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.
標簽： Transmission Handbooks Systems Design
上傳時間： 2020-06-01
上傳用戶：shancjb
Wavelength division multiplexing (WDM) refers to a multiplexing and transmission scheme in optical telecommunications fibers where different wavelengths, typically emitted by several lasers, are modulated independently (i.e., they carry independent information from the transmitters to the receivers). These wavelengths are then multiplexed in the transmitter by means of passive WDM filters, and likewise they are separated or demultiplexed in the receiver by means of the same filters or coherent detection that usually involves a tunable LOCAL oscillator (laser).
標簽： Multiplexing Wavelength Division
上傳時間： 2020-06-01
上傳用戶：shancjb
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.
標簽： TM Bluetooth Zigbee Wi-Fi WiMax and
上傳時間： 2020-06-01
上傳用戶：shancjb
Notwithstanding its infancy, wireless mesh networking (WMN) is a hot and growing field. Wireless mesh networks began in the military, but have since become of great interest for commercial use in the last decade, both in LOCAL area networks and metropolitan area networks. The attractiveness of mesh networks comes from their ability to interconnect either mobile or fixed devices with radio interfaces, to share information dynamically, or simply to extend range through multi-hopping.
標簽： Multi-hop Networks WiMAX WiFi Mesh LTE and
上傳時間： 2020-06-01
上傳用戶：shancjb
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).
標簽： Communications Networking Wireless
上傳時間： 2020-06-01
上傳用戶：shancjb
This chapter provides extensive coverage of existing mobile wireless technologies. Much of the emphasis is on the highly anticipated 3G cellular networks and widely deployed wireless LOCAL area networks (LANs), as the next-generation smart phones are likely to offer at least these two types of connectivity. Other wireless technologies that either have already been commercialized or are undergoing active research and standardization are introduced as well. Because standardization plays a crucial role in developing a new technology and a market, throughout the discussion standards organizations and industry forums or consortiums of some technologies are introduced. In addition, the last section of this chapter presents a list of standards in the wireless arena.
標簽： Networking Wireless Complete
上傳時間： 2020-06-01
上傳用戶：shancjb
This book paves the path toward fourth generation (4G) mobile communica- tion by introducing mobility in heterogeneous IP networks with both third generation (3G) and wireless LOCAL area networks (WLANs), which is seen as one of the central issues in the becoming 4G of telecommunications networks and systems. This book presents a thorough overview of 3G networks and standards and discusses interworking and handover mechanisms between WLANs and the Universal Mobile Telecommunication System (UMTS).
標簽： Wireless towards WLANs WPANs 4G
上傳時間： 2020-06-01
上傳用戶：shancjb
Battery systems for energy storage are among the most relevant technologies of the 21 st century. They – in particular modern lithium-ion batteries (LIB) – are enablers for the market success of electric vehicles (EV) as well as for stationary energy storage solutions for balancing fluctuations in electricity grids resulting from the integrationofrenewableenergysourceswithvolatilesupply 1 .BothEVandstationary storage solutions are important because they foster the transition from the usage of fossil energy carriers towards cleaner renewable energy sources. Furthermore, EV cause less LOCAL air pollution and noise emissions compared to conventional combustion engine vehicles resulting in better air quality especially in urban areas. Unfortunately, to this day, various technological and economic challenges impede a broad application of batteries for EV as well as for large scale energy storage and load leveling in electricity grids.
標簽： Multiscale Simulation Approach
上傳時間： 2020-06-07
上傳用戶：shancjb
THIS PUBLICATION IS COPYRIGHT PROTECTEDCopyright ? 2014 IEC, Geneva, SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any formor by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing fromeither IEC or IEC's member National Committee in the country of the requester. If you have any questions about IECcopyright or have an enquiry about obtaining additional rights to this publication, please contact the address below oryour LOCAL IEC member National Committee for further information.Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduiteni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopieet les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez desquestions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisezles coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.
標簽： iec標準
上傳時間： 2021-10-21
上傳用戶：kent
LAN9254 + SAME54 MCU 從站設計?1.支持2/3個port口的EtherCat Slave控制器，并內置有8個FMMU 和8個SyncManagers; 并有8KB的更大的DPRAM存儲資源；?2. 8/16bit總線，支持和大多數8/16bit以及32bit的host MCU通訊； ?3. 內部集成了支持HP Auto-MDIX的以太網PHY芯片； ?4. 支持Wake on Lan以太網遠程喚醒技術；兼容EtherCat P協議； ?5. 具有低功耗工作模式，可以允許系統進入睡眠模式以節省更多功耗，直到被Master訪問； ?6. 支持線纜診斷技術； ?7. 支持1.8V~3.3V的靈活可變的IO電壓，省去需要外加Voltage shifter芯片的成本； ?8. 多功能GPIO，可以配置為LOCAL Bus，SPI, PWM，通用GPIO等多種接口功能； ?9. 工業級溫度范圍，最高可以支持105度工業溫度要求；
標簽： mcu lan9254 ethercat從站
上傳時間： 2021-11-09
上傳用戶：
