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1.
结合信道借用和流量转移技术提出了一种混合动态流量均衡算法。使用该算法热点小区可以向紧凑模式中的同类型轻负载小区借用信道,同时还可以按一定条件将呼叫转移到与热点小区重叠覆盖的异构轻负载小区中,每个流量周期借用的信道数和转移的呼叫数将根据热点小区的剩余可用信道数和新呼叫到达率来计算。仿真结果表明,该流量均衡算法能够显著降低热点小区系统和整个异构系统的新呼叫阻塞概率、切换呼叫掉线率,而且整个异构系统的利用率也得到了相应提高。  相似文献   

2.
分层异构无线网络(HetNet)能显著提高无线网络容量,扩展无线覆盖范围和节省基站能耗,已经成为后4G和5G的热门技术,但其网络理论性能以及如何优化设计逼近理论性能一直是业界研究的难点和热点问题。针对分层异构无线网络节点服从泊松点分布的特性,给出了分层异构网络在专门接入和共享接入策略下的网络理论性能,如成功接入概率、平均面积频谱效率、能量效率等,并仿真评估了影响理论性能的关键因素,探讨了优化分层异构无线网络性能的各种方法。  相似文献   

3.
异构无线网络中基于业务转移和接入控制的混合负载均衡   总被引:1,自引:0,他引:1  
盛洁  唐良瑞  郝建红 《电子学报》2013,41(2):321-328
 针对现有异构无线网络负载均衡方法未能综合考虑重载网络业务转移和新业务接入控制的问题,提出了一种混合负载均衡算法.该算法首先根据各小区负载水平和终端移动性,将重载小区的适量业务向重叠覆盖的轻载小区转移;其次通过资源预留和强占优先的接入控制策略,为不同优先级的新到业务提供有差别的服务.仿真结果表明,本文算法在保证系统资源利用率的同时,保障了实时与非实时业务的QoS,并相对于参考算法有效降低了系统阻塞率和业务切换概率.  相似文献   

4.
传统宏蜂窝(macro cell)与低功率小蜂窝(small cell)共存的分层异构组网方案能有效地提高无线通信系统的容量.但宏蜂窝与小蜂窝间的同频干扰严重影响了通信质量,并阻碍了系统容量的进一步提升.近年来,利用MIMO预编码及空域衰落特性进行干扰抑制的相关技术成为新的研究热点.本文着重介绍分层异构无线网络中基于MIMO预编码的干扰抑制技术的研究进展.以典型的双层异构下行网络为例,分析了利用多天线预编码进行干扰抑制的基本方法,并在此基础上介绍了多种基于MIMO预编码的新型干扰抑制方案,最后讨论了分层异构网络中干扰抑制技术的未来研究方向.  相似文献   

5.
分层异构密集无线网络节点部署更加密集,对系统模型和场景部署都有了新的要求。与之前的分层异构网络相比,大规模小小区的部署不仅使异构节点的干扰环境更加复杂,能量消耗也更大。针对小小区增强技术的系统模型和部署场景,从系统级的角度对分层异构密集无线网络的能效性能进行了分析,并仿真了不同pico数目对系统能效性能的影响。这些性能分析对以后分层异构密集无线网络中能效的优化以及研究具有指导意义。  相似文献   

6.
针对异构无线网络环境中,大容量业务传输质量不可靠、网络资源利用率低的问题,提出了一种基于异构无线自组织网络的多路径传输路由算法。该算法有效避免了单路通信方式下的传输链路拥塞、吞吐量低等问题,并结合大容量业务的特点,通过一定的法则合理表征网络环境信息,依据表征结果提出发端到终端的多路径策略,使得重要性不同的业务可选择相应链路质量的路径进行并行传输,避免了网络中的每个自组网节点独立寻找路由导致的源节点难以获得中间节点路由信息的现象。仿真结果表明,该算法可实现整个网络负载均衡,缓解网络链路拥塞,有效降低传输中的丢包率,降低传输时延。  相似文献   

