With the rapid expansion of wireless consumer products,there has been a con- siderable increase in the need for radio-frequency (RF) planning, link plan- ning, and propagation modeling.A network designer with no RF background may find himself/herself designing a wireless network. A wide array of RF planning software packages can provide some support, but there is no substi- tute for a fundamental understanding of the propagation process and the lim- itations of the models employed. Blind use of computer-aided design (CAD) programs with no understanding of the physical fundamentals underlying the process can be a recipe for disaster. Having witnessed the results of this approach, I hope to spare others this frustration.
標簽: Introduction Propagation to RF
上傳時間: 2020-05-27
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Fixed-mobile.convergence.and.voice-data.networks.have.merged.next-gen- eration,.value-added.applications.and.integrated.multimedia.services,.com- bining. Web. browsing,. instant. messaging,. presence,. voice. over. IP,. video. conferencing,. application. sharing,. telephony,. unified. messaging,. multi- media.content.delivery,.etc..on.top.of.different.network.technologies..The. convergence.of.the.communications.networks.is.motivated.by.the.need.to. support.many.forms.of.digital.traffic.as.well.as.to.amortize.implementation. and.operational.costs.of.the.underlying.networks..Historically,.the.approach. to. build. and. deploy. multimedia. services. has. focused. upon. single-point. solutions..
標簽: Multimedia Subsystem Handbook IMS IP
上傳時間: 2020-05-27
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For nearly a hundred years telecommunications provided mainly voice services and very low speed data (telegraph and telex). With the advent of the Internet, several data services became mainstream in telecommunications; to the point that voice is becoming an accessory to IP-centric data networks. Today, high-speed data services are already part of our daily lives at work and at home (web surfing, e-mail, virtual private networks, VoIP, virtual meetings, chats...). The demand for high-speed data services will grow even more with the increasing number of people telecommuting.
上傳時間: 2020-05-27
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Mobilenetworkoperatorswillmeetmanychallengesinthecomingyears.Itisexpectedthatthe numberofpeopleconnected,wirelineandwireless,willreachfivebillionby2015.Atthesame time, people use more wireless services and they expect similar user experience to what they can now get from fixed networks. Because of that we will see a hundred-fold increase in network traffic in the near future. At the same time markets are saturating and the revenue per bit is dropping.
標簽: Self-Organising Networks LTE
上傳時間: 2020-05-27
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Wireless is one of the most rapidly developing technologies in our time, with dazzling new products and services emerging on an almost daily basis. These developments present enormous challenges for communications engineers, as the demand for increased wireless capacity grows explosively. Indeed, the discipline of wireless communications presents many challenges to designers that arise as a result of the demanding nature of the physical medium and the complexities in the dynamics of the underlying network.
標簽: Communications Wireless MIMO
上傳時間: 2020-05-28
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Mobile multimedia communication is increasingly in demand because of the basic need to communi- cate at any time, anywhere, using any technology. In addition, to voice communication, people have a desire to access a range of other services that comprise multimedia elements—text, image, animation, high fidelity audio and video using mobile communication networks. To meet these demands, mobile communication technologies has evolved from analog to digital, and the networks have passed through a number of generations from first generation (1G) to fourth generation (4G).
標簽: Communications Multimedia Concepts Mobile
上傳時間: 2020-05-30
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Mobile radio networks have risen in prominence over the last few years, primarily by the rise in popularity of cellular phones. It is important to recognise however that mobile radio technology fulfils a far wider range of applications that meet the demands of the modern world. These include the networks that allow police and emergency services to serve the public, military networks for operations and humanitarian support, and the mobile technol- ogies that are vital to the safety of aircraft.
標簽: Network Mobile Design Radio
上傳時間: 2020-05-30
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Mobile telecommunications emerged as a technological marvel allowing for access to personal and other services, devices, computation and communication, in any place and at any time through effortless plug and play. This brilliant idea became possible as the result of new technologies developed in the areas of computers and communications that were made available and accessible to the user.
標簽: Telecommunications Protocols Mobile
上傳時間: 2020-05-30
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Wireless metropolitan area networks (WirelessMANs) is emerging as a promising broadband wireless access (BWA) technology to provide high-speed, high bandwidth efficiency and high-capacity multimedia services for residential as well as enterprise applications. It is observed that WirelessMAN (e.g., WiMAX) is even regarded as a 4G technology. For the success of the WirelessMANs, international standardization organiza- tions are very actively specifying the standards IEEE 802.16, ETSI HiperMAN and Korea WiBro.
標簽: BroadbanMobile WiMAX Toward Broadband Wirelessd Wireless Mobile Toward WiMAX
上傳時間: 2020-05-30
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Informationnetworkinghasemergedasamultidisciplinarydiversifiedareaofresearchover thepastfewdecades.Fromtraditionalwiredtelephonytocellularvoicetelephonyandfrom wired access to wireless access to the Internet, information networks have profoundly impactedourlifestyle.Atthetimeofwriting,over3billionpeoplearesubscribedtocellular services and close to a billion residences have Internet connections.
上傳時間: 2020-05-31
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