小蜂窝网络中不活跃用户的最优能量效率资源分配方案

针对5G网络中因小区重叠覆盖区域的干扰问题,为缓解密集小蜂窝网络中移动用户的业务连续性,提高频谱资源利用率,进而最大化整个网络平均能量效率问题。该文提出一种基于不活跃用户的最优能量效率资源分配方案(EEI)。首先,该方案依据不活跃用户通知区域,建立以用户为中心的虚拟小区,小区内小蜂窝基站可协作为用户提供通信服务,提高用户通信质量,缓解小蜂窝同层干扰,减少切换信令开销。其次,基于Lyapunov优化理论,该方案将整体网络平均能量效率优化问题,转换为用户最优传输资源分配和最优功率分配两个子问题,在最大化系统平均能量效率同时保证系统队列稳定性。由于该文将原优化问题进行了松弛,所得结果是局部最优解,而不是全局最优解。仿真结果表明,该文提出的基于不活跃用户的最优能量效率资源分配算法,其系统能量效率优于对比算法而计算复杂度较高。

     

校园WiFi组网与覆盖方案

目前,校园WiFi网络覆盖是各大运营商激烈竞争的进驻场景.通过WiFi覆盖有线网未能到达的众多区域,让用户随时随地接入移动网络,享受其便利的服务.WiFi在当今校园组网中扮演着重要角色,用户对其日益亲睐.本文主要针对校园内各种场景建筑物的组网方式、覆盖方案进行探讨.     

多频带混合场景下终端直通通信用户最优用户密度与功率分配研究

该文分析了蜂窝与终端直通(Device-to-Device, D2D)混合网络中多频带资源的场景下D2D用户最佳密度和功率分配问题。在混合网络中包含一个或者多个蜂窝网络,D2D用户复用蜂窝系统上行频谱资源。通过采用随机几何理论,上述问题可以建模成一个以最大化D2D网络容量为目标并以蜂窝用户和D2D用户的中断概率为约束条件的优化问题。由于上述优化问题非凸,因此分成两步解决原问题：首先证明当D2D用户密度确定的时候原问题对于功率分配是凸问题,并通过拉格朗日对偶方法得到了最优功率分配方案;随后证明中断约束条件将D2D用户密度的定义域分成有限个子区间,在每个子区间上可以通过求导的方式得到D2D传输容量局部最优解,基于上述两个结论,文中设计了一种子区间最优值搜索算法。通过仿真验证了算法的有效性,并且反映出D2D传输容量主要由中断约束条件和来自蜂窝网络的干扰决定。     

颠覆传统：摩托罗拉3G系统创新方案——AXPT——降低成本和复杂性，实现室内移动数据宽带化

室内宽带移动数据业务是运营商今后重要的业务增长点。但是由于设备庞大、价格昂贵以及传输等问题,单纯使用移动蜂窝技术无法很好地解决室内宽带移动数据的覆盖问题。摩托罗拉(中国)电子有限公司《颠覆传统:摩托罗拉3G系统创新方案——AXPT》一文向我们介绍了将WiFi的优势与蜂窝通信技术相结合,在室内部署UMTS／HSDPA网络从而实现宽带移动数据业务的AXPT方案。在AXPT方案中。AXPT接入节点的尺寸小、容量高、扩展性强,集成了RNC、分组核心网(SGSN)和NodeB功能,并复制了许多WiFi接入节点的特性,能够很好地满足宽带移动数据的室内覆盖要求,为运营商快速部署宽带移动数据业务提供了很好的技术选择。     

家庭基站用户的移动性管理

家庭基站通过宽带接入技术(如xDSL,有线电缆等)把家庭室内或小的商业机构与运营商网络连接起来,不仅可以帮助运营商实现室内覆盖,也可以为特定用户提供更高速率的移动业务,实现移动网络和固定网络有机结合.本文研究在3G网络中家庭基站用户的移动性管理.     

