày tải lên: 01/06/2014, 09:38

Ngày tải lên: 27/06/2014, 15:20

Ngày tải lên: 04/07/2014, 08:31

... the system operation before the system is actually built. If the modeling process shows that the system performance is inadequate, then the design can be adjusted until the predicted performance ... processes the power in an effort to recover exactly the source information that was originally transmitting. For some systems this process can be quite complex, with methods for decoding signals, correcting ... transmitted source information is a broad general measure of the quality of the communication system and the success of the system design. 20 FIXED BROADBAND WIRELESS SYSTEMS challenges to system designers...

Ngày tải lên: 03/06/2014, 00:52

Ngày tải lên: 22/06/2014, 06:20

... Techniques for 4G Mobile Communications, Shinsuke Hara and Ramjee Prasad OFDM for Wireless Multimedia Communications, Richard van Nee and Ramjee Prasad Radio over Fiber Technologies for Mobile Communications ... present and future mobile communi- cations systems. As an evolutional form of mobile phone systems, Interna- tional Mobile Telecommunications (IMT)-2000 [4, 5], which corresponds to 3G systems, aims ... (2G) systems in the 1990s, such as Global Systems for Mobile Telecommunications (GSM) [1], Personal Digital Cellular (PDC) [2], and Interim Standard (IS)-95 [3], on digital technologies for voice-oriented...

Ngày tải lên: 26/04/2013, 09:50

... present and future mobile communi- cations systems. As an evolutional form of mobile phone systems, Interna- tional Mobile Telecommunications (IMT)-2000 [4, 5], which corresponds to 3G systems, aims ... (2G) systems in the 1990s, such as Global Systems for Mobile Telecommunications (GSM) [1], Personal Digital Cellular (PDC) [2], and Interim Standard (IS)-95 [3], on digital technologies for voice-oriented ... 1 Introduction 1.1 Mobile Communications Systems: Past, Present, and Future There has been a paradigm shift in mobile communications systems every decade. The first generation (1G) systems in the...

Ngày tải lên: 20/01/2014, 23:20

... Propagation and Subsystems Research for the Evolution of Mobile Communications, ’’ IEEE Comm. Mag., Vol. 34, No. 2, February 1996, p. 58. [2] Prasad, R., Universal Wireless Personal Communications, ... Communication Systems and Techniques, New York: IEEE Press, 1996. [4] Jakes, Jr., C., Microwave Mobile Communications, New York: John Wiley & Sons, 1974. [5] Lee, W. C. Y., Mobile Communications ... written in a column vector form as S = [s (iT s + t spl ), ,s(iT s + qt spl ), ,s(iT s + N SC t spl )] T (3.8) = W − 1 (N SC )C i 28 Multicarrier Techniques for 4G Mobile Communications Figure 3.1...

Ngày tải lên: 20/01/2014, 23:20

... personal health information system and the medical guidance. 1) Personal health information system: The personal health system can store physiological data and other information in the database ... Our system is also a mobile health system for the elderly with tailored services depending on their personal health condition. However, it is not only a remote and real-time monitoring system ... platform and medical knowledge database. Therefore, the main functions of our system are described below. ã A real-time mobile health monitoring system for the elderly to monitor the health condition...

Ngày tải lên: 28/03/2014, 19:21

Ngày tải lên: 03/06/2014, 01:37

Ngày tải lên: 21/06/2014, 11:20

Ngày tải lên: 22/06/2014, 19:20

Ngày tải lên: 24/08/2014, 17:56

... McKusick, M., "Performance Effects of Disk Subsystem Choices for VAX Systems Running 4.2BSD UNIX", Computer Systems Research Group, SMM:05-12 A Fast File System for UNIX administration ... byte block UNIX file system. The new file system uses less space than the 512 byte or 1024 byte file systems for indexing information for large files and the same amount of space for small files. These ... [Operating Systems]: Performance − measurements, operational analysis; H.3.2 [Information Systems]: Information Storage − file organization Additional Keywords and Phrases: UNIX, file system organization,...

Ngày tải lên: 12/09/2012, 14:16