Wireless penetration has witnessed explosive growth over the last two decades. Accordingly, wireless devices have become much denser per unit area, resulting in an overcrowded usage of wireless resources. To avoid radio interferences and packet collisions, wireless stations have to exchange control messages to coordinate well. The existing wisdoms of conveying control messages could be classified into three categories: explicit, implicit, or hybrid.
标签： Transmission Attachment Networks Wireless in
上传时间： 2020-05-26
上传用户：shancjb
According to the statistics of the Federal Communications Commission (FCC), temporal and geographical variations in the utilization of the as- signed spectrum range from 15% to 85%. The limited available radio spec- trum and the inefficiency in spectrum usage necessitate a new commu- nication paradigm to exploit the existing spectrum dynamically.
上传时间： 2020-05-26
上传用户：shancjb
The new digital radio system DAB (Digital Audio Broadcasting, nowadays often called Digital Radio) is a very innovative and universal multimedia broadcast system which will replace the existing AM and FM audio broadcast services in many parts of the world in the future. It was developed in the 1990s by the Eureka 147/DAB project. DAB is very well suited for mobile reception and provides very high robustness against multipath reception. It allows use of single frequency networks (SFNs) for high frequency efficiency.
标签： Broadcasting Principles Digital Audio
上传时间： 2020-05-26
上传用户：shancjb
The first Third Generation Partnership Project (3GPP) Wideband Code Division Multiple Access (WCDMA) networks were launched during 2002. By the end of 2005 there were 100 open WCDMA networks and a total of over 150 operators having frequency licenses for WCDMA operation. Currently, the WCDMA networks are deployedinUniversalMobileTelecommunicationsSystem(UMTS)bandaround2GHz in Europe and Asia including Japan and Korea. WCDMA in America is deployed in the existing 850 and 1900 spectrum allocations while the new 3G band at 1700/2100 is expected to be available in the near future. 3GPP has defined the WCDMA operation also for several additional bands, which are expected to be taken into use during the coming years.
标签： HSDPAHSUPA Access Speed Radio UMTS High for
上传时间： 2020-05-27
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This paper covers the keynote address delivered by the Chairman of the COST Action 285 at the Symposium. It outlines the studies undertaken by the members of the Action with the objective of enhancing existing modeling and simulation tools and to develop new ones for research in emerging multiservice telecommunication networks. The paper shows how the scope of COST Action 285 has been enriched by the contributions made at the Symposium.
标签： Simulation Modeling Tools and
上传时间： 2020-05-30
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All wireless communication standards, existing and under development, adopt or consider adopting orthogonal frequency-division multiplexing (OFDM) as the modulation technique. It is clear that OFDM has become the definitive modulation scheme in current and future wireless communication systems.
标签： Baseband Receiver Design OFDM
上传时间： 2020-05-31
上传用户：shancjb
Developers, manufacturers and marketers of products incorporating short- range radio systems are experts in their fields—security, telemetry, medical care, to name a few. Often they add a wireless interface just to eliminate wires on an existing wired product. They may adapt a wireless subsystem, which is easy to integrate electrically into their system, only to find that the range is far short of what they expected, there are frequent false alarms, or it doesn’t work at all. It is for these adapters of wireless subsystems that this book is primarily intended.
标签： Communication Short-range Wireless
上传时间： 2020-05-31
上传用户：shancjb
Rapid progress in information and communications technology (ICT) induces improved and new telecommunications services and contributes greatly to society in general and to vendors and network and service providers. In addition to existing services such as telephony or leased line services, spread of the Internet, the Internet Protocol (IP) phone, and new communications services like IPTV are making great progress with the development of digital subscriber lines (DSL) and high - speed communications technologies like fi ber to the home (FTTH).
标签： Telecommunications Networks
上传时间： 2020-06-01
上传用户：shancjb
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
上传时间： 2020-06-01
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Visible light communications (VLC) is the name given to an optical wireless communication system that carries information by modulating light in the visible spectrum (400–700 nm) that is principally used for illumination [1–3]. The communications signal is encoded on top of the illumination light. Interest in VLC has grown rapidly with the growth of high power light emitting diodes (LEDs) in the visible spectrum. The motivation to use the illumination light for communication is to save energy by exploiting the illumination to carry information and, at the same time, to use technology that is “green” in comparison to radio frequency (RF) technology, while using the existing infrastructure of the lighting system.
标签： Communication Visible Light
上传时间： 2020-06-01
上传用户：shancjb
