• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.3
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• pp.430-435
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• 2022

In this paper, we consider the non-orthogonal multiple access (NOMA) technique in the heterogeneous network (HetNET) consisting of a single macro base station (BS) and multiple small BSs, where the perfect successive interference cancellation is assumed for the NOMA signals. In this paper, we propose a deep learning-based user association and power allocation scheme to maximize the data rate in the NOMA-based HetNET. In particular, the proposed scheme includes the deep neural network (DNN)-based user association process for load balancing and the DNN-based power allocation process for data-rate maximization. Through the simulation assuming path loss and Rayleigh fading channels between BSs and users, the performance of the proposed scheme is evaluated, and it is compared with the conventional maximum signal-to-interference-plus-noise ratio (Max-SINR) scheme. Through the performance comparison, we show that the proposed scheme provides better sum rate performance than the conventional Max-SINR scheme.

• Journal of Communications and Networks
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• v.18 no.1
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• pp.112-122
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• 2016

Cognitive radio (CR) is considered an attractive technology to deal with the spectrum scarcity problem. Multi-radio access technology (multi-RAT) can improve network capacity because data are transmitted by multiple RANs (radio access networks) concurrently. Thus, multi-RAT embedded in a cognitive radio network (CRN) is a promising paradigm for developing spectrum efficiency and network capacity in future wireless networks. In this study, we consider a new CRN model in which the primary user networks consist of heterogeneous primary users (PUs). Specifically, we focus on the energy-efficient resource allocation (EERA) problem for CR users with a special location coverage overlapping region in which heterogeneous PUs operate simultaneously via multi-RAT. We propose a two-tier crossover genetic algorithm-based search scheme to obtain an optimal solution in terms of the power and bandwidth. In addition, we introduce a radio environment map to manage the resource allocation and network synchronization. The simulation results show the proposed algorithm is stable and has faster convergence. Our proposal can significantly increase the energy efficiency.

• International Journal of Advanced Culture Technology
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• v.3 no.2
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• pp.77-86
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• 2015

In this paper there is an overview of some standards and security models which are implemented in such an IP-based and heterogeneous networks and we also present some security models in an open environment and finally we obtain that as a result of the nature of 4G networks there are still more security holes and open issues for expert to notice. Our survey shows that a number of new security threats to cause unexpected service interruption and disclosure of information will be possible in 4G due mainly to the fact that 4G is an IP-based, heterogeneous network. Other than that, it tells about the security issues and vulnerabilities present in the above 4G standards are discussed. Finally, we point to potential areas for future vulnerabilities and evaluate areas in 4G security which warrant attention and future work by the research and advanced technology industry.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.350-351
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• 2011

In this paper we study the impact of heterogeneous round trip times on multipath TCP (MPTCP) performance via analysis the fluid model and simulation. Using parameter 'a' in MPTCP can alleviate poor performance due to divergent RTTs between paths. Moreover, divergent RTIs in MPTCP can affect response to changes in the network conditions.

• 연구논문집
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• s.26
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• pp.69-84
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• 1996

Regional INformation Network Center has constructed integrated VAN among the heterogeneous computers and core technical information database for machinery & materials-oriented enterprises in the Changwon & Masan Industrial complex. As the result of RINNet project, regional industrial companies can take advantage of getting core technical information for developing new technology and strengthening competitive power. Accordingly, RINNet(Regional INformation Network for science & technology) makes regional industrial companies possible to collect, acquire and use technical information rapidly and motivates regional society to form the rapid technical interchange system and cooperative system among industrial-educational-institutal complex.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.8
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• pp.3958-3971
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• 2016

With Internet of Things (IoT) technology, home environment becomes smarter than ever. Not only smart devices such as smart phone or smart TV, but also various IoT devices including sensor, smart thermostat, and smart scale has now become very common on the market. These devices have connectivity to the Internet, so that user can read data from the device or control the device using Internet technology. However, due to diversity of smart home requirements, device collaboration in smart home remains a challenging task still. Usually smart home is built with various technologies to fulfill its own purpose, and these purposes cover very wide area from controlling low-power sensor devices to controlling high-performance devices like smart TV and smart phone. This variety of smart home requirements makes smart home very complicated due to mixed network architecture, protocol and technology. In this paper, a framework to enable managing and collaborating heterogeneous IoT devices in smart home environment is proposed. Several programming models are defined in the proposed framework to make application development for heterogeneous devices more intuitive. The proposed framework has been implemented as a web service, and a case study with real-world smart home IoT devices is presented.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.7B
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• pp.583-594
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• 2006

WPANs (Wireless personal area networks) have developed as various forms according to requirements such as data rate, coverage, subscriber volume, and supported mobile velocity. And mobile device with multiple network interfaces is very common. To make these multi-mode devices communicate with any WPAN device at anytime, anywhere, the framework for heterogeneous wireless networks is essential. Therefore, we propose the integration framework to converge heterogeneous WPANs. In this paper, we explain the requirements and detailed design of our framework, and then present the emulation test results.

• Journal of the Korea Society of Computer and Information
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• v.15 no.11
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• pp.125-133
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• 2010

A policy based resource management framework is proposed, that supports the optimal QoS by applying resources management function which is changed according to the status of mobile terminal and heterogeneous connections to hand-over process of mobile terminals based on heterogeneous network. To assess the performance of policy based resource management framework proposed in this thesis, in case of applying weighted policy for selecting optimal cell in hand-over occurring among duplicated heterogeneous connections, the transmission delay was remarkably enhanced as the number of multimedia sessions increased. This means, in case of QoS deterioration of multimedia session occurring in service connection, hand-over was executed with the optimal connection.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.7
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• pp.829-836
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• 2019

IoT devices are widely used in network construction and are increasing. If necessary, heterogeneous IoT devices are used for data transmission. This paper proposes to prevent the method of data loss due to differences in throughput when the local network is constructed by Bluetooth 5 and long range network does by LoRa(Long Range). Data loss occur when the data transmits through LoRa, due to the throughputs of Bluetooth 5 faster than that of LoRa. The prevent method proposed by this paper can apply not only Bluetooth 5 and LoRa but heterogeneous IoT devices and expect to prevent data loss due to differences in throughput between heterogeneous IoT devices. Also, this paper shows the simulation result by applying the proposed avoid method. In this paper, two way to the preventive method shows the data transmission ratio and amount of memory that of necessity.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.7
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• pp.51-59
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• 1996

The current network environment is composed of heterogeneous H/W and S/W resources. Integrating CSCW applications in such heterogeneous environments is highly complex. This paper describes the design and implementation of ASS (application sharing server) which supprot sharing of a single application between different operating systems. The ASS supports cooperative work among user group using its own window system (X-windwo or MS-windwos). We adopted improved managing heavy-weight data. ASS also provides development environment for vaious groupware application.