共查询到20条相似文献，搜索用时 15 毫秒
1.
为了满足OFDMA-WLAN系统下行通信中多用户的不同业务需求,提出一种基于公平性和QoS服务保障的资源分配算法.不同的QoS要求被转换成不同的速率要求来计算QoS满意等级;优化目标被修改为公平性驱动的优化函数以提供公平性保障;复杂的资源分配问题被划分为信道分配和功率分配问题,并通过二分图匹配和注水法得到分配结果.与其他算法相比,所提出的算法牺牲了较少的数据速率换取更高的公平性和QoS满意度.仿真结果表明所提算法具有保障QoS和公平性的能力,且在QoS、公平性和速率之间权衡折中时表现更好. 相似文献
2.
提出了一种能在承载多媒体业务的移动通信网络中提供较高服务质量保证的接入控制方法 .该方法将接入控制与带宽预留相结合 ,保证传输业务服务质量的要求 .仿真结果表明 ,与两种传统的接入控制算法相比 ,本文所提出的算法能够使强行中止概率降低 .该算法能用于未来多媒体通信系统中 相似文献
3.
在分析IP over WDM光网络综合路由原理的基础上,提出了一种全新的基于QoS约束的IP over WDM网络综合路由算法.并通过与最短路径—首次命中标准算法进行仿真比较,证明该路由算法可以有效地降低总业务与QoS业务的阻塞率,更好地提供QoS服务保证. 相似文献
4.
谢丽英 《广东教育学院学报》2011,(5):46-50
IEEE 802．11e协议是在802．11 MAC协议的基础上考虑到支持服务质量（Quality of Service,QoS）而提出的,其中增强分布信道接入机制EDCA可应用于AdHoc网络．但EDCA机制仅提供了对业务优先级的区分,并没有考虑吞吐量和延迟等性能．为此,提出一种基于冲突概率和发送概率的CTPB（Collision and Transmission Probabilities based Baekoff）退避算法,该算法能有效地提高EDCA机制的延迟性能,并且没有影响AdHoc网络的吞吐量． 相似文献
5.
针对移动Ad Hoc网络中的Qo S路由问题,提出一种基于DNA算法的全新优化算法,该算法采用DNA编码方式,对每条路径进行编码,利用合成技术完成NP完全路径,最后通过实验得出优化数据.实验结果验证了该算法的有效性,并且在降低算法复杂程度下,得到了路由优化的最优解. 相似文献
6.
Xin-yu Wang Xiao-hu Yang Jian-ling Sun Wei Li Wei Shi Shan-ping Li 《浙江大学学报(A卷英文版)》2008,9(10):1318-1325
This paper proposes a connected dominating set （CDS） based mobility management algorithm, CMMA, to solve the problems of node entering, exiting and movement in mobile ad hoc networks （MANETs）, which ensures the connectivity and efficiency of the CDS. Compared with Wu＇s algorithm, the proposed algorithm can make full use of present network conditions and involves fewer nodes. Also it has better performance with regard to the approximation factor, message complexity, and time complexity. 相似文献
7.
A dynamic network Qo S control mechanism was proposed based on traffic prediction. It first predicts network traffic flow and then dynamically distributes network resources, which makes full use of network flow self-similarity and chaos. So it can meet changing network needs very well. The simulation results show that the dynamic Qo S control mechanism based on prediction has better network performance than that based on measurement. 相似文献
8.
9.
陈翠娟 《安阳师范学院学报》2021,(2):28-31
计算机软件蕴含大量工作信息,有效挖掘软件数据信息之间的内在关联是信息时代对软件应用的潜在要求。针对经典Apriori算法挖掘数据效率低、复杂度高的问题,提出一种改进Apriori算法用于挖掘计算机软件数据的关联规则。为计算机软件算法设置双重支持度阈值,即频繁项集与非频繁项集支持度阈值,快速获得强关联的频繁项集;在此基础上基于映射规则重构事务数据库,压缩数据库规模,减少算法的剪枝操作,降低计算机软件数据关联规则挖掘复杂度。以人力资源类计算机软件数据为例展开关联分析测试,结果显示,该算法挖掘的关联信息与人力资源实际管理情况一致,相比经典Apriori算法其效率有所提升。 相似文献
10.
