星地融合网络通过实现卫星网络与地面蜂窝网络的有机融合,可为用户提供灵活的网络接入服务,满足多场景用户应用需求.然而,卫星网络拓扑结构的动态变化、星地链路的复杂特性、多网和多用户资源调度粒度的显著差异性,以及资源共享模式的...星地融合网络通过实现卫星网络与地面蜂窝网络的有机融合,可为用户提供灵活的网络接入服务,满足多场景用户应用需求.然而,卫星网络拓扑结构的动态变化、星地链路的复杂特性、多网和多用户资源调度粒度的显著差异性,以及资源共享模式的多样性,均对星地融合网络用户关联及资源调度问题带来困难及挑战.本文针对星地融合网络下行链路增强型移动宽带用户(Enhanced mobile broadband User,EU)及高可靠低延迟通信用户(ultra-Reliable and low latency communications User,RU)数据传输场景,研究用户关联及资源调度问题.在满足用户传输需求、网络可用资源、资源共享模式等约束条件下,将联合用户关联及资源块调度问题建模为系统效用函数最大化问题.由于该优化问题为强耦合问题,不易直接求解,本文将原优化问题分解功率分配子问题、用户关联及资源调度子问题.针对功率分配子问题,利用拉格朗日部分松弛法对离散变量进行连续化,进而将功率分配子问题转换为凸优化问题,采用拉格朗日对偶算法进行求解.基于得到的功率分配策略,本文提出一种启发式算法确定用户关联模式及资源块分配策略,在对蜂窝网络可用时频资源状态进行评估的基础上,分别针对时频资源充足及时频资源不充足的情况设计用户关联及资源块调度策略.针对时频资源充足情况,根据用户资源调度模式,分别定义RU及EU的时空资源调度粒度,进而针对采用正交频分多址接入(Orthogonal Frequency Division Multiple Access,OFDMA)模式的RU及EU,基于KM匹配算法优化确定时频资源块调度策略;进而,针对采用穿孔模式的RU与EU,提出一种基于贪婪算法的EU资源块重调度策略,以满足用户最小传输速率;针对占用相邻子信道的EU优化确定OFDMA模式及非正交多址接入(Non-Orthogonal Multiple Access,NOMA)模式,以实现效用函数的提升.针对蜂窝网络时频资源不充足的情况,为无法接入蜂窝网络的用户分配卫星关联模式,并设计基于Kuhn-Munkres匹配算法的资源块调度策略.最后,通过仿真验证本文所提算法的有效性.展开更多
The question of optimal portfolio is that finds the trading strategy satisfying the maximal expected utility function subject to some constraints. There is the optimal trading strategy under the risk neutral probabili...The question of optimal portfolio is that finds the trading strategy satisfying the maximal expected utility function subject to some constraints. There is the optimal trading strategy under the risk neutral probability measure （martingale measure） if and only if there is no-arbitrage opportunity in the market. This paper argues the optimal wealth and the optimal value of expected utility with different utility function.展开更多
In this study,an explicit adaptive traffic allocation scheme for Machine-to-Machine(M2M)service is proposed to achieve optimum distribution in heterogeneous networks.Based on the characteristics of M2M services,the pr...In this study,an explicit adaptive traffic allocation scheme for Machine-to-Machine(M2M)service is proposed to achieve optimum distribution in heterogeneous networks.Based on the characteristics of M2M services,the presented scheme is formulated as a convex optimization problem that maximises the utility of the M2M service,and then determines how to allocate the total rate among the multiple access networks.The analysis and numerical simulations indicate that the proposed scheme makes a significant improvement in performance compared with the traditional schemes.展开更多
In heterogeneous network with hybrid energy supplies including green energy and on-grid energy, it is imperative to increase the utilization of green energy as well as to improve the utilities of users and networks. A...In heterogeneous network with hybrid energy supplies including green energy and on-grid energy, it is imperative to increase the utilization of green energy as well as to improve the utilities of users and networks. As the difference of hybrid energy source in stability and economy, thus, this paper focuses on the network with hybrid energy source, and design the utility of each user in the hybrid energy source system from the perspective of stability, economy and environment pollution. A dual power allocation algorithm based on Stackelberg game to maximize the utilities of users and networks is proposed. In addition, an iteration method is proposed which enables all players to reach the Stackelberg equilibrium(SE). Simulation results validate that players can reach the SE and the utilities of users and networks can be maximization, and the green energy can be efficiently used.展开更多
Decreasing the flow completion time(FCT) and increasing the throughput are two fundamental targets in datacenter networks(DCNs), but current mechanisms mostly focus on one of the problems. In this paper, we propose OF...Decreasing the flow completion time(FCT) and increasing the throughput are two fundamental targets in datacenter networks(DCNs), but current mechanisms mostly focus on one of the problems. In this paper, we propose OFMPC, an Open Flow based Multi Path Cooperation framework, to decrease FCT and increase the network throughput. OFMPC partitions the end-to-end transmission paths into two classes, which are low delay paths(LDPs) and high throughput paths(HTPs), respectively. Short flows are assigned to LDPs to avoid long queueing delay, while long flows are assigned to HTPs to guarantee their throughput. Meanwhile, a dynamic scheduling mechanism is presented to improve network efficiency. We evaluate OFMPC in Mininet emulator and a testbed, and the experimental results show that OFMPC can effectively decrease FCT. Besides, OFMPC also increases the throughput up to more than 84% of bisection bandwidth.展开更多
