Adaptive bitrate video streaming(ABR)has become a critical technique for mobile video streaming to cope with time-varying network conditions and different user preferences.However,there are still many problems in achi...Adaptive bitrate video streaming(ABR)has become a critical technique for mobile video streaming to cope with time-varying network conditions and different user preferences.However,there are still many problems in achieving high-quality ABR video streaming over cellular networks.Mobile Edge Computing(MEC)is a promising paradigm to overcome the above problems by providing video transcoding capability and caching the ABR video streaming within the radio access network(RAN).In this paper,we propose a flexible transcoding strategy to provide viewers with low-latency video streaming services in the MEC networks under the limited storage,computing,and spectrum resources.According to the information collected from users,the MEC server acts as a controlling component to adjust the transcoding strategy flexibly based on optimizing the video caching placement strategy.Specifically,we cache the proper bitrate version of the video segments at the edge servers and select the appropriate bitrate version of the video segments to perform transcoding under jointly considering access control,resource allocation,and user preferences.We formulate this problem as a nonconvex optimization and mixed combinatorial problem.Moreover,the simulation results indicate that our proposed algorithm can ensure a low-latency viewing experience for users.展开更多
Abnormal movement states for a mobile robot were identified by four multi-layer perceptron. In the presence ot abnormality, avoidance strategies were designed to guarantee the safety of the robot. Firstly, the kinemat...Abnormal movement states for a mobile robot were identified by four multi-layer perceptron. In the presence ot abnormality, avoidance strategies were designed to guarantee the safety of the robot. Firstly, the kinematics of the normal and abnormal movement states were exploited, 8 kinds of features were extracted. Secondly, 4 multi-layer pereeptrons were employed to classify the features for four 4-driving wheels into 4 kinds of states, i.e. normal, blocked, deadly blocked, and slipping. Finally, avoidance strategies were designed based on this. Experiment results show that the methods can identify most abnormal movement states and avoid the abnormality correctly and timely.展开更多
Increasing urbanization rates observed in the last decades have significantly contributed to a higher number of travelers to urban environments. The objective of this study was to identify measures and factors that en...Increasing urbanization rates observed in the last decades have significantly contributed to a higher number of travelers to urban environments. The objective of this study was to identify measures and factors that encourage the use of alternative transportation in the cities of Washington D.C., USA and Porto Alegre, Brazil. The methodology used to compare these two cities was an evaluation of their urban mobility plans, including strategic analyses and measures to promote the use of public transport. This approach was based on factors described in the following document： ＂Urban Sustainability： Impacts of Economic Development and Their Consequences on the Process of Urbanization in Emerging Countries＂, prepared by the United Nations. The results indicate different planning strategies, ranging from focusing on tax integration policies in order to become more financially attractive to the user, to using different modes of mass transportation integrated with active mobility. In Washington D.C., an innovative strategy was developed in preparation to forecast scenarios, as the measures comprised projection for the year 2040, which will respond to mobility demands in the coming decades.展开更多
A mobile transmission strategy, PMPatching (Proxy-based Mobile Patching) transmission strat-egy is proposed, it applies to the proxy-based mobile streaming media system in Wideband Code Division Multiple Access (WCDMA...A mobile transmission strategy, PMPatching (Proxy-based Mobile Patching) transmission strat-egy is proposed, it applies to the proxy-based mobile streaming media system in Wideband Code Division Multiple Access (WCDMA) network. Performance of the whole system can be improved by using patching stream to transmit anterior part of the suffix that had been played back, and by batching all the demands for the suffix arrived in prefix period and patching stream transmission threshold period. Experimental results show that this strategy can efficiently reduce average network transmission cost and number of channels consumed in central streaming media server.展开更多
The article briefly introduces the situation of the global mobile communications market,and based on the development status quo of China's mobile communications market,studies the strategy for China Telecom to ent...The article briefly introduces the situation of the global mobile communications market,and based on the development status quo of China's mobile communications market,studies the strategy for China Telecom to enter the mobile market,mainly focusing on mo- bile technologies selection,differentiable services,regional strate- gies and price policies.展开更多
With the development of economic globalization and the information industry, the competition among the mobile phone companies is increasingly fierce. This requires the mobile phone companies to re-examine the traditio...With the development of economic globalization and the information industry, the competition among the mobile phone companies is increasingly fierce. This requires the mobile phone companies to re-examine the traditional marketing strategies, to seek and implement new feasible marketing strategy. This paper introduces the definition of virtual marketing, dissertates four virtual marketing strategies implemented by the mobile phone companies, and points out the problems in the process of implementing virtual marketing strategies and proposes the corresponding countermeasures.展开更多
The package offered by Bouygues Télécoms includes a MicroSD card that can be used to store multimedia contents （picture, music, videos） and offers up to 8GB of memory.
