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Licensed spectrum remains 3GPP operators’ top priority to deliver advanced services and user experience Opportunistic use of unlicensed spectrum is becoming an important complement for operators to meet the growing traffic demand Moving forward 3GPP operators will have two options to offload traffic to unlicensed spectrum: 1. Wi-Fi (via LTE/Wi-Fi interworking) 2. LTE over unlicensed It will then be up to each individual operator to choose which approach to use, which will depend on a number of factors
標簽： 3GPP_unlicensed_Dino_Flore 2015 01
上傳時間： 2020-05-26
上傳用戶：shancjb
Wireless Fidelity (Wi-Fi) networks have become mainstream over the last few years. What started out as cable replacement for static desktops in indoor networks has been extended to fully mobile broadband applications involving moving vehicles, high-speed trains, and even airplanes.
標簽： Technologies Emerging Wireless Theory LANs in
上傳時間： 2020-05-27
上傳用戶：shancjb
Following chapter introduces the mobile communication, gives a short history of wireless communication evolution, and highlights some application scenarios predestined for the use of mobile devices. Cellular and wireless based systems related to different generations of mobile communication, including GSM, IS-95, PHS, AMPS, D-AMPS, cdma2000 and WCDMA are also described by this Chapter. Much attention in this chapter is given to express the wireless based networks, such as Wi-Fi and WiBro/WiMax, and wireless broadcasting systems, including DMB, DVB-H, and ISDB-T. We conclude the chapter with the future vision of mobile communication evolution
標簽： Technologies Enhanced Access Radio
上傳時間： 2020-05-27
上傳用戶：shancjb
Digital mobile wireless communication and the Internet have undergone a fantastic growth in the last few years and, despite originating from two different worlds, they are converging. This convergence corresponds to the evolution of mobile systems towards the highest broadband data transmissions (GSM, EDGE/GPRS, UMTS then HSDPA), while the computing world gets equipped with wireless technologies such as Wi-Fi or Wi-Max.
標簽： Reconfigurable Systems Mobile Radio
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
Although the origins of radio frequency based wireless networking can be traced back to the University of Hawaii’s ALOHANET research project in the 1970s, the key events that led to wireless networking becoming one of the fastest growing technologies of the early 21st century have been the ratification of the IEEE 802.11 standard in 1997, and the subsequent development of interoperability certification by the Wi-Fi Alliance (formerly WECA).
標簽： Networking Technology Wireless
上傳時間： 2020-06-01
上傳用戶：shancjb
設計了一種基于STM32F103單片機的甲醛檢測報警儀，采用ESP8266 Wi-Fi模塊實現通信連接與數據傳遞，采用M-01傳感器實時采集室內環境的甲醛濃度，通過LCD12864液晶模塊顯示甲醛濃度，并在甲醛濃度超標時進行聲光報警。該甲醛檢測報警儀成本低，精度高，可以滿足室內環境甲醛濃度監測的需要。
上傳時間： 2022-04-28
上傳用戶：
移動通信網絡由于帶寬和技術的限制，遠遠不能滿足人們不斷高漲的無線上網需求。Wi-Fi作為無線接入技術MLAN的主流標準口益成熟，它能夠隨時隨地高速連接到Internet，極大地滿足了用戶對無線上網需求，受到消費者的青睞。因而越來越多的移動終端都集成了Wi-Fi功能，Wi-Fi和藍牙樣成為移動終端的標配。隨之而來的是Wi-Fi和藍牙都工作在2.4CHZz ISM頻段而引發的互相 擾問題，導致數據吞吐量下降，語音質量惡化失真，極端狀況下甚至導致鏈路斷開而不能正常工作。因此，必須尋求有效的措施和方法，實現兩種技術在近距離的和諧共存，這已成為非常迫切的技術需要，也成為人們研究的一個熱點和難點。近距離WiFi和藍牙互相1擾的問題，目前已經形成了非常多的有效解決機制，包括基于Wi-Fi的PTA（Packet Traffic Arbitration）、AWMA（Alternating Wireless Medium Access）和DSE（Deterministic Spectral Excision），其中PTA和AWMA機制在Wi-Fi側MAC層實現，通過協調Wi-Fi和藍牙的幀發射時間來避免相互干擾：而DSE是在Wi-Fi側物理層PHY實現，通過一個可編程帶阻濾波器（Notch Filter）來阻止來白藍牙的窄帶干擾。還有基于藍牙側的AFH（Adaptive Frequency Hopping），它通過跳頻，自動避開被干擾的頻點，從而大大提高了藍牙傳輸性能。
上傳時間： 2022-06-20
上傳用戶：zhanglei193
本文開展的主要工作如下：1，設計實現了可通過藍牙、語音和Wi-Fi三種方式控制的智能家居電源開關控制器。設計了元器件電路、PCB線路和Android UI界面，可應用于Android手機、平板、藍牙程式實施進程控制，改變了傳統家居布線模式，可免開關布線，也可相容已有線路布局，還可與各種智能家庭系統實現無縫連接。借助熱成像實驗測試了環境溫度對該控制器的影響，并對控制器的性能做了全面的分析和研究。2基于穩定性、安全性、易于擴展及便于施工的原則，規劃了整個智能家居終端控制系統的通信協議和組網方式，選用支持OpenWrt系統的哦耶路由器改裝成中控智能家庭網關。以CO傳感器監控報警為例，實驗驗證了整個系統的可行性。3本文使用藍牙組網，相對于ZigBee功耗更低。在消費電子領域，藍牙具有更多優勢，也得到了越來越多的青睞。隨著藍牙自組網技術（BLE Mesh）的發布，進一步規范了基于IPv6數據包的交換設備間的藍牙通信，克服了短距離通信和限制通信拓撲結構的缺陷，可免疫電磁干擾。藍牙的另一大優勢就是可直接與手機連接，必將成為近程通信發展的主要方向。注：本文第三章電源開關控制器是獨立開發準備投放市場的產品，后來和藍牙CSR廠商有合作，其提供了CSR1010藍牙芯片及開發API，所以在架構整個智能家居終端控制系統時，整個系統內所選用的藍牙芯片都用的是廠商提供的CSR1010芯片，組建BLE mesh網絡。
上傳時間： 2022-06-23
上傳用戶：
MT7688 family integrates a 1T1R 802.11n Wi-Fi radio,a 580MHz MIPS? 24KEcTM CPU,1-port fast Ethernet PHY, USB2.0 host, PCIe, SD-XC,I2S/PCM and multiple slow IOs. MT7688 provides two operation modes-IoT gateway mode and IoT device mode. In IoT gateway mode, the PCI Express interface can connect to 802.1lac chipset for 1lac dual-band concurrent gateway. The high performance USB2.0 allows MT7688 to add 3G/LTE modem support or add a H.264 ISP for wireless IP camera. For the IoT device mode, MT7688 supports eMC, SD-XC and USB 2.0. MT7688 can support the Wifi high quality audio via 192Kbps/24bits I2S interface and VolP application through PCM. In IoT device mode, it further supports PWM, SPI slave,3d UARI and more GPIOs. For IoT gateway, it canl connect to touch panel and BLE, Zigbee/Z-Wave and sub-1G RF for smart home control.
上傳時間： 2022-07-24
上傳用戶：
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