用户密集区域WiFi覆盖质量的优化

随着WiFi无线覆盖网络的不断扩大,用户数量急据增长,出现了以高校为典型代表的WiFi用户密集区域,随之也出现的WiFi设备集中区域。在用户和设备密集的区域,带来了频率干扰、设备利用率低、忙时用户上网时延长、用户带宽不稳定等诸多问题,给WiFi无线网络优化工作带来了很大的困难。介绍了解决用户密集区域WiFi覆盖质量主要问题的技术和方案,并详细介绍了用户密集区域WiFi覆盖质量优化的具体案例。     

TD-LTE高铁覆盖解决方案

4G高铁覆盖成为运营商竞争的新阵地,TD-LTE高铁规划对未来高铁网络覆盖具有重要的指导意义,通过精确规划,合理进行网络布局可以确保网络质量达到最优,满足网络用户的业务需求,提升用户满意度,建立运营商的企业品牌价值。     

TD-LTE高铁覆盖解决方案

4G高铁覆盖成为运营商竞争的新阵地,TD-LTE高铁规划对未来高铁网络覆盖具有重要的指导意义,通过精确规划,合理进行网络布局可以确保网络质量达到最优,满足网络用户的业务需求,提升用户满意度,建立运营商的企业品牌价值。     

新型扁平化Femto网络架构探讨

1 引言 宏基站与室内用户间有墙体相隔,信号衰减严重(典型范围是10～20dB),终端和基站的功率消耗大,无线频谱资源占用多.Femto基站不仅能为室内用户提供更好的覆盖和用户体验,也节省宏蜂窝资源以便分配给室外用户,这就是Femto方案的双重优点. 由于历史原因,蜂窝无线接入网在网络拓扑和协议架构方面采用分级架构.不同的是,BSR采用扁平化架构,将无线网络的分级功能整合到一个"盒子"中.将不同的协议栈整合到单个节点可以改善往返延迟;不通过中间网元直接连接到IP网,降低了网络成本和复杂度,消除原有分级网络中的拥塞点.     

WiFi业务IPv4地址优化的思考

如何利用WiFi业务网络部署,为解决公网 IP 地址不足对 WiFi 业务开展造成的影响,保障 WiFi 业务的可持续发展,是运营商需要解决的关键问题。首先介绍了WiFi业务的系统架构,WiFi业务IPv4地址的优化措施,然后重点对WiFi业务IPv4地址私网化改造时的承载方案、NAT部署及用户溯源进行了明确。     

SDN assisted Stackelberg Game model for LTE-WiFi offloading in 5G networks

The data traffic that is accumulated at the Macro Base Station (MBS) keeps on increasing as almost all the people start using mobile phones. The MBS cannot accommodate all user’s demands, and attempts to offload some users to the nearby small cells so that the user could get the expected service. For the MBS to offload data traffic to an Access Point (AP), it should offer an optimal economic incentive in a way its utility is maximized. Similarly, the APs should choose an optimal traffic to admit load for the price that it gets from MBS. To balance this tradeoff between the economic incentive and the admittance load to achieve optimal offloading, Software Defined Networking (SDN) assisted Stackelberg Game (SaSG) model is proposed. In this model, the MBS selects the users carefully to aggregate the service with AP, so that the user experiencing least service gets aggregated first. The MBS uses the Received Signal Strength Indicator (RSSI) value of the users as the main parameter for aggregating a particular user for a contract period with LTE and WiFi. Each player involved in the game tries to maximize their payoff utilities, and thus, while incorporating those utilities in real-time scenario, we obtain maximum throughput per user which experiences best data service without any lack in Quality of Experience (QoE). Thus, the proposed SaSG model proves better when compared with other game theory models, and hence an optimal data offloading is achieved.     