7.
针对现有异构无线网络基于模糊逻辑及神经网络的接入选择方法未能合理考虑网络负载状况的问题,提出一种基于RBF(径向基函数)模糊神经网络的接入选择方法.该方法以可接入网络的接入阻塞率相等为模糊神经网络参数强化学习的目标,对网络负载程度具有很好的动态适应性,实现了智能化的接入判决.仿真结果表明,该方法能有效均衡异构无线网络间的负载,保障实时与非实时业务的QoS,并且相对于负载均衡算法(MLB算法)降低了网络的接入阻塞率.  相似文献   

8.
为有效降低异构无线网络拥塞,提高网络收益,提出了网络收益最大化的呼叫接纳控制(Call Admission Control,CAC)算法。首先模拟异构无线网络场景,考虑网络带宽及时延参数,定义网络收益函数,其次解决网络收益最优化问题。仿真结果显示,该算法可以高效地降低网络拥塞,均衡负载并提高网络收益。  相似文献   

9.
首先描述了流量管理在异构无线网络中产生的背景,存在问题及研究现状.然后从博弈论、机制设计和最优化理论学科交叉领域出发,对异构无线网络的流量管理问题进行建模分析.最后对未来发展进行了展望.  相似文献   

10.
江琴  刘俊  彭冲 《广东通信技术》2013,(11):32-35,79
当前负载均衡算法中,超负载小区在负载均衡切换决策阶段主要考虑把负载转移到邻近轻负载小区,而忽略该轻负载小区是否适合接受来自超负载小区的负载转移。文章提出了一种基于位置预测的双层负载均衡算法,结合用户运动机制和方向改变规律预测下一时刻的接收信号强度,同时在超负载小区的负载转移时考虑两层信息。仿真结果表明,当呼叫到达率低于1时,使用基于位置预测的双层负载均衡算法可以有效地降低整个系统的呼叫阻塞率,提高全网资源利用率。  相似文献   

11.
    
Mobility load balancing (MLB) redistributes the traffic load across the networks to improve the spectrum utilisation. This paper proposes a self‐organising cluster‐based cooperative load balancing scheme to overcome the problems faced by MLB. The proposed scheme is composed of a cell clustering stage and a cooperative traffic shifting stage. In the cell clustering stage, a user‐vote model is proposed to address the virtual partner problem. In the cooperative traffic shifting stage, both inter‐cluster and intra‐cluster cooperations are developed. A relative load response model is designed as the inter‐cluster cooperation mechanism to mitigate the aggravating load problem. Within each cluster, a traffic offloading optimisation algorithm is designed to reduce the hot‐spot cell's load and also to minimise its partners’ average call blocking probability. Simulation results show that the user‐vote‐assisted clustering algorithm can select two suitable partners to effectively reduce call blocking probability and decrease the number of handover offset adjustments. The relative load response model can address public partner being heavily loaded through cooperation between clusters. The effectiveness of the traffic offloading optimisation algorithm is both mathematically proven and validated by simulation. Results show that the performance of the proposed cluster‐based cooperative load balancing scheme outperforms the conventional MLB. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

12.
In the micro-cell-based PCS networks, due to the high user mobility, handoffs occur more frequently. Hence, the classical assumptions, such as the exponential assumptions for channel holding time and call inter-arrival time, may not be valid. In this paper, we investigate the call blocking performance for PCS networks using a semi-analytic and semi-simulation approach. We first construct a simulation model as the base for our performance study, using which the handoff traffic is studied. Then we present a few possible approximation models from which analytical results for call blocking performance metrics can be obtained and compared with the simulation results. We show that for a certain parameter range, such approximations may provide appropriate results for call blocking performance. Finally, using the simulation model, we investigate how various factors, such as the high moments, the variance of cell residence time, mobility factors and the new call traffic load affect the call blocking performance. Our study shows that all these factors may have a significant impact on call blocking performance metrics such as call blocking probability, call incompletion probability and call dropping probability. This research provides a strong motivation for the necessity of reexamining the validity of analytical results obtained from classical teletraffic theory when dealing with the emerging wireless systems.  相似文献   

13.
苏宁  荆涛  廖凤华 《信息通信》2007,20(3):26-29
文章针对现有的以Poisson过程作为输入业务流模型分析系统性能的不足,提出采用马尔可夫调制泊松过程(MMPP)作为输入业务流来分析系统的呼叫阻塞率和掉话率.数值和仿真结果表明,MMPP能够较好的对蜂窝移动网中的业务输入流近似建摸,它考虑了业务流本身的相关特性和突发特性,可以更加准确的用于分析系统性能.  相似文献   

