Data Transmission Implementation on Broad-Band Networks

Broad-band networks present many advantages for the implemention of data transmission circuits. Whereas communication system concepts are universally applicable, there are many unique details and practial considerations involved in design and operation of broad-band networks. This paper describes broad-band configurations and their system design implications and includes a discussion of current modem designs, spectral occupancy, and modulation characteristics configurations and protocols, interference, and error control, as well as broad-band network control and maintenance. In addition, a data transmission network addressing many of the basic factors and providing multiple services is described.     

Classification and Assessment of Telecommunication Services in Broad-Band Networks

Communication systems have become a fundamental utility for many facets of private and public life. Increasing system capabilities and advances in technology stimulate expectations of the public for new telecommunication services. Quite a variety of new services have been proposed which will have to be analyzed as to their utility, customer acceptance, and feasibility of implementation. In this paper an analytical approach is selected to assess these services by defining their communication structure and arranging them into classes corresponding to information flow, mode of information exchange, and communication pattern. Services requiring considerable technical expenditures and having a significant impact on future network configurations are pointed out. These services reqmre subscriber-individual and broad-band communication channels. For selected classes of services, a conceptual implementation in three types of networks is presented. It is recommended that several new services be implemented by using facilities of the existing public telecommunication network.     

一种适用于虚拟机网络的数据包高效传输方法

为了提高数据包在云计算数据中心中基于虚拟机构成网络中的传输性能,提出了一种基于网络编码的高效数据包传输方法.基于网络编码机制,采用对传输过程中丢失数据包高效的编码组合策略,多个虚拟机终端可以在一次多播或广播传输中获取多个从交换机优先传输的数据包,因此,提出的方法可以提高基于虚拟机网络的多播及广播业务的数据包传输延迟,并提高多播及广播业务的网络吞吐量.仿真结果表明提出的方法在典型信道条件下均获得了较好的数据包传输时延及网络吞吐量性能.     

基于聚类的无线传感网络的合作MIMO传输方案

Wireless sensor network is becoming more and more popular in recent years, but energy-constrained characteristic of sensor nodes is one of the critical issues that we must consider in system design. In this paper, a cluster-based virtual V-BLAST transmission scheme is proposed to achieve energy savings for energy-constrained wireless sensor networks. In the proposed scheme, instead of using cluster member as cooperative nodes, multiple cluster heads cooperate to form virtual antenna array so that V-BLAST based virtual MIMO transmission can be implemented. Based on the communication energy consumption model, a way to optimize the parameters for the scheme is given. In addition, detailed simulation is performed to evaluate the performance of the proposed scheme for both densely and sparsely deployed sensor networks. Theoretical analysis and simulation results verify the energy efficiency of the proposed scheme.     

A Per-Flow Based Node Architecture for Integrated Services Packet Networks

As the Internet transforms from the traditional best-effort service network into QoS-capable multi-service network, it is essential to have new architectural design and appropriate traffic control algorithms in place. This paper presents a network node architecture and several traffic management mechanisms that are capable of achieving QoS provisioning for the guaranteed service (GS), the controlled-load (CL) service, and the best-effort (BE) service for future integrated services networks. A key feature of our architecture is that it resolves the out-of-sequence problem associated with the traditional design. We also propose two novel packet discarding mechanisms called selective pushout (SP) and selective pushout plus (SP+). Simulation results show that, once admitted into the network, our architecture and traffic management algorithms provide, under all conditions, hard performance guarantees to GS flows and consistent (or soft) performance guarantees to CL flows, respectively; minimal negative impact to in-profile GS, CL and BE traffic should there be any out-of-profile behavior from some CL flows.     

A LP-based Admission Control Using Artificial Neural Networks for Integrated Services in Mobile Networks

In mobile networks the traffic fluctuation is unpredictable dueto mobility and varying resource requirements of multimedia applications.Henceit is essential to maintain the traffic within the network capacity to providethe service guarantees to running applications. Thispaper proposes an Admission Control (AC) scheme in a single mobile cellularenvironment supporting real-time and non-real-time application traffic. In thecase of a real-time and non-real-time multimedia applications, eachapplication has its own distinct range of acceptable Quality of Service (QoS)requirements(e.g., packet loss, delay, jitter, etc.). The network provides the service bymaintaining the application specified QoS range. We propose a LinearProgrammingResource Reduction (LP-RR) principle for admission control by maintainingQoSguarantees to existing applications and to increase the percentage ofadmissionto real-time and non-real-time applications. Artificial Neural Networks (ANNs)are used to solve linear programming problem, which facilitates an on-lineadmissioncontrol decision in the practical systems.The simulation results demonstrate that the proposed AC schemeperforms well in terms of admitted applications and maintains lower percentageof rejection to hand-off and new applications of different traffic classes.The suggested principle also shown that it is appropriate for the fairresourceallocation with improved resource utilization.     

