Short-Distance Low-Power Wireless Access System

The short-distance low-power technologies for wireless access communications, including Bluetooth, Ultra-Wideband (UWB) and Wireless Fidelity (Wi-Fi), focus on the physical layer and Medium Access Control (MAC) layer. Bluetooth is a wireless protocol for exchanging data over short distances. It is an alternative to RS232 data cables. UWB is a radio technology that can be used at very low energy levels for short range. It provides flexible high-bandwidth wireless access. Wi-Fi enables the wireless connection of fast-access devices and mobile devices in Wireless Local Access Network (WLAN) and it is suitable for long distances. The standardizations of the above technologies have been developed and published soon after the emergence of these technologies. Among all the standards, Bluetooth and Wi-Fi are the most important ones.

ZTE's Broadband Wireless Access System

1 IntroductionWith the rapid development of backbonenetworks,the subscriber accessnetwork,a major component of publictelecom network equipment and so-called the“last kilometer”,has turned out to bethe focus of attention.Among various access technologies,thebroadband wireless access system featuresquick network construction,rapid investmentreturn and large bandwidth.It enables newnetwork operators to provide services quickly

Research and Development of New Broadband Wireless Access System

Broadband Wireless Access (BWA) has become one of the major evolution trends in the fields of broadband access and mobile communications. However,some difficulties emerged during the application and industrialization of the BWA system,which calls for typical service models,key technology innovations and backbone support from broadband Internet. This article introduces a Broadband Wireless Multimedia (BWM) access system. It aims to build a new-type "triple play" BWA network by integrating terrestrial digital TV system and the BWA system,and by taking broadband Internet as its core network platform. A primary research shows that the new BWA system is an effective solution to the existing difficulties of BWA system. Moreover,it is quite competitive in service provision,service coverage,frequency planning,terminal power consumption and cost for network construction.

Modelling a Learning-Based Dynamic Tree Routing Model for Wireless Mesh Access Networks

Link asymmetry in wireless mesh access networks(WMAN)of Mobile ad-hoc Networks(MANETs)is due mesh routers’transmission range.It is depicted as significant research challenges that pose during the design of network protocol in wireless networks.Based on the extensive review,it is noted that the substantial link percentage is symmetric,i.e.,many links are unidirectional.It is identified that the synchronous acknowledgement reliability is higher than the asynchronous message.Therefore,the process of establishing bidirectional link quality through asynchronous beacons underrates the link reliability of asym-metric links.It paves the way to exploit an investigation on asymmetric links to enhance network functions through link estimation.Here,a novel Learning-based Dynamic Tree routing(LDTR)model is proposed to improve network performance and delay.For the evaluation of delay measures,asymmetric link,interference,probability of transmission failure is evaluated.The proportion of energy consumed is used for monitoring energy conditions based on the total energy capacity.This learning model is a productive way for resolving the routing issues over the network model during uncertainty.The asymmetric path is chosen to achieve exploitation and exploration iteratively.The learning-based Dynamic Tree routing model is utilized to resolve the multi-objective routing problem.Here,the simulation is done with MATLAB 2020a simulation environment and path with energy-efficiency and lesser E2E delay is evaluated and compared with existing approaches like the Dyna-Q-network model(DQN),asymmetric MAC model(AMAC),and cooperative asymmetric MAC model(CAMAC)model.The simulation outcomes demonstrate that the anticipated LDTR model attains superior network performance compared to others.The average energy consump-tion is 250 J,packet energy consumption is 6.5 J,PRR is 50 bits/sec,95%PDR,average delay percentage is 20%.

Polling Algorithm Based on Traffic Burst Characteristics of Broadband Wireless Access Systems

In this paper,we propose a novel polling algorithm to decrease the number of idle slots and collission slots during the polling cycle by evaluating the bandwidth request of the subscribe stations(SSs) in the next polling cycle for broadband wireless access(BWA) systems.We firstly analyze the feature of silent time intervals and deduce the Hurst index which symbolizes the degree of self-similarity and long-relative nature.Then we represent the inactive OFF time intervals by the Pareto model and estimate the shape parameterαby the group measured data.Finally we can evaluate the transmission probability of a silent SS before the next polling cycle. By this algorithm,we can find the optimal transmission opportunities for the base station(BS) to achieve the least collision or void timeslots in order to achieve the largest bandwidth efficiency.The theoretical analysis and simulation results show that this polling algorithm can improve the performance for BWA system.

A SDN-Based Energy Saving Strategy in Wireless Access Networks

This paper investigates on the base stations(BSs) sleeping control and energy saving in wireless network. The objective is to find the sleeping control and energy saving configuration between total power consumption and average video's quality. On the Software Defined Network(SDN) access network architecture, a type of sleeping control and active BSs' optimal transmitting time strategy is considered, the BS sleeps when there is no active users, and wakes up after a period of vacation time. In this paper, we study the active users grouping strategy, In order to spare more BSs into sleeping mode. Then this paper proposes an active BS transmitting time optimal strategy according to the users' Qo S. In the proposed strategy, the active BSs' transmitting time is minimized in order to save energy. This paper employs the mixed integer-programming model to present this optimization problem. Then we utilized a novel algorithm to save the energy in access networks and also meet the Qo S requirements. Both the analytical and simulation results show that the algorithm can effectively save energy in the access network BSs.

Performance Analysis of WLAN Medium Access Control Protocols in Simulcast Radio-Over-Fiber-Based Distributed Antenna Systems

The performance of three wireless local-area network(WLAN) media access control(MAC) protocols is investigated and compared in the context of simulcast radioover-fiber-based distributed antenna systems(RoF-DASs) where multiple remote antenna units(RAUs) are connected to one access point(AP) with different-length fiber links.The three WLAN MAC protocols under investigation are distributed coordination function(DCF) in basic access mode,DCF in request/clear to send(RTS/CTS) exchange mode,and point coordination function(PCF).In the analysis,the inter-RAU hidden nodes problems and fiber-length difference effect are both taken into account.Results show that adaptive PCF mechanism has better throughput performances than the other two DCF modes,especially when the inserted fiber length is short.

Thinking About Developing 3G and Broadband Wireless Access Technologies

It is wise for fixed operators to make use of broadband wireless access technologies,such as IEEE802.16d,to develop mobile access based on their existing fixed broadband IP networks.Mobile operators have to evolve their networks from 2G to 3G for making full use of their current resources. However,the AII-IP core network will be a general trend since broadband wireless access adopts the connectionless statistical packet multiplexing technology.Based on the introduction of IEEE802.16d,High Speed Downlink Packet Access (HSDPA) and CDMA2000 1x EV-DV technologies,this paper discusses the development trend of broadband wireless access technologies, and concludes that 3G's packet access technologies are the same as IEEE802.16d/e,and AII-IP is the goal.It emphasizes that Chinese TD-SCDMA should develop toward connectionless statistical packet multiplexing as early as possible.

Ubiquitous Access Technology for Wireless Digital Home Networks

As an important branch of telecommunication technology, digital home networks have quickly developed in recent years. Although architecture of the digital home network based on telecommunication networks has been standardized in China, only wireless access is defined to be allowable. Therefore, it becomes the focus of further research how to establish a wireless digital home network. This article proposes the concept and shows the architecture of ubiquitous access for wireless digital home networks. Moreover, key technologies for ubiquitous access are discussed here, including cognitive radio, the concept of wireless Mesh, generic link transfer mechanism, Quality of Service (QoS) guarantee mechanism, Electromagnetic Compatibility (EMC) and coexistence of heterogeneous systems.

