当历史的车轮滚滚向前,人类阔步迈进21世纪时,一种新的破坏力强、影响大的网络攻击手段分布式拒绝服务(DDoS:Distributed Denial of Service)也变得日益猖獗,它肆无忌惮地侵扰着国内外著名的网络服务商和政府、金融证券等机构.2000年初...当历史的车轮滚滚向前,人类阔步迈进21世纪时,一种新的破坏力强、影响大的网络攻击手段分布式拒绝服务(DDoS:Distributed Denial of Service)也变得日益猖獗,它肆无忌惮地侵扰着国内外著名的网络服务商和政府、金融证券等机构.2000年初,全球顶级网络服务商yahoo,ebay,amazon.com,ZDNnet,Buy com,Excite,microsoft先后因遭到大规模DDoS攻击而瘫痪.2002年10月,全球互联网的核心基础设施互联网根服务器受到严重DDoS攻击.事后安全专家心有余悸地说,只要攻击再持续一个小时,整个互联网的域名服务体系就会陷入崩溃.2003年3月20日美伊战争打响后,被誉为中东CNN的半岛电视台(Al-Jazeera)因为播放战俘画面,引起强烈反应,网站因而遭受DDoS攻击,导致无法联机.DDoS已成为网络安全的大敌.展开更多
In the future fifth generation(5G) systems,non-orthogonal multiple access(NOMA) is a promising technology that can greatly enhance the network capacity compared to orthogonal multiple access(OMA) .In this paper,we pro...In the future fifth generation(5G) systems,non-orthogonal multiple access(NOMA) is a promising technology that can greatly enhance the network capacity compared to orthogonal multiple access(OMA) .In this paper,we propose a novel random access(RA) and resource allocation scheme for the coexistence of NOMA-based and OMAbased machine-to-machine(M2M) communications,which aims at improving the number of successful data packet transmissions and guaranteeing the quality of service(Qo S) (e.g.,the minimum data rate requirement) for M2 M communications.The algorithm of joint user equipment(UE) paring and power allocation is proposed for the coexisting RA(i.e.,the coexistence of NOMA-based RA and OMA-based RA) .The resource allocation for the coexisting RA is investigated,thus improving the number of successful data packet transmissions by more efficiently using the radio resources.Simulation results demonstrate that the proposed RA and resource allocation scheme outperforms the conventional RA in terms of the number of successful data packet transmissions,thus is a promising technology in future M2 M communications.展开更多
In this paper, a new Random Packet Access Protocol (RPAP) is proposed in WCDMA systems. The new proposed RPAP can efficiently prevent unnecessary interference by stopping a transmission if it is bound to be collided w...In this paper, a new Random Packet Access Protocol (RPAP) is proposed in WCDMA systems. The new proposed RPAP can efficiently prevent unnecessary interference by stopping a transmission if it is bound to be collided with others. Throughput about the new RPAP is deliberated and analyzed. Computer simulation shows that this protocol has better throughput performance compared with conventional one currently used in WCDMA.展开更多
This paper applies the concepts and methods of complex networks to the development of models and simulations of master-slave distributed real-time systems by introducing an upper bound in the allowable delivery time o...This paper applies the concepts and methods of complex networks to the development of models and simulations of master-slave distributed real-time systems by introducing an upper bound in the allowable delivery time of the packets with computation results. Two representative intercom nection models are taken into account： Uniformly random and scale free （Barabasi-Albert）, including the presence of background traffic of packets. The obtained results include the identification of the uniformly random interconnectivity scheme as being largely more efficient than the scale-free counterpart. Also, increased latency tolerance of the application provides no help under congestion.展开更多
文摘当历史的车轮滚滚向前,人类阔步迈进21世纪时,一种新的破坏力强、影响大的网络攻击手段分布式拒绝服务(DDoS:Distributed Denial of Service)也变得日益猖獗,它肆无忌惮地侵扰着国内外著名的网络服务商和政府、金融证券等机构.2000年初,全球顶级网络服务商yahoo,ebay,amazon.com,ZDNnet,Buy com,Excite,microsoft先后因遭到大规模DDoS攻击而瘫痪.2002年10月,全球互联网的核心基础设施互联网根服务器受到严重DDoS攻击.事后安全专家心有余悸地说,只要攻击再持续一个小时,整个互联网的域名服务体系就会陷入崩溃.2003年3月20日美伊战争打响后,被誉为中东CNN的半岛电视台(Al-Jazeera)因为播放战俘画面,引起强烈反应,网站因而遭受DDoS攻击,导致无法联机.DDoS已成为网络安全的大敌.
基金supported by the National Natural Science Foundation of China(61501056)National Science and Technology Major Project of China(No.2016ZX03001012)the Research Fund of ZTE Corporation
文摘In the future fifth generation(5G) systems,non-orthogonal multiple access(NOMA) is a promising technology that can greatly enhance the network capacity compared to orthogonal multiple access(OMA) .In this paper,we propose a novel random access(RA) and resource allocation scheme for the coexistence of NOMA-based and OMAbased machine-to-machine(M2M) communications,which aims at improving the number of successful data packet transmissions and guaranteeing the quality of service(Qo S) (e.g.,the minimum data rate requirement) for M2 M communications.The algorithm of joint user equipment(UE) paring and power allocation is proposed for the coexisting RA(i.e.,the coexistence of NOMA-based RA and OMA-based RA) .The resource allocation for the coexisting RA is investigated,thus improving the number of successful data packet transmissions by more efficiently using the radio resources.Simulation results demonstrate that the proposed RA and resource allocation scheme outperforms the conventional RA in terms of the number of successful data packet transmissions,thus is a promising technology in future M2 M communications.
文摘In this paper, a new Random Packet Access Protocol (RPAP) is proposed in WCDMA systems. The new proposed RPAP can efficiently prevent unnecessary interference by stopping a transmission if it is bound to be collided with others. Throughput about the new RPAP is deliberated and analyzed. Computer simulation shows that this protocol has better throughput performance compared with conventional one currently used in WCDMA.
文摘This paper applies the concepts and methods of complex networks to the development of models and simulations of master-slave distributed real-time systems by introducing an upper bound in the allowable delivery time of the packets with computation results. Two representative intercom nection models are taken into account： Uniformly random and scale free （Barabasi-Albert）, including the presence of background traffic of packets. The obtained results include the identification of the uniformly random interconnectivity scheme as being largely more efficient than the scale-free counterpart. Also, increased latency tolerance of the application provides no help under congestion.
