• ETRI Journal
• /
• 제45권5호
• /
• pp.781-794
• /
• 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.

• 인터넷정보학회논문지
• /
• 제19권4호
• /
• pp.95-105
• /
• 2018

As the IT industry has developed, the frequency of mobile communication usage has increased sharply. Mobile communication has many advantages such as improving work performance, communication beyond time and local constraints, and rapid and vast amounts of information exchange. However, mobile communication also allows supervisors to give their subordinates work at any time. Thus, mobile communication may also have a negative impact on workers' stress levels during non-work time. This study examined required time, urgent business, personal engagement, and trivial matters as sub-dimensions of mobile communication messages that workers could receive during non-work time. Further, the nature of the relationship between team leaders and members explains how these messages may increase the stress levels of workers. Supervisors should prohibit the use of such mobile communication, and efforts should be made at the enterprise level. Through this research, we aim to explain the dual nature of mobile communication, and understand how to optimize the usage of this innovative technology

• Journal of Communications and Networks
• /
• 제9권3호
• /
• pp.296-311
• /
• 2007

Mobile multi-robot teams are useful in many critical applications such as search and rescue. Explicit communication among robots in such mobile multi-robot teams is useful for the coordination of such teams as well as exchanging data. Since many applications for mobile robots involve scenarios in which communication infrastructure may be damaged or unavailable, mobile robot teams frequently need to communicate with each other via ad hoc networking. In such scenarios, low-overhead and energy-efficient routing protocols for delivering messages among robots are a key requirement. Two important primitives for communication are essential for enabling a wide variety of mobile robot applications. First, unicast communication (between two robots) needs to be provided to enable coordination and data exchange. Second, in many applications, group communication is required for flexible control, organization, and management of the mobile robots. Multicast provides a bandwidth-efficient communication method between a source and a group of robots. In this paper, we first propose and evaluate two unicast routing protocols tailored for use in ad hoc networks formed by mobile multi-robot teams: Mobile robot distance vector (MRDV) and mobile robot source routing (MRSR). Both protocols exploit the unique mobility characteristics of mobile robot networks to perform efficient routing. Our simulation study show that both MRDV and MRSR incur lower overhead while operating in mobile robot networks when compared to traditional mobile ad hoc network routing protocols such as DSR and AODV. We then propose and evaluate an efficient multicast protocol mobile robot mesh multicast (MRMM) for deployment in mobile robot networks. MRMM exploits the fact that mobile robots know what velocity they are instructed to move at and for what distance in building a long lifetime sparse mesh for group communication that is more efficient. Our results show that MRMM provides an efficient group communication mechanism that can potentially be used in many mobile robot application scenarios.

• Journal of information and communication convergence engineering
• /
• 제13권2호
• /
• pp.86-96
• /
• 2015

In mobile communication, mobile services [MSs] (e.g., phone calls, short/multimedia messages, and Internet data) incur a cost to both mobile users (MUs) and mobile service providers (MSPs). The proposed model MobPrice consists of dynamic data pricing schemes for mobile communication in order to achieve optimal usage of MSs at minimal prices. MobPrice inspires MUs to subscribe MSs with flexibility of data sharing and intra-peer exchanges, thereby reducing overall cost. The main contributions of MobPrice are three-fold. First, it proposes a novel k-level data-pricing (kDP) scheme for MSs. Second, it extends the kDP scheme with the notion of service-sharing-based pricing schemes to a collaborative peer-to-peer data-pricing (pDP) scheme and a cluster-based data-pricing (cDP) scheme to incorporate the notion of 'cluster' (made up of two or more MUs) in mobile communication. Third, our performance study shows that the proposed schemes are indeed effective in maximizing MS subscriptions and minimizing MS's price/user.

• Journal of information and communication convergence engineering
• /
• 제11권3호
• /
• pp.167-172
• /
• 2013

Recently, mobile communication systems are suffering from exponentially increasing data traffic. As a promising solution to the increase in data traffic, a coordinated multi-point transmission and reception (CoMP) scheme has been proposed. Although a great deal of research has been done on this new technology, the performance of mobile communication systems with CoMP has not been evaluated properly in a typical indoor environment. To address this, we have developed a system-level simulator and evaluated the performance of mobile communication systems with CoMP. Unlike previous works, we have used an actual antenna pattern in our simulator and link-level results are properly taken into account through link-level abstraction. By using a system-level simulator, we have evaluated the performance of mobile communication systems with CoMP in an indoor environment and found that unlike an outdoor cellular environment, CoMP may not improve the performance of overall mobile communication systems in an indoor environment.

• 한국IT서비스학회지
• /
• 제12권3호
• /
• pp.55-71
• /
• 2013

Mobile communication industry is attracting a lot of attention all over the world and is expected to continue developing endlessly with the current rapid development of IT industry. Nowadays, mobile communication companies of vietnam are competing about service quality in order to retain existing customers and improve customer satisfaction and customer loyalty. This study attempts to research about the effect of mobile communication service quality on customer satisfaction and affecting relationship between customers satisfaction and customer loyalty. In this research empirically examine how mobile communication service quality influence customer loyalty in Vietnam. To do this, after considering characteristics of mobile communication service quality, quality measurement instrument was designed including call quality, call charge, cellphone, added service quality, corporate image, employee's attitude, and behavior. The study finds that all factors of call quality, added servces quality, corporate image, employee's attitude and behavior have positive effect on customer satisfaction except call charge and customers satisfaction also effects customers loyalty positively. From these results, Vietnam domestic mobile communication companies and foreign companies can grasp the general information about Vietnam mobile communication industry, and then, establish customers satisfaction strategies more effectively.