面向5G网络的传输承载方案

针对5G(第5代移动通信技术)网络对传输承载的新需求:超大带宽、超低时延、灵活调度、网络切片等,以及承载网组网架构特点,文章从不同场景、不同运营商分析5G承载网的前传、中传、回传方案,并从网络架构升级、基础设施建设以及光缆和综合业务区建设等方面给出具体建议。对于5G传输承载网,运营商需根据自身网络现状,围绕基础设施,结合综合接入区和DC机房整体规划,快速推进传输承载网建设。     

Integrated Circuits for Broad-Band Communications Systems

Integrated circuits for broad-band communication systems which enable broad-band communication between subscribers require LSI's with a performance concerning speed, complexity, and power dissipation which cannot be fully met by present semiconductor technologies. The requirements for coders and decoders, line transmission circuits, and broad-band switching network elements depend upon the system concept chosen. For one chosen system concept, these requirements are derived. By using a representative model for the development of the demand, characteristic curves for the demand of subscriber-line circuits and for central unit elements are resulting. From these curves the optimum semiconductor technologies, complexities, and design strategies are derived. It can be assumed that the results are rather independent of variations of system concept and introduction models.     

A Novel Multimedia Streaming Scheme for N-Screen Services in Wireless USB Networks

Ultra wideband (UWB) technology has emerged as a solution for the wireless interface between medical sensors and a personal server in future telemedicine systems. Wireless universal serial bus (USB) is the USB technology merged with UWB technology. Wireless USB can be applied to wireless personal area network applications as well as personal area network applications like wired USB. In case of n-screen service applications, data traffics must broadcast to the adjacent devices However, the current wireless USB is designed to support the communication through the point-to-point connection between the host and the device only. This policy increases delay and energy consumption of wireless host and devices significantly. Therefore, in this paper, we propose a novel multimedia streaming scheme for n-screen service in wireless USB networks. The simulation results show that proposed protocol can enhance the throughput and delay performance and improve energy efficiency by minimizing the multimedia data delivery process.     

MSTP综合专线业务解决方案

在分析了大客户业务需求及专线网络的发展基础上,指出MSTP是现阶段理想的综合专线网络技术。详细阐述了MSTP提供TDM专线、以太网专线、ATM专线等各类专线接入能力及技术特点、MSTP专线业务的端到端管理以及MSTP专线的业务保护。最后总结了MSTP技术发展及设备应用状况。     

基于网络编码的延迟容忍移动传感器网络低时延广播传输机制

针对延迟容忍移动传感器网络(Delay Tolerant Mobile Sensor Networks, DTMSN)提出一种基于网络编码的广播传输机制 (Netcoding-based Broadcast Transmission scheme, NBT)。NBT中,基站(Base Station, BS)将原始数据分批进行传输,每个批次包含的原始数据包的数量一定;BS将同一批次数据包以单播方式传输给不同传感器节点时采用的编码向量互不相关,传感器节点之间采用泛洪的机制交换彼此缺少的编码数据包。由于BS对原始数据包进行了编码,因此传感器节点具有相同编码数据包的可能性大大降低,从而减小了节点间的数据相关度,有效降低了广播时延。在随机路点移动模型(Random WayPoint, RWP)下的仿真结果表明,与目前广播时延最小的泛洪机制相比,NBT能够在通信开销基本相同的情况下有效降低广播传输时延。     

A Massive Transmission Scheme in Contention-Based MAC for Wireless Multimedia Sensor Networks

For transmitting the data which is composed of sensed information in sensors, wireless sensor networks have been developed and researched for the improvement of energy efficiency, hence, many MAC protocols in WSN employ the duty cycle mechanism. Since the progressed development of the low power transceiver and processor let the high energy efficiency come true, the delivery of the multimedia data which occurs in the area of sensor work should be needed to provide supplemental information. In this paper, we design a new scheme for massive transmission of large multimedia data where the duty cycle is used in contention based MAC protocol, for WMSN. The proposed scheme can be applied into the previous duty cycle mechanism because it provides two operations between normal operation and massive transmission operation. Measuring the status of the buffer in a sender and the condition of current radio channel can be criteria for the decision of the above two operations. This paper shows the results of the experiment by performing the simulation. The target protocol of the experiment is X-MAC which is contention-based MAC protocol for WSN. Two approaches, both X-MAC which operates only duty cycle mechanism and X-MAC(MTS) which operates combined massive transmission scheme, are used for the comparative.     

An Evaluation Model for Integrated Services on Wireless Broadband CDMA Networks

This paper proposes a performance evaluation approach for integrated voice and data services on a broadband code division multiple access (CDMA) network. For random access schemes, the dynamic behavior of a CDMA channel infers that we must be cautious with a performance judgment. We must be especially careful when choosing a mathematical model that has to include the effect of dynamic error rates. The approach shown in this paper is to employ a Poisson error model that takes the occurrence of errors as a Poisson process with the occurring rate dependent on the channel traffic. Based on this assumption, we developed a continuous-time Markov chain model to evaluate the throughput and delay performance. This approach can certainly apply to the evaluation of many integrated services protocols.     

