• Korean Business Review
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• v.17 no.2
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• pp.203-228
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• 2004

This dissertation investigated the evaluation model of IT Service quality: concentrated on the quality components in mobile communication service. Today, mobile communication service is changing dramatically. The first and second generation's mobile communication services were designed for voice and SMS(Short Message Service). However, while the mobile communication industry grows, the mobile technology made more services available for customers. Customers' changing needs brought a new opportunities to the market. Now, mobile communication service is facing a new era as multi-functioning, multimedia service, and high speed data transfer service are being introduced. There has been a lot of theoretical literature on service quality components of mobile communication, but most of the literature was focused on the voice service and SMS(1st and 2nd generation). As mobile communication service evolves, the components may have to be altered or rebuilt. To identify which service quality components ought to be utilized, prior studies on service quality components, service quality, and customer satisfaction were reviewed. Also, a survey was conducted on the various aspects of mobile communication service. This study suggests 6 components of service quality: those are supporting facilities, cellular phone(facilitating goods), quality of the voice service(explicit service), supplementary services, supporting services, and cost. Empirical results supported that all of these components are proven as the service quality components, but, with regards to customer satisfaction, only cellular phone(facilitating goods) and supplementary services are effective. As previously stated, the relationship between service quality and customer satisfaction is also proven. This study is a point of departure for the success of upcoming generation's mobile communication service. It identifies what is valuable from the customer's point of view. Furthermore, it suggests some ideas to prepare for future market opportunities.

• Journal of Information Technology Services
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• v.7 no.2
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• pp.181-195
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• 2008

The rapid growth of mobile communication technology has provided the expansion of mobile internet services, particularly mobile realtime transaction takes much weight among mobile fields. There is an increasing demand for various mobile applications to process transactions in a mobile computing fields. Thus, During transmission in wireless networks a base station failure inevitably causes data loss of the base station buffer. It is required to compensate the loss for communication. The existing methods for a base station failure are not adequate because they all suffer from too much overhead and resolve only the link failure. In this paper, we study an efficient recovry systems for a mobile DBMS. We propose SLL (Segment Log List) that enables the mobile host to compensate data loss efficiently in the case of base station failure. In SLL, a base station deliveries an output information of data cells to a mobile host. when a base station fails, the mobile host can retransmit just next data cells. We also prove the efficiency of new method.

• Journal of Information Technology Services
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• v.12 no.3
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• pp.55-71
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• 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.

• International Journal of Contents
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• v.2 no.2
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• pp.29-31
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• 2006

Mobile Ad hoc network is a self configuring network of mobile nodes. It allows mobile nodes to configure network spontaneously and share their services. In these networks, service discovery is very important because all nodes do not have same resources in term of memory and computing power. Nodes need to use different services offered by different servers. Some service discovery protocols have been proposed in last couple of years but they include significant traffic overhead and for small scale MANETS. In this paper, we present extensible lookup service scheme based on distributed mechanism. In our scheme neighboring nodes of service provider monitor service provider and send notification to lookup server when the service provider terminates its services unexpectedly. Lookup server can find other service provider or other alternative services in advance because of advance notification method and can provide consistent lookup services. In our scheme neighboring nodes also monitor lookup server and send notification to network when lookup server terminates unexpectedly. Simulation results show that our scheme can reduce up to 70% and 30% lookup failure as compare to centralize and simple distributed mechanism respectively.

• Journal of Advanced Navigation Technology
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• v.18 no.3
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• pp.223-228
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• 2014

Recently mobile communication systems have supported various multimedia services based on wideband code division multiple access (WCDMA). In November 2013, the statistics reported that the domestic subscriber number of mobile communication systems was totally 54 million 514 thousand 397 in using feature phones and smart phones. Therefore, the user number of mobile communication services has surpassed over 4 million rather than the whole number of population. The sharp increase of the mobile user number has made the network management and analysis for mobile communication services more important than before. Besides, the service quality has been studied in various ways. This paper has implemented the simulator calculating the channel capacity of mobile communication systems to support secure and stable services for both feature phones on CDMA and smart phones on WCDMA. By using the simulator, this paper has analyzed the characteristics of the various channel capacity in mobile communication environments.

• Journal of Information Technology Services
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• v.7 no.3
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• pp.215-237
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• 2008

As the paradigm of communications changes from technology-centered service provision to human-centric services, the future wireless communication systems is expected to be able to provide user-centric customized and optimized services. In order to cope with such paradigm shift in communications, various research activities on next generation mobile communication systems are being carried by a number of international organization and research centers to take initiative in future ubiquitous wireless communication environment. In this paper we propose a generic research and development framework consisting of four different research and development phases, a vision and strategy establishment phase, a service development phase, a service reference model creation phase and future service foresight phase. In particular, we give prospect of future ubiquitous wireless communication services covering different service areas of future life style based on our research frameworks.

• Electronics and Telecommunications Trends
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• v.38 no.1
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• pp.55-64
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• 2023

Recently, preparations for 6G have led to the increasing interest in integrated or hybrid communication networks considering low-orbit satellite communication networks with terrestrial mobile communication networks. In addition, the demand for frequency allocation for new mobile services from low-orbit small satellites to provide global internet of things (IoT) services is increasing. The operation of such satellites and terrestrial mobile communication networks may inevitably cause interference in adjacent bands and the same band frequency between satellites and terrestrial systems. Focusing on the results of the recent ITU-R WP4C meeting, this study introduces the current status of frequency sharing and interference issues between satellites and terrestrial systems, and frequency allocation issues for new mobile satellite operations. Coexistence and compatibility studies with terrestrial IMT in L band and 2.6 GHz band, operated by Inmassat and India, respectively, and a new frequency allocation study (WRC-23 AI 1.18) are carried out to reflect satellite IoT demand. For the L band, technical requirements have been developed for emission from IMT devices at 1,492 MHz to 1,518 MHz to bands above 1,518 MHz. Related studies in the 2 GHz and 2.6 GHz bands are not discussed due to lack of contributions at the recent meeting. In particular, concerning the WRC-23 agenda 1.18 study on the new frequency allocation method of narrowband mobile satellite work in the Region 1 candidate band 2,010 MHz to 2,025 MHz, Region 2 candidate bands 1,695 MHz to 1,710 MHz, 3,300 MHz to 3,315 MHz, and 3,385 MHz to 3,400 MHz, ITU-R results show no new frequency allocation to narrow mobile satellite services. Given the expected various collaborations between satellites and the terrestrial component are in the future, interference issues between terrestrial IMT and mobile satellite services are similarly expected to continuously increase. Therefore, participation in related studies at ITