共查询到20条相似文献,搜索用时 15 毫秒
1.
简单数据链路协议(SDL)作为一种新型的IP over技术,其简单性和低开销更能适应高速传输链路的要求,并提供下一代光分组交换网所需要的操作维护管理功能,如何提供服务质量保证(QoS)是IP传输中的核心技术之一,文章介绍了IETF提出的两种实现QoS的业务模型;集成业务模型和差分业务模型,以及SDL;提出了一种基于SDL链路协议上的Diffserv over MPLS的QoS实现方案。 相似文献
2.
于鹏 《太赫兹科学与电子信息学报》2015,13(2):220-225
自动请求重传(ARQ)机制是一种常用差错控制方法。典型的ARQ机制有选择重发ARQ(SR-ARQ)和回退N-ARQ(GBN-ARQ)。针对选择重发ARQ性能高,但复杂,而GBN-ARQ实现简单,但是性能较差的问题,在GBN-ARQ机制的基础上,做出改进,利用接收数据控制字段本身的统计关联关系,设计了一种适用于无线ATM的主动容错的ARQ机制,并在性能和实现复杂度上与常规SR-ARQ和GBN-ARQ分别进行了理论和仿真对比。实验结果表明,相同条件下AFT-ARQ实现复杂度明显低于SR-ARQ,而性能上较常规GBN-ARQ机制有了显著提高,并接近于SR-ARQ。 相似文献
3.
ATM网络中语音编码和传输的新方案 总被引:2,自引:0,他引:2
本文针对未来新的ATM通信方式,提出了一种新的语音可变速率编码和可变时延传输系统方案,为了将信号源和人耳听觉的特征,与ATM网络的统计复用性相结合,实现语音的码率在缩和低时延传输,该方案将ATM网络环境和语音编码系统中最优信号分析区间的选取、编码系统参数的确定相结合。文中基于一种新的分布熵进行信号特征判断,对输入信号构成不同的处理系统,具体编码由小波变换分带、多带二进树VQ构成,输出码率可调,改变 相似文献
4.
本文根据地无线ATM通信网中快速越区切换问题的研究,提出了一种新的基于虚道路(VP)的快速越区切换方案,并通过建立简化的呼叫模型对该方案的切换性能进行了理论分析和比较,其结果表明,该方案的各项性能均比虚拟连接树(VCT)方案和永久虚连接(PVC)方案优越。 相似文献
5.
GPON系统中基于QoS的动态带宽分配算法的研究 总被引:1,自引:1,他引:1
为了实现吉比特无源光网络(GPON)带宽分配的公平性,降低网络的丢包率及传输延时,研究了GPON系统传输汇聚层的帧结构及带宽分配的实现方法,提出了一种新的动态带宽分配(DBA)算法--基于QoS的二层动态带宽分配算法.性能分析与对比表明,这种算法对不同用户和不同等级的业务都具有很好的公平性,并可以降低低等级业务的传输延时. 相似文献
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一个移动IP组播原型结合了无线异步传输模式标签交换,它的核心建立在组播的体系结构上。MCOM创建了独立于成员所属网络的多核心的第二层多点交换树,并通过Internet第三层多点交换路由来互相连接。Internet与无线ATM边界的网关把IP包转换成ATM信元,但需要改变ATM阻塞传送能力解决信元交叉问题。另外,讨论了动态组管理、组播重选路由和可靠组播与现在的各种网络协议的关系。 相似文献
8.
A new scheduling algorithm is proposed to improve on existing algorithms designed for input-queued ATM switches. By assigning a session weight according to its queue length normalised by its rate and using maximum weight matching to obtain a match, the proposed algorithm can avoid starvation of slow sessions, thus providing good delay properties as well as fair services, and at the same time reducing traffic burstiness 相似文献
9.
LiXiaohui KouWeidong LiuNai'an YiKechu 《电子科学学刊(英文版)》2005,22(4):416-421
Based on the Distributed Coordination Function (DCF) and the Enhanced DCF (EDCF) mechanisms in IEEE 802.11 and 802.11e, a novel backoff scheme for Wireless Local Area Network (WLAN) is proposed. The scheme is to solve the problem of the packet loss and the decrease of performance due to the increasing Contention Window (CW) when there are continuous collisions. In the proposed scheme, the CW of the packet will change dynamically with different delay for the different traffics. Mathematic formulas are presented to indicate the relationship between the CW and the delay character. The performance of the new scheme is also discussed with simulation results. The results show that it helps WLAN system handle multimedia simultaneously. 相似文献
10.
The goal of this letter is to present a model to compute a quality-of-service (QoS) index to characterize IP services. Then, we show how such a score may be used in a clear and flexible way for defining advanced usage-based tariff criteria to charge QoS guaranteed network services to address the dynamics of the expected future telecommunications scenario. 相似文献
11.
Chen Huimin Wang Pu Li Yanda 《电子科学学刊(英文版)》1999,16(1):7-15
In this paper, the main schemes of connection admission control (CAC) in ATM networks are briefly discussed especially the principle of dynamic bandwidth allocation. Then the fair share of the bandwidth among different traffic sources is analyzed based on cooperative game model. A CAC scheme is proposed using the genetic algorithm (GA) to optimize the bandwidth-delay-product formed utilization function that ensures the fair share and accuracy of accepting/rejecting the incoming calls. Simulation results show that the proposed scheme ensures fairness of the shared bandwidth to different traffic sources. 相似文献
12.
