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arXiv 2017年

作者： Yu, Liang Jiang, Tao Zou, Yulong Key Laboratory of Broadband Wireless Communication and Sensor Network Technology of Ministry of Education Nanjing University of Posts and Telecommunications Nanjing210003 China Wuhan National Laboratory for Optoelectronics School of Electronics Information and Communications Huazhong University of Science and Technology Wuhan430074

—In this paper, we investigate the problem of minimizing the sum of energy cost and thermal discomfort cost in a long-term time horizon for a sustainable smart home with a Heating, Ventilation, and Air Conditioning (HVAC) load. Specifically, we first formulate a stochastic program to minimize the time average expected total cost with the consideration of uncertainties in electricity price, outdoor temperature, renewable generation output, electrical demand, the most comfortable temperature level, and home occupancy state. Then, we propose an online energy management algorithm based on the framework of Lyapunov optimization techniques without the need to predict any system parameters. The key idea of the proposed algorithm is to construct and stabilize four queues associated with indoor temperature, electric vehicle charging, and energy storage. Moreover, we theoretically analyze the feasibility and performance guarantee of the proposed algorithm. Extensive simulations based on real-world traces show the effectiveness of the proposed algorithm. Copyright © 2017, The Authors. All rights reserved.

关键词： Stochastic systems

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Fog-assisted operational cost reduction for cloud data centers

arXiv

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arXiv 2017年

作者： Yu, Liang Jiang, Tao Zou, Yulong Key Laboratory of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing210003 China Wuhan National Laboratory for Optoelectronics School of Electronics Information and Communications Huazhong University of Science and Technology Wuhan430074 China

In this paper, we intend to reduce the operational cost of cloud data centers with the help of fog devices, which can avoid the revenue loss due to wide-area network propagation delay and save network bandwidth cost by serving nearby cloud users. Since fog devices may not be owned by a cloud service provider, they should be compensated for serving the requests of cloud users. When taking economical compensation into consideration, the optimal number of requests processed locally by each fog device should be decided. As a result, existing load balancing schemes developed for cloud data centers can not be applied directly and it is very necessary to redesign a cost-ware load balancing algorithm for the fog-cloud system. To achieve the above aim, we first formulate a fog-assisted operational cost minimization problem for the cloud service provider. Then, we design a parallel and distributed load balancing algorithm with low computational complexity based on Proximal Jacobian Alternating Direction Method of Multipliers (PJ-ADMM). Finally, extensive simulation results show the effectiveness of the proposed algorithm. Copyright © 2017, The Authors. All rights reserved.

关键词： Fog

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Distributed real-time HVAC control for cost-efficient commercial buildings under smart grid environment

arXiv

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arXiv 2017年

作者： Yu, Liang Di Xie Jiang, Tao Zou, Yulong Wang, Kun Key Laboratory of Broadband Wireless Communication Sensor Network Technology of Ministry of Education Nanjing University of Posts and Telecommunications Nanjing210003 China Wuhan National Laboratory for Optoelectronics School of Electronics Information and Communications Huazhong University of Science and Technology Wuhan430074 China

In this paper, we investigate the problem of minimizing the long-term total cost (i.e., the sum of energy cost and thermal discomfort cost) associated with a Heating, Ventilation, and Air Conditioning (HVAC) system of a multizone commercial building under smart grid environment. To be specific, we first formulate a stochastic program to minimize the time average expected total cost with the consideration of uncertainties in electricity price, outdoor temperature, the most comfortable temperature level, and external thermal disturbance. Due to the existence of temporally and spatially coupled constraints as well as unknown information about the future system parameters, it is very challenging to solve the formulated problem. To this end, we propose a realtime HVAC control algorithm based on the framework of Lyapunov optimization techniques without the need to predict any system parameters and know their stochastic information. The key idea of the proposed algorithm is to construct and stabilize virtual queues associated with indoor temperatures of all zones. Moreover, we provide a distributed implementation of the proposed realtime algorithm with the aim of protecting user privacy and enhancing algorithmic scalability. Extensive simulation results based on real-world traces show that the proposed algorithm could reduce energy cost effectively with small sacrifice in thermal comfort. Copyright © 2017, The Authors. All rights reserved.

