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Second Generation (2G)- 2.5 Generatlon (2.5G) : 1990s, CHADTER, Introduction to Mobile, Computing, Unit I, Syllabus, 1.1, Introduction to Mobile Computing, Telecommunication Generations, Cellular systems,, 1.2, Electromagnetic Spectrum, Antenna, Signal Propagation, Signal Characteristics, Multiplexing, Spread Spectrum :, DSSS & FHSS, Introduction to mobile computing, Mobile Computing is a technology that allows transmission of data, voice and multimedia via any wireless enabled, device without having to be connected to a fixed physical link. This chapter basically introduces the reader with the basics, of mobile computing and communication. It also covers the journey of wireless communication from 1G to 5G and focuses, on fundamental aspects of wireless transmission at physical layer such as signals, antenna, modulation, multiplexing. Most, of today's wireless telecommunication systems are based on the concept of cellular systems. With billions of mobile, phones in use around the globe today, it is necessary to re-use the available frequencies many times over without mutual, interference of one cell phone to another., 1.1, Telecommunication Generations, The following section discusses different mobile generations (1G, 2G, 3G,4G and 5G)., First Generation (1G) : 1980s, Analog cellular systems were the first generation of mobile telephone communication systems., They use analog frequency modulation and circuit switched techniques for voice transmission., The individual calls used different frequencies and shared the available spectrum through Frequency Division Multiple, Access (FDMA).., 1G system provided only voice communicatlon., 1G was not supporting roamlng between different network operators and countries., Examples of 1G networks are:, AMPS (Advanced Mobile Phone System) USA, NMT (Nordic Mobile Telephone) Sweden, The second generation (2G) of moble cellular started In the early 1990s., It was completely digital and used elther Time Dlvislon Multiple Access (TDMA) or Code Division Multiple Access, (CDMA)., Scanned by CamScanner

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2G systems not only provide better voice quality using digital voice telephony but also a new range of low data rate, They provide the ablity to transfer simultaneously both volce data (a telephone call) and non-volce data (such as, 3G mobile technologies support greater number of volce and data customers as well as hlgher data rates at lower, The 3G revolution allowed mobile telephone customers to use audlo, graphics and video applications., Introduction to Mobile Computing, Mobile Communication & Computing (MU-Sem. 7-Comp), 1-2, It provides increased capacity and security due to the uses of digital cellular technology., 2G systems support international roaming., services such as mobile Fax, voice mail, short message service (SMS)., " addition to digital voice telephony, Cordless, public mobile radio, satellite and wireless-local area network (WLANI, solutions began to emerge., 2.5G, Between 2G and 3G there was not much change in the technology hence an intermediary phase, 2.5G was introduced, in the late 1990s., 2.5G is used to describe 2G-systems that have implemented a packet-switched domain in addition to the circuit-, switched domain., GPRS (General Packet Radio Service) is a 2G service, which delivers packet-switched data capabilities to existing GSM, networks. It allows users to send graphics-rich data as packets., The importance of packet-switching increased with the rise of the Internet and the Internet Protocol (IP)., Another example of 2.5G mobile technology is EDGE (Enhanced Data rates for GSM Evolution). EDGE provides data, rate up to 384 kbps which is higher than GSM., Advantages of 2G over 1G, 2G standards support roaming between different operators and countries., In addition to circuit-switched voice services, 2G enabled the first wave of mobile data and Internet services, now, widely adopted by users., 2.5G services enable high speed data transfer over upgraded existing 2G networks., Some 2G standards are :, GSM(TDMA-based), D-AMPS, IS-95/CDMAone, PDC(Personal Digital Cellular), PHS (Personal Handy Phone System), HSCSD (High Speed Circuits Switched Data) (2.5), GPRS (General Packet Radio Service) (2.5), EDGE (Enhanced Data rates for Global Evolution)(2.5), Third Generation (3G) - 2000, The third generation (3G) systems started in 2000., Over 3G it is possible to watch streaming video and engage in video telephony., downloading information, exchanging emall and Instance messaging), incremental cost than 2G., Tech Knowledg, Scanned by CamScanner

