To cope with the rapid growth of mobile video, video providers have leveraged cloud technologies to deploy their mobile video service system for more cost-effective and scalable performance. The emergence of Software-...To cope with the rapid growth of mobile video, video providers have leveraged cloud technologies to deploy their mobile video service system for more cost-effective and scalable performance. The emergence of Software-Defined Networking(SDN) provides a promising solution to manage the underlying network. In this paper, we introduce an SDN-enabled cloud mobile video distribution architecture and propose a joint video placement, request dispatching and traffic management mechanism to improve user experience and reduce the system operational cost. We use a utility function to capture the two aspects of user experience: the level of satisfaction and average latency, and formulate the joint optimization problem as a mixed integer programming problem. We develop an optimal algorithm based on dual decomposition and prove its optimality. We conduct simulations to evaluate the performance of our algorithm and the results show that our strategy can effectively cut down the total cost and guarantee user experience.展开更多
Cooperative utilization of multidimensional resources including cache, power and spectrum in satellite-terrestrial integrated networks(STINs) can provide a feasible approach for massive streaming media content deliver...Cooperative utilization of multidimensional resources including cache, power and spectrum in satellite-terrestrial integrated networks(STINs) can provide a feasible approach for massive streaming media content delivery over the seamless global coverage area. However, the on-board supportable resources of a single satellite are extremely limited and lack of interaction with others. In this paper, we design a network model with two-layered cache deployment, i.e., satellite layer and ground base station layer, and two types of sharing links, i.e., terrestrial-satellite sharing(TSS) links and inter-satellite sharing(ISS) links, to enhance the capability of cooperative delivery over STINs. Thus, we use rateless codes for the content divided-packet transmission, and derive the total energy efficiency(EE) in the whole transmission procedure, which is defined as the ratio of traffic offloading and energy consumption. We formulate two optimization problems about maximizing EE in different sharing scenarios(only TSS and TSS-ISS),and propose two optimized algorithms to obtain the optimal content placement matrixes, respectively.Simulation results demonstrate that, enabling sharing links with optimized cache placement have more than 2 times improvement of EE performance than other traditional placement schemes. Particularly, TSS-ISS schemes have the higher EE performance than only TSS schemes under the conditions of enough number of satellites and smaller inter-satellite distances.展开更多
Content-centric networking （CCN） proposes a content-centric paradigm which changes the waist hourglass from Internet protocol （IP） to content chunk. In this paper, based on content chunks, an optimization model of...Content-centric networking （CCN） proposes a content-centric paradigm which changes the waist hourglass from Internet protocol （IP） to content chunk. In this paper, based on content chunks, an optimization model of minimizing the total delay time in information centric networking （ICN） is established, and branch-and-bound method and greedy （BG） algorithm is proposed to get the content placement method. As the multipath is natural supported in CCN, chunk-based content placement can decline delay time obviously, even it would increase the calculation amount which can be solved easily by the node＇s capacity. Simulation results indicate that the chunk-based content placement scheme is better than the single-based cache policy on the network total delay time, and the best number of each content chunk split is decided by the link density and the number of the nodes in the network.展开更多
随着第五代移动通信(5G)技术的快速发展,车联网(Internet of Vehicles,IoV)已成为5G的重要应用场景之一.针对IoV应用对即时性内容缓存的迫切需求,本文研究了支持动态内容缓存的移动边缘缓存方案以确保动态内容的时效性,该方案允许车辆...随着第五代移动通信(5G)技术的快速发展,车联网(Internet of Vehicles,IoV)已成为5G的重要应用场景之一.针对IoV应用对即时性内容缓存的迫切需求,本文研究了支持动态内容缓存的移动边缘缓存方案以确保动态内容的时效性,该方案允许车辆从边缘缓存接入点(Caching-enabled Access Point,CAP)获得具有新鲜度约束的缓存内容.此外,本文基于协作缓存,利用概率论建立了CAP缓存刷新和交付的随机模型.同时,以基于信息年龄(Age of Information,AoI)的缓存命中率为IoV缓存的服务质量(Quality of Service,QoS)指标,建立了系统缓存命中的价值模型.为确保缓存内容的有效性,本文在分层切片框架中考虑了两种具有不同AoI要求的车辆内容请求.最后,本文提出了一个基于协作内容放置的系统内容缓存命中价值最大化的优化问题,这是一个NP-hard多目标多维多选择背包问题.因此,本文将其划分为若干个相互独立的优化问题并设计了一种基于内容年龄价值的最大增量算法进行求解.仿真结果表明,本文采用的CAP协作内容放置策略的性能优于其他传统方法.展开更多