在单无人机辅助的移动边缘计算系统中,为使无人机能服务于大区域中的所有用户设备,可将大区域分成多个子区域,并设定无人机以固定路线在各个子区域间飞行来为用户设备提供计算服务。考虑到用户设备计算资源较匮乏且无人机覆盖区域外的...在单无人机辅助的移动边缘计算系统中,为使无人机能服务于大区域中的所有用户设备,可将大区域分成多个子区域,并设定无人机以固定路线在各个子区域间飞行来为用户设备提供计算服务。考虑到用户设备计算资源较匮乏且无人机覆盖区域外的用户可选择移动至覆盖区域内进行任务卸载以最大化自身效用,可将用户设备的部分卸载问题转化为每个用户设备的效用最大化问题,并利用混合策略博弈和子模博弈来分别确定用户设备的移动概率和卸载数据量,从而得出最优卸载策略,且分别证明了混合策略纳什均衡和纯策略纳什均衡的存在性。仿真结果表明,所提方案与MBO(Binary Offloading Based on Mixed Strategy Game)等经典方案相比可有效提高用户设备的效用,并验证了其收敛性和稳定性。展开更多
文摘在移动边缘计算网络中,联合考虑用户的移动性和服务满意度,实现数字孪生(Digital Twin, DT)的有效部署是一个极大的挑战。针对该问题,提出了一种边缘网络中基于用户移动性预测的数字孪生部署策略。首先,利用双向长短期记忆网络(Bidirectional Long Short-Term Memory Network, Bi-LSTM)和注意力机制建立一种轨迹预测模型,对移动用户进行轨迹序列预测;然后,利用整数线性规划(Integer Linear Programming, ILP)对数字孪生的部署问题进行建模;最后,以最大化由信息新鲜度(Age of Information, AoI)定义的效用增益函数为优化目标,提出一种基于用户移动性预测的数字孪生部署策略算法对提出的问题进行求解。该算法根据获取到的移动用户轨迹数据,利用数字孪生部署的边际效用递减特性进行设计,以实现最优的数字孪生部署策略。仿真分析验证了所提算法在预测精度和效用增益方面的有效性,且该算法与基准算法相比显示出性能提升不低于10.7%。
基金This work was supported by National Natural Science Foundation of China(No.61771070)National Natural Science Foundation of China(No.61671088).
文摘Adaptive bitrate video streaming(ABR)has become a critical technique for mobile video streaming to cope with time-varying network conditions and different user preferences.However,there are still many problems in achieving high-quality ABR video streaming over cellular networks.Mobile Edge Computing(MEC)is a promising paradigm to overcome the above problems by providing video transcoding capability and caching the ABR video streaming within the radio access network(RAN).In this paper,we propose a flexible transcoding strategy to provide viewers with low-latency video streaming services in the MEC networks under the limited storage,computing,and spectrum resources.According to the information collected from users,the MEC server acts as a controlling component to adjust the transcoding strategy flexibly based on optimizing the video caching placement strategy.Specifically,we cache the proper bitrate version of the video segments at the edge servers and select the appropriate bitrate version of the video segments to perform transcoding under jointly considering access control,resource allocation,and user preferences.We formulate this problem as a nonconvex optimization and mixed combinatorial problem.Moreover,the simulation results indicate that our proposed algorithm can ensure a low-latency viewing experience for users.
