• Electronics and Telecommunications Trends
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• v.28 no.6
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• pp.1-12
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• 2013

미래 데이터 트래픽은 유선에서 무선으로 트래픽의 비중이 증가하고 있으며 데이터 트래픽의 규모도 급격히 증가될 것으로 예측되고 있다. 데이터 트래픽을 효과적으로 수용하기 위하여 단일한 전송 기술을 이용하는 방식 보다는 다양한 유무선 전송 기술을 기반으로 효과적으로 다양한 유무선 자원을 제어하고 상황에 따라 최적의 전송 기술을 적용함으로써 제한된 유무선 자원을 효율적으로 이용하는 기술이 필요하다. 미래 통신 네트워크는 다양한 액세스 망을 통합 관리함으로써 망구축 비용 및 운영비용을 절감하고 효과적으로 망 자원을 이용하며 새로운 요구사항을 가지는 신규 서비스에 적절히 대응하기 위하여 유연하고 지능화된 유무선 융합 네트워크 구조로 발전되어야 한다. 본 문서에서는 유무선 융합 네트워크 기술을 중심으로 지금까지 진행된 융합 기술에 대해 간단히 살펴보고 유럽을 중심으로 현재 연구되고 있는 유무선 융합 기술에 대하여 설명한다. 그리고, 2020년의 1,000배 트래픽을 수용하기 위한 5G 모바일 코어망의 요구사항에 대하여 살펴 본다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.9
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• pp.4242-4263
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• 2017

Multi-User Multiple-Input Multiple-Output (MU-MIMO) technology has recently attracted significant attention from academia and industry because of it is increasingly important role in improving networks' capacity and data rate. Moreover, MU-MIMO systems for the Fifth Generation (5G) have already been researched. High Quality of Service (QoS) and efficient operations at the Medium Access Control (MAC) layer have become key requirements. In this paper, we propose a downlink MU-MIMO MAC protocol based on adaptive Channel State Information (CSI) feedback (called MMM-A) for Wireless Local Area Networks (WLANs). A modified CSMA/CA mechanism using new frame formats is adopted in the proposed protocol. Specifically, the CSI is exchanged between stations (STAs) in an adaptive way, and a packet selection strategy which can guarantee a fairer QoS for scenarios with differentiated traffic is also included in the MMM-A protocol. We then derive the expressions of the throughput and access delay, and analyze the performance of the protocol. It is easy to find that the MMM-A protocol outperforms the commonly used protocols in terms of the saturated throughput and access delay through simulation and analysis results.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.5
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• pp.891-898
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• 2022

Along with global interest, drones are expanding the base of utilization such as transportation of goods, forest protection, and safety management, and cluster flights are being applied in various fields such as military operations and environmental monitoring. Currently, specialized networks such as e-UM 5G for services in specific industries are being established in Korea. In this regard, drone systems are also moving to establish specialized networks to provide services that are fused with AI and autonomous flight. As drones converge with various services, various security threats in various environments are also subordinated, and in response, requirements and guidelines for drone security are being prepared in Korea. In this paper, we propose a technology method for peer identification and safe information provision between cluster flight drones by utilizing a cryptographic module equipped with wireless LAN and quantum entropy-based random number generator in a cluster flight system and a mobile communication network such as e-UM 5G.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.5
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• pp.1369-1389
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• 2024

In the era of 6G, the rapid increase in communication data volume poses higher demands on traditional channel estimation techniques and those based on deep learning, especially when processing large-scale data as their computational load and real-time performance often fail to meet practical requirements. To overcome this bottleneck, this paper introduces quantum computing techniques, exploring for the first time the application of Quantum Generative Adversarial Networks (QGAN) to broadband channel estimation challenges. Although generative adversarial technology has been applied to channel estimation, obtaining instantaneous channel information remains a significant challenge. To address the issue of instantaneous channel estimation, this paper proposes an innovative QGAN with a dual-module design in the generator. The adversarial loss function and the Mean Squared Error (MSE) loss function are separately applied for the parameter updates of these two modules, facilitating the learning of statistical channel information and the generation of instantaneous channel details. Experimental results demonstrate the efficiency and accuracy of the proposed dual-module QGAN technique in channel estimation on the Pennylane quantum computing simulation platform. This research opens a new direction for physical layer techniques in wireless communication and offers expanded possibilities for the future development of wireless communication technologies.

• Journal of Information Technology Applications and Management
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• v.17 no.2
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• pp.207-223
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• 2010

Mobile banking is a subset of electronic banking which underlies not only the determinants of the banking business but also the special conditions of mobile commerce. Nowadays wireless networks are being evolved and diversified. In this situation The wireless e-commerce is in the limelight on new profits of Carriers. Especially from current year when Carriers in domestic plans to provide the services using 2.5G networks the service providers choose wireless e-commerce as the main parts of wireless internet strategy and will provide a various of services. Because of this situation, the importance of mobile billing service is being emphasized. This paper searches the definition and service types of mobile banking, and suggests status and prospects of domestic mobile banking. We suggest the basic direction, the stage of development and functions of services by analyzing the cases of Nonghyup's. Finally we derive the critical factors from those and suggest the effect of introduction and the direction of development. From the customer perspective, mobile banking has many strengths. For example, it allows that all customers access banking service at anytime, anywhere more easily than telephone banking or pc banking. And it reduces the time and the effort for using the service. It enables the company to make a business against global customers. On the other hand, from the company perspective, it has a lot of potential that affect market share and reduce the costs of human and material resources which used to operate and support branches. However, it needs many efforts to reach at the stage of completion. And We will have to solve the problems that develop many contents, expend the range of services and raise the service convenience.