Auction–Stackelberg game framework for access permission in femtocell networks with multiple network operators

With the explosive growth of indoor data traffic in forthcoming fifth generation cellular networks, it is imperative for mobile network operators to improve network coverage and capacity. Femtocells are widely recognized as a promising technology to address these demands. As femtocells are sold or loaned by a mobile network operator (MNO) to its residential or enterprise customers, MNOs usually employ refunding scheme to compensate the femtocell holders (FHs) providing indoor access to other subscribers by configuring the femtocell to operate in open or hybrid access mode. Due to the selfishness nature, competition between network operators as well as femtocell holders makes it challenging for operators to select appropriate FHs for trading access resources. This inspires us to develop an effective refunding framework, with aim to improve overall network resource utilization, through promoting FHs to make reasonable access permission for well-matched macro users. In this paper, we develop a two-stage auction–Stackelberg game (ASGF) framework for access permission in femtocell networks, where MNO and mobile virtual network operator lease access resources from multiple FHs. We first design an auction mechanism to determine the winner femtocell that fulfils the access request of macro users. We next formulate the access permission problem between the winner femtocell and operators as a Stackelberg game, and theoretically prove the existence of unique equilibrium. As a higher system payoff can be gained by improving individual players’ payoff in the game, each player can choose the best response to others’ action by implementing access permission, while avoiding solving a complicated optimization problem. Numerical results validate the effectiveness of our proposed ASGF based refunding framework and the overall network efficiency can be improved significantly.     

Pricing strategies and categories for LTE networks

Long Term Evolution (LTE) systems will provide a large number of users with various high quality wireless Internet services including but not limited to voice over IP, real-time gaming, multimedia streaming and several others. A suitable pricing policy is an important component in order to bring benefits to both the operators and the customers. In fact, through this, the operator can efficiently manage the radio resources of cellular networks. For different types of services, the operator can maintain user Quality of Service and through which, the revenue can be optimized. This article analyzes various possible LTE pricing schemes, including the one proposed, based on different criteria: network load and congestion, operator revenue, traffic differentiation and user categorization. We provide comparative graphs to highlight the pros and cons of the studied pricing strategies. We highlight the importance for the operator to move from the often used flat-rate style policies towards more dynamic pricing strategies taking into account the user and service classes.     

Offloading in Software Defined Network at Edge with Information Asymmetry: A Contract Theoretical Approach

The proliferation of highly capable mobile devices such as smartphones and tablets has significantly increased the demand for wireless access. Software defined network (SDN) at edge is viewed as one promising technology to simplify the traffic offloading process for current wireless networks. In this paper, we investigate the incentive problem in SDN-at-edge of how to motivate a third party access points (APs) such as WiFi and smallcells to offload traffic for the central base stations (BSs). The APs will only admit the traffic from the BS under the precondition that their own traffic demand is satisfied. Under the information asymmetry that the APs know more about own traffic demands, the BS needs to distribute the payment in accordance with the APs’ idle capacity to maintain a compatible incentive. First, we apply a contract-theoretic approach to model and analyze the service trading between the BS and APs. Furthermore, other two incentive mechanisms: optimal discrimination contract and linear pricing contract are introduced to serve as the comparisons of the anti adverse selection contract. Finally, the simulation results show that the contract can effectively incentivize APs’ participation and offload the cellular network traffic. Furthermore, the anti adverse selection contract achieves the optimal outcome under the information asymmetry scenario.     

双层分级蜂窝网最优频谱分配与定价

针对异频组网的双层分级蜂窝网,提出了一种基于纳什谈判解法的最优频谱分配与定价策略,该策略能激励家庭基站采用开放用户组模式,最大化频谱效益。通过Stackelberg博弈建模,分析了频谱定价与用户需求的关系。通过纳什谈判解法,获得了最佳的频谱分配与定价策略,按需地为宏基站与家庭基站分配了带宽资源,定量地分析了家庭基站所提高的频谱效益。仿真结果表明,该策略相比非合作博弈方法,可有效提高运营商以及家庭基站拥有者所能获得的频谱效益,部署家庭基站将提高蜂窝网络的总效益。      

