Mobile wireless communications are in constant evolution due to the continu- ously increasing requirements and expectations of both users and operators. Mass multimedia* ServiCEs have been for a long time expected to generate a large amount of data traffic in future wireless networks [1]. Mass multimedia ServiCEs are, by definition, purposed for many people. In general, it can be distinguished between the distribution of any popular content over a wide area and the distribu- tion of location-dependent information in highly populated areas. Representative examples include the delivery of live video streaming content (like sports compe- titions, concerts, or news) and file download (multimedia clips, digital newspa- pers, or software updates).
标签： Broadcasting Generation Mobile Next
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Never have telecommunications operations and network management been so important. Never has it been more important to move away from practices that date back to the very beginning of the telecommunications industry. Building and con- necting systems internally at low cost, on an as - needed basis, and adding software for supporting new networks and ServiCEs without an overall architectural design will not be cost effective for the future. Defi ning operations and network manage- ment requirements at the 11th hour for new technologies, networks, and ServiCEs deployments must also change.
标签： Telecommunications Generation Networks Next
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The telecommunications industry has seen a rapid boost within the last decade. New realities and visions of functionalities in various telecommunications networks have brought forward the concept of next-generation networks (NGNs). The competitions among operators for support- ing various ServiCEs, lowering of the cost of having mobile and cellular phones and smartphones, increasing demand for general mobility, explosion of digital traffic, and advent of convergence network technologies added more dynamism in the idea of NGNs. In fact, facilitating con- vergence of networks and convergence of various types of ServiCEs is a significant objective of NGNs.
标签： Next-Generation Converged Networks
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Rapid growth of wireless communication ServiCEs in recent decades has created a huge demand of radio spectrum. Spectrum scarcity and utilization inefficiency limit the development of wireless networks. Cognitive radio is a promising tech- nology that allows secondary users to reuse the underutilized licensed spectrum of primary users. The major challenge for spectrum sharing is to achieve high spectrum efficiency while making non-intrusive access to the licensed bands. This requires in- formation of availability and quality of channel resources at secondary transmitters, however, is difficult to be obtained perfectly in practice.
标签： Opportunistic Spectrum Sharing
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The roots of this book were planted about a decade ago. At that time, I became increasingly convinced that wide-area and metropolitan-area networks, where much of my group’s research has been centered at that time, were in good shape. Although research in these fields was (and still is) needed, that’s not where the networking bottleneck seemed to be. Rather, the bottleneck was (and still is in many places) in the access networks, which choked users’ access to information and ServiCEs. It was clear to me that the long-term solution to that problem has to involve optical fiber access networks.
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Recent decades have shown a tremendous expansion of the Internet. The number of connected terminals has increased by orders of magnitude, traffic has grown exponen- tially, coverage has become ubiquitous and worldwide, and today’s sophisticated Web 2.0 applications are increasingly providing ServiCEs which hitherto have been the realm of telecommunications, such as Skype and video conferencing. This has even led to the thought that access to the Internet might one day be a universal right of every citizen. This evolution will accelerate in the coming decades.
标签： Networking Personal Networks Wireless
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Soon after Samuel Morse’s telegraphing device led to a deployed electri- cal telecommunications system in 1843, waiting lines began to form by those wanting to use the system. At this writing queueing is still a significant factor in designing and operating communications ServiCEs, whether they are provided over the Internet or by other means, such as circuit switched networks.
标签： Telecommunication Queueing Packet Theory with
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One of the prerequisites for the development of telecommunication ServiCEs is the understanding of the propagation of the waves, either acoustic, electromagnetic, radio or light waves, which are used for the transmission of information. In this work, we shall limit ourselves to the study of radio waves: this term apply to the electromagnetic waves used in radio communications. Their frequency spectrum is very broad, and is divided into the following frequency bands : ELF waves (f < 3 kHz), VLF (3-30 kHz), LF waves (30-300 kHz), MF waves (300-3000 kHz), HF (3-30 MHz), VHF waves (30-300 MHz), UHF waves (300-3000 MHz), SHF waves (3-30 GHz), EHF waves (30-300 GHz) and sub- EHF waves (300-3000 GHz).
标签： Propagation Radio Wave
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We are currently witnessing an increase in telecommunications norms and standards given the recent advances in this domain. The increasing number of normalized standards paves the way for an increase in the range of offers and ServiCEs available for each consumer. Moreover, the majority of available radio frequencies have already been allocated.
标签： Allocation Resource Radio
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Wireless communications and networking technology are advancing at a very rapid pace. Newer technologies and standards are evolving to serve the ever-increasing num- ber of users demanding different types of mobile applications and ServiCEs. Research and development activities on wireless technology constitute one of the most impor- tant segments of research and development in the telecommunications area today.
标签： Management Resource Radio
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