关键词： Smart power grids

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A TDMA Based Cooperative Communication MAC Protocol for Vehicular Ad Hoc networks

A TDMA Based Cooperative Communication MAC Protocol for Vehi...

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IEEE Vehicular technology Conference

作者： Tianjiao Zhang Qi Zhu Jiangsu Key Lab of Wireless Communications Key Lab on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education Nanjing University of Posts and Telecommunications

ISBN: (纸本)9781509016990

In a VANET (Vehicular Ad Hoc network), the collisions caused by vehicles' mobility lead to poor network performance, especially in high-density network. In order to increase the flexibility of communication, this paper presents a communication protocol with dynamic choosing relay node and automatic cooperative communication called VC-TDMA (Vehicular Cooperative TDMA). The nodes can choose the multi-hop relay nodes rationally and other idle nodes can provide cooperative communication automatically. Considering batch arrival data traffic, the buffer queue state of nodes in the network is numerical analyzed by Markov Chain. The simulation results show that VC-TDMA can improve the throughput of the network compared with the conventional TDMA protocol.

关键词： VANETs Markov Chain Cooperative Communication TDMA time division multiple access Markov chain cooperative communication V2V Communication protocols Ganglia Trunk Node network node Simulation results

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Optimal power allocation based on sum-throughput maximization for energy harvesting cognitive radio networks

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IOP Conference Series: Earth and Environmental Science 2017年第1期52卷

作者： Zhenwei Xie Qi Zhu The Key Wireless Laboratory of Jiangsu Province Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Laboratory on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education Jiangsu Nanjing 210003 China

In this study, an optimal power allocation algorithm by maximizing the sum-throughput in energy harvesting cognitive radio networks is proposed. Under the causality constraints of the harvested energy by solar radiation, electromagnetic waves and so on in the two secondary users (SUs), and the interference constraint in the primary user (PU), the sum-throughput maximization problem is formulated. The algorithm decomposes the interference threshold constraint to the power upper bounds of the two SUs. Then, the power allocation problems of the two SUs can be solved by a directional water-filling algorithm (DWA) with the power upper bounds, respectively. The paper gives the algorithm steps and simulation results, and the simulation results verify that the proposed algorithm has obvious advantages over the other two algorithms.

关键词：

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Power allocation and relay selection scheme based on system outage probability for energy-harvesting cooperative network

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Journal of communications 2016年第10期11卷 903-909页

作者： Hao, Wang Qi, Zhu The Key Wireless Laboratory of Jiangsu Province School of Telecommunication and Information Engineering Nanjing University of Posts and Telecommunications Nanjing210003 China Key Laboratory on Wideband Wireless Communications Sensor Network Technology of Ministry of Education Nanjing210003 China

A power allocation and single relay selection scheme is proposed to improve the outage performance for a wireless cooperative network with multiple energy-harvesting relay nodes. The optimization problem is formulated to minimize the system outage probability under the constraints of both relay joint maximum transmit power and individual energy limitation caused by energy-harvesting. By using Lagrange multiplier method and KKT (Karush-Kuhn-Tucker) conditions, the optimal transmit power of multi-relay can be solved. Taking into consideration that single relay is more feasible to implement in practical communication scenarios, a best relay can be selected by calculating the contribution factor of relay nodes. In addition, the lower bound of system outage probability is derived in this paper. Simulation results show that the proposed power allocation and single relay selection scheme can reduce system outage probability efficiently, and verify the conclusion of the lower bound of outage probability. © 2016 Journal of communications.

关键词： Cooperative communication

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A QoS-based channel allocation and power control algorithm for device-to-device communication underlaying cellular networks

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Journal of communications 2016年第7期11卷 624-631页

作者： Yu, Bao-Zhou Qi, Zhu The Key Wireless Laboratory of Jiangsu Province School of Telecommunication and Information Engineering Nanjing University of Posts and Telecommunications Nanjing210003 China Key Laboratory on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education NanjingJiangsu210003 China

