【作者】 陆绍飞；

【导师】 王建新；

【作者基本信息】 中南大学 ， 计算机应用技术， 2012， 博士

【摘要】 随着Internet的迅速发展和个人对数据通信需求的急速增长,全球计算机网络和通信技术的发展逐渐呈现三大趋势：无线化、宽带化和IP化。同有线接入系统一样,无线接入系统经历了由窄带到宽带,由面向语音业务到面向数据、多媒体业务的转变。在众多的宽带技术中,以IEEE802.16e(移动WiMAX)为代表的宽带无线移动通信网络技术成为近年来通信技术领域的最大亮点,是构成未来通信网络技术的重要组成部分。在宽带无线移动通信网中,如何控制能量消耗延长以电池为主要能量供给的移动终端的使用时间是实现“宽带移动化”必须要解决的核心议题之一。论文围绕IEEE802.16e的无线通信协议展开移动终端的节能研究,分别针对高业务量、低业务量以及多业务连接并存等不同应用场景,分别给出了有效的节能控制策略,同时基于OPNET仿真平台实现了节能机制的建模与仿真。论文的主要工作包括以下几个方面：1、针对IEEE802.16e的节能类型Ⅰ,提出了一种基于幂函数增长的统一节能控制机制,通过设置增长因子调节休眠模式中休眠间隔的增长幅度,全面分析了不同休眠间隔增长趋势以及不同的休眠参数值对休眠性能的影响。实验得出,增长因子a=2的幂函数增长算法相比IEEE802.16e协议中建议的指数递增算法在能耗与延时方面能同时取得较大改进。2、针对在低业务场景中,采用休眠间隔从小到大递增变化的休眠模式会产生过多的休眠周期,导致消耗过多的监听与切换能耗,同时也会造成较大的数据包的等待延时,降低了服务质量等问题,基于下行链路数据包到达时间间隔的实时预测,提出了一种基于流量预测动态调整休眠参数的节能机制(P-PSCI),并分别采用幂函数递减、指数递减与线性递减三种不同的休眠间隔递减趋势给出了三种P-PSCI休眠模式算法：PSCI-PFD、PSCI-ED与PSCI-LD。仿真实验表明,由于考虑了业务流量模式与速率变化,P-PSCI在终端能耗与延时两方面都得到了同时改善,并且得出a=-2的幂函数递减休眠算法取得了最好的性能表现。3、针对移动终端有多业务连接同时并存时,由于各连接上休眠模式操作中的侦听间隔不同步,从而降低了移动终端的实际节能效果,提出了一种参数集归一化优化策略：Multi-PSC。该优化策略通过同步所有业务连接的侦听间隔,实现移动终端的最大节能。针对移动站点仅有PSCⅠ业务连接并存、仅有PSCⅡ业务连接并存以及多种PSC Ⅰ与PSC Ⅱ业务混合并存三大典型应用场景,基于Multi-PSC分别提出了三种节能操作机制：Multi-PSCI, Multi-PSCII和Multi-PSCI&Ⅱ。分析表明,Multi-PSC不仅大幅度提高了多业务并存时移动终端的节能效率,同时还降低了数据包的额外延时。4、在休眠模式算法研究基础上,针对目前现有主流仿真平台都没有提供对IEEE802.16e节能机制的仿真支持,采用OPNET三层建模机制,通过扩展OPNET WiMAX MAC进程模型,设计与实现了IEEE802.16e节能机制的仿真模块,为IEEE802.16e节能机制的研究提供了公平与可信的仿真环境。论文对IEEE802.16e移动终端在通信协议层面的节能控制进行了深入研究,针对不同业务量分别提出了统一的基于幂函数增长的节能控制策略与基于预测的节能控制机制,针对移动终端多业务并存下的节能,提出了参数集归一化优化策略Multi-PSC,并基于OPNET设计与实现了休眠模式仿真平台,这些研究成果在移动WiMAX中具有良好的应用前景,对移动终端节能机制的研究有着重要的促进意义。更多还原

