Gsm channels

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  • GSM (Global System for Mobile Communications, originally Groupe Spécial Mobile), is a standard set developed by the European Telecommunications Standards Institute (ETSI) to describe technologies for second generation (2G) digital cellular networks. Developed as a replacement for first generation (1G) analog cellular networks, the GSM standard originally described a digital, circuit switched network optimized for full duplex voice telephony.

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  • Hard to fathom, but it really wasn't all that long ago that even a plain old telephone was a luxury item. But, as we all know, technology's only constant is change. In this day and age, many folks need to be accessible everywhere, whether they're at work or play, in the office or at home. To meet this demand, the GSM standard (Global System for Mobile Communications) for mobile telephony was introduced in the mid- 1980s. Today, GSM is the most popular mobile radio standard in the world. A boom is underway, such that many GSM users find life without their phone practically inconceivable....

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  • Be familiar with the development of 2G mobile systems. Describe the architecture of a GSM network. Appreciate the main services provided within a GSM network. Understand the various facets of the GSM air interface including, access structures, frequency allocations, physical and logical channels.

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  • All voice codecs include speech coding (source coding), channel coding (error protection and bad frame detection), concealment of erroneous or lost frames (bad frame handling), Voice Activity Detection (VAD), and a low bit rate source controlled mode for coding background noise. The codecs operate either in the GSM full-rate traffic channel at the gross bit rate of 22.8 kbit/s (FR, EFR, AMR-WB), or in the half-rate channel at the gross bit rate of 11.4 kbit/s (HR), or in both (AMR). AMR and AMR-WB have also been...

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  • Wireless communications is one of the most active areas of research over the past and the current decades. In fact, the demand for wireless services has been changing from the regular voice telephony services to mixed voice, data, and multimedia services over the wireless media. Since the mid-1990s, the wireless industry has been advancing at an incredible speed. For example, the 2G cellular systems (such as GSM, D-AMPS, and IS-95) have significantly improved the spectral efficiency and network capacity to support wireless telephony services....

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  • Phân loại kênh logic a. Kênh lưu lượng TCH: Có hai loại kênh lưu lượng: − Bm hay kênh lưu lượng toàn tốc (TCH/F), kênh này mang thông tin tiếng hay số liệu ở tốc độ 22,8 kbit/s. − Lm hay kênh lưu lượng bán tốc (TCH/H), kênh này mang thông tin ở tốc độ 11,4 kbit/s b. Kênh điều khiển CCH (ký hiệu là Dm): bao gồm: − Kênh quảng bá BCH (Broadcast Channel). − Kênh điều khiển chung CCCH (Common Control Channel). − Kênh điều khiển riêng DCCH (Dedicate Control Channel). Kênh quảng bá BCH: BCH =...

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  • Our first chapter puts LTE into its historical context, and lays out its requirements and key technical features. We begin by reviewing the architectures of UMTS and GSM, and by introducing some of the terminology that the two systems use. We then summarize the history of mobile telecommunication systems, discuss the issues that have driven the development of LTE, and show how UMTS has evolved first into LTE and then into an enhanced version known as LTE-Advanced. The chapter closes by reviewing the standardization process for LTE....

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  • The third generation (3G) mobile communication system is the next big thing in the world of mobile telecommunications. The first generation included analog mobile phones [e.g., Total Access Communications Systems (TACS), Nordic Mobile Telephone (NMT), and Advanced Mobile Phone Service (AMPS)], and the second generation (2G) included digital mobile phones [e.g., global system for mobile communications (GSM), personal digital cellular (PDC), and digital AMPS (D-AMPS)].

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  • Many measures, functions and protocols in digital mobile radio networks are based on the properties of the radio channel and its speci®c qualities in contrast to information transmission through guided media. For the understanding of digital mobile radio networks it is therefore absolutely necessary to know a few related basic principles. For this reason, the most important fundamentals of the radio channel and of cellular and transmission technology will be presented and brie¯y explained in the following. For a more detailed treatment, see the extensive literature [4,42,50,64]. ...

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  • General Packet Radio Service (GPRS) Packet data transmission has already been standardized in GSM phase 2, offering access to the Packet Switched Public Data Network (PSPDN); see Sections 9.5.3 and 9.6.2. However, on the air interface such access occupies a complete circuit switched traf®c channel for the entire call period. In case of bursty traf®c (e.g. Internet traf®c), such access leads to a highly inef®cient resource utilization. It is obvious that in this case, packet switched bearer services result in a much better utilization of the traf®c channels.

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  • Past decade has seen a surge of research activities in the field of wireless communication. Emerging from this research thrust are new points of view on how to communicate effectively over wireless channels. The goal of this course is to study in a unified way the fundamentals as well as the new research developments. The concepts are illustrated using examples from several modern wireless systems (GSM, IS-95, CDMA 2000 1x EV-DO, Flarion's Flash OFDM, ArrayComm systems.)

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  • This book is a training document and contains simplifications. Therefore, it must not be considered as a specification of the system. The contents of this document are subject to revision without notice due to ongoing progress in methodology, design and manufacturing. Ericsson assumes no legal responsibility for any error or damage resulting from the usage of this document. This document is not intended to replace the technical documentation that was shipped with your system. Always refer to that technical documentation during operation and maintenance....

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  • Communications is a process by which information is exchanged between individuals through a common system of symbols, signs, or behaviour “It is about communication between people; the rest is technology” Communication systems are reliable, economical and efficient means of communications Public switched telephone network (PSTN), mobile telephone communication (GSM, 3G, 4G...), broadcast radio or television, navigation systems, ... The course is aiming at introducing fundamental issues required for understanding and designing a (digital) communication system...

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  • Physical communication channels in wireless technology are inherently insecure. As a wire only has two ends, the wired communication technology has a means of supporting integrity of communication, whereas in wireless communication dedicated technology is needed—even to control a basic point-to-point connection.

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  • The total bandwidth is divided into many narrowband channels. (200 kHz in GSM) Users are given time slots in a narrowband channel (8 users) Multiple access is orthogonal: users within the cell never interfere with each other. Interference between users on the same channel in different cells is minimized by reusing the same channel only in cells far apart.

    ppt23p nhq_khtn 12-03-2011 39 5   Download


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