文摘星地融合网络通过实现卫星网络与地面蜂窝网络的有机融合,可为用户提供灵活的网络接入服务,满足多场景用户应用需求.然而,卫星网络拓扑结构的动态变化、星地链路的复杂特性、多网和多用户资源调度粒度的显著差异性,以及资源共享模式的多样性,均对星地融合网络用户关联及资源调度问题带来困难及挑战.本文针对星地融合网络下行链路增强型移动宽带用户(Enhanced mobile broadband User,EU)及高可靠低延迟通信用户(ultra-Reliable and low latency communications User,RU)数据传输场景,研究用户关联及资源调度问题.在满足用户传输需求、网络可用资源、资源共享模式等约束条件下,将联合用户关联及资源块调度问题建模为系统效用函数最大化问题.由于该优化问题为强耦合问题,不易直接求解,本文将原优化问题分解功率分配子问题、用户关联及资源调度子问题.针对功率分配子问题,利用拉格朗日部分松弛法对离散变量进行连续化,进而将功率分配子问题转换为凸优化问题,采用拉格朗日对偶算法进行求解.基于得到的功率分配策略,本文提出一种启发式算法确定用户关联模式及资源块分配策略,在对蜂窝网络可用时频资源状态进行评估的基础上,分别针对时频资源充足及时频资源不充足的情况设计用户关联及资源块调度策略.针对时频资源充足情况,根据用户资源调度模式,分别定义RU及EU的时空资源调度粒度,进而针对采用正交频分多址接入(Orthogonal Frequency Division Multiple Access,OFDMA)模式的RU及EU,基于KM匹配算法优化确定时频资源块调度策略;进而,针对采用穿孔模式的RU与EU,提出一种基于贪婪算法的EU资源块重调度策略,以满足用户最小传输速率;针对占用相邻子信道的EU优化确定OFDMA模式及非正交多址接入(Non-Orthogonal Multiple Access,NOMA)模式,以实现效用函数的提升.针对蜂窝网络时频资源不充足的情况,为无法接入蜂窝网络的用户分配卫星关联模式,并设计基于Kuhn-Munkres匹配算法的资源块调度策略.最后,通过仿真验证本文所提算法的有效性.
文摘The question of optimal portfolio is that finds the trading strategy satisfying the maximal expected utility function subject to some constraints. There is the optimal trading strategy under the risk neutral probability measure （martingale measure） if and only if there is no-arbitrage opportunity in the market. This paper argues the optimal wealth and the optimal value of expected utility with different utility function.
基金supported by the National Natural Science Foundation of Chinaunder Grant No.60971125the National Science and Technology Major Project of the Ministry of Science and Technology of Chinaunder Grant No.2012ZX03005-010the China Scholarship Council
文摘In this study,an explicit adaptive traffic allocation scheme for Machine-to-Machine(M2M)service is proposed to achieve optimum distribution in heterogeneous networks.Based on the characteristics of M2M services,the presented scheme is formulated as a convex optimization problem that maximises the utility of the M2M service,and then determines how to allocate the total rate among the multiple access networks.The analysis and numerical simulations indicate that the proposed scheme makes a significant improvement in performance compared with the traditional schemes.
基金supported by the Beijing Natural Science Foundation (4142049)863 project No. 2014AA01A701the Fundamental Research Funds for Central Universities of China No. 2015XS07
文摘In heterogeneous network with hybrid energy supplies including green energy and on-grid energy, it is imperative to increase the utilization of green energy as well as to improve the utilities of users and networks. As the difference of hybrid energy source in stability and economy, thus, this paper focuses on the network with hybrid energy source, and design the utility of each user in the hybrid energy source system from the perspective of stability, economy and environment pollution. A dual power allocation algorithm based on Stackelberg game to maximize the utilities of users and networks is proposed. In addition, an iteration method is proposed which enables all players to reach the Stackelberg equilibrium(SE). Simulation results validate that players can reach the SE and the utilities of users and networks can be maximization, and the green energy can be efficiently used.
基金supported by the State Key Development Program for Basic Research of China under Grant No.2012CB315806the National Natural Science Foundation of China under Grant Nos.61103225 and 61379149+1 种基金Jiangsu Province Natural Science Foundation of China under Grant No.BK20140070Jiangsu Future Networks Innovation Institute Prospective Research Project on Future Networks under Grant No.BY2013095-1-06
文摘Decreasing the flow completion time(FCT) and increasing the throughput are two fundamental targets in datacenter networks(DCNs), but current mechanisms mostly focus on one of the problems. In this paper, we propose OFMPC, an Open Flow based Multi Path Cooperation framework, to decrease FCT and increase the network throughput. OFMPC partitions the end-to-end transmission paths into two classes, which are low delay paths(LDPs) and high throughput paths(HTPs), respectively. Short flows are assigned to LDPs to avoid long queueing delay, while long flows are assigned to HTPs to guarantee their throughput. Meanwhile, a dynamic scheduling mechanism is presented to improve network efficiency. We evaluate OFMPC in Mininet emulator and a testbed, and the experimental results show that OFMPC can effectively decrease FCT. Besides, OFMPC also increases the throughput up to more than 84% of bisection bandwidth.
