When 3GPP started standardizing the IMS a few years ago, most analysts expected the number of IMS deploymentsto grow dramatically as soon the initial IMS specifications were ready (3GPP Release 5 was functionallyfrozenin the first half of 2002and completedshortly after that). While those predictions have proven to be too aggressive owing to a number of upheavals hitting the ICT (Information and Communications Technologies) sector, we are now seeing more and more commercial IMS-based service offerings in the market. At the time of writing (May 2008), there are over 30 commercial IMS networks running live traffic, addingup to over10million IMS users aroundthe world; the IMS is beingdeployedglobally. In addition, there are plenty of ongoing market activities; it is estimated that over 130 IMS contracts have been awarded to all IMS manufacturers. The number of IMS users will grow substantially as these awarded contracts are launched commercially. At the same time, the number of IMS users in presently deployed networks is steadily increasing as new services are introduced and operators running these networks migrate their non-IMS users to their IMS networks.
标签： Multimedia Subsystem The IMS 3G IP
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The first practical examples of mobile communications were used in many countries like the USA, the UK and Germany in military services, and played a significant role in the First World War to transfer important information from the front to headquarters to take further actions. Good and secure wireless communications were an important need for all military services – army, navy and air force. In this respect, the Second World War was a big experimental battlefield for the development and evolution of mobile radio. It was in the interests of governments that after the Second World War the military investment should be paid back by civilian use, and all western European countries started their so-called first generation of mobile communication networks.
标签： Multimedia Business Mobile The
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The digital dilemma: Telecoms fi rms prepare for the future is an Economist Intelligence Unit (EIU) report commissioned by WIPRO. The report strives to identify the key issues that companies within the telecoms sector are facing as they attempt to reshape their businesses to compete in a more digitised world.
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Changes in telecommunications are impacting all types of user group, which include business users, traveling users, small and home offices, and residential users. The acceptance rate of telecom- munications and information services is accelerating significantly. Voice services needed approximately 50 years to reach a very high teledensity; television needed just 15 years to change the culture and lives of many families; the Internet and its related services have been penetrating and changing business practices and private com- munications over the last 2 to 3 years.
标签： Telecommunications Handbook The
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Public telephone operators and new independent wireless operators through- out the world are deploying wireless access in an effort to drastically reduce delivery costs in the most expensive part of the network?the local loop. Available radio technology enables both existing and new entrants to access subscribers in a rapid manner and deliver their basic telephony products and broadband-enhanced services.
标签： Transmission Handbooks Systems Design
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As I have increasingly moved away from the world of research and into thatofmanagementandbusiness,ithasbecomeapparenttomethatthere are many people from a nontechnical background who need to under- standcellularsystemsinmoredetailinordertobeabletoperformtheir job,beitanalyzingfinancialinvestments,runningcallcenters,ormarket- ing cellular services.
标签： Understanding Cellular Radio
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Today wireless is becoming the leader in communication choices among users. It is not anymore a backup solution for nomadic travellers but really a newmoodnaturallyusedeverywhereevenwhenthewiredcommunicationsare possible. Many technologies evolve then continuously, changing the telecom- munication world. We talk about wireless local area networks (WLANs), wire- less personal area networks (WPANs), wireless metropolitan area networks (WMANs), wireless wide area networks (WWANs), mobile ad hoc networks (MANETs), wireless sensor networks (WSNs) and mesh networks. Since we can find today a multitude of wireless technologies we decided to group a numberofcomplementarytechnologiesintoonedocumenttomakeiteasierfor areadertounderstandsomeofthetechnicaldetailsofeachmedia.
标签： TM Bluetooth Zigbee Wi-Fi WiMax and
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Welcome to the world of wireless communications and the logical extension to the broadband architectures that are emerging as the future of the industry. No aspect of communications will be untouched by the wireless interfaces;no part of our working environment will be left untouched either. As the world changes and the newer technologies emerge, we can expect to see more in the line of untethered communications than in the wired inter- faces.
标签： Broadband Wireless Handbook
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During the past three decades, the world has seen signifi cant changes in the telecom- munications industry. There has been rapid growth in wireless communications, as seen by large expansion in mobile systems. Wireless communications have moved from fi rst-generation (1G) systems primarily focused on voice communications to third-generation (3G) systems dealing with Internet connectivity and multi-media applications. The fourth-generation (4G) systems will be designed to connect wire- less personal area networks (WPANs), wireless local area networks (WLANs) and wireless wide-area networks (WWANs).
标签： Communications Networking Wireless
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Digital radios have undergone an astonishing evolution in the last century. Born as a set of simple and power-hungry electrical and electromechanical devices for low data rate transmission of telegraph data in the Marconi age, they have transformed, thanks to substantial advances in electronic technology, into a set of small, reliable and sophisticated integrated devices supporting broadband multimedia communications. This, however, would not have been possible unless significant progress had been made in recent decades in the field of signal processing algorithms for baseband and passband signals. In fact, the core of any modern digital radio consists of a set of algorithms running over programmable electronic hardware. This book stems from the research and teaching activities of its co-authors in the field of algorithmic techniques for wireless communications. A huge body of technical literature has accumulated in the last four decades in this area, and an extensive coverage of all its important aspects in a single textbook is impossible. For this reason, we have selected a few important topics and, for ease of reading, organized them into two parts.
标签： Communications Algorithmic Techniques Wireless
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