Performance Analysis and Optimization of TDMA Network With Wireless Energy Transfer

Niyato, Dusit,Ping Wang,Dong In Kim IEEE 2014 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS Vol.13 No.8

<P>With wireless energy transfer capability, network nodes can rely on the energy supplied wirelessly from a network hub or access point. As a result, there is no need for the nodes to replace or recharge their battery using any wire. This paper considers such a scenario and proposes the performance analysis and optimization framework for the network operating on a TDMA protocol with wireless energy transfer. We first present the analysis and optimization of an individual node in the network. The objective is to maximize the network utility defined in terms of throughput and the number of packets in the queue such that the packet loss probability is maintained below the threshold. We solve the optimization problem to obtain an optimal policy to operate the node (i.e, to be active or inactive). We next formulate the network optimization problem for the network hub. The problem can be solved to determine the amount of wireless energy transfer to meet the quality of service (QoS) requirements of all the nodes in the network. We reveal the special structure of the problem, that we can decompose the network optimization into small subproblems. These subproblems can be solved efficiently using the standard algorithm.</P>

Relay-centric radio resource management and network planning in IEEE 802.16j mobile multihop relay networks

Niyato, D.,Hossain, E.,Dong In Kim,Zhu Han IEEE 2009 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS Vol.8 No.12

<P>Mobile multihop relay (MMR) networks based on the IEEE 802.16j standard are able to extend the service area as well as improve the performance of mobile WiMAX networks. In this paper, we present a relay-centric hierarchical optimization model for jointly optimizing the radio resource management (RRM) and network planning for the relay stations in MMR networks. We consider an in-band relaying system. For a relay station, the RRM problem deals with optimizing the amount of bandwidth reserved from the base station and admission control for the mobile subscriber stations (MSSs) using relay-based transmissions so that the utility of a relay station is maximized. A Markov decision process (MDP) model is formulated to obtain the short-term optimal action of a relay station. Based on the optimal action of each relay station, the network planning problem is solved for a group of relay stations by optimizing the relay placement and base station selection over a longer period of time considering uncertainties in user mobility and traffic load in the network. A chance-constrained assignment problem (CCAP) is formulated to obtain the optimal decisions to maximize the total utility of relay stations under the probabilistic constraint on the total bandwidth usage of the base stations. Numerical results show that the proposed scheme outperforms a static scheme. The proposed radio resource management and network planning framework will be useful for design and optimization of multihop cellular wireless networks in general.</P>

Performance Modeling and Analysis of Heterogeneous Machine Type Communications

Niyato, Dusit,Ping Wang,Dong In Kim IEEE 2014 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS Vol.13 No.5

<P>With the pervasiveness of wireless devices, machine-to-machine (M2M) communications or machine-type-communications (MTC) is emerging to support data transfer among devices without human interaction. In this paper, we introduce a tractable queueing model for performance modeling and analysis for heterogeneous MTC. We then demonstrate versatile applications of the proposed queueing model. Firstly, we use the queueing model to study the coexistence between M2M communications of MTC devices and human-to-human (H2H) communications in the same networks. We also consider more sophisticated settings, where the MTC user equipments (UEs) are able to perform the transmission to the macro Evolved Node B (eNodeB) or small-cell eNodeB, or perform the relay transmission. In addition, we extend our study to analyze the eNodeB selection and coalition formation for relay transmission when MTC UEs coexist with H2H UEs. In this case, we formulate the non-transferable utility (NTU) coalitional game to model the eNodeB selection and coalition formation for relay transmission. The performance evaluation reveals some interesting results. For example, the throughput of MTC UEs can be improved when the MTC UEs spend more time inactive due to lower contention in the network, compared with the case when the MTC UEs are mostly active.</P>

Economics of Internet of Things: an information market approach

Niyato, Dusit,Lu, Xiao,Wang, Ping,Kim, Dong In,Han, Zhu IEEE 2016 IEEE wireless communications Vol.23 No.4