The Design of an Intelligent Security Access Control System Based on Fingerprint Sensor FPC1011C

This paper deals with the design of an intelligent access control system based on the fingerprint sensor FPC- 1011C. The design uses the S3C2410 and TMS320VC5510A as the system processor. A fingerprint acquisition module and a wireless alarm module were designed by using the fingerprint sensor FPC1011C and GPRS module SIM100 respectively. The whole system was implemented wireless alarm through messages and GPRS-Internet in the GSM/GPRS web. In order to achieve the simple and high Real-time system, the μC-Linux system migration was also implemented.

具有无线携能技术的MIMO-NOMA系统

用户干扰降低了毫米波大规模多输入多输出(MIMO)非正交多址接入(NOMA)系统的频谱效率和能量效率,针对这一问题,提出将无线携能技术(SWIPT)引入基于混合预编码(HP)的MIMO-NOMA系统,并设计了用户分组、混合预编码以及功率分配方案。首先,提出了簇头选择算法,以设计模拟预编码,基于等效信道相关性进行用户分组,并最大化等效信道增益设计数字预编码;其次,为追求用户间的公平性,提出一种基于二分的功率分配方案,以实现最小可达速率最大化。理论分析和仿真结果表明,信噪比(SNR)为5dB时,相较于现有的具有无限携能的正交多址方案,所提方案在全连接架构下频谱效率提升约24.8%,在子连接架构下能量效率提升约24.6%。

基于深度学习的6G可见光通信多址接入解调方法

发光二极管的调制带宽较窄,导致可见光通信系统的容量受限,通过多址接入技术可提高频谱效率和终端用户数量。然而,可见光通信系统多址接入的用户间存在较强的干扰。针对此问题,利用可见光通信系统接收信号间的相关性,提出一种基于深度神经网络的多址接入多用户检测与信号还原方法。基于稀疏码多址接入给出了可见光通信系统的发送端模型与接收端模型,采用时域卷积网络学习长序列的信号间时域相关性,再传入密集层学习信号序列的空间域映射关系,最终在可见光通信系统的接收端还原所有用户的信号。实验结果表明,该方法有效提高了可见光通信系统多址接入的通信性能,在不同通信距离、信噪比、发送速率下均能发挥积极作用。

IEEE 802.11aj(45GHz):A New Very High Throughput Millimeter-Wave WLAN System

This paper presents an overview of a new very high throughput millimeterwave WLAN system operating at 45 GHz band. We begin by reviewing standards process of IEEE 802.11aj(45GHz). Then the frequency spectrum allocation at 45 GHz band is introduced. Next, the channel measurement and mod-eling is given. Specifically, the millimeter-wave MIMO for physical layer enhancement is given in detail.

On Minimizing Delay with Probabilistic Splitting of Traffic Flow in Heterogeneous Wireless Networks

In the paper,we propose a framework to investigate how to effectively perform traffic flow splitting in heterogeneous wireless networks from a queue point.The average packet delay in heterogeneous wireless networks is derived in a probabilistic manner.The basic idea can be understood via treating the integrated heterogeneous wireless networks as different coupled and parallel queuing systems.The integrated network performance can approach that of one queue with maximal the multiplexing gain.For the purpose of illustrating the effectively of our proposed model,the Cellular/WLAN interworking is exploited.To minimize the average delay,a heuristic search algorithm is used to get the optimal probability of splitting traffic flow.Further,a Markov process is applied to evaluate the performance of the proposed scheme and compare with that of selecting the best network to access in terms of packet mean delay and blocking probability.Numerical results illustrate our proposed framework is effective and the flow splitting transmission can obtain more performance gain in heterogeneous wireless networks.

Analysis of Traffic Parameter Estimation and Its Impacts on Wireless Channel

Wide band or broadband access was paid much attention with the development of radio transmission technique. The wireless access control procedure play an important role in this type of system and efficiency of control algorithm has a great impact on throughput of channel resource. Based on wide band network control model and the characteristics of radio channel, this paper proposed a channel traffic estimation method and then performed a dynamic parameter control procedure and give detail analysis on estimation error and its impact on channel throughput and delay performance. Computation and simulation of system performance show a positive solntion on system design.

