Browsing by Author "Niu, Yong"
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Item Exploiting Device-to-Device Communications to Enhance Spatial Reuse for Popular Content Downloading in Directional mmWave Small Cells(IEEE Transactions on Vehicular Technology, 8/11/2015) Niu, Yong; Su, Li; Gao, Chuhan; Li, Yong; Jin, Depeng; Han, ZhuWith the explosive growth of mobile demand, small cells in millimeter-wave (mmWave) bands underlying macrocell networks have attracted intense interest from both academia and industry. MmWave communications in the 60-GHz band are able to utilize the huge unlicensed bandwidth to provide multiple Gb/s transmission rates. In this case, device-to-device (D2D) communications in mmWave bands should be fully exploited because there is no interference with the macrocell networks and higher achievable transmission rates. In addition, because there is less interference by directional transmission, multiple links including D2D links can be scheduled for concurrent transmissions (spatial reuse). With the popularity of content-based mobile applications, popular content downloading in the small cells needs to be optimized to improve network performance and enhance user experience. In this paper, we develop an efficient scheduling scheme for popular content downloading in mmWave small cells called popular content downloading scheduling (PCDS), where both D2D communications in close proximity and concurrent transmissions are exploited to improve transmission efficiency. In PCDS, a transmission path selection algorithm is designed to establish multihop transmission paths for users, aiming at better utilization of D2D communications and concurrent transmissions. After transmission path selection, a concurrent transmission scheduling algorithm is designed to maximize the spatial reuse gain. Through extensive simulations under various traffic patterns, we demonstrate that PCDS achieves near-optimal performance in terms of delay and throughput, as well as superior performance, compared with other existing protocols, particularly under heavy load. The impact of the maximum number of hops of transmission paths on its performance is also analyzed for a better understanding of the role of D2D communications.Item Exploiting Device-to-Device Communications to Enhance Spatial Reuse for Popular Content Downloading in Directional mmWave Small Cells(IEEE Transactions on Vehicular Technology, 8/11/2015) Niu, Yong; Su, Li; Gao, Chuhan; Li, Yong; Jin, Depeng; Han, ZhuWith the explosive growth of mobile demand, small cells in millimeter-wave (mmWave) bands underlying macrocell networks have attracted intense interest from both academia and industry. MmWave communications in the 60-GHz band are able to utilize the huge unlicensed bandwidth to provide multiple Gb/s transmission rates. In this case, device-to-device (D2D) communications in mmWave bands should be fully exploited because there is no interference with the macrocell networks and higher achievable transmission rates. In addition, because there is less interference by directional transmission, multiple links including D2D links can be scheduled for concurrent transmissions (spatial reuse). With the popularity of content-based mobile applications, popular content downloading in the small cells needs to be optimized to improve network performance and enhance user experience. In this paper, we develop an efficient scheduling scheme for popular content downloading in mmWave small cells called popular content downloading scheduling (PCDS), where both D2D communications in close proximity and concurrent transmissions are exploited to improve transmission efficiency. In PCDS, a transmission path selection algorithm is designed to establish multihop transmission paths for users, aiming at better utilization of D2D communications and concurrent transmissions. After transmission path selection, a concurrent transmission scheduling algorithm is designed to maximize the spatial reuse gain. Through extensive simulations under various traffic patterns, we demonstrate that PCDS achieves near-optimal performance in terms of delay and throughput, as well as superior performance, compared with other existing protocols, particularly under heavy load. The impact of the maximum number of hops of transmission paths on its performance is also analyzed for a better understanding of the role of D2D communications.Item Mobility-Aware Fog Computing in Dynamic Environments: Understandings and Implementation(IEEE Access, 11/27/2018) Waqas, Muhammad; Niu, Yong; Ahmed, Manzoor; Li, Yong; Jin, Depeng; Han, Zhuof the network, and nearer to end devices. Fog computing is not a counterfeit for cloud computing but a persuasive counterpart. However, the mobility of end users and/or fog nodes brings a major dilemma in the implementation of real-life scenarios. Therefore, we deliver the state-of-the-art research about mobility in fog computing. By identifying the mobility problems, requirements, and features of different proposals, we discover the open problems from subsisting studies and summarize the advantages of mobility for readers. This will help the researchers and developers avoid the current misapprehensions and capture the real-life scenarios, such as business, government, and education institutions. In spite of the extensive state-of-the-art research work, we also present the diverse mobility factors to investigate the correlation between dynamic nodes with fog nodes in order to accomplish better successful tasks. We conceive that the investigations of mobility factors in the fog computing will furnish the novel perspective on not only dynamic connections but also network dynamics. To revolutionize the follow-up research, we distinguish and foreground futurity directions concerning real-life scenarios of people and vehicles in a dynamic fog environment.Item Resource Allocation for Device-to-Device Communications in Multi-Cell Multi-Band Heterogeneous Cellular Networks(IEEE Transactions on Vehicular Technology, 3/8/2019) Chen, Yali; Ai, Bo; Niu, Yong; He, Ruisi; Zhong, Zhangdui; Han, ZhuHeterogeneous cellular networks (HCNs) with millimeter wave (mm-wave) communications are considered as a promising technology for the fifth-generation mobile networks. Mm-wave has the potential to provide multiple gigabit data rate due to the broad spectrum. Unfortunately, additional free space path loss is also caused by the high carrier frequency. On the other hand, mm-wave signals are sensitive to obstacles and more vulnerable to blocking effects. To address this issue, highly directional narrow beams are utilized in mm-wave networks. Additionally, device-to-device (D2D) users make full use of their proximity and share uplink spectrum resources in HCNs to increase the spectrum efficiency and network capacity. Toward the caused complex interferences, the combination of D2D-enabled HCNs with small cells densely deployed and mm-wave communications poses a big challenge to the resource allocation problems. In this paper, we formulate the optimization problem of D2D communication spectrum resource allocation among multiple micro-wave bands and multiple mm-wave bands in HCNs. Then, considering the totally different propagation conditions on the two bands, a heuristic algorithm is proposed to maximize the system transmission rate and approximate the solutions with sufficient accuracies. Compared with other practical schemes, we carry out extensive simulations with different system parameters, and demonstrate the superior performance of the proposed scheme. In addition, the optimality and complexity are simulated to further verify effectiveness and efficiency.Item Resource Allocation for Device-to-Device Communications Underlaying Heterogeneous Cellular Networks Using Coalitional Games(IEEE Transactions on Wireless Communications, 4/16/2018) Chen, Yali; Ai, Bo; Niu, Yong; Guan, Ke; |Han, ZhuHeterogeneous cellular networks (HCNs) with millimeter wave (mm-wave) communications included are emerging as a promising candidate for the fifth generation mobile network. With highly directional antenna arrays, mm-wave links are able to provide several Gbps transmission rate. However, mm-wave links are easily blocked without line of sight. On the other hand, device to device (D2D) communications have been proposed to support many content-based applications and need to share resources with users in HCNs to improve spectral reuse and enhance system capacity. Consequently, an efficient resource allocation scheme for D2D pairs among both mm-wave and the cellular carrier band is needed. In this paper, we first formulate the problem of the resource allocation among mm-wave and the cellular band for multiple D2D pairs from the view point of game theory. Then, with the characteristics of cellular and mm-wave communications considered, we propose a coalition formation game to maximize the system sum rate in statistical average sense. We also theoretically prove that our proposed game converges to a Nash-stable equilibrium and further reaches the near-optimal solution with fast convergence rate. Through extensive simulations under various system parameters, we demonstrate the superior performance of our scheme in terms of the system sum rate compared with several other practical schemes.