有线无线融合的卫星时间敏感网络流调度研究

随着空间通信任务日趋复杂化,尤其是对时间敏感的需求不断提升,一方面要求星内系统的高带宽、可靠性和实时性;另一方面星间无线链路也应具备低时延和高可靠性.但由于卫星内部有线链路与星间无线链路差异大,业务数据经过有线和无线链路联合传输时,容易引发节点拥塞,而无法保障时敏业务的时延有界需求.为了提升数据在空间网络传输的实时性,...     

基于门控制的星载时间敏感网络调度算法

空间信息网络中时间敏感业务的实时性、确定性和可靠性要求对基于存储转发方式的传统以太网交换提出巨大挑战。提出一种基于门控制的星载时间敏感网络调度算法,设计星载时间敏感网络交换方案;针对卫星业务突发的特点,提出一种基于时分复用的门控制列表生成方法,对该调度算法在不同业务流量特征背景下的确定性时延及时延抖动性能进行仿真分析。仿真结果表明,所提算法的最小时延减小至10 μs量级,最小时延抖动为0,满足空间时间时敏业务的确定性传输要求,提高了空间信息网络业务传输的确定性、可靠性、灵活性。     

端边协同保障时延确定性技术研究

工业自动控制等5G垂直行业对网络传输时延与可靠性有着苛刻的要求。聚焦自动导引车（automated guided vehicle,AGV）协同搬运业务场景,深入分析AGV业务关键质量指标（key quality indicator,KQI）与网络时延可靠性需求。现有的5G低时延技术,比如预调度机制通过大量预留空口时频资源降低传输调度等待时延,降低了频谱效率。此外,无线信道弱覆盖、干扰等质差因素会引发较大的时延抖动,难以满足业务时延可靠性需求。针对现有5G网络面临的挑战,设计了一种端边协同时延确定性保障技术方案,基于业务特征进行网络资源预留,同时感知空口信道状态,开启质差保障机制,提升传输可靠性。测试结果表明,端边协同技术方案可以有效提升时延可靠性,降低大时延抖动与优化业务KQI。     

基于OMNeT++的大规模确定性网络仿真实践

时间敏感网络（TSN）和确定性网络（DetNet）是确定性网络整体解决方案的重要组成部分,目前产业界还缺少这两种技术在大规模联合组网方面的研究。在OMNeT++仿真平台基于时隙调度实现了TSN和DetNet联合组网的确定性转发,并打通了控制器和仿真系统的通道,实现了转控协同的确定性仿真网络。重点介绍了对于仿真系统的改造,以及基于此的大规模跨域场景下确定性业务的端到端时延和抖动性能研究。结果表明,在大规模跨域场景下,时隙调度的机制可以提供端到端的确定性业务保障。     

时间敏感网络时隙感知循环排队转发流量整形机制

时间敏感网络是智能工厂内网的核心技术之一。智能工厂内存在多种需求各异的业务流。为保证关键业务流的性能，同时提升网络带宽利用率，该文提出一种时隙感知循环排队转发流量整形机制(TSA-CQF)。TSACQF通过将低优先级流量插入CQF奇偶队列中剩余可用时隙中传输提高带宽利用率。TSA-CQF机制包括低优先级流量的时隙感知插入和全局流量规划两个部分。低优先级流量的时隙感知插入是在CQF队列出队时，通过感知奇偶队列剩余时隙的大小，将低优先级流量插入到奇偶队列的剩余时隙进行传输。将全局流量规划建模为多条件约束目标优化问题，通过模拟退火算法求解，完成全局流量的调度，提高可调度流数目，进一步提高资源利用率。仿真结果表明，在混合流量条件下TSA-CQF比传统CQF机制平均提高了带宽利用率11.29%。与传统的CQF相比，TSA-CQF在牺牲一定调度策略生成时间的前提下，能明显提高带宽利用率并且降低最坏端到端时延。     

保证NGN端到端QoS的软时隙技术

QoS无保障,一直是NGN不能广泛商用的障碍所在。该文提出一种"软时隙"技术,融合TDM中的时隙控制技术与分组网络的数据传输技术于一体,为NGN中的流媒体业务提供端到端的服务质量(QoS)保证。"软时隙技术"在数据链路层的数据包头,插入"软时隙标签"来区分普通数据业务与流媒体业务,对两类业务分别采用独立的控制机制来保证各业务需要的QoS。对普通数据业务,采用分组网络成熟的路由与交换机制;对流媒体业务,采用PSTN网络的信令模式控制路由呼叫过程与建立端到端面向连接的业务通道。统一分组传送与区别交换控制相结合,兼顾数据业务性能,充分保证流媒体业务连接端到端具有稳定带宽与稳定时延的服务质量(QoS)。     

军用无线网络资源管理方法研究

针对战术无线通信网的具体特点和工作环境，给出了一种有中心控制的TDMA端到端战术无线通信网络结构，给出TDMA动态分配方案并分析了动态时隙分配机制．建立了时隙资源分配模型，给出了一种时隙分配算法——需求线路序贯处理法，以解决网络节点在动态变化下可靠通信的关键问题。     

战术无线网网络管理方法研究

针对战术无线通信网的具体特点和工作环境,给出了一种有中心控制的TDMA端到端战术无线通信网络结构,给出TDMA动态分配方案并分析了动态时隙分配机制,建立了时隙资源分配模型,给出了一种时隙分配算法--需求线路序贯处理法,以解决网络节点在动态变化下可靠通信的关键问题.     

基于二次独立集的数据融合调度算法简

针对无线传感器网络数据融合中服务质量与加权公平性保证问题,提出了一种基于二次独立集的数据融合调度算法MISS。该算法采用时分复用思想,通过2次构造最大独立集实现对加权数据的无冲突调度。首先构建以最大独立集为基础的树型结构,并根据能量消耗预测进行调整形成最终的数据融合平衡树;然后通过优化调度对象集合,利用近似最大加权独立集为允许通信的链路分配传输时隙。实验结果表明,该算法能够在降低融合时延、加权公平性保证以及延长网络生命周期等方面实现性能平衡。     

四表集抄通信网络虚拟化方案及组网算法研究

为了实现四表(水,电,气,热)集抄行业之间的业务数据隔离,提升本地网络的稳定性和覆盖能力,该文提出四表集抄通信网络虚拟化方案。该方案采用虚拟接入点名称(APN)技术以及软件定义网络(SDN)切片技术构成端到端隔离的业务数据采集通道;采用微功率无线和低压电力线载波构成实时可靠的本地双模虚拟网络,进一步提出基于全局链路状态和分层迭代的组网算法。仿真及现场验证结果表明,该方案降低了采集数据的丢包率和传输时延,提高业务支撑能力,保障行业之间的业务数据隔离,提升通信网络基础设施复用能力。     

一种基于聚合流的端到端统计时延界的新算法

为分析融合网络中聚合业务的端到端时延性能,提出一种基于聚合流的融合网络端到端统计时延界的新算法.该算法利用MGF(矩母函数)重新表征了网络端到端时延界的MGF形式的概率模型.数值分析结果表明了该算法的有效性和优越性,该算法很大程度上提高了独立统计复用,对融合网络性能评价具有参考意义.     

A novel scheduling scheme to share dropping ratio while guaranteeing a delay bound in a MultiCode-CDMA network

A MultiCode-CDMA network that is capable of providing quality-of-service guarantees will find widespread application in future wireless multimedia networks. However, providing delay guarantees to time-sensitive traffic in such a network is challenging because its transmission capacity is variable even in the absence of any channel impairment. We propose and evaluate the performance of a novel transmission scheduling scheme that is capable of providing such a delay guarantee in a MultiCode-CDMA network. The proposed scheme drops packets to ensure that delays for all transmitted packets are within the guaranteed target bounds, but packets are dropped in a controlled manner such that the average dropping ratios of a set of time-sensitive flows can be proportionally differentiated according to the assigned weighting factors or shares. We provide extensive simulation results to show the effectiveness of the proposed scheme as well as to study the effects of various parameters on its performance. In particular, we show that it can simultaneously guarantee a delay upper bound and a proportionally differentiated dropping ratio in a fading wireless channel for different traffic loads, peak transmission rates, and weighting factors of individual flows.     

A Queuing Theory-Enabled Dynamic Bandwidth Allocation Algorithm for a Wired-Wireless Converged Network

Multi-sink wireless sensor networks (WSNs) are being increasingly deployed in an ever-widening range of application scenarios, especially as they are reliable and exhibit low power consumption. Providing a backhaul for WSN traffic has become an important issue because the sensor data must usually be sent to the Internet or the core network. Passive optical networks (PONs) represent one next-generation access network technology which is appropriate for such a backhaul, however existing research appears to have concentrated on either WSN performance or PON performance, without considering the overall performance of both networks converged together. This paper proposes a new architecture which converges multi-sink WSNs and PONs, then provides a novel queuing-theory analysis of the converged network performance. Results from this analytical model are then used to motivate a new a DBA algorithm which optimizes grant size allocation. Numerical results show that this algorithm outperforms existing proposals when minimizing the system queue length in the converged network, while providing shorter end-to-end packet delay and higher throughput. We believe that this first resource allocation algorithm which considers the performance of both networks as one converged unit.     

A prioritized resource allocation algorithm for multiple wireless body area networks

This paper presents a prioritized resource allocation algorithm to share the limited communication channel resource among multiple wireless body area networks. The proposed algorithm is designed based on an active superframe interleaving scheme, one of the coexistence mechanisms in the IEEE 802.15.6 standard. It is the first study to consider the resource allocation method among wireless body area networks within a communication range. The traffic source of each wireless body area network is parameterized using the traffic specification, and required service rate for each wireless body area networks can be derived. The prioritized resource allocation algorithm employs this information to allocate the channel resource based on the wireless body area networks’ service priority. The simulation results verified that the traffic specification and the wireless body area network service priority based resource allocation are able to increase quality of service satisfaction, particularly for health and medical services.     