基于事件驱动的动态分簇网络的协作传输方法

针对事件驱动的无线传感器网络的传输可靠性问题,该文利用节点间的互助,提出一种基于事件驱动的动态分簇网络的协作传输方法.无事件发生时,各节点按预先形成的静态簇低频传输数据.而一旦有事件发生,能感知事件发生的节点快速组成事件簇,向簇头发送采集的数据,簇头融合数据后发往汇聚节点.为提升传输可靠性,当簇头传输失败时,由最佳中继协作转发数据给汇聚节点.在最佳中继的选择上,考虑到事件的连续移动,以及处于事件前向通道上的节点具有较大的感应值和较好的协作能力等条件,该文提出了基于前向通道的最佳中继选择策略.仿真和实验结果表明,所提协作传输方法能够有效提高传输可靠性.     

密集小基站网络中的下行乒乓中继传输机制

研究了密集小基站网络中的下行放大转发中继传输机制。由于半双工限制,传统中继传输机制会带来一定的频谱效率损失,同时在密集系统中获取全局信道状态信息也较为困难,为此提出了一种分布式乒乓中继传输机制。该机制避免了传统机制的半双工损失,同时也可以有效地解决中继间干扰问题。分析了传统传输机制以及乒乓中继传输机制的可达速率,并且给出了两者在中继数很大时的渐进性能。分析与数值仿真表明该机制相较于传统中继机制可以带来较大性能增益。     

基于事件驱动的动态分簇网络的协作传输方法

针对事件驱动的无线传感器网络的传输可靠性问题,该文利用节点间的互助,提出一种基于事件驱动的动态分簇网络的协作传输方法.无事件发生时,各节点按预先形成的静态簇低频传输数据.而一旦有事件发生,能感知事件发生的节点快速组成事件簇,向簇头发送采集的数据,簇头融合数据后发往汇聚节点.为提升传输可靠性,当簇头传输失败时,由最佳中继...     

Deterministic Time-Varying Packet Fair Queueing for Integrated Services Networks

In integrated services networks, the provision of Quality of Service (QoS) guarantees depends critically upon the scheduling algorithm employed at the network layer. In this work we review fundamental results on scheduling, and we focus on Packet Fair Queueing (PFQ) algorithms, which have been proposed for QoS wireline-wireless networking. The basic notion in PFQ is that the bandwidth allocated to a session is proportional to a positive weight _i . Because of the fixed weight assignment, the inherent in PFQ delay-bandwidth coupling imposes limitations on the range of QoS that can be supported. We develop PFQ with deterministic time-varying weight assignments, and we propose a low-overhead algorithm capable of supporting arbitrary piecewise linear service curves which achieve delay-bandwidth decoupling. Unlike existing service-curve based algorithms, our time-varying PFQ scheme does not exhibit the punishment phenomenon, and allows sessions to exploit the extra bandwidth in under-loaded networks.     

Blockchain Based Secure Relay Scheme for Space-Terrestrial Integrated Networks

The future 6G networks will integrates space and terrestrial networks to realize a fully connected world with extensive collaboration. However,how to build trust between multiple parties is a difficult problem for secure cooperation without a reliable third-party. Blockchain is a promising technology to solve this problem by converting the trust between multi-parties to the trust to the common shared data. Several works have proposed to apply the incentive mechanism in blockchain to encourage ef...     

A Practical Traffic Scheduling Scheme for Differentiated Services of Healthcare Systems on Wireless Sensor Networks

Wireless sensor networks have recently been extensively researched due to the flexibility and cost savings they provide. One of the most promising applications of sensor networks is human health monitoring: wireless sensors are placed on the human body to form a wireless body network where the sensor node can continuously monitor real-time physiological parameters or human activities (motion detection). However, along with the flexibility, many problems arise due to a number of factors, including the bad quality of transmission media and the scarcity of resources. Moreover, sensor networks have different characteristics such as a variety of devices, different generated data, etc. From a quality of service (QoS) point of view, the healthcare domain can be seen as a real-time application demand to consider application requirements. Healthcare domains principally have stringent delay and loss requirements. Thus, considering different capabilities and ensuring time data delivery become necessary. Because wireless body area networks (WBAN) deal with human life, any delayed or lost data can endanger the user’s life. This paper proposes a differentiated traffic and scheduling scheme for WBAN. It is based on patients’ data classification and prioritization according to their current status and diseases. Through queue scheduling and path choice issues, the urgent data are delivered on time to provide a QoS guarantee for WBAN. Finally, it is shown that the proposed scheme is efficient for timely data transfer in WBAN.