<P>Internet of Things (IoT) has been proposed to be a new paradigm of connecting devices and providing services to various applications, e.g., transportation, energy, smart cities, and health care. In this paper we focus on an important issue, i.e., the economics of IoT, that can have a great impact on the success of IoT applications. In particular, we adopt and present the information economics approach with its applications in IoT. We first review existing economic models developed for IoT services. Then we outline two important topics of information economics that are pertinent to IoT, i.e., the value of information and proper pricing of information. Finally, we propose a game theoretic model to study the price competition of IoT sensing services. Perspectives on future research directions to apply information economics to IoT are discussed.</P>

Joint admission control and antenna assignment for multiclass QoS in spatial multiplexing MIMO wireless networks

Niyato, D.,Hossain, E.,Dong Kim IEEE 2009 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS Vol.8 No.9

<P>We consider the problem of quality-of-service (QoS) provisioning for multiple traffic classes in a MIMO wireless network. This QoS provisioning is posed as a radio resource management (RRM) problem at a wireless node (e.g., a wireless mesh router) with multiple antennas. We decompose this RRM problem into two tractable subproblems, namely, the antenna assignment and the admission control problems. The objective of antenna assignment is to minimize the weighted packet dropping probability for the different traffic classes under constrained packet delay. The objective of admission control is to maximize the revenue of the wireless node gained from the ongoing connections for different traffic classes under constrained connection blocking probability and average per-connection throughput. The decision of antenna assignment is made in a short-term basis (e.g., for every packet transmission interval) while that of admission control is made in a long-term basis (i.e., when a connection arrives). Constrained Markov decision process (CMDP) models are formulated to obtain the optimal decisions on antenna assignment and admission control. To provide efficient channel utilization, the RRM framework considers adaptive modulation at the physical layer which exploits channel state information. Performance evaluation results show that this joint antenna assignment and admission control framework can provide class-based service differentiation while satisfying both the connection-level and packet-level QoS requirements.</P>

Mobile Energy Sharing Networks: Performance Analysis and Optimization

Niyato, Dusit,Ping Wang,Dong In Kim,Saad, Walid,Zhu Han IEEE 2016 IEEE Transactions on Vehicular Technology VT Vol.65 No.5

<P>Energy is a scarce resource in wireless communications and mobile networking. In this paper, a novel concept of mobile energy sharing networks is proposed to enhance the energy usage of wireless networks. In such networks, mobile users can share energy with one another when they move and meet, thus minimizing the chances of ending up with insufficient energy for their consumption. This concept is similar to the notion of opportunistic mobile social networks in which the users can share information when they travel and encounter each other. To optimize the operation of the proposed network, a performance analysis and optimization framework tailored toward mobile energy sharing networks is developed. This framework has two main components. The first component allows obtaining the optimal energy sharing policy between mobile users who agree to share energy (i.e., a pair of matched users). To obtain this optimal policy, a stochastic optimization problem is formulated while taking into account the mobility and energy levels of the users' batteries. The second component of the proposed framework is to determine stable user matching for energy sharing. The user will find another user with whom to share energy. The policy obtained from the first component is applied such that the matched users achieve the minimum energy outage probability. An extensive performance evaluation of the proposed mobile sharing networks and framework is conducted in order to highlight their potential benefits.</P>

Smart data pricing models for the internet of things: a bundling strategy approach

Niyato, Dusit,Dinh Thai Hoang,Nguyen Cong Luong,Ping Wang,Dong In Kim,Zhu Han IEEE 2016 IEEE network Vol.30 No.2

