DiffServ网络中一种改进的round robin公平加权调度算法

文中提出了DiffServ网络中一种改进的公平加权round robin调度算法。该算法在网络发生拥塞时，根据各优先业务粪的不同服务等级，动态地改变奋优先业务类的调度权重，并同时保持了各优先业务类的相对公平性。通过仿真显示，该算法在适度满足尽力服务类的同时．能有效处理不同业务类的炙发数据，比较迅速地缓解网络的拥塞状况。     

调度机制对网络QoS影响的研究分析

在网络中采用的调度机制与网络的服务质量有很密切的关系.为了满足不同网络业务服务的要求.QoS网络必须提供不同的排队规则.利用网络模拟器NS-2仿真分析各种队列调度算法,包括:去尾算法,基于轮循的调度算法,分组公平队列,基于类的队列算法,随机早期检测算法对QoS各个因子的影响以及队列调度算法的特点,根据算法特点指出不同调度算法运用的最佳场合.     

业务优先级感知的网络流量调度机制

针对网络中业务数据流过大、分布不均匀所造成的网络拥塞,提出一种优先级感知的动态网络流量调度机制.利用令牌桶算法,根据业务优先级的不同为不同业务分配不同速率的令牌,以实现业务优先级的划分;综合考虑业务的优先级及用户节点剩余缓存空间,对不同的业务采取不同的处理方式;同时,以流量到达因素、服务因素及节点缓存为指标定义了一种网络流量调度机制性能指标——分组丢失率.数值结果表明,所提机制可以对网络中业务优先级进行合理的划分,从而有效利用网络资源,预防网络拥塞,提升网络性能,为用户提供更加稳定可靠的网络服务.     

具有优先服务机制的嵌套式DRR算法

针对DRR算法在保证业务时延性能上的固有不足,该文提出了具有优先服务策略的嵌套式DRR算法,该算法对需要保证延时的业务类实施专门的服务策略,利用漏桶控制和虚令牌的分配机制,并改善服务队列的调度策略,在不增加算法复杂度的情况下,有效地减小了时延敏感业务队列中包的延迟。文章证明了算法在获得延时保证的同时,选择合适的参数,仍然能够维持调度算法的公平性。仿真结果表明算法对时延性能的改善是明显的。     

交换式工业以太网的队列调度算法分析

为了保证交换式工业以太网中实时数据端到端的传输时延和业务流传输的公平性,避免网络拥塞的出现,在对工业现场业务流类型分析的基础上,提出了一种基于SPQ_WRR队列调度的算法。为了验证该调度算法的有效性,采用了OPNET进行仿真,仿真结果表明,相比于传统的队列调度算法而言,该调度算法有效的保证了实时数据传输的实时性和业务流传输的公平性,同时起到了流量控制的作用,有效的避免了网络拥塞的出现。     

支持优先级与公平策略的队列规程

首先介绍了队列调度算法在流量控制中的关键地位,然后讨论了现有队列调度算法,如基于优先级的调度算法、轮询调度算法与公平队列调度算法,最后提出了一种新的队列规程,该队列规程融合了优先级调度算法与DRR调度算法。在网络正常情况下,不同业务流公平地共享网络带宽,在网络出现拥塞的情况下,高优先级业务流能够抢占带宽,保证其较低的丢包率,并能够实现两种调度算法的快速切换。     

无线Mesh网络中的自适应队列调度算法研究

针对无线mesh网络的网络特性,分析了无线网络中的队列调度算法,提出了一种自适应的队列调度算法AQSM,详细讨论了该算法的具体实现过程及参数变化规则,通过仿真验证了该算法在提高网络性能的同时还可以实现对不同业务流的业务区分。     

基于Crossbar的可重构网络输入排队分域调度研究

为解决传统网络技术体系中交换结构无法满足大量差异化业务规模化应用的问题,本文基于可重构网络技术体系,采用选择关闭部分Crossbar交叉节点的分域模型,提出了分域调度的思想,分析并推导了承载组内的SDRR调度算法和域内最长队列优先调度算法。最后采用交换性能仿真平台对该调度算法进行了复杂度和时延的仿真比较,结果表明:分域调度的最长队列优先算法比一般最长队列优先算法相对复杂度低,且随着调度域个数增加,相对复杂度降低。在相同业务源输入条件下,Crossbar三分域调度算法的时延小于非分域调度算法的时延,接近公平输出排队调度算法的时延。     

基于WRR的改进型队列调度算法

基于Diffserv(区分服务)体系,研究实现QoS(服务质量)控制的核心技术之一的队列调度技术。基于WRR(加权轮询)队列调度算法,提出新型的改进算法。改进的队列调度算法主要由流量调节器和调度策略两部分构成,将网络上的包按照Diffserv体系分为EF(加速转发)、AF(保证转发)、BE(尽力服务)三种业务类型,对不同的类型采用不同的调度策略。针对高优先级的EF业务直接采用PRI(优先级调度),针对AF业务采用改进后的WRR调度。仿真结果表明,该改进型调度算法在网络资源分配上具有一定的优越性。     

蜂窝网络中切换业务优先的资源调度算法

下一代无线蜂窝网络将提供具有不同服务质量要求的多种类型的业务,同时为了提高频率资源利用率,小区的划分越来越小,切换也越来越频繁。本文在针对多业务类型、切换频繁的蜂窝网络,提出了一种切换业务优先的分层资源调度策略。在调度过程中,优先考虑切换业务的数据包,从而降低了切换掉话率,系统整体性能得到提高。     

基于多优先级时延预留的接入控制机制

该文提出一种多优先级时延预留的呼叫接入控制机制,通过对不同的优先级业务采用不同的时延门限来控制业务的接入来保证网络服务质量(QoS)。仿真结果表明,该机制不但较好地提供了对高优先级业务的服务率,也保证了对低优先级业务的服务,同时网络利用率也相应得到了提高。     

Performance analysis of a preemptive and priority reservation handoff scheme for integrated service-based wireless mobile networks

We propose an analytical model for integrated real-time and non-real-time services in a wireless mobile network with priority reservation and preemptive priority handoff schemes. We categorize the service calls into four different types, namely, real-time and non-real-time service originating calls, and real-time and non real-time handoff service request calls. Accordingly, the channels in each cell are divided into three parts: one is for real-time service calls only, the second is for non-real-time service calls only, and the last one is for overflow of handoff requests that cannot be served in the first two parts. In the third group, several channels are reserved exclusively for real-time service handoffs so that higher priority can be given to them. In addition, a realtime service handoff request has the right to preempt non-real-time service in the preemptive priority handoff scheme if no free channels are available, while the interrupted non-real-time service call returns to its handoff request queue. The system is modeled using a multidimensional Markov chain and a numerical analysis is presented to estimate blocking probabilities of originating calls, forced termination probability, and average transmission delay. This scheme is also simulated under different call holding time and cell dwell time distributions. It is observed that the simulation results closely match the analytical model. Our scheme significantly reduces the forced termination probability of real-time service calls. The probability of packet loss of non-real-time transmission is shown to be negligibly small, as a non-real-time service handoff request in waiting can be transferred from the queue of the current base station to another one.     

定长光突发交换节点的QoS性能分析

分析了光突发交换网络中基于附加偏移时间(EOT,extra offset time)的业务优先等级区分服务的变长突发方案的不足，提出了一种定长光突发方案。它能在较小附加延迟的情况下保证高优先级的业务完全不受低优先级业务的阻塞，即使每个优先级的附加等待时间都减小到变长突发方案的1/3，同时使最高优先级业务的阻塞率更小，而且具有现实可行性。     