分别在平坦衰落和频率选择性衰落的无线信道模型中建立了基于多用户正交频分复用技术（OFDM）和分布式天线的认知无线电系统中子载波分配模型.该模型不再用＂干扰温度＂限制认知用户来保护主用户,而是规定主用户在其所有子载波上的吞吐量之和需要高于一定的门限.然后,根据不同信道模型的特点提出了最优子载波分配方案,该方案利用分支定界法和隐枚举法最大化系统的吞吐量.最后,利用Pegging算法提出了效率与公平折中的子载波分配方案.仿真证明,在不同场景中所提出的子载波分配方案与现有方案相比在吞吐量和公平性方面均具有较大的优势. 相似文献
11.
WANG Yang ZHAN Yi-chun YU Shao-hua 《重庆大学学报(英文版)》2007,6(4):265-272
This paper investigates the routing among autonomous systems (ASs) with quality of service (QoS) requirements. To avoid the intractability of the problem, abstract QoS capability must be informed among ASs, because the routhing which constrained QoS has been proved to be nondeterministic polynomial-time (NP) hard even inside an AS. This paper employs the modified Dijkstra algorithm to compute the maximum bottleneck bandwidth inside an AS. This approach lays a basis for the AS-level switching capability on which interdomain advertisement can be performed. Furthermore, the paper models the aggregated traffic in backbone network with fractional Brownian motion (FBM), and by integrating along the time axis in short intervals, a good estimation of the distribution of queue length in the next short intervals can be obtained. The proposed advertisement mechanism can be easily implemented with the current interdomain routing protocols. Numerical study indicates that the presented scheme is effective and feasible. 相似文献
12.
为提高交叉口通行效率,以最短平均延误、最小平均停车次数为多目标,建立了单点交叉口信号配时的非线性优化函数模型.对非劣遗传算法(NSGA-Ⅱ)进行了改进,引入经典遗传算法降低其时间复杂度,采用临近个体修剪策略改善解集分布的均匀性,从而提高了算法的运行效率.通过仿真验证了所设计的多目标配时优化模型及其算法能够有效地提高交叉口的通行能力. 相似文献
13.
基于CTM的大型活动突发事件交通影响范围确定(英文) 总被引：1，自引：0，他引：1
为了确定大型活动下突发事件的交通影响范围,以元胞传输模型(CTM)为基础,对大型活动中消散过程中交通流时空分布状况进行模拟研究.结合突发事件下常用的交通管制和疏导措施的特点,将静态多路径交通分配方法与元胞传输模型结合,设计出适合突发事件下的准动态交通分配方法.以一个小规模路网为研究对象,通过仿真研究了大型活动条件下路网交通流随交通控制方案的实时调整而变化的时空规律,提出了依据突发事件下各交叉口节点的拥堵时刻划定突发事件交通影响范围的方法.通过对比车辆的平均延误指标,研究了不同交通管控方案下交通拥堵的疏散效率.算例结果表明,基于CTM的准动态交通分配方法可以细致地描述路网中任一位置交通流的时空变化,确定突发事件的动态影响范围,可以为大型活动突发事件下交通组织方案的制定和评价提供定量依据. 相似文献
14.
Inrecent years ,IEEE802.11 wirelesslocal area net-work (WLAN) has emerged as a prevailing technology forthe (indoor) broadband wireless access to internet for themobile/portable devices . In IEEE 802.11 standards ,802.11b has become the most widely used v… 相似文献
15.
Time allocation scheme in IEEE 802.15.3 TDMA mechanism 总被引：1，自引：0，他引：1
In network with a shared channel in TDMA mechanism, it is a core issue to effectively allocate channel time to provide service guarantees for flows with QoS requirements. This paper proposes a simple and efficient time allocation scheme called MES-ESRPT (MCTA at the End of Superframe-Enhanced Shortest Remaining Processing Time) for delay-sensitive VBR traffic in accordance with IEEE 802.15.3 standard. In this algorithm, PNC (piconet coordinator) allocates one MCTA (Management Channel Time Allocation) for each stream which is the process of communication at the end of superframe. During the MCTA period, each transmitter should report current fragments number of the first MSDU (MAC Service Data Unit) and the fragments number of the remainder MSDUs to PNC. In the next superframe, PNC firstly allocates part CTAs (Channel Time Allocation) for each stream based on the remainder fragments number of the first MSDU by SRPT rule, then allocates remainder CTAs for each stream based on all fragments number of remainder MSDUs by the same SRPT rule. Simulation results showed that our proposed MES-ESRPT method achieves significantly better performance in QoS for multimedia streams compared to the existing schemes. 相似文献
16.
基于语义与QoS全局感知的web服务组合 总被引：1，自引：0，他引：1
针对服务组合流程,提出了语义与QoS全局感知的服务组合.在全局语义匹配过程中,既考虑了全局匹配,又考虑了从QoS角度进行匹配.当对服务组合有全局语义满足及QoS约束要求时,在全局范围里选择满足整个服务组合流程的QoS约束和语义匹配度要求的具体服务集,并实现服务组合的优化解.建立了全局匹配的QoS模型及其评价方法,基于该模型及评价方法,采用遗传算法实现全局语义匹配度最大化及满足用户的QoS指标需求.实验结果和分析表明,基于语义与QoS感知的服务匹配算法是可行和有效的. 相似文献
17.
网络中的拥塞来源于网络资源和网络流量分布的不均衡性。随着互联网规模的增长,互联网上的用户和应用都在快速的增长,如果不在互联网中使用拥塞控制算法,拥塞崩溃的发生会严重降低网络的性能。在互联网中使用有效的拥塞控制算法成为一个很有研究价值的重要课题。在比较了现有的拥塞控制算法及其优缺点,针对FRED算法提出了一种改进后的FRED算法、对算法进行了抓包实验,并且从服务质量及网络公平性原则方面做了进一步的研究与探讨。 相似文献
18.
We propose the spectrum allocation and resource scheduling algorithms in cognitive point to multipoint （PMP） networks with rapid changes of spectrum opportunities and present a media access control （MAC） protocol based on these algorithms. The objective of spectrum allocation is to make efficient use of the spectrum while maintaining the transceiver synchronization on frequency and time in the network. The objective of resource scheduling is to guarantee the quality of service （QoS） requirements of different kinds of connections and to minimize the total energy consumption in the network as well. By sensing only a small set of possible channels in each slot based on the state transition probability of each channel, our spectrum allocation algorithm achieves high spectrum efficiency in the network. The resource scheduling problem is divided into three sub problems and we derive optimal solutions to these problems by greedy algorithm and convex optimization. The simulation results show that our algorithm can make efficient use of the spectrum and the network resources at a cost of low computational complexity. 相似文献
19.
With the rapid growth of service scale, there are many services with the same functional properties but different non-functional
properties on the Internet. There have been some global optimizing service selection algorithms for service selection. However,
most of those approaches cannot fully reflect users’ preferences or are not fully suitable for large-scale services selection.
In this paper, an ant colony optimization (ACO) algorithm for the model of global optimizing service selection with various
quality of srevice (QoS) properties is employed, and a user-preference based large-scale service selection algorithm is proposed.
This algorithm aims at optimizing user-preferred QoS properties and selecting services that meet all user-defined QoS thresholds.
Experiment results prove that this algorithm is very efficient in this regard. 相似文献
20.
万泉 《深圳信息职业技术学院学报》2006,4(4):14-18,37
本文分析了连接接纳控制策略的相关内容并重点介绍了基于测量的接纳控制算法,提出了新的接纳控制算法来改善VoWLAN的QoS(Quality of Service)性能。该算法对应于不同的业务类型采用不同的时间窗阀值测量机制,根据负载的实时情况动态调整时间窗大小,从而可以改变系统的接纳性能,并提供相应的动态带宽分配机制,有效地保障VoWLAN系统的QoS需求。最后通过仿真实验对该算法进行了验证。 相似文献