• 한국언론정보학보
• /
• 제21권
• /
• pp.87-113
• /
• 2003

이 연구는 대인커뮤니케이션 매체로서의 이동전화 이용을 우리의 전통적인 커뮤니케이션 가치관과 연결시켜 다뤄보자는 의도에서 출발했다. 온라인조사방법을 통해 수집된 자료를 분석한 결과, 어린 세대보다 나이 많은 세대에서 전통적 커뮤니케이션 가치관이 더 큰 영향력을 유지하고 있으며, 전통적 커뮤니케이션 가치관은 특히 나이 많은 세대에 있어서는 대인커뮤니케이션 매체로서 이동전화의 매체인식에 보다 큰 영향을 미치고 있음을 볼 수 있었다. 즉, 전통적 커뮤니케이션 가치관에 공감하는 정도가 높은 나이 많은 세대는 어린 세대에 비해 이동전화의 효율성은 내심 인정하면서도 우리 사회의 전통적 커뮤니케이션 가치관에 영향을 받아 이동전화의 적합성은 낮게 평가하는, 소위 ‘이동전화에 대한 매체인식의 이중성’의 일단을 보여주었다는 것이다. 특히 커뮤니케이션 상대가 윗사람이고 커뮤니케이션 상황이 개인적인 부탁을 해야하는 인간관계의 부담이 큰 상황일수록 나이 많은 세대의 이러한 '이중성'은 어린 세대에 비해 더 극명하게 드러났다.

• 통상정보연구
• /
• 제7권1호
• /
• pp.35-54
• /
• 2005

The rapid growth of wide Korean Mobile Communication Market in recent years. in order for Korean Mobile Communication Market to be Successful, it must have a Competitive Advantage. But as of yet, there virtually no such strategies. Hitting upon this situation, this study intends to discover the Competitive Advantage in Korean Mobile Communication Market The Purpose of this paper Investigates Competitive Advantage that Evaluation in Korean Mobile Communication Market. Especially, we Focused on Competitive forces model of Porter. Consequently, the study results show that Competitive Advantage like M-commerce, CS and high technology product in Korean Mobile Communication Market.

• Journal of Information Processing Systems
• /
• 제20권1호
• /
• pp.38-52
• /
• 2024

The 5G is the 5th generation mobile network that provides enhanced mobile broadband, ultra-reliable & low latency communications, and massive machine-type communications. New services can be provided through multi-access edge computing, network function virtualization, and network slicing, which are key technologies in 5G mobile communication. However, these new technologies provide new attack paths and threats. In this paper, we analyzed the overall threats of 5G mobile communication through a literature review. First, defines 5G mobile communication, analyzes its features and technology architecture, and summarizes possible security issues. Addition, it presents security threats from the perspective of user devices, radio access network, multi-access edge computing, and core networks that constitute 5G mobile communication. After that, security requirements for threat factors were derived through literature analysis. The purpose of this study is to conduct a fundamental analysis to examine and assess the overall threat factors associated with 5G mobile communication. Through this, it will be possible to protect the information and assets of individuals and organizations that use 5G mobile communication technology, respond to various threat situations, and increase the overall level of 5G security.

• 한국언론정보학보
• /
• 제19권
• /
• pp.155-184
• /
• 2002

이 연구는 이동전화에 대한 채널 정향, 면 대 면 커뮤니케이션의 회피 등 이용자들의 인적 속성이 이동전화 이용의 다양성, 이동전화의 적합성 거부감 그리고 이동전화를 통한 커뮤니케이션 네트워크에 미치는 영향을 살펴보려는 목적에서 출발했다. 대학생과 40대 이상의 그들의 가족들로 구성된 피조사자들을 대상으로 설문조사한 바를 분석한 결과, 응답자들은 이동전화에 대한 사회적 실재감과 친밀도가 높을수록 이동전화 서비스를 더욱 다양하게 이용하고 대인커뮤니케이션 매체로서 더욱 긍정적으로 평가하며, 이동전화에 대한 거부감도 더 작은 것으로 밝혀졌다. 아울러 면 대 면 커뮤니케이션이 원활하지 못한 사림들은 이동전화를 통한 대인커뮤니케이션 네트워크의 폭과 이동전화 이용량도 상대적으로 제한돼 있음을 알 수 있었다. 즉시성, 직접성, 이동성, 접근용이성 등 이동전화의 여러 가지 기술적 강점에도 불구하고 면 대 면 커뮤니케이션이 원만하지 못한 이용자들은 새로운 인간관계의 형성보다는 그들의 편협한 대인관계의 유지 강화에 이동전화를 주로 이용하고 있음을 이 연구결과는 보여주고 있다.