14.
盛洁  马冬 《电子学报》2016,44(2):282-288
提出了一种应用于异构无线网络环境的基于多目标优化的业务接入控制算法.该算法以业务占用总资源最少、业务阻塞率最低和网络间负载最均衡为目标建立了多目标优化控制模型,采用高斯和戒上型组合隶属函数将多目标问题模糊化,利用最大化满意度指标法将多目标问题转化为单目标问题,并通过遗传算法求得最优解.仿真结果表明,所提算法能在兼顾各网络资源高效利用的同时,保证业务接入的可靠性,并相对于参考算法有效降低了业务阻塞率.  相似文献   

15.
    
Resource reservation or the other prioritization strategies adopted by Call Admission Control (CAC) schemes in wireless networks lead to unfair resource allocation to users belonging to different service classes (SCs) due to high divergence among the respective call blocking probabilities (CBPs). In this paper, we propose dynamic optimization of probabilistic CAC (P‐CAC) schemes to assure CAC fairness among users of different SCs in wireless networks. The approach is based on users utility combined with fairness optimization, aiming at dynamically determining the probability value in the P‐CAC scheme. This optimal probability is adjusted to network ongoing traffic, CBPs of each SC, prioritization levels characterizing the SCs supported, and the users risk aversion, which reflects their behavior toward the perceived QoS. The existence and uniqueness of the optimal probability that leads to absolute fairness among the users of a wireless network are proven. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

16.
Call admission control is one of the key elements to guarantee the handoff call dropping probability in cellular networks. Among numerous proposals in the literature, the distributed call admission control policy (DCAC) seems to be promising, due to its simplicity and adaptability to changing traffic. However, one crucial assumption used in DCAC is that the actually admitted new calls has to obey a Poisson process to enter the network after the call admission control. Given the dynamic and distributed nature of the control process, this can neither be validated nor be easily implemented. In this paper, we will first discuss a generalized DCAC which eliminates the above assumption and can be used in general environments. Then, a mobility-aware DCAC is introduced, which considers the difference of handoff support between low and high mobility calls in making the CAC decision in order to improve channel utilization. The performance of the modified DCAC scheme is investigated through simulation studies.  相似文献   

17.
    
In this paper, we present an analytical model of adaptive channel preemption (ACP) for small‐cell embedded large‐cellular (SCELC) networks. An SCELC network consists of a fixed base station (FBS) with large coverage and many embedded base stations (EBS) with relatively small coverage. Channel capacity in an FBS cell may become insufficient when traffic is unexpectedly increased particularly in some special occasion. This paper considers two aspects of dynamically allocating channels for an SCELC network. First, by increasing one or more EBS cells within an FBS cell, the proposed ACP can reduce blocking probability of new calls. Second, to reduce dropping probability of handoff calls, the proposed ACP allows a handoff call to preempt an on‐going call, when the latter is located in an EBS cell or in the overlapping area of two adjacent FBS cells. For the purpose of performance evaluation, we build an analytical model with 4‐tuple Markov chains. Numerical results reveal that embedding one or more EBS cells inside an FBS cell needs to be done carefully since it results in a tradeoff between the reduction of new‐call blocking probability and the increase of handoff‐call dropping probability. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

18.
    
To solve the problem of unbalanced loads and the short network lifetime of heterogeneous wireless sensor networks, this paper proposes a node-selection algorithm based on energy balance and dynamic adjustment. The spacing and energy of the nodes are calculated according to the proximity to the network nodes and the characteristics of the link structure. The direction factor and the energy-adjustment factor are introduced to optimize the node-selection probability in order to realize the dynamic selection of network nodes. On this basis, the target path is selected by the relevance of the nodes, and nodes with insufficient energy values are excluded in real time by the establishment of the node-selection mechanism, which guarantees the normal operation of the network and a balanced energy consumption. Simulation results show that this algorithm can effectively extend the network lifetime, and it has better stability, higher accuracy, and an enhanced data-receiving rate in sufficient time.  相似文献   

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