电信运营企业引入P4P技术的风险约束策略研究

当前P2P流量是互联网流量的主要组成部分,它造成电信运营企业的网络拥塞。而P4P作为一种互联网流量管理技术在现网中有着良好的实验效果,可以有效地疏导优化电信运营企业的网络流量,但是由于P4P技术需要提供网络拓扑信息才能运作,这对于电信运营企业而言是一种巨大的风险。为了让电信运营企业能够引进此类效果良好但同时具有巨大风险的技术。通过建立重复博弈模型,提出了电信运营企业对于风险惩罚力度及惩罚期的相关策略并进行了详细分析,为其提供理论参考依据。     

On the Traffic Offloading in Wi-Fi Supported Heterogeneous Wireless Networks

Heterogeneous small cell networks (HetSNet) comprise several low power, low cost (SBSa), (D2D) enabled links wireless-fidelity (Wi-Fi) access points (APs) to support the existing macrocell infrastructure, decrease over the air signaling and energy consumption, and increase network capacity, data rate and coverage. This paper presents an active user dependent path loss (PL) based traffic offloading (TO) strategy for HetSNets and a comparative study on two techniques to offload the traffic from macrocell to (SBSs) for indoor environments: PL and signal-to-interference ratio (SIR) based strategies. To quantify the improvements, the PL based strategy against the SIR based strategy is compared while considering various macrocell and (SBS) coverage areas and traffic–types. On the other hand, offloading in a dense urban setting may result in overcrowding the (SBSs). Therefore, hybrid traffic–type driven offloading technologies such as (WiFi) and (D2D) were proposed to en route the delay tolerant applications through (WiFi) (APs) and (D2D) links. It is necessary to illustrate the impact of daily user traffic profile, (SBSs) access schemes and traffic–type while deciding how much of the traffic should be offloaded to (SBSs). In this context, (AUPF) is introduced to account for the population of active small cells which depends on the variable traffic load due to the active users.     

多主多从Stackelberg博弈下的边缘缓存资源分配算法

为鼓励视频服务提供商参与到缓存过程中,本文提出一种基于Stackelberg博弈的激励缓存资源分配算法。与传统激励缓存资源分配方案不同,本文考虑同时存在多个网络运营商和多个视频服务提供商,视频服务提供商从网络运营商处购买存储空间以缓存热门视频。针对该场景,本文将该激励缓存模型建模为多主多从Stackelberg博弈问题,分别构建主方和从方的效用函数,证明了在网络运营商价格确定的情况下,视频服务提供商之间的非合作博弈存在纳什均衡。文章利用分布式迭代算法对该博弈模型进行求解,获得了视频服务提供商的最优缓存策略和网络运营商的最优价格策略。仿真结果表明,本文提出的激励缓存机制可使视频服务提供商获得比其他缓存分配算法更高的单位成本收益。      

基于注意力机制ConvLSTM的UAV节能预部署策略

无人机(UAV)可以作为空中基站而凭借其移动性灵活地实现热点区域的覆盖。如何预测流量的分布而优化UAV部署是运营商面临的挑战。针对此问题,该文提出一种基于注意力机制卷积长短期记忆网络(A-ConvLSTM)的UAV节能预部署策略：提出一种融合注意力机制的卷积长短期记忆深度时空网络模型A-ConvLSTM,用于预测用户与流量的时空分布;基于预测结果优化UAV的覆盖和位置,在满足用户接入速率要求的前提下,以最小化UAV系统发射功率为目标建立优化模型,将目标问题解耦成两个子问题并提出一种节能部署算法迭代求解。实验结果表明A-ConvLSTM性能高于各基线模型;节能部署算法能够有效降低UAV系统发射功耗,并能以更少数量的UAV实现整体区域覆盖。     

UMA:固定与移动融合发展的新机遇

UMA可支持移动语音与数据从蜂窝网络到无线局域网(WLAN/WiFi)的无缝转换,是实现移动/固定网络融合的技术之一。目前UMA标准正逐渐成熟,不少厂商推出了基于UMA的解决方案和终端设备,欧洲、北美及亚太的运营商也开展了运作和测试。UMA为运营商开辟了新的业务途径;可帮助移动运营商解决室内覆盖、提高频谱利用率;有利于固网运营商提高话务量和收入。