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Mobile Communication & Computing (MU-Sem. 7-Comp), 1-3, Introduction to Mobile Computing, 3G standards are :, W-CDMA, CDMA2000, UWC-136, TD-CDMA / TD-SCDMA, DECT, Fourth Generation (4G) - 2004, The fourth generation will be fully IP-based integrated systems., It will allow accessing the Internet anytime from anywhere, global roaming, and wider support for multimedia, applications., It will be network of networks achieved after the convergence of wired and wireless networks as well as computer,, consumer electronics, communication technology, and several other convergences., These networks will be capable of providing 100 Mbps in outdoor environment and 1Gbps in indoor with end-to-end, QoS and high security., 4G standards are :, LTE (Long Term Evolution), WIMAX (Worldwide Interoperability for Microwave Access), Fifth Generation - 5G (2018), 5G is not just one technology, it is actually a combination of several technologies in one. The system, however, will be, a smart and know when to make use of which technology for maximum efficiency., 5G will be much more faster than 4G. It will provide data rate up to 10Gbps. It will provide 100% coverage area. That is, better coverage even at the cell boundaries., 5G will also provide low network latency (up to 1 msec) which will be helpful for the critical applications. like industry,, healthcare and medical. 5G technology aims to provide wide range of future industries from retail to education,, transportation to entertainment and smart homes to healthcare., 5G technology will provide ubiquitous connectivity means everything from vehicles to mobile networks to industries, to smart homes will be connected together., 5G will utilize Extremely High frequency spectrum band between 3GHZ to 30 GHz. These are called millimetre waves., These wave can travel at very high speed but covers short distance since they cannot penetrate obstacles., Unlike 4G that requires high powered cellular base stations to transmit signal over long distance, 5G will use a large, number of small cell stations that may be located on small towers or building roofs., 5G makes the use of Massive MIMO (Multiple Input Multiple Output) standards to make is 100 times faster as, opposed to standard MIMO. Massive MIM0 makes the use of as much as 100 antennas. Multiple antennas allow for, better and faster data transmission. The 5G network will come with 100 times more devices in market.", 5G standards, 5G technology standard are still under development. So, no firm standards is in place at this time; the market is still, figuring out the essential 5G features and functionalities., The primary 5G standards bodies involved in these processes are the 3rd Generation Partnership Project (3GPP), the, Internet Engineering Task Force (IETF), and the International Telecommunication Union (ITU)., Tech Kmowledgi, Publications, Scanned by CamScanner

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Mobile Communication & Computing (MU-Sem. 7-Comp), 1-5, Introduction to Mobile Computing, Parameter., 1G, 2G, 3G, 4G, 5G, Disadvantages | Limited, Low network, High power, Hard to, Hard to implement, Many of, capacity, not, range, slow, data rates, consumption,, Low network, the old devices would not be, implement,, complicated, secure, poor, battery life,, large phone, coverage, High, cost of spectrum, competent to 5G, Developing, infrastructure needs high cost., hardware, required, size,, license, background, interference, Voice Calls, Super High speed mobile, networks, Smart Vehicles, loT, Virtual and Augmented Reality,, Low latency mission critical, applications etc., Applications, Voice calls,, Video, High speed, applications,, mobile TV,, Short, conferencing,, mobile TV, GPS, messages,, browsing, (partial), Wearable, devices, 1.2, Cellular Systems, Cellular systems are mobile systems for two-way wireless communication between the fixed part of the system, (transmitters or base stations) and the mobile part of the system (mobile stations) which move in the area covered by, each base station., In a cellular system, the entire coverage area is divided into 'cells' i.e. they implement SDM (Space Division, Multiplexing). Each cell is served by a single base station. Each cell has a size depending on the number of users. More, the users, smaller the cell size., Cell radii ranges from tens of meters in buildings, and hundreds of meters in cities, up to tens of kilometers in the, country side., The shapes of cells are never perfect circles or hexagons actually, it depends on environment, on whether conditions, etc. Hexagon shape cellular system is shown in Fig. 1.2.1., Fig.1.2.1 : Diagrammatic cell Fig. 1.2.2 : Cellular System with seven cell cluster, vs. actual cell coverage, 1.2.1 Frequency Reuse in Cellular Systems, MU - May 14, (May 14, 5 Marks), QWhat is frequency reuse concept in cellular communication?, Frequency reuse is the technique of using the same radio frequencies on radio transmitter sites within a geographic, area that are separated by sufficient distance to cause minimal interference with each other., Tech Knomledgi, Publications, Scanned by CamScanner