基金Project (60234030) supported by the National Natural Science Foundation of China
文摘Abnormal movement states for a mobile robot were identified by four multi-layer perceptron. In the presence ot abnormality, avoidance strategies were designed to guarantee the safety of the robot. Firstly, the kinematics of the normal and abnormal movement states were exploited, 8 kinds of features were extracted. Secondly, 4 multi-layer pereeptrons were employed to classify the features for four 4-driving wheels into 4 kinds of states, i.e. normal, blocked, deadly blocked, and slipping. Finally, avoidance strategies were designed based on this. Experiment results show that the methods can identify most abnormal movement states and avoid the abnormality correctly and timely.
文摘Increasing urbanization rates observed in the last decades have significantly contributed to a higher number of travelers to urban environments. The objective of this study was to identify measures and factors that encourage the use of alternative transportation in the cities of Washington D.C., USA and Porto Alegre, Brazil. The methodology used to compare these two cities was an evaluation of their urban mobility plans, including strategic analyses and measures to promote the use of public transport. This approach was based on factors described in the following document： ＂Urban Sustainability： Impacts of Economic Development and Their Consequences on the Process of Urbanization in Emerging Countries＂, prepared by the United Nations. The results indicate different planning strategies, ranging from focusing on tax integration policies in order to become more financially attractive to the user, to using different modes of mass transportation integrated with active mobility. In Washington D.C., an innovative strategy was developed in preparation to forecast scenarios, as the measures comprised projection for the year 2040, which will respond to mobility demands in the coming decades.
基金Supported by: (1) Specialized Research Fund for the Doctoral Program of Higher Education (No. 20030013006) (2) National Specialized R&D Project for the Product of Mobile Communications (Develop-ment and Application of Next Generation Mobile Intel-ligent Network)+3 种基金 (3) Development Fund Key Project for Electronic and Information Industry (Core Service Plat-form for Next Generation Network) (4) Development Fund Project for Electronic and Information Industry (Value-added Service Platform and Application System for Mobile Communications) (5) Development Fund Project for Electronic and Information Industry (Con-tent-based Integrated Charging Platform for Telecom-munication Networks) (6) National Specific Project for Hi-tech Industrialization and Information Equipments (Mobile Intelligent Network Supporting Value-added Data Services).
文摘A mobile transmission strategy, PMPatching (Proxy-based Mobile Patching) transmission strat-egy is proposed, it applies to the proxy-based mobile streaming media system in Wideband Code Division Multiple Access (WCDMA) network. Performance of the whole system can be improved by using patching stream to transmit anterior part of the suffix that had been played back, and by batching all the demands for the suffix arrived in prefix period and patching stream transmission threshold period. Experimental results show that this strategy can efficiently reduce average network transmission cost and number of channels consumed in central streaming media server.
文摘The article briefly introduces the situation of the global mobile communications market,and based on the development status quo of China's mobile communications market,studies the strategy for China Telecom to enter the mobile market,mainly focusing on mo- bile technologies selection,differentiable services,regional strate- gies and price policies.
文摘With the development of economic globalization and the information industry, the competition among the mobile phone companies is increasingly fierce. This requires the mobile phone companies to re-examine the traditional marketing strategies, to seek and implement new feasible marketing strategy. This paper introduces the definition of virtual marketing, dissertates four virtual marketing strategies implemented by the mobile phone companies, and points out the problems in the process of implementing virtual marketing strategies and proposes the corresponding countermeasures.
文摘The package offered by Bouygues Télécoms includes a MicroSD card that can be used to store multimedia contents （picture, music, videos） and offers up to 8GB of memory.
文摘在单无人机辅助的移动边缘计算系统中,为使无人机能服务于大区域中的所有用户设备,可将大区域分成多个子区域,并设定无人机以固定路线在各个子区域间飞行来为用户设备提供计算服务。考虑到用户设备计算资源较匮乏且无人机覆盖区域外的用户可选择移动至覆盖区域内进行任务卸载以最大化自身效用,可将用户设备的部分卸载问题转化为每个用户设备的效用最大化问题,并利用混合策略博弈和子模博弈来分别确定用户设备的移动概率和卸载数据量,从而得出最优卸载策略,且分别证明了混合策略纳什均衡和纯策略纳什均衡的存在性。仿真结果表明,所提方案与MBO(Binary Offloading Based on Mixed Strategy Game)等经典方案相比可有效提高用户设备的效用,并验证了其收敛性和稳定性。
