This book gives a comprehensive overview of the technologies for the advances of mobile radio access networks. The topics covered include linear transmitters, superconducting filters and cryogenic radio frequency (RF) front head, radio over fiber, software radio base stations, mobile terminal positioning, high speed downlink packet access (HSDPA), multiple antenna systems such as smart antennas and multiple input and multiple output (MIMO) systems, orthogonal frequency division multiplexing (OFDM) systems, IP-based radio access networks (RAN), autonomic networks, and ubiquitous networks.
標簽: Advances Networks Access Mobile Radio in
上傳時間: 2020-05-26
上傳用戶:shancjb
The General Packet Radio Service (GPRS) allows an end user to send and receive data in packet transfer mode within a public land mobile network (PLMN) without using a permanent connection between the mobile station (MS) and the external network during data transfer. This way, GPRS opti- mizes the use of network and radio resources (RRs) since, unlike circuit- switched mode, no connection between the MS and the external network is established when there is no data flow in progress. Thus, this RR optimiza- tion makes it possible for the operator to offer more attractive fees.
上傳時間: 2020-05-27
上傳用戶:shancjb
Currently, the information and communications technology (ICT) industry sector accounts for about 2–6% of the energy consumption worldwide, and a significant por- tion of this is contributed by the wireless and mobile communications industry. With the proliferation of wireless data applications, wireless technology continues to increase worldwide at an unprecedented growth rate. This has resulted in an increased number of installed base stations and higher demand on power grids and device power usage, causing an increased carbon footprint worldwide.
標簽: Communication Networks Green Radio
上傳時間: 2020-05-27
上傳用戶:shancjb
Commoditization is a serious threat to the telecommunications industry. Most CSPs offer similar services at rates designed to win what has become a price war. As a result, many face decreasing margins and difficulty sustaining differentiation based on prices or products alone. On top of commoditization, CSPs also face competition from OTT providers and an increasingly knowledgeable and demanding customer base. With access to growing amounts of data from an ever-increasing number of sources and devices, today’s empowered, savvy consumers know what they want and expect to get it.
標簽: RestoringConnections_IBM_CPL
上傳時間: 2020-06-01
上傳用戶:shancjb
A wireless communication network can be viewed as a collection of nodes, located in some domain, which can in turn be transmitters or receivers (depending on the network considered, nodes may be mobile users, base stations in a cellular network, access points of a WiFi mesh etc.). At a given time, several nodes transmit simultaneously, each toward its own receiver. Each transmitter–receiver pair requires its own wireless link. The signal received from the link transmitter may be jammed by the signals received from the other transmitters. Even in the simplest model where the signal power radiated from a point decays in an isotropic way with Euclidean distance, the geometry of the locations of the nodes plays a key role since it determines the signal to interference and noise ratio (SINR) at each receiver and hence the possibility of establishing simultaneously this collection of links at a given bit rate. The interference seen by a receiver is the sum of the signal powers received from all transmitters, except its own transmitter.
標簽: Stochastic Geometry Networks Wireless Volume and II
上傳時間: 2020-06-01
上傳用戶:shancjb
Long-TermEvolution(LTE)isarguablyoneofthemostimportantstepsinthecurrentphaseof the development of modern mobile communications. It provides a suitable base for enhanced services due to increased data throughput and lower latency figures, and also gives extra impetus to the modernization of telecom architectures. The decision to leave the circuit- switched domainoutofthescope ofLTE/SAEsystem standardization might soundradical but itindicatesthatthetelecomworldisgoingstronglyfortheall-IPconcept----andthedeployment of LTE/SAE is concrete evidence of this global trend.
標簽: Deployment Handbook LTE-SAE The
上傳時間: 2020-06-01
上傳用戶:shancjb
Fun. We (your authors) wanted a word to describe our ultimate goal for this book, as well as a word we hope you (our reader) will use to describe it, and that’s the one we chose. There are others goals, of course, but in the end, when you’ve finished the book, we’re hoping you’ll have enjoyed the activities described in these pages. Many books use the Introduction to explain exactly what the book is about, what the reader will learn, what the reader needs (a skill or maybe an item or piece of software), and what the reader will be left with when that last page is completed. And this Introduction will do those things, but … hopefully it’ll make you excited to get started.