【Abstract】 With the rapid development of Internet and the growth of personal need for data communication, the development of global computer networks and communication technologies presents three major trends: wireless, broadband and IP-based. Just as the wired access system, the wireless access system has transformed from narrowband to broadband, voice service orientation to data, multimedia service orientation. Among the large number of broadband technologies, the mobile broadband wireless communication network technology established by the IEEE802.16e (Mobile WiMAX) has become the most impressive highlight of the communication technology field. Moreover, it is also playing an important part in the next generation communication network technology.In the mobile broadband wireless communication network, how to ensure the quality of service of communication when a mobile terminal moves between different base stations, and control the energy consumption powered mainly by battery to prolong the standby time are crucial issues for mobile broadband. In order to reduce the power consumption of a mobile station and the air interface resource utilization of serving base stations, this dissertation mainly focus on providing different power-saving control strategies for mobile terminals in the IEEE802.16e mobile broadband wireless communication network under different conditions, such as high-speed traffic business, low traffic business and the co-existence of multi-traffic services. Meanwhile, the modeling and simulation for power-saving mechanism of mobile terminals has been implemented based on the OPNET simulation platform.The main contributions of this dissertation are presented as follows:1. To improve the power saving class of type I (PSC I) proposed by IEEE802.16e for NRT-VR and Best Effort (BE) services, this dissertation presents a unified power saving mechanism based on power-increasing function. In particular, the proposed mechanism can combine with several existing classical sleep mode algorithms by adjusting the sleep interval with growth factor. Furthermore, the impact to sleep performance from different sleep parameter values and the growth trend of different sleep intervals has been studied thoroughly. Experiment results show that, power-increasing function with growth factor a setting to2(a=2) achieves considerable improvement in both energy saving and packet delay of mobile terminals compared with the recommended exponential-increasing function in IEEE802.16e.2. In the low traffic condition, the sleep mode in which a sleep cycle always increases from the fixed minimum sleep interval to the maximum sleep interval based on binary exponential increasing can generate unnecessarily high number of sleep cycles, thus leading to excessive listening and switching power consumption. In addition, arriving packets may fall into a relatively long sleep interval, causing a longer packet delay, which eventually reduces the quality of service. Thus a novel and highly efficient power saving mechanism P-PSCI is proposed that can dynamically adjust the values of sleep parameters based on the real-time prediction of the downlink inter-packet interval. In addition, the dissertation proposes three P-PSCI sleep mode algorithms for different adjustment functions:the power-function decreasing sleep algorithm PSCI-PFD, the exponential decreasing sleep algorithm PSCI-ED and the linear decreasing sleep algorithm PSCI-LD. Simulation results and theoretical analysis reveal that the P-PSCI can achieve much better results on reducing the power consumption and the packet delay due to the consideration of the traffic characteristics and rate changes, compared with the other sleep mode algorithms. Moreover, the power-function decreasing sleep algorithm (a=-2) achieves the best performance in both power saving and delay reducing.3. With multiple services existing on the mobile stations, the listening intervals in each sleep mode operation are not synchronized all the time. Thus this can bring out some negative impact on the actual energy-saving efficiency of the mobile terminal. To resolve this problem, this dissertation proposes a parameter set optimization strategy (Multi-PSC) that synchronizes all the connected listening intervals while different service connections coexist to achieve maximum energy saving of mobile terminals. In addition, the dissertation also establishes three corresponding parameter set optimization strategies:Multi-PSCI, Multi-PSCII and Multi-PSCI&PSCII, for the three typical scenarios of multiple connections co-existence:co-existence of multiple PSCI connections, co-existence of multiple PSCII connections of, and the co-existence of multiple PSCI and PSCII connections. Theoretical analysis and simulation experiments show that the Multi-PSC mechanism not only greatly improves the energy-saving efficiency of mobile terminals when multiple service connections exist, but also reduces the additional packet delay.4. Since the current mainstream simulation platforms do not offer simulation support for IEEE802.16e sleep mode, we adopt three-layer modeling mechanism of OPNET design and implement the simulation module of the IEEE802.16e sleep mode by extending OPNET WiMAX MAC process model, thus providing a convenient, fair, and credible simulation environment for the sleep mode.The dissertation performed an in-depth research on IEEE802.16e mobile terminal power-saving control strategy, and proposed a unified power saving mechanism based on the power function growth and power saving mechanism based on prediction for the PSCI, respectively. Moreover, the dissertation established parameter sets optimization strategy, Multi-PSC, for power saving of multiple service connections co-existence. Furthermore, it also designed and implemented the sleep mode simulation platform based on OPNET. These research findings not only have excellent application prospects for mobile WiMAX, but also entail impressive significance for future energy-saving research towards mobile terminals.更多还原