• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.7
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• pp.1802-1814
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• 2012

In order to guide users to select the most optimal access network in heterogeneous wireless networks, a network selection algorithm is proposed which is designed based on multi-objective discrete particle swarm optimization (Multi-Objective Discrete Particle Swarm Optimization, MODPSO). The proposed algorithm keeps fast convergence speed and strong adaptability features of the particle swarm optimization. In addition, it updates an elite set to achieve multi-objective decision-making. Meanwhile, a mutation operator is adopted to make the algorithm converge to the global optimal. Simulation results show that compared to the single-objective algorithm, the proposed algorithm can obtain the optimal combination performance and take into account both the network state and the user preferences.

• Journal of Satellite, Information and Communications
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• v.11 no.3
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• pp.123-126
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• 2016

Energy efficiency in heterogeneous network is considered as one of the main issues when deploying the wireless sensor network. In heterogeneous network, the random distribution of initial energy at each node could lead to an instability of the network. Therefore, a resonable policy must be established in order to maintain the fairness in energy consumption and extend the working time of each node in the network. In this paper, we evaluate the performance of the distributed clustering protocol (DCP) in heterogeneous network on different scenarios. Simulation results are compared with the results of a LEACH protocol in a heterogeneous network. In addition, the performance of system in heterogeneous network are also compared with the homogeneous network to illustrate the effect of imbalance in the initial energy on the life time of each node in the system. The result illustrates that the DCP protocol demonstrates better performance than LEACH protocol in both the heterogeneous and the homogeneous networks.

• Journal of Internet Computing and Services
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• v.9 no.6
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• pp.63-72
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• 2008

Recent heterogeneous network management researches on information security, however, deal only with simple management using PKI and could not sufficiently address the different kinds of security problems that could arise in a heterogeneous network. Thus, various security requirements should first be satisfied and a security management protocol should first be developed to achieve a secure heterogeneous network. Hence, in this paper, various secure and effective heterogeneous network management that address security issues, which were merely a consideration in existing studies, are proposed. The proposed scheme for the protection of the user privacy is the central object and static middle objects of the process used to mutual authentication, also if communication between users is required 1-out-2 oblivious transfer to communicate by using secret communication, as well as the effectiveness and security conscious approach. Specially The proposed scheme is designed to enhance security and efficiency related to various services required in heterogeneous network, based on the reliable peripheral devices for TTP. Using Mobile device, which has been applied to electronic commerce transactions in existing schemes, this study also proposed an appropriate management scheme that is suitable for a dynamic environment and setting a temporary group to provide various services.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.11
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• pp.5276-5298
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• 2019

Internet of Things (IoT) based sensor networks have gained unprecedented popularity in recent years. With the exponential explosion of the objects (sensors and mobiles), the bandwidth and the speed of data transmission are dwarfed by the anticipated emergence of IoT. In this paper, we propose a novel heterogeneous IoT model integrated the power line communication (PLC) and WiFi network to increase the network capacity and cope with the rapid growth of the objects. We firstly propose the mean transmission delay calculation algorithm based the 3D Markov chain according to the multi-priority of the objects. Then, the attractor selection algorithm, which is based on the adaptive behavior of the biological system, is exploited. The combined the 3D Markov chain and the attractor selection model, named MASM, can select the optimal path adaptively in the heterogeneous IoT according to the environment. Furthermore, we verify that the MASM improves the transmission efficiency and reduce the transmission delay effectively. The simulation results show that the MASM is stable to changes in the environment and more applicable for the heterogeneous IoT, compared with the other algorithms.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.10
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• pp.4662-4677
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• 2018

