1 New network architecture To realize intelligent optical wireless network, designing a good network architecture is the first issue to be considered. Combining the advantages of the current mainstream network architecture worldwide and avoiding its deficiencies, we propose the fiber optic radio (RoF) network architecture shown in Figure 1. The architecture is divided into 3 layers, from bottom to top, distributed wireless access layer, optical switching layer and lumped base station pool. In response to the application requirements of a wide range of low-cost Wi-Fi coverage and the access needs of high-data services such as Gigabit HD video in smart homes, we have specified the above-mentioned general-purpose intelligent optical carrier wireless network architecture, and proposed two Network architecture with specific scope of application 1.1 Design and implementation of distributed optical Wi-Fi network architecture for broadband access and ubiquitous sensing applications The typical structure of the Internet of Things includes three layers, namely the perception layer, the transmission layer and the application layer [2]. This paper proposes a transport layer network based on the heterogeneous structure of optical Wi-Fi. The network architecture is shown in Figure 2. The structure of the ROF link based on optical Wi-Fi is shown in Figure 3. We use the analog direct modulation ROF network architecture based on the coarse wavelength division multiplexing (CWDM) method. After the analog direct modulation, the light of different wavelengths passes through the CWDM device Multiplexed into a fiber for transmission, the other end of the fiber is demultiplexed by the other, the optical signal is distributed to each remote antenna unit (RAU), the radio frequency signal is recovered by the photodetector, and then amplified by the antenna Go out to achieve wireless coverage. The completion of the two-way link can meet the application requirements of broadband wireless access. The transparent structure is easy to upgrade and can meet the transmission of 3G and other wireless standard signals with a small amount of hardware modification [3]. 1.2 Multi-band dynamic controllable ROF network architecture design and link implementation for multi-service integration access in the building Figure 4 is a diagram of the ROF network architecture for multi-service integrated access in the 2.4 GHz band and 60 GHz band. At the optical network unit (ONU) of the Ethernet passive optical network, an additional intelligent residential gateway (IGR) is used to implement the up-conversion of baseband signals to 2.4 GHz and 60 GHz, as well as the management and scheduling of radio frequency resources, and Use indoor fiber optic network transmission. In order to solve the cost and technical problems in the upstream process, considering that upstream services such as video on demand (VOD) generally do not require a particularly high-speed transmission rate, here through terminal design and gateway processing functions, the existing Wi-Fi in adjacent rooms is used Fi signal coverage to perform the upstream demand of Gigabit downstream services. In this way, through the construction of the Wi-Fi distributed antenna system and the establishment of the 60 GHz frequency band Gigabit wireless communication link, users in each room in the building can provide Gigabit uncompressed high-definition TV and its on-demand services, Wi-Fi signals Internet of Things services such as broadband access and health monitoring, video monitoring and environmental monitoring, so as to realize the construction of intelligent ubiquitous home networks. Figure 5 shows the transmission link of a dynamically controllable ROF network with multi-service integration in the building. Inside the ONU and the intelligent residential gateway (IRG), the Gigabit HDTV service source in the Internet is provided to users in the building via EPON by wire. In order to support wireless access, the conversion interface is used to convert Ethernet parallel data to serial The return-to-zero code is modulated onto the continuous optical carrier emitted by the direct modulation laser, and then the Mach-Zehnder modulator (MZM) is used to generate the millimeter wave and transmit it through the millimeter wave antenna. At the receiving end, the millimeter wave signal is received and amplified by the receiving antenna, down-converted by self-mixing, and finally filtered by a low-pass filter to obtain the baseband signal. In order to realize the allocation of resources, we propose a radio frequency switching technology based on a micro-electromechanical system (MEMS) optical switch matrix to realize the construction of a dynamically controllable ROF network. In Figure 5, internally, the command sent by the central control unit is used to control the routing of the MEMS optical switch. In this way, using the 60 GHz and 2.4 GHz band networks and the optical switch matrix can realize wireless intelligent coverage of multi-band and multi-service in the building, greatly increasing the spectrum efficiency and effectively reducing the overall energy consumption. Mtu Generator Set,Diesel Power Generator,Diesel Engine Generator,Silent Diesel Generator Yangzhou Hengyuan Electromechanical Equipment Co., Ltd. , https://www.lchygeneratorset.com