Dual bus MAN's with multiple-priority traffic

A protocol with strictly preemptive priorities that does not admit low-priority traffic if the load from high-priority traffic exceeds the capacity of the transmission channel in a MAN is presented. The protocol guarantees fairness for transmissions at the highest priority level. By introducing a general characterization of bandwidth allocation schemes for dual bus networks, existing priority mechanisms can be categorized according to the provided quality of service. The unique existence of a bandwidth allocation scheme for multiple priority traffic is shown with a full utilization of the channel capacity, with a fair distribution of bandwidth respective to traffic from a particular priority level, and with preemptive priorities. The performance of the presented protocol is compared to existing proposals for multiple priority mechanisms. It is shown that adopting the new protocol results in shorter access delays for high-priority transmissions. The protocol allows the stations of the network to react quickly to load changes. It is shown that the effectiveness of the priority scheme, compared to priority schemes using the bandwidth-balancing mechanism, is less dependent on increasing the transmission speed of the network     

基于动态复合优先级的海上节点网络选择算法

针对海上移动节点完成业务时出现高优先级业务完成率低、业务拥堵率大、网络接入算法对波动环境适应性不足的问题,提出一种基于动态复合优先级的网络接入算法.首先,移动节点收集周围机动站点的网络属性参数,计算产生业务的执行紧迫性和剩余价值,再将不同类型业务的参数权重加入VIKOR法,形成最终的动态复合优先级,针对环境网络参数提供...     

RSVP在数字视频网络传输中的应用研究

数字视频网络的广泛应用,要求实时性传输中IP能够提供足够的带宽、较高的优先级以及较低的包丢失率,为此,Internet工程任务组(IETF)开发了一套用于因特网的综合服务协议和标准,通过RSVP来管理网络资源分配以提供不同级别的服务,讨论怎样将该协议与典型的数字视频网络传输方案相结合,使现有支持QoS的网络可以达到更为稳定流畅的传输效果.     

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.     

无线双通道网络话音业务信道接入性能分析

无线双通道网络能够有效解决战术环境下码分组网数目过小造成的码分资源浪费问题。混合业务传输环境下,实时话音业务信道接入性能是衡量无线双通道网络性能的关键指标之一。通过使用一种理想的固定时分信道带宽分配方案,在保障话音业务传输实时性的条件下,分别从单跳网络拓扑和多跳网络拓扑结构给出了双通道网络可用信道数目。使用基于优先权的混合业务多服务台离散时间排队模型分析了双通道网络的话音业务平均数目、呼叫阻塞概率、平均网络吞吐量和信道利用率等性能。数值计算结果证明：相比传统网络,双通道网络在混合业务高负载条件下能够容纳更多的话音业务并具有更低的呼叫阻塞概率。     

A novel contention solution strategy based on priority for optical burst switching networks

A fundamental issue in optical burst switching (OBS) networks is to solve the burst contention for the core node. In this paper, a novel priority-based contention solution strategy for OBS networks is proposed. When the contention occurs, the burst priority is considered firstly, and then the burst segmentation method is used for the low priority bursts in this strategy. Ensuring the integrity of high priority bursts, part of the segmented bursts can be transmitted to the destination node via combining wavelength conversion and optical buffer method. Simulation results show that the proposed scheme not only ensures the integrity of high priority bursts, but also reduces the packet loss rate of the low priority bursts maximally, so that it can support good quality of service (QoS) for the network.     

HSPA 差异化服务的研究

从3G视频监控业务入手,对用户的优先接入和保证带宽进行了研究,提出了为保证端到端的QoS,从发射端到接收端的所有网络设备需要精密合作.用户在业务签约时定义高优先级并且存储在HLR中.当用户发送一个业务请求时,核心网根据签约信息与无线网、UE进行协商.协商成功后所有的网元节点会获取一组满足业务的QoS参数.基于这些参数,无线网进行优先级映射,启动准入控制和拥塞控制算法,分配无线资源给该用户提供服务.当所有的网元节点都满足了用户业务的QoS要求,该用户就能够实现优先接入和带宽保证,享受专线化的差异服务.