• ETRI Journal
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• v.42 no.5
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• pp.643-657
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• 2020

Sixth generation will exploit satellite, aerial, and terrestrial platforms jointly to improve radio access capability and unlock the support of on-demand edge cloud services in three-dimensional (3D) space, by incorporating mobile edge computing (MEC) functionalities on aerial platforms and low-orbit satellites. This will extend the MEC support to devices and network elements in the sky and forge a space-borne MEC, enabling intelligent, personalized, and distributed on-demand services. End users will experience the impression of being surrounded by a distributed computer, fulfilling their requests with apparently zero latency. In this paper, we consider an architecture that provides communication, computation, and caching (C3) services on demand, anytime, and everywhere in 3D space, integrating conventional ground (terrestrial) base stations and flying (non-terrestrial) nodes. Given the complexity of the overall network, the C3 resources and management of aerial devices need to be jointly orchestrated via artificial intelligence-based algorithms, exploiting virtualized network functions dynamically deployed in a distributed manner across terrestrial and non-terrestrial nodes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.7
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• pp.1329-1345
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• 2011

After the 9.11 terror attack, lawful Interception (LI) has emerged as an important tool for anti-terrorist activity. Law enforcement agents and administrative government bodies effectively monitor suspicious target users of permanent IP-based network devices by LI in Packet Data Networks (PDNs). However, it is difficult to perform LI in monitoring migrating users from a location to another, who change their IPs due to the proliferation of portable Internet devices enabling 3G IP Multimedia Subsystems (IMS). The existing, manual handover technique in 3G IMS makes it even more difficult to continue the LI activities due to time-lag reissuance of LI authority warrants when the target users move to a new LI jurisdiction via a roaming service. Our proposed model is a seamless LI handover mechanism in 3G IMS to support mobility detection of the target users. The LI warrants are transferred to the new LI agent automatically with the target users when they move to a new LI jurisdiction. Thus, time-lag human intervention of reissuance of the LI warrants is removed and enables the LI authorities to continue monitoring. In the simulation of our proposed mechanism, the quality of lawful interception achieves a mean score of over 97.5% out of the possible 100% maximum score, whereas the quality of the existing mechanism has a mean score of 22.725%.

• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.601-606
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• 2020

In this paper, we designed a microstrip patch antenna that can be applied to the Wimax/LTE 5G system among wireless media usable in coastal ships. The substrate of the proposed antenna is FR-4 (er=4.3), the size is 22 mm × 30 mm, and it can be used in the 3.5 GHz and 5.8 GHz bands of Wimax/LTE 5G by constructing a simple structure using a microstrip patch antenna. CST Microwave Studio 2014 was used for simulation, and the gain of the simulation result is 2.41dB at 2.4 GHz and 3.96 dB at 3.5 GHz. S-Parameter also showed a result of less than -10 dB (VSWR 2:1) in the desired frequency band, and designed a small variable and a miniaturized antenna so that the antenna can be used in mobile phones or electronic devices.

• ETRI Journal
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• v.45 no.5
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• pp.781-794
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• 2023

Uncrewed aerial vehicles (UAVs) have become a vital element in nonterrestrial networks, especially with respect to 5G communication systems and beyond. The use of UAVs in support of 4G/5G base station (uncrewed aerial vehicle base station [UAV-BS]) has proven to be a practical solution for extending cellular network services to areas where conventional infrastructures are unavailable. In this study, we introduce a UAV-BS system that utilizes a high-capacity wireless backhaul operating in millimeter-wave frequency bands. This system can achieve a maximum throughput of 1.3 Gbps while delivering data at a rate of 300 Mbps, even at distances of 10 km. We also present the details of our testbed implementation alongside the performance results obtained from field tests.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1070-1073
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• 2010

모바일 기기의 통신에 있어 가장 중요한 요소는 이동성 지원이다. 이에 따라 3G 와 같은 이동통신을 지원하는 기술이 출현하게 되었고 이를 통해 이동 중에도 데이터 통신이 가능하게 되었다. 하지만 이동통신은 많은 에너지 소비와 높은 통신 비용문제 등으로 대용량 전송에 적합하지 않은 문제점이 있다. 이에 반해 Wi-Fi 와 같은 Wireless 네트워크는 이동성을 지원하지 않는 대신 허가 받지 않은 주파수 대역을 이용하여(예: Wi-Fi 의 2.4GHz, 5GHz) 높은 대역폭을 제공할 뿐만 아니라 전력을 적게 사용하는 장점이 있다. 본 논문에서는 3G 와 Wi-Fi 을 동시 다중 연결을 통해 서로의 장점을 극대화하고 단점을 보안한 기법을 제시하고 시뮬레이션을 통해 이를 검증 한다.