The interference coexistence performance between the systems of a Long Term Evolution(LTE) network and Mobile Satellite Service(MSS) system,both of which work around the frequency of approximately 2 GHz according to t...The interference coexistence performance between the systems of a Long Term Evolution(LTE) network and Mobile Satellite Service(MSS) system,both of which work around the frequency of approximately 2 GHz according to the bandwidth allocation in China,is proposed in this article.The related background of an MSS system and the common terminologies are introduced.Further,the coexistence scenarios of different coverage situations shared by the two systems are discussed.The interference impact of an MSS transmission on an LTE system is evaluated using a specific Monte Carlo method.Finally,simulation results show that although no crucial issues for the coexistence of an LTE downlink and the MSS are observed,the LTE uplink suffers a considerable amount of interference from the MSS transmission.Given the insufficient isolation between LTE and MSS existing networks,and the rapid advance in the field of LTE,problems may emerge in the near future.Further,this article can be of significance in providing reference for frequency spectrum planning in the existing LTE networks.展开更多
Long Term Evolution(LTE) and IEEE 802.16 WiMAX are competing access network technologies adopted in 4G wireless networks in recent years.LTE complies with3 GPP standards whereas 802.16 WiMAX is regulated by the Instit...Long Term Evolution(LTE) and IEEE 802.16 WiMAX are competing access network technologies adopted in 4G wireless networks in recent years.LTE complies with3 GPP standards whereas 802.16 WiMAX is regulated by the Institute of Electrical and Electronics Engineers(IEEE).Although WiMAX is already operating commercially in Taiwan,the system is limited to an independent new system that is incompatible with the current 3G system.Hence,the cost of implementing the WiMAX system is relatively high,this being an impediment to its rapid uptake and widespread use.On the other hand,LTE conforms to 3GPP that is supported by telecommunication manufacturers and operators and is,moreover,backward compatible with 3G/UMTS cellular systems.The LTE specifications define how user equipment(UE) connects and communicates with evolved Node B(eNB) base stations.The enhanced version,LTE-Advanced,adds a new entity called the relay node(RN) to widen service coverage,although this change has resulted in a more complex architecture.Mobility management and data forwarding are essential components in wireless mobile networking.This paper focuses on the efficient handover procedure in LTE-Advanced networks,and proposes a Smart Forwarding mechanism to improve the handover performance.Simulation studies show that the proposed Smart Forwarding scheme employs a better operational transmission path that effectively reduces handover latency and signal overhead.展开更多
Present mobile communication system suffers from the exponentially increased mobile traffic and research on the fifth generation(5G) mobile network architectures is ongoing to solve this problem. We investigate the fe...Present mobile communication system suffers from the exponentially increased mobile traffic and research on the fifth generation(5G) mobile network architectures is ongoing to solve this problem. We investigate the feasibility of the proposals used for the network architecture evolution from 4G to 5G and first propose a compatible network architecture, which decouples the management plane, the control plane and the user plane based on NO Stack framework proposed in our previous study. We mainly design detail procedures including UE attachment, service request and dedicated bearer activation/deactivation for our proposal network architecture. Finally, we establish a clear analytical mode of the application and system states to evaluate the signaling loads of new architecture. Simulation results show that our proposal network architecture with elaborated signaling procedures has much impact on the total signaling loads of system and could obviously decrease the signaling overhead compared with LTE.展开更多
The majority of existing papers about spectrum sensing have the assumption that secondary users(SUs) are stationary. However,mobility is an essential feature of mobile communications networks. In this paper,the detect...The majority of existing papers about spectrum sensing have the assumption that secondary users(SUs) are stationary. However,mobility is an essential feature of mobile communications networks. In this paper,the detection performance of spectrum sensing by mobile SUs was analyzed. Three performance metrics,i.e.,detection probability,miss detection probability and false alarm probability,were thoroughly investigated. In our analysis,a critical variable was the real-time received primary user signal power by a mobile SU. Its probability distribution and mathematical expectation were analytically derived. Moreover,the three performance metrics in single-node spectrum sensing and multi-node collaborative spectrum sensing systems were also derived. Extensive simulations were performed. The results are consistent with the theoretical analysis. And it is concluded that SU mobility has a significant impact on the detection probability and the miss detection probability,but not on the false alarm probability.展开更多