<P>The Internet of Things (IoT) has emerged as a new paradigm for the future Internet. In IoT, devices are connected to the Internet and thus are a huge data source for numerous applications. In this article, we focus on addressing data management in IoT through using a smart data pricing (SDP) approach. With SDP, data can be managed flexibly and efficiently through intelligent and adaptive incentive mechanisms. Moreover, data is a major source of revenue for providers and partners. We propose a new pricing scheme for IoT service providers to determine the sensing data buying price and IoT service subscription fee offered to sensor owners and service users, respectively. Additionally, we adopt the bundling strategy that allows multiple providers to form a coalition and offer their services as a bundle, attracting more users and achieving higher revenue. Finally, we outline some important open research issues for SDP and IoT.</P>

Wireless Powered Communication Networks: Research Directions and Technological Approaches

Niyato, Dusit,Kim, Dong In,Maso, Marco,Han, Zhu IEEE 2017 IEEE wireless communications Vol.24 No.6

<P>Current wireless and cellular networks are destined to undergo a significant change in the transition to the next generation of network technology. The so called wireless powered communication network (WPCN) has been recently emerging as a promising candidate for achieving the target performance of future networks. According to this paradigm, nodes in a WPCN can be equipped with hardware capable of harvesting energy from wireless signals, that is, their battery can be ubiquitously replenished without physical connections. Recent technological advances in the field of wireless power harvesting and transfer are providing strong evidence of the feasibility of this vision, especially for low-power devices. The future deployment of WPCN is more and more concretely foreseen. The aim of this article is therefore to provide a comprehensive review of the basics and backgrounds of WPCN, current major developments, and open research issues. In particular, we first give an overview of WPCN and its structure. We then present three major advanced approaches whose adoption could increase the performance of future WPCN: backscatter communications with energy harvesting; duty-cycle based energy management; and transceiver design for self-sustainable communications. We discuss implementation perspectives and tools for WPCN. Finally, we outline open research problems for WPCN.</P>

Ambient Backscatter Assisted Wireless Powered Communications

Lu, Xiao,Niyato, Dusit,Jiang, Hai,Kim, Dong In,Xiao, Yong,Han, Zhu IEEE 2018 IEEE wireless communications Vol.25 No.2

<P>Ambient backscatter communication technology has been introduced recently, and is quickly becoming a promising choice for self-sustainable communication systems, as an external power supply or a dedicated carrier emitter is not required. By leveraging existing RF signal resources, ambient backscatter technology can support sustainable and independent communications and consequently open up a whole new set of applications that facilitate Internet of things (IoT). In this article, we study an integration of ambient backscatter with wireless powered communication networks (WPCNs). We first present an overview of backscatter communication systems with an emphasis on the emerging ambient backscatter technology. Then we propose a novel hybrid transmitter design by combining the advantages of both ambient backscatter and wireless powered communications. Furthermore, in the cognitive radio environment, we introduce a multiple access scheme to coordinate hybrid data transmissions. The performance evaluation shows that the hybrid transmitter outperforms traditional designs. In addition, we discuss open issues related to ambient backscatter networking.</P>

Dynamic Coalition Formation for Network MIMO in Small Cell Networks

Guruacharya, Sudarshan,Niyato, Dusit,Bennis, Mehdi,Dong In Kim IEEE 2013 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS Vol.12 No.10

<P>In this paper, we apply the concepts of network multiple-input-multiple-output (MIMO) to small cell networks. To do so, the issue of imperfect channel state information (CSI) at the transmitter is considered when frequency-division duplexing is used, for which the feedback channel is limited. We first introduce a regret based learning approach to optimize the transmit beamforming parameters for the cases when the feedback channel is temporarily unavailable during deep fades. We then propose a coalition formation game model to cluster the small cell base stations so that they can perform cluster-wise joint beamforming. We take the \tit{recursive core} as the solution concept of the coalition formation game. To obtain the recursive core, we first consider a typical merge-split algorithm. However, we show that this algorithm can be unstable. Alternatively, we adopt the merge-only algorithm which guarantees the formation stability and show that its outcome belongs to the recursive core. Finally, we analyze the average number and the average size of coalitions that can form during such a coalition formation process. Numerical simulations are given to illustrate the behavior of the coalition formation among small cell base stations.</P>