共查询到18条相似文献,搜索用时 93 毫秒
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多业务移动通信系统中的呼叫接入控制 总被引:4,自引:0,他引:4
在多业务无线移动通信系统的呼叫接入控制中,不仅要考虑业务之间的优先级,同时也必须考虑切换呼叫的优先级。本文结合可移动边界算法和保护信道策略,提出了一种有效的多业务呼叫接入控制算法。为了方便地分析方案的性能,设计了一个二维的Markov链对方案的性能进行理论上的分析。通过数值分析结果表明,提出的算法同时保证了两种优先级,并提高了系统的性能。1 相似文献
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TD-SCDMA中基于实测功率的上行接纳算法 总被引:1,自引:0,他引:1
第三代移动通信系统TD-SCDMA是一种自干扰的系统,随着未来用户的增多,无线资源相对有限的情况下,有效控制干扰的要求越来越高,而呼叫接纳控制技术就是解决这一问题的关键技术之一。对传统的接纳控制算法进行研究,提出了基于实测功率的上行接纳控制算法,并计算出接入判决的门限值,以实现用户接入系统后对QoS的保证。实验表明该算法相对于传统的算法而言,判决精度更高,并且具有门限自适应的优势。 相似文献
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演进的3GPP(第三代合作伙伴计划)系统是支持若干无线电接入技术和若干移动机制的混合移动网络结构。本文简要回顾该系统的结构及其关键组成,重点强调若干部署情形中支持话音呼叫移动性的方法。首先介绍称之为单模无线电话音呼叫连续性的机制,该机制能使从E-UTRAN(演进的通用移动电信系统陆地无线接入网)接入到遗留的UTRAN/GERAN(通用移动电信系统陆地无线接入网/增强数据率的全球移动通信系统演进无线接入网)或1xRTT的VoIP呼叫进行中间呼叫切换。然后着重描述不支持E-UTRAN上话音服务的部署情形,并介绍称为回落原地的机制,该机制能在话音呼叫的开始从E-UTRAN到UTRAN/GERAN或1xRTT进行切换。最后介绍由IP多媒体子系统实现的应用层话音呼叫切换机制。本文的结论是,下一代3GPP系统是高度完善的移动通信系统,它支持广泛的话音呼叫移动性机制,并能满足所有的商业部署需要。 相似文献
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CDMA是第三代移动通信系统主要采用的多址接入方式。CDMA系统的容量是干扰受限的;如何最优化地分配无线资源,利用CDMA系统的软容量,为不同的业务类型提供相应的业务质量(QoS)保证,是第三代移动通信中一个重要的研究课题。介绍了WCDMA系统的无线资源分配,对其中的容量估计、呼叫控制和基于QoS的资源调度等进行了分析,并给出了一些仿真的实验结果。 相似文献
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分析比较了地面蜂窝移动通信系统和卫星通信系统在呼叫接入控制中的差异,并在此基础上重点分析讨论了卫星通信系统在呼叫接入控制中所必须考虑的策略。 相似文献
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文章研究QoS优化下WCDMA系统的上行接入控制算法。从QoS分层结构,可度量参数出发,结合新用户呼叫到达率和用户切换到达率,提出WCDMA上行信号呼叫接入控制算法,考虑和平衡新接入用户阻塞率和已接入用户中断率。通过满足不同业务需要的QoS优化策略来控制上行允许接入用户,从而保证系统有稳定的通信质量。仿真分析结果表明,文中给出算法使系统阻塞率和掉话率下降,系统性能得到改善。 相似文献
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In wireless multimedia communication systems, call admission control (CAC) is critical for simultaneously achieving a high resource utilization efficiency and maintaining quality-of-service (QoS) to mobile users. User mobility, heterogeneous nature of multimedia traffic, and limited radio spectrum pose significant challenges to CAC. QoS provisioning to both new calls and handoff calls comes with a cost of low resource utilization. This paper proposes a CAC policy for a wireless communication system supporting integrated voice and dataservices. In particular, soft QoS (or relaxed target QoS) is incorporated in the CAC policy to make compromises among different objectives.Numerical results are presented to demonstrate that (a) in dealing with the dilemma between QoS satisfaction and high resource utilization, how the resource utilization efficiency can be increased by introducing soft QoS; and (b) in accommodating different types of traffic, how the QoS of low priority traffic can be improved by specifying soft QoS to high priority traffic. 相似文献
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呼叫接纳控制(Call Admission Control,CAC)是移动通信系统资源管理的主要内容之一。它通过接纳或者拒绝一种用户服务请求,来保持系统的正常运行,是平衡用户服务满意度与系统资源最大化利用矛盾的主要手段。该文主要研究小区间业务非均匀分布时基于公平性保证的动态CAC策略,提出了一种新的CAC策略,可适用于多业务且有变速率(Variable BitRate,VBR)业务的情况。该策略采用贪婪算法,用户请求接入以全系统的预期信干比作为判决条件,从而实现了不同到达率小区之间阻塞率的均衡,保证了用户接入的公平性,对于实际系统的应用具有重要的意义。 相似文献
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基于第三代(3G)移动通信系统的时分同步码分多址(TD-SCDMA)集群通信系统,可以承载不同类型的集群业务,并能够为用户提供服务质量(QoS)保证。在无线网中提供QoS保证,呼叫接纳控制(CAC)扮演着重要的角色。在学习总结常规移动通信系统CAC方面研究成果的基础上,结合集群通信的特点,给出了适用于TD-SCDMA集群通信系统的呼叫接纳控制流程。 相似文献
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HSDPA中支持实时业务的调度算法在吞吐量方面的仿真分析 总被引:1,自引:0,他引:1