This article aims at designing a new Multivariate Quadratic (MQ) public-key scheme to avoid the linearization attack and differential attack against the Matsumoto-Imai (MI) scheme. Based on the original scheme, our new scheme, named the Multi-layer MI (MMI) scheme, has a structure of multi-layer central map. Firstly, this article introduces the MI scheme and describes linearization attack and differential attack; then prescribes the designation of MMI in detail, and proves that MMI can resist both linearization attack and differential attack. Besides, this article also proves that MMI can resist recent eXtended Linearization (XL)-like methods. In the end, this article concludes that MMI also maintains the efficiency of MI. 相似文献
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This paper introduces a 3-level multiagent architecture for QoS control in WATM. The ultimate aim of the proposed architecture
is to provide a self-regulating network congestion control management by means of global network state awareness and agent
interactions. The agents dynamically manage the buffer space at the level of a switch and interact to reduce the cell loss
ratio while guaranteeing a bounded transit delay. We particularly address video transmission over UBR services using a per-VP
queuing approach and an adaptive cell discarding congestion control scheme. Furthermore, a dynamic reconfiguration of the
agents is performed during handoffs in order to continue meeting user end-to-end QoS requirements. The handoff delay absorption
is also addressed.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
15.
Julio Barbancho Carlos León F. Javier Molina Antonio Barbancho 《Telecommunication Systems》2007,36(1-3):73-83
For the past ten years, many authors have focused their investigations in wireless sensor networks. Different researching issues have been extensively developed: power consumption, MAC protocols, self-organizing network algorithms, data-aggregation schemes, routing protocols, QoS management, etc. Due to the constraints on data processing and power consumption, the use of artificial intelligence has been historically discarded. However, in some special scenarios the features of neural networks are appropriate to develop complex tasks such as path discovery. In this paper, we explore and compare the performance of two very well known routing paradigms, directed diffusion and Energy-Aware Routing, with our routing algorithm, named SIR, which has the novelty of being based on the introduction of neural networks in every sensor node. Extensive simulations over our wireless sensor network simulator, OLIMPO, have been carried out to study the efficiency of the introduction of neural networks. A comparison of the results obtained with every routing protocol is analyzed. This paper attempts to encourage the use of artificial intelligence techniques in wireless sensor nodes. 相似文献
16.
Giuseppe Bianchi Vittorio Trecordi 《International Journal of Communication Systems》1994,7(4):265-273
In this paper we outline a simple strategy to manage bandwidth allocation and congestion control and to guarantee service requirements in a multiservice ATM (asynchronous transfer mode) network. We propose a network architecture based on a core network, making available a limited number of quality of service profiles, and an access network, made of edge adapters in charge to match the user's requirements with the network's available quality of service profiles and to shape input traffic to achieve high network throughput. The connection admission rule is presented, and edge adapter architecture and design examples are given. The effectiveness of the scheme is demonstrated by numerical results which report the network utilization performance when the proposed core network policies and edge adapter design apply. 相似文献
17.
Many applications in telecommunications engineering lead to highly degenerate partitioned Markov chains of QBD type. In this paper, we study a traffic shaping scheme which is based on a generalization of the bucket method. The arrival process is modeled by a discrete Markovian arrival process. For this model, a detailed mathematical analysis leads to special algorithms involving matrices of lower order. The characteristics of the model are discussed from this viewpoint. Some performance measurements are derived and numerical examples are shown to demonstrate the effectiveness of the rate control scheme.This research was supported in part by Grant No. DDM-8915235 from the National Science Foundation. 相似文献
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In this paper, we propose an input access scheme for input-queued ATM multicast switches, achieving high system throughput, low packet delay and packet loss probability. Multicast and unicast packets of each input port are separately queued. Multicast queues take priority over the unicast queues, and both types of queues are fairly served in a cyclic-priority access discipline. In particular, each unicast queue is handled on a window-service basis, and each multicast packet is switched in a one-shot scheduling manner. To evaluate the performance of the access scheme, we propose an approximate analysis based on a simplified cyclic-priority model for anN×N finite-buffer multicast switch possessing Bernoulli multicast and unicast arrivals, with window-service (for unicasting) and one-shot scheduling (for multicasting) both taken into account. Finally, we show simulation results to demonstrate the accuracy of the approximate analysis and the superiority of the scheme over existing schemes with respect to normalized system throughput, mean packet delay, and packet loss probability.An earlier version of this paper appeared in IEEE ICC'96. 相似文献
20.
VIDEO CODING SCHEME FOR ATM NETWORKS 总被引:2,自引:0,他引:2
A new variable bit rate layered coding scheme based on subband coding is given in this paper. It can make full use of the merits of ATM transmission, as well as compensation for the quality degradation caused by cell loss, which is an inherent problem of ATM networks, and thus a stable, high quality video transmission is achieved. This paper presents the coding scheme, cell construction and simulation results. 相似文献