In this paper, we first overview some traditional relaying technologies, and then present a Network Coding-Aware Cooperative Relaying （NC2R） scheme to improve the performance of downlink transmission for relayaided ...In this paper, we first overview some traditional relaying technologies, and then present a Network Coding-Aware Cooperative Relaying （NC2R） scheme to improve the performance of downlink transmission for relayaided cellular networks. Moreover, systematic performance analysis and extensive simulations are performed for the proposed NC2R and traditional relaying and non-relaying schemes. The results show that NCR outperforms conventional relaying and non-relaying schemes in terms of blocking probability and spectral efficiency, especially for cell-edge users. Additionally, the location selections for relays with NCR are also discussed. These results will provide some insights for incorporating network coding into next-generation broadband cellular relay mobile systems.展开更多
This paper proposes a new access architecture onmobile cloud,which introduces a middle layer sitting between mobile devices and their cloud infrastructure.This middle layer is composed of cloudlets which are deployed ...This paper proposes a new access architecture onmobile cloud,which introduces a middle layer sitting between mobile devices and their cloud infrastructure.This middle layer is composed of cloudlets which are deployed by cloud services providers,such as wireless network access points(APs),to improve the performance of mobile cloud servicesand be different from traditional mobile operator mode.Then based on this new architecture.we improve our previous(Attribute-basedencryption) ABE access control scheme on cloud for mobile cloud,which is proposed to offload the main amount of computations to the cloudlet as the function of cloud.Simulationresults demonstratethe new access control scheme takes into consideration response time constraints and network statusof access task execution,while satisfying certain network security for mobile cloud.展开更多
The virtualized radio access network(v RAN) could implement virtualized baseband functions on general-purpose platforms and expand the processing capacity of the radio access network(RAN) significantly.In this paper,a...The virtualized radio access network(v RAN) could implement virtualized baseband functions on general-purpose platforms and expand the processing capacity of the radio access network(RAN) significantly.In this paper,a Not Only Stack(NO Stack) based vR AN is proposed to be employed in the fifth generation(5G) mobile communication system.It adopts advanced virtualization technologies to maintain flexible and sustainable.The baseband processing and storage resources should be sliced and orchestrated agilely to support multi radio access technology(multiRAT) .Also it is analyzed and demonstrated by different use cases to validate the benefits.The proposed v RAN reduces signaling overheads and service response time in the bearer establishment procedure.Concluded from the analyses and demonstrations,the NO Stack based v RAN could support multi-RAT convergence and flexible networking effectively.展开更多
This paper presents a universal platform "uSensing" to support smartphones to communicate with sensor nodes in Wireless Sensor Networks (WSNs).Since phones have different CPU processers and operating systems...This paper presents a universal platform "uSensing" to support smartphones to communicate with sensor nodes in Wireless Sensor Networks (WSNs).Since phones have different CPU processers and operating systems,it is a challenge to merge these heterogeneities and develop such a universal platform.In this paper,we design both hardware and software to support the "universal" feature of uSensing:1) "uSD" card:an IEEE 802.15.4 physical communication card with SD interface;2) "uSinkWare":a WSNs middleware running on smartphones.Integrated with uSD card and uSinkWare,phones become mobile data sinks to access into WSNs and parse messages from sensor nodes.We demonstrate the proposed uSensing platform in a commercial smartphone to connect with our WSNs testbed,and validate that the smartphone has the same WSNs functions as commercial fixed sink.Additionally,we evaluate the performance of uSensing platform through measuring phone's CPU load and power consumption,and analyze the performance of these metrics theoretically.The results suggest that the phone-based mobile sink has enough capability to serve as a mobile sink of WSNs and can work up to twenty hours due to low power consumption.展开更多
文摘The interference coexistence performance between the systems of a Long Term Evolution(LTE) network and Mobile Satellite Service(MSS) system,both of which work around the frequency of approximately 2 GHz according to the bandwidth allocation in China,is proposed in this article.The related background of an MSS system and the common terminologies are introduced.Further,the coexistence scenarios of different coverage situations shared by the two systems are discussed.The interference impact of an MSS transmission on an LTE system is evaluated using a specific Monte Carlo method.Finally,simulation results show that although no crucial issues for the coexistence of an LTE downlink and the MSS are observed,the LTE uplink suffers a considerable amount of interference from the MSS transmission.Given the insufficient isolation between LTE and MSS existing networks,and the rapid advance in the field of LTE,problems may emerge in the near future.Further,this article can be of significance in providing reference for frequency spectrum planning in the existing LTE networks.