为了克服现有Internet架构存在的众所周知的缺点,未来网络的研究成为热点.ICN(information-centricnetworking)在众多新架构中正逐渐被公认为最有前途的方案.它把传输的内容缓存到沿途的节点.高效的缓存机制是它的一个重要研究方面.为此...为了克服现有Internet架构存在的众所周知的缺点,未来网络的研究成为热点.ICN(information-centricnetworking)在众多新架构中正逐渐被公认为最有前途的方案.它把传输的内容缓存到沿途的节点.高效的缓存机制是它的一个重要研究方面.为此,提出了一种在分布式缓存机制中嵌入中心式缓存决策的机制(content-awareplacement,discovery and replacement,简称APDR),它把内容的放置、发现、替换统一起来考虑,实现内容的有序缓存,提高网络的性能.APDR的主要思想是:Interest报文除了携带对内容的请求以外,还收集沿途各节点对该内容的潜在需求、空闲缓存等信息,使得Interest的汇聚点和目的地节点可以据此计算出一个缓存方案,并把该方案附加在Data报文上,通知返程途中的某些节点缓存该内容并设置指定的缓存时间.在多种实验条件下对APDR进行了仿真验证,结果表明,APDR可以改善网络性能,包括缓存命中率、接入代价、替换数量、转发效率以及缓存鲁棒性等;而且APDR的额外开销也不大.展开更多
This paper investigates the content placement problem to maximize the cache hit ratio in device-to-device(D2D)communications overlaying cellular networks.We consider offloading contents by users themselves,D2D communi...This paper investigates the content placement problem to maximize the cache hit ratio in device-to-device(D2D)communications overlaying cellular networks.We consider offloading contents by users themselves,D2D communications and multicast,and we analyze the relationship between these offloading methods and the cache hit ratio.Based on this relationship,we formulate the content placement optimization as a cache hit ratio maximization problem,and propose a heuristic algorithm to solve it.Numerical results demonstrate that the proposed scheme can outperform existing schemes in terms of the cache hit ratio.展开更多
基金supported by the State Key Program of National Natural Science Foundation of China(Grant No.61233003)National Natural Science Foundation of China(Grant No.61503358)
文摘To cope with the rapid growth of mobile video, video providers have leveraged cloud technologies to deploy their mobile video service system for more cost-effective and scalable performance. The emergence of Software-Defined Networking(SDN) provides a promising solution to manage the underlying network. In this paper, we introduce an SDN-enabled cloud mobile video distribution architecture and propose a joint video placement, request dispatching and traffic management mechanism to improve user experience and reduce the system operational cost. We use a utility function to capture the two aspects of user experience: the level of satisfaction and average latency, and formulate the joint optimization problem as a mixed integer programming problem. We develop an optimal algorithm based on dual decomposition and prove its optimality. We conduct simulations to evaluate the performance of our algorithm and the results show that our strategy can effectively cut down the total cost and guarantee user experience.
基金supported by National Natural Sciences Foundation of China(No.62271165,62027802,61831008)the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515030297,2021A1515011572)Shenzhen Science and Technology Program ZDSYS20210623091808025,Stable Support Plan Program GXWD20231129102638002.
文摘Cooperative utilization of multidimensional resources including cache, power and spectrum in satellite-terrestrial integrated networks(STINs) can provide a feasible approach for massive streaming media content delivery over the seamless global coverage area. However, the on-board supportable resources of a single satellite are extremely limited and lack of interaction with others. In this paper, we design a network model with two-layered cache deployment, i.e., satellite layer and ground base station layer, and two types of sharing links, i.e., terrestrial-satellite sharing(TSS) links and inter-satellite sharing(ISS) links, to enhance the capability of cooperative delivery over STINs. Thus, we use rateless codes for the content divided-packet transmission, and derive the total energy efficiency(EE) in the whole transmission procedure, which is defined as the ratio of traffic offloading and energy consumption. We formulate two optimization problems about maximizing EE in different sharing scenarios(only TSS and TSS-ISS),and propose two optimized algorithms to obtain the optimal content placement matrixes, respectively.Simulation results demonstrate that, enabling sharing links with optimized cache placement have more than 2 times improvement of EE performance than other traditional placement schemes. Particularly, TSS-ISS schemes have the higher EE performance than only TSS schemes under the conditions of enough number of satellites and smaller inter-satellite distances.
基金supported by the Dr. Start-up Fund of North China University of Water Resources and Electric Power in China (4001/40460)the Focus on Research Programs of Henan (172102210365)the Scientific Research Project of Henan University (16A520061)
文摘Content-centric networking （CCN） proposes a content-centric paradigm which changes the waist hourglass from Internet protocol （IP） to content chunk. In this paper, based on content chunks, an optimization model of minimizing the total delay time in information centric networking （ICN） is established, and branch-and-bound method and greedy （BG） algorithm is proposed to get the content placement method. As the multipath is natural supported in CCN, chunk-based content placement can decline delay time obviously, even it would increase the calculation amount which can be solved easily by the node＇s capacity. Simulation results indicate that the chunk-based content placement scheme is better than the single-based cache policy on the network total delay time, and the best number of each content chunk split is decided by the link density and the number of the nodes in the network.
文摘随着第五代移动通信(5G)技术的快速发展,车联网(Internet of Vehicles,IoV)已成为5G的重要应用场景之一.针对IoV应用对即时性内容缓存的迫切需求,本文研究了支持动态内容缓存的移动边缘缓存方案以确保动态内容的时效性,该方案允许车辆从边缘缓存接入点(Caching-enabled Access Point,CAP)获得具有新鲜度约束的缓存内容.此外,本文基于协作缓存,利用概率论建立了CAP缓存刷新和交付的随机模型.同时,以基于信息年龄(Age of Information,AoI)的缓存命中率为IoV缓存的服务质量(Quality of Service,QoS)指标,建立了系统缓存命中的价值模型.为确保缓存内容的有效性,本文在分层切片框架中考虑了两种具有不同AoI要求的车辆内容请求.最后,本文提出了一个基于协作内容放置的系统内容缓存命中价值最大化的优化问题,这是一个NP-hard多目标多维多选择背包问题.因此,本文将其划分为若干个相互独立的优化问题并设计了一种基于内容年龄价值的最大增量算法进行求解.仿真结果表明,本文采用的CAP协作内容放置策略的性能优于其他传统方法.
文摘为了克服现有Internet架构存在的众所周知的缺点,未来网络的研究成为热点.ICN(information-centricnetworking)在众多新架构中正逐渐被公认为最有前途的方案.它把传输的内容缓存到沿途的节点.高效的缓存机制是它的一个重要研究方面.为此,提出了一种在分布式缓存机制中嵌入中心式缓存决策的机制(content-awareplacement,discovery and replacement,简称APDR),它把内容的放置、发现、替换统一起来考虑,实现内容的有序缓存,提高网络的性能.APDR的主要思想是:Interest报文除了携带对内容的请求以外,还收集沿途各节点对该内容的潜在需求、空闲缓存等信息,使得Interest的汇聚点和目的地节点可以据此计算出一个缓存方案,并把该方案附加在Data报文上,通知返程途中的某些节点缓存该内容并设置指定的缓存时间.在多种实验条件下对APDR进行了仿真验证,结果表明,APDR可以改善网络性能,包括缓存命中率、接入代价、替换数量、转发效率以及缓存鲁棒性等;而且APDR的额外开销也不大.
基金partly supported by the Na-tional Natural Science Foundation of China (No.61601334,61601509)
文摘This paper investigates the content placement problem to maximize the cache hit ratio in device-to-device(D2D)communications overlaying cellular networks.We consider offloading contents by users themselves,D2D communications and multicast,and we analyze the relationship between these offloading methods and the cache hit ratio.Based on this relationship,we formulate the content placement optimization as a cache hit ratio maximization problem,and propose a heuristic algorithm to solve it.Numerical results demonstrate that the proposed scheme can outperform existing schemes in terms of the cache hit ratio.