Wireless Communication Networks' Planning in Underdeveloped Countries

The planning of wireless communication networks in underdeveloped countries is studied for landline telephone, fixed broadband wireless access and PLMN systems via investigation and discussion of the LDC networks＇ characteristic, technology selection, deployment consideration, network configuring, civil work evaluation and investment estimation. An example is embedded all through providing a general

Shaped Offset Quadrature Phase Shift Keying Based Waveform for Fifth Generation Communication

Fifth generation(5G)wireless networks must meet the needs of emerging technologies like the Internet of Things(IoT),Vehicle-to-everything(V2X),Video on Demand(VoD)services,Device to Device communication(D2D)and many other bandwidth-hungry multimedia applications that connect a huge number of devices.5G wireless networks demand better bandwidth efficiency,high data rates,low latency,and reduced spectral leakage.To meet these requirements,a suitable 5G waveform must be designed.In this work,a waveform namely Shaped Offset Quadrature Phase Shift Keying based Orthogonal Frequency Division Multiplexing(SOQPSK-OFDM)is proposed for 5G to provide bandwidth efficiency,reduced spectral leakage,and Bit Error Rate(BER).The proposed work is evaluated using a real-time Software Defined Radio(SDR)testbed-Wireless open Access Research Platform(WARP).Experimental and simulation results show that the proposed 5G waveform exhibits better BER performance and reduced Out of Band(OOB)radia-tion when compared with other waveforms like Offset Quadrature Phase Shift Key-ing(OQPSK)and Quadrature Phase Shift Keying(QPSK)based OFDM and a 5G waveform candidate Generalized Frequency Division Multiplexing(GFDM).BER analysis shows that the proposed SOQPSK-OFDM waveform attains a Signal to Noise Ratio(SNR)gain of 7.2 dB at a BER of 10�3,when compared with GFDM in a real-time indoor environment.An SNR gain of 8 and 6 dB is achieved by the proposed work for a BER of 10�4 when compared with QPSK-OFDM and OQPSK-OFDM signals,respectively.A significant reduction in OOB of nearly 15 dB is achieved by the proposed work SOQPSK-OFDM when compared to 16 Quadrature Amplitude Modulation(QAM)mapped OFDM.

基于ZigBee无线控制的门禁系统设计

本门禁系统设计基于计算机技术、ZigBee无线网络技术以及单片机等技术的交叉融合,通过ZigBee终端节点和协调器向上位机发送电子密码锁的实时状态,上位机记录和管理发送的数据,并据此控制电子密码锁。该系统主要由CC2530传输处理模块、STC15单片机模块(含最小系统电路)、光耦隔离继电器模块、4×3矩阵键盘、OLED显示模块、蜂鸣器报警模块等组成,通过继电器模块的开关模拟门禁锁的状态,构建了基于继电器控制的电子密码锁ZigBee终端节点。系统设计功能完整,成本低,具有良好的扩展性和应用性。

小水电运行数据调度自动化主站接入系统研究

针对小水电站信息难以上传调度自动化系统,无法实现集群调控的问题,采用无线公网信息安全接入技术,利用微型纵向加密装置建立三层安全接入防护体系,将小水电站信息连通调度自动化系统。结果表明,该方法解决了小水电站信息接入问题,不仅突破了地域、光缆资源等限制,还有效降低了维护总成本,极大提高了电力系统运行管理水平,保证了电力系统安全稳定运行。

高速铁路宽带无线接入系统架构与关键技术

本文阐述了高速铁路(以下简称高铁)宽带无线接入系统的需求,研究了高铁宽带无线接入系统的特点,分析了现有无线接入技术的优势与不足,探讨了一种新型的高铁宽带无线接入结构High Speed Mobile Cell(Himocell),最后讨论了高铁宽带无线接入中的几个关键技术。