基金supported in part by the National Science Council,Taiwan,"R.O.C.",under grant no.NSC 101-2221-E-164-019 and NSC 101-2221-E-164-020
文摘Long Term Evolution(LTE) and IEEE 802.16 WiMAX are competing access network technologies adopted in 4G wireless networks in recent years.LTE complies with3 GPP standards whereas 802.16 WiMAX is regulated by the Institute of Electrical and Electronics Engineers(IEEE).Although WiMAX is already operating commercially in Taiwan,the system is limited to an independent new system that is incompatible with the current 3G system.Hence,the cost of implementing the WiMAX system is relatively high,this being an impediment to its rapid uptake and widespread use.On the other hand,LTE conforms to 3GPP that is supported by telecommunication manufacturers and operators and is,moreover,backward compatible with 3G/UMTS cellular systems.The LTE specifications define how user equipment(UE) connects and communicates with evolved Node B(eNB) base stations.The enhanced version,LTE-Advanced,adds a new entity called the relay node(RN) to widen service coverage,although this change has resulted in a more complex architecture.Mobility management and data forwarding are essential components in wireless mobile networking.This paper focuses on the efficient handover procedure in LTE-Advanced networks,and proposes a Smart Forwarding mechanism to improve the handover performance.Simulation studies show that the proposed Smart Forwarding scheme employs a better operational transmission path that effectively reduces handover latency and signal overhead.
基金supported by the Chinas 863 Project (No.2015AA01A706)the National Science and Technology Major Project (No. 2016ZX03001017)+1 种基金the Science and Technology Program of Beijing (No. D161100001016002)the Science and Technology Cooperation Projects (No. 2015DFT10160B)
文摘Present mobile communication system suffers from the exponentially increased mobile traffic and research on the fifth generation(5G) mobile network architectures is ongoing to solve this problem. We investigate the feasibility of the proposals used for the network architecture evolution from 4G to 5G and first propose a compatible network architecture, which decouples the management plane, the control plane and the user plane based on NO Stack framework proposed in our previous study. We mainly design detail procedures including UE attachment, service request and dedicated bearer activation/deactivation for our proposal network architecture. Finally, we establish a clear analytical mode of the application and system states to evaluate the signaling loads of new architecture. Simulation results show that our proposal network architecture with elaborated signaling procedures has much impact on the total signaling loads of system and could obviously decrease the signaling overhead compared with LTE.
基金supported by National Natural Science Foundation of China under Grand No.61671183
文摘The majority of existing papers about spectrum sensing have the assumption that secondary users(SUs) are stationary. However,mobility is an essential feature of mobile communications networks. In this paper,the detection performance of spectrum sensing by mobile SUs was analyzed. Three performance metrics,i.e.,detection probability,miss detection probability and false alarm probability,were thoroughly investigated. In our analysis,a critical variable was the real-time received primary user signal power by a mobile SU. Its probability distribution and mathematical expectation were analytically derived. Moreover,the three performance metrics in single-node spectrum sensing and multi-node collaborative spectrum sensing systems were also derived. Extensive simulations were performed. The results are consistent with the theoretical analysis. And it is concluded that SU mobility has a significant impact on the detection probability and the miss detection probability,but not on the false alarm probability.