In device-to-device (D2D) communication system, rational resource allocation can effectively reduce the interference between cellular users and D2D users. In this paper, based on the QoS requirement of cellular users and D2D users, we propose a channel allocation and power control optimization algorithm, which takes limit transmission power of each cellular user and total D2D users into consideration when maximizing the system capacity of total D2D users. We can achieve the candidate cellular users set of D2D users according to the minimum SINR requirement of D2D users. And then, the transmission power of cellular users and D2D users are optimized with Lagrange multiplier method, meanwhile we calculate the capacity of each D2D user by optimal power and allocate channel to the D2D pair, which has the maximum value of capacity. However, the optimal algorithm has a high complexity. We further propose a low complexity suboptimal algorithm, which allocates channel and controls power in different stages. Simulation results show that the proposed algorithms effectively improve the capacity of D2D users under the condition of guaranteeing the QoS of cellular users and the suboptimal algorithm greatly reduces the complexity compared with the optimal algorithm. © 2016 Journal of communications.

关键词： Resource allocation

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ACK-based adaptive backoff for random access protocols

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Science China(Information Sciences) 2015年第4期58卷 37-50页

作者： YANG Yang SONG GuanNan WEI Kun ZHANG WuXiong YOU XiaoHu Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai Research Center for Wireless Communications Key Laboratory of Wireless Sensor Network & Communication Chinese Academy of Sciences National Mobile Communications Research Laboratory Southeast University

In contention-based networks, ALOHA and CSMA are the most popular random access protocols,wherein a station transmits packets after a certain delay according to a particular backoff policy, such as binary exponential backoff(BEB). When a contention-based network is heavily loaded, system performance, in terms of transmission success rate and throughput, degrades dramatically under random backoff policies without considering the backoff choices of the neighborhood. To alleviate this problem, we propose and verify in this paper a highly efficient backoff policy, namely "ACK-based adaptive backoff "(AAB), which takes into account the total number of successful packet transmissions(with ACKs) among neighboring stations in determining a station’s subsequent backoff period before its next packet(re)transmission. By doing this, AAB can effectively reduce the overall packet collisions under heavy-loaded conditions, even with hidden-stations. On comparing with BEB and its modified policy, multiple increase linear decrease(MILD), AAB can achieve about 17% and10% performance gains of transmission success rate under CSMA protocol in a network with 20 stations with new packet arrival rate of 0.9, and 43% and 16% performance gains of energy efficiency respectively when the former two protocols reach their saturated points.

关键词： backoff policy contention-based networks medium access control(MAC) energy efficiency green communications

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A New Fragmentation Strategy for Video of HTTP Live Streaming

A New Fragmentation Strategy for Video of HTTP Live Streamin...

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International Conference on Mobile Ad-hoc and sensor networks, MSN

作者： Xiaorui Li Lei Wang Jingwu Cui Baoyu Zheng National Mobile Communications Research Laboratory Southeast University Nanjing China Key Lab of Broadband Wireless Communication and Sensor Network Technology (NUPT) Nanjing China

ISBN: (纸本)9781509056972

To achieve the flexible and efficient transmission of files in the video on demand system, this paper proposed a three-tier fragmentation strategy which provided a unfiled method of fragmentation for video of HTTP Live Streaming and large file. In order to prove the rationality of the three-tier fragmentation strategy, we compared it with the two layers fragmentation strategy and the fragmentation strategy of equal time. And the comparisons proved the superiority of three-tier fragmentation strategy.

关键词： Peer-to-peer computing IPTV Packet loss Video on demand Data communication

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Design of P2P Application Layer Protocol

Design of P2P Application Layer Protocol

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International Conference on Mobile Ad-hoc and sensor networks, MSN

作者： Yujie Ma Lei Wang Jingwu Cui Baoyu Zheng National Mobile Communications Research Laboratory Southeast University Nanjing China Network Technology (NUPT) Key Lab of Broadband Wireless Communication and Sensor Nanjing China

ISBN: (纸本)9781509056972

On the basis of studying the principle and application technology of P2P protocol, we design the private protocol of P2P application layer to meet the needs of P2P communication. This application layer protocol splits up video into three types of blocks in order to improve transmission efficiency. Besides, the protocol can be expanded when needed since there are some invalid bits in the state list.

关键词： Peer-to-peer computing Protocols Streaming media Authentication Servers Sockets Law

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