共查询到17条相似文献,搜索用时 78 毫秒
1.
无线资源管理中的呼叫允许控制是WCDMA的重要组成部分,性能优良的呼叫允许控制策略可以尽可能高地提高网络资源利用率。描述了基于功率、基于干扰和基于LA的呼叫允许控制方案,比较分析了它们的性能。 相似文献
2.
3.
多业务无线蜂窝移动通信系统的一种呼叫允许控制策略 总被引:6,自引:0,他引:6
第三代移动通信系统要求支持宽带多媒体业务,如话音、视频、数据等多种业务,不同业务有不同的QoS要求。本文提出的多业务无线蜂窝移动通信系统中一种基于QoS的呼收允许控制策略,对不同业务的切换呼叫给予不同的优先权。本文分析了两种呼叫允许控制(CAC)算法,一种是各种业务的切控呼叫无缓冲器,不进入排队系统;另一种是各种业务的切换呼叫设置有缓冲器,进入排除系统,并且话音、视频业务的切切呼叫比数据业务的切换呼叫有更高的优先权,系统的空闲信道应首先分配给话音、视频业务的切换呼叫,再分配给数据业务的切换呼叫。在分析两种CAC算法的呼叫阻塞概率、切换失败概率以及系统吞吐量的基础上,给出了计算机仿真结果。 相似文献
4.
无线资源管理中的呼叫允许控制是TD-SCDMA的重要组成部分,性能优良的呼叫允许控制策略可以尽可能高地提高网络资源利用率。对于单纯的CDMA系统,呼叫允许控制必须依据目标信干比保证所有激活用户的服务质量.然而,TD-SCDMA系统的呼叫允许控制与其时隙分配方法有密切的关系,考虑了两种呼叫允许控制方案并给出仿真结果。 相似文献
5.
6.
一种优化无线多媒体业务接入允许控制和资源分配算法 总被引:1,自引:1,他引:1
无线网络中的多媒体业务具有很大吸引力。本文将多媒体业务分为实时业务和非实时业务,提出了一种呼叫接入控制优化算法CAC-RA,此算法通过采用马尔科夫方法,排队论和非线性规划模型,同时解决呼叫允许控制和资源优化分配问题。提出的利益函数考虑了最大利用资源,同时满足无线网络各类用户的QoS要求,同时尽量减少用户的资源重新分配的频率和幅度变化,仿真实验数据显示CAC-RA算法能较好地适应业务变化的网络,同时实现了较为理想的利益值,满足无线网络多媒体用户的QoS要求。 相似文献
7.
8.
9.
本文分析了高空平台通信系统中利用地理位置信息的呼叫密度受限和切换间隔时间受限的CAC(Call Admission Control,CAC)策略.设计了切换性能受限的CAC策略,该策略利用地理位置信息在每次新呼叫到达时计算可能引起的切换失败的概率,并且通过设置切换性能门限来约束切换性能,在满足切换性能的同时,能够尽量提高新呼叫阻塞性能.仿真结果表明,在相同切换掉话概率门限要求情况下,与新呼叫切换时间间隔受限的CAC策略相比,改进的切换时间间隔受限的CAC策略可提升新呼叫阻塞性能13.6%以上.在实际应用过程中,可以根据当前流量自适应地改变切换间隔时间门限,达到在满足切换性能的同时最小化新呼叫阻塞概率的目的.切换性能受限的CAC策略在业务量较高的条件下能够较好地保证了系统的切换掉话性能;比其它策略具有更好的呼叫阻塞性能,比呼叫密度受限的CAC至少提升25.3%,比切换时间间隔受限的CAC策略至少提升6.5%. 相似文献
10.
11.
12.
13.
In this paper we design and evaluate the performance of a unified mechanism for downlink scheduling and call admission control
of multimedia traffic in a high-capacity TDMA wireless channel. In our scheme, the Base Station interacts with the Call Admission
Controller and incorporates predictions on the channel condition in its decision making. Our results show that, with the use
of the “intelligent” scheduler-admission controller mechanism, system performance is significantly enhanced compared to two
other schemes without prediction on the channel condition.
Polychronis Koutsakis was born in Hania, Greece, in 1974. He received his 5-year Diploma in Electrical Engineering in 1997 from the University
of Patras, Greece and his MSc and Ph.D. degrees in Electronic and Computer Engineering in 1999 and 2002, respectively, from
the Technical University of Crete, Greece. He is currently a Visiting Lecturer at the Electronic and Computer Engineering
Department of the same University. His research interests focus on the design, modeling and performance evaluation of wireless
personal communication networks, and especially on the design and evaluation of multiple access schemes for multimedia integration
over wireless and mobile satellite networks, on call admission control and traffic policing schemes for both wireless and
wired networks and on traffic modeling. Dr. Koutsakis has authored more than 25 peer-reviewed papers in the above mentioned
areas, and serves as a reviewer for many of the major journal publications focused on his research field. He is a member of
the Greek Chamber of Professional Engineers and of the Greek Association of Electrical and Mechanical Engineers. 相似文献
14.
Spectral efficiency of WCDMA based spread spectrum 3G/4G air interface technology is highly influenced by the common channel interference, hence the applied Call Admission Control method has great importance because it determines the number of active users admitted to the network. In this paper we present a dynamic air interface CAC algorithm which provides efficient usage of radio resources and allows real-time adaptation to the always changing network parameters. Required CAC parameters are derived for generalized multiplicative fading and generalized memory-less traffic sources. In order to validate its capabilities our proposed CAC method was investigated with ON/OFF traffic sources and lognormal fading channels. 相似文献
15.
16.
Yan Zhang Yifan Chen Jianhua He Cheng-Xiang Wang Athanasios V. Vasilakos 《Wireless Personal Communications》2009,50(1):99-114
Orthogonal frequency division multiplexing (OFDM) is becoming a fundamental technology in future generation wireless communications.
Call admission control is an effective mechanism to guarantee resilient, efficient, and quality-of-service (QoS) services
in wireless mobile networks. In this paper, we present several call admission control algorithms for OFDM-based wireless multiservice
networks. Call connection requests are differentiated into narrow-band calls and wide-band calls. For either class of calls,
the traffic process is characterized as batch arrival since each call may request multiple subcarriers to satisfy its QoS
requirement. The batch size is a random variable following a probability mass function (PMF) with realistically maximum value.
In addition, the service times for wide-band and narrow-band calls are different. Following this, we perform a tele-traffic
queueing analysis for OFDM-based wireless multiservice networks. The formulae for the significant performance metrics call
blocking probability and bandwidth utilization are developed. Numerical investigations are presented to demonstrate the interaction
between key parameters and performance metrics. The performance tradeoff among different call admission control algorithms
is discussed. Moreover, the analytical model has been validated by simulation. The methodology as well as the result provides
an efficient tool for planning next-generation OFDM-based broadband wireless access systems.
相似文献
Athanasios V. VasilakosEmail: |