標簽: Adventures Arduino Station Escape Gemini from
上傳時間: 2020-06-09
上傳用戶:shancjb
產品型號:VK0384 產品品牌:VINTEK/元泰/VINKA 封裝形式: LQFP64 替代型號:HT1623 原廠直銷,工程服務,技術支持,價格更具優勢! 概述: VK0384是一個48x8的LCD駆動器. 可軟件程控使其適用于多樣化的LCD應用線路. 僅用到3至4條訊號線便可控制LCD駆動器,除此之外亦可介由指令使其進入省電模式 特色 工作電壓: 2.4V~5.2V 內建256KHz RC oscillator 提供1/4 偏壓1/8 COM 周期 省電模式 48x8 LCD駆動器 內建48x8 bit 顯示內存 3-wire serial interface 軟件程控 資料及指令模式 VLCD 腳位可用來調整LCD輸出電壓 內建電阻式偏壓產生線路 8種WDT的基頻選擇 定時器及WDT的溢位輸出 兩種蜂鳴器頻率(2KHz/4KHz) 內建time base generator 以及WDT Time base or WDT 溢位輸出
上傳時間: 2020-09-19
上傳用戶:2937735731
This design uses Common-Emitter Amplifier (Class A) with 2N3904 Bipolar Junction Transistor. Use “Voltage Divider Biasing” to reduce the effects of varying β (= ic / ib) (by holding the Base voltage constant) Base Voltage (Vb) = Vcc * [R2 / (R1 + R2)] Use Coupling Capacitors to separate the AC signals from the DC biasing voltage (which only pass AC signals and block any DC component). Use Bypass Capacitor to maintain the Q-point stability. To determine the value of each component, first set Q-point close to the center position of the load line. (RL is the resistance of the speaker.)
上傳時間: 2020-11-27
上傳用戶:
產品型號:VK1072B VK1072C 產品品牌:永嘉微電/VINKA 封裝形式:SOP28 SSOP28 產品年份:新年份 聯 系 人:陳先生 聯 系 QQ:3618885898 聯系手機:18824662436 原廠直銷,工程服務,技術支持,價格最具優勢! LCD/LED液晶控制器及驅動器系列芯片簡介如下: RAM映射LCD控制器和驅動器系列: VK1024B 2.4V~5.2V 6seg*4com 6*3 6*2 偏置電壓1/2 1/3 S0P-16 VK1056B 2.4V~5.2V 14seg*4com 14*3 14*2 偏置電壓1/2 1/3 SOP-24/SSOP-24 VK1072B 2.4V~5.2V 18seg*4com 18*3 18*2 偏置電壓1/2 1/3 SOP-28 VK1072C 2.4V~5.2V 18seg*4com 18*3 18*2 偏置電壓1/2 1/3 SOP-28 VK1088B 2.4V~5.2V 22seg*4com 22*3 偏置電壓1/2 1/3 QFN-32L(4MM*4MM) VK0192 2.4V~5.2V 24seg*8com 偏置電壓1/4 LQFP-44 VK0256 2.4V~5.2V 32seg*8com 偏置電壓1/4 QFP-64 VK0256B 2.4V~5.2V 32seg*8com 偏置電壓1/4 LQFP-64 VK0256C 2.4V~5.2V 32seg*8com 偏置電壓1/4 LQFP-52 VK1621 2.4V~5.2V 32*4 32*3 32*2 偏置電壓1/2 1/3 LQFP44/48/SSOP48/SKY28/DICE裸片 VK1622 2.7V~5.5V 32seg*8com 偏置電壓1/4 LQFP44/48/52/64/QFP64/DICE裸片 VK1623 2.4V~5.2V 48seg*8com 偏置電壓1/4 LQFP-100/QFP-100/DICE裸片 VK1625 2.4V~5.2V 64seg*8com 偏置電壓1/4 LQFP-100/QFP-100/DICE VK1626 2.4V~5.2V 48seg*16com 偏置電壓1/5 LQFP-100/QFP-100/DICE (高品質 高性價比:液晶顯示驅動IC 原廠直銷 工程技術支持!) VK1072B/C/D概述: VK1072B/C /D是一個18*4的LCD驅動器,可軟體程式控制使其適用於多樣化的LCD應用線路,僅用到3條訊號線便可控制LCD驅動器,除此之外也可介由指令使其進入省電模式 特色: ★工作電壓:2.4-5.2V ★內建256KHz RC oscillator ★可選擇1/2,1/3 偏壓,也可選擇1/2,1/3或1/4的COM周期 ★省電模式, 節電命令可用于減少功耗 ★內 嵌 時 基 發 生 器 和 看 門 狗 定 時 器(WDT) ★內建time base generator ★18X4 LCD 驅動器VLCD 腳位可用來調整LCD輸 ★三種數據訪問模式 ★內建32X4 bit 顯示記憶體 ★三線串行接口 ★軟體程式控制 ★資料及指令模式 ★自動增加讀寫位址 ★提供VLCD 腳位可用來調整LCD輸出電壓 ★ 此篇產品敘述為功能簡介,如需要完整產品PDF資料可以聯系陳先生索取!
上傳時間: 2021-12-09
上傳用戶:15218646864