The dynamic opportunistic device-to-device (DO-D2D) network will frequently emerge in the fifth generation (5G) wireless communication due to high-density and fast-moving mobile devices. In order to improve the Quality of Experience (QoE) of users with different computing capacity devices in the DO-D2D network, in this paper, we focus on the study of how to reduce the packets retransmission delay and satisfy heterogeneous devices. To select as many devices as possible to transmit simultaneously without interference, the concurrent transmitters-selecting algorithm is firstly put forward. It jointly considers the number of packets successfully received by each device and the device's connectivity. Then, to satisfy different devices' demands while primarily ensuring the base-layer packets successfully received by all the devices, the layer-cooperation instantly decodable network coding is presented, which is used to select transmission packets combination for each transmitter. Simulation results illustrate that there is an appreciable retransmission delay gain especially in the poor channel quality network compared to the traditional base-station (BS) retransmission algorithm. In addition, our proposed algorithms perform well to satisfy the different demands of users with heterogeneous devices.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.4
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• pp.51-58
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• 2017

This paper deals with the improvement of cluster head selection method in L-SEP for heterogeneous nodes among hierarchical routing protocols of wireless sensor network. Wireless sensor networks are classified into homogeneous and heterogeneous network. In heterogeneous network, SEP, L-SEP are mainly used because cluster head selection probability is different depending on node type. But, since protocol based on SEP has different cluster head selection probabilities depending on the node type, clusters that transmit data inefficiently can be formed. to improve this, it is necessary to select the cluster head that minimizes the transmission distance of member node and the cluster head. Therefore, we propose a protocol that improve the cluster head selection method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.79-81
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• 2009

NEMO is technique to support mobility of a network, not a node, and ensures session continuity for all the nodes in a Mobile Network. However NEMO basic support protocol causes high handover latency, thus it is incongruent real-time services such as VoIP. One of schemes to reduce handover latency is FNEMO. FNEMO that combines conventional NEMO and FMIPv6, reduces latency during the handover, thus it supports fast handover. In this paper, we compare/analyze handover of FNEMO in heterogeneous/homogeneous network, and propose schemes to reduce handover latency.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.11
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• pp.4611-4624
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• 2020

Future network scenario will be a heterogeneous wireless network environment composed of multiple networks and multimode terminals (MMT). Seamless switching and optimal connectivity for MMT among different networks and different services become extremely important. Here, a vertical handoff algorithm combined an improved entropy weighting method based on grey relational analysis (GRA) is proposed. In which, the improved entropy weight method is used to obtain the objective weights of the network attributes, and GRA is done to rank the candidate networks in order to choose the best network. Through simulation and comparing the results with other vertical handoff decision algorithms, the number of handoffs and reversal phenomenon are reduced with the proposed algorithm, which shows a better performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.5
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• pp.2243-2257
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• 2019

A heterogeneous cellular network (HCN) is useful to increase the spectral and energy efficiency of wireless networks and to reduce the traffic load from the macro cell. The performance of the secondary user equipment (SUE) is affected by interference from the eNodeB (eNB) in a macro cell. To decrease the interference between the macro cell and the small cell, allocating resources properly is essential to an HCN. This study considers the scenario of a software-defined heterogeneous cellular network and performs the resource allocation process. First, we show the system model of HCN and formulate the optimization problem. The optimization problem is a complex process including power and frequency resource allocation, which imposes an extremely high complexity to the HCN. Therefore, a hierarchical resource allocation scheme is proposed, which including subchannel selection and a particle swarm optimization (PSO)-based power allocation algorithm. Simulation results show that the proposed hierarchical scheme is effective in improving the system capacity and energy efficiency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.8
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• pp.499-509
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• 2014

In this paper, we propose that a FDL(Freeze DeadLine) Algorithm to solve handover problems in heterogeneous wireless networks. Many previous studies concentrated on low level layer to solve handover problems. In this paper, however, we concentrate on high level handover problems such as network layer and transport layer. We analyze handover's problems of transport layer in Heterogeneous wireless network, propose the FLD algorithm for better performance than others studies. The Proposed method is analyzed by theoretical frames and we verify that the propose method using the NS-2(Network Simulation - 2).