随着移动通信技术的飞速发展,未来的移动通信系统将以数据业务为主,所以无线分组调度算法将成为影响系统性能和保证用户服务质量的关键所在。在HSDPA系统中无线资源管理是通过分组调度算法来实现的。理想的调度算法应满足各类业务的QoS要求和用户之间的公平性,使系统资源利用率达到最大。主要介绍了EXP算法和M-LWDF算法,并对两种算法在吞吐量方面进行了仿真分析,说明了M-LWDF算法具有更高的吞吐量。 相似文献
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In wireless cellular communication systems, call admission control (CAC) is to ensure satisfactory services for mobile users and maximize the utilization of the limited radio spectrum. In this paper, we propose a new CAC scheme for a code division multiple access (CDMA) wireless cellular network supporting heterogeneous self-similar data traffic. In addition to ensuring transmission accuracy at the bit level, the CAC scheme guarantees service requirements at both the call level and the packet level. The grade of service (GoS) at the call level and the quality of service (QoS) at the packet level are evaluated using the handoff call dropping probability and the packet transmission delay, respectively. The effective bandwidth approach for data traffic is applied to guarantee QoS requirements. Handoff probability and cell overload probability are derived via the traffic aggregation method. The two probabilities are used to determine the handoff call dropping probability, and the GoS requirement can be guaranteed on a per call basis. Numerical analysis and computer simulation results demonstrate that the proposed CAC scheme can meet both QoS and GoS requirements and achieve efficient resource utilization. 相似文献
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Kwon Taekyoung Choi Yanghee Bisdikian Chatschik Naghshineh Mahmoud 《Wireless Networks》2003,9(1):51-59
Recently there is a growing interest in the adaptive multimedia networking where the bandwidth of an ongoing multimedia call can be dynamically adjusted. In the wireless/mobile multimedia networks using the adaptive framework, the existing QoS provisioning focused on the call blocking probability and the forced termination probability should be modified. We, therefore, redefine a QoS parameter – the cell overload probability – from the viewpoint of the adaptive multimedia networking. Then, we propose a distributed call admission control (CAC) algorithm that guarantees the upper bound of the cell overload probability. Also, a bandwidth adaptation algorithm which seeks to minimize the cell overload probability is also presented. Simulation experiments are carried out to verify the performance of the proposed CAC algorithm. Furthermore, the performance of the adaptive wireless/mobile network is compared to that of the existing non-adaptive wireless/mobile networks. As a further step in QoS provisioning, we propose another QoS parameter, the degradation period ratio, and discuss analytically how the CAC algorithm guarantees the upper bound of the degradation period ratio. 相似文献
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This paper presents a novel utility-based connection admission control (CAC) scheme for IEEE 802.16e broadband wireless access networks. We develop specific utility functions for real-time and non-real-time services coupled with a handover process. Given these utility functions we characterize the network utility with respect to the allocated bandwidth, and further propose a CAC algorithm which admits a connection that conducts to the greatest utility so as to maximize the total resource utilization. The simulation results demonstrate the effectiveness of the proposed CAC algorithm in terms of network utility. 相似文献