泛在无线环境中多无线接入网协同的业务分配策略

This paper introduces an adaptive traffic allocation scheme with cooperation of multiple Radio Access Networks (RANs) in universal wireless environments. The different cooperation scenarios are studied, and based on the scenario of cooperation in both network layer and terminal layer, an open queuing system model, which is aiming to depict the characteristics of packet loss rate of wireless communication networks, is proposed to optimize the traffic allocation results. The analysis and numerical simulations indicate that the proposed scheme achieves internetworking load balance to minimize the whole transmission delay and expands the communication ability of single-mode terminals to support high data rate traffics.     

Congestion-free communication in high-speed packet networks

The process of packet clustering in a network with well-regulated input traffic is studied and a strategy for congestion-free communication in packet networks is proposed. The strategy provides guaranteed services per connection with no packet loss and an end-to-end delay which is a constant plus a small bounded jitter term. It is composed of an admission policy imposed per connection at the source node, and a particular queuing scheme practiced at the switching nodes, which is called stop-and-go queuing. The admission policy requires the packet stream of each connection to possess a certain smoothness property upon arrival at the network. This is equivalent to a peak bandwidth allocation per connection. The queuing scheme eliminates the process of packet clustering and thereby preserves the smoothness property as packets travel inside the network. Implementation is simple     

基于多终端协同的高清视频多流并发自适应传输控制方法

摘要：针对高清视频在异构无线网络中以多流并发的方式进行传输,以提高传输速率,从而增强用户体验的问题,以最小化系统传输时延以及各路径间时延差为优化目标,联合考虑了视频发送端和接收端,自适应调整视频发送速率和接收端缓存大小以提高用户体验,建立了异构无线网络中视频多流并发传输的控制模型,并基于Pareto分布和P/P/1排队理论对具有自相似性和长相关性的视频流进行了研究,推导了并发传输系统的时延统计特性,并在此基础上提出了一种异构无线网络视频流自适应分流决策方法。仿真结果表明,与一般的负载均衡分流决策方法相比,提出的异构网络多流并发自适应传输控制方法在时延和分组丢失率方面都有一定的优越性。     

Network coding based joint signaling and dynamic bandwidth allocation scheme for inter optical network unit communication in passive optical networks

As an innovative and promising technology, network coding has been introduced to passive optical networks (PON) in recent years to support inter optical network unit (ONU) communication, yet the signaling process and dynamic bandwidth allocation (DBA) in PON with network coding (NC-PON) still need further study. Thus, we propose a joint signaling and DBA scheme for efficiently supporting differentiated services of inter ONU communication in NC-PON. In the proposed joint scheme, the signaling process lays the foundation to fulfill network coding in PON, and it can not only avoid the potential threat to downstream security in previous schemes but also be suitable for the proposed hybrid dynamic bandwidth allocation (HDBA) scheme. In HDBA, a DBA cycle is divided into two sub-cycles for applying different coding, scheduling and bandwidth allocation strategies to differentiated classes of services. Besides, as network traffic load varies, the entire upstream transmission window for all REPORT messages slides accordingly, leaving the transmission time of one or two sub-cycles to overlap with the bandwidth allocation calculation time at the optical line terminal (the OLT), so that the upstream idle time can be efficiently eliminated. Performance evaluation results validate that compared with the existing two DBA algorithms deployed in NC-PON, HDBA demonstrates the best quality of service (QoS) support in terms of delay for all classes of services, especially guarantees the end-to-end delay bound of high class services. Specifically, HDBA can eliminate queuing delay and scheduling delay of high class services, reduce those of lower class services by at least 20%, and reduce the average end-to-end delay of all services over 50%. Moreover, HDBA also achieves the maximum delay fairness between coded and uncoded lower class services, and medium delay fairness for high class services.     

基于多门限预留机制的自适应带宽分配算法

针对异构无线网络融合环境提出了一种基于多门限预留机制的自适应带宽分配算法,从而为多业务提供QoS保证。该算法采用多宿主传输机制,通过预设各个网络中不同业务的带宽分配门限,并基于各个网络中不同业务和用户的带宽分配矩阵,根据业务k支持的传输速率等级需求和网络状态的变化,将自适应带宽分配问题转化为一个动态优化问题并采用迭代方法来求解,在得到各个网络中不同业务和用户优化的带宽分配矩阵的同时,在带宽预留门限和网络容量的约束条件下实现网络实时吞吐量的最大化,以提高整个异构网络带宽的利用效率。数值仿真结果显示,所提算法能够支持满足QoS需求的传输速率等级,减小了新用户接入异构网络的阻塞概率,提高了平均用户接入率并将网络吞吐量最大提高40%。