基金supported by the State Key Laboratory of Rail Traffic Control and Safety,Beijing Jiaotong University under Grant No.RCS2012ZT008the National Key Basic Research Program of China(973Program)under Grant No.2012CB316100(2)+1 种基金the National Natural Science Foundation of China under Grants No.61201203,No.61171064the Fundamental Research Funds for the Central Universities under Grant No.2012JBM030
文摘In this paper, we first overview some traditional relaying technologies, and then present a Network Coding-Aware Cooperative Relaying （NC2R） scheme to improve the performance of downlink transmission for relayaided cellular networks. Moreover, systematic performance analysis and extensive simulations are performed for the proposed NC2R and traditional relaying and non-relaying schemes. The results show that NCR outperforms conventional relaying and non-relaying schemes in terms of blocking probability and spectral efficiency, especially for cell-edge users. Additionally, the location selections for relays with NCR are also discussed. These results will provide some insights for incorporating network coding into next-generation broadband cellular relay mobile systems.
基金supported by National Natural Science Foundation of China(No.U 1405254, 61472092)China Postdoctoral Science Foundation(No.2015M581101)National Science and Technology SupportingFoundation of China(No.2014BAH41B00)
文摘This paper proposes a new access architecture onmobile cloud,which introduces a middle layer sitting between mobile devices and their cloud infrastructure.This middle layer is composed of cloudlets which are deployed by cloud services providers,such as wireless network access points(APs),to improve the performance of mobile cloud servicesand be different from traditional mobile operator mode.Then based on this new architecture.we improve our previous(Attribute-basedencryption) ABE access control scheme on cloud for mobile cloud,which is proposed to offload the main amount of computations to the cloudlet as the function of cloud.Simulationresults demonstratethe new access control scheme takes into consideration response time constraints and network statusof access task execution,while satisfying certain network security for mobile cloud.
基金supported by the China's 863 Project(No.2015AA01A706)the National Science and Technology Major Project(No.2016ZX03001017)+1 种基金the Science and Technology Program of Beijing(No.D161100001016002)the Science and Technology Cooperation Projects(No.2015DFT10160B)
文摘The virtualized radio access network(v RAN) could implement virtualized baseband functions on general-purpose platforms and expand the processing capacity of the radio access network(RAN) significantly.In this paper,a Not Only Stack(NO Stack) based vR AN is proposed to be employed in the fifth generation(5G) mobile communication system.It adopts advanced virtualization technologies to maintain flexible and sustainable.The baseband processing and storage resources should be sliced and orchestrated agilely to support multi radio access technology(multiRAT) .Also it is analyzed and demonstrated by different use cases to validate the benefits.The proposed v RAN reduces signaling overheads and service response time in the bearer establishment procedure.Concluded from the analyses and demonstrations,the NO Stack based v RAN could support multi-RAT convergence and flexible networking effectively.
基金supported by the National Natural Science Foundation of China under Grant No.60932005China and Europe Government Cooperation Projects of the Ministry of Science and Technology under Grant No.2010DFA11680the Tsinghua Sci-Tech Project under Grant No.2011THZ0
文摘This paper presents a universal platform "uSensing" to support smartphones to communicate with sensor nodes in Wireless Sensor Networks (WSNs).Since phones have different CPU processers and operating systems,it is a challenge to merge these heterogeneities and develop such a universal platform.In this paper,we design both hardware and software to support the "universal" feature of uSensing:1) "uSD" card:an IEEE 802.15.4 physical communication card with SD interface;2) "uSinkWare":a WSNs middleware running on smartphones.Integrated with uSD card and uSinkWare,phones become mobile data sinks to access into WSNs and parse messages from sensor nodes.We demonstrate the proposed uSensing platform in a commercial smartphone to connect with our WSNs testbed,and validate that the smartphone has the same WSNs functions as commercial fixed sink.Additionally,we evaluate the performance of uSensing platform through measuring phone's CPU load and power consumption,and analyze the performance of these metrics theoretically.The results suggest that the phone-based mobile sink has enough capability to serve as a mobile sink of WSNs and can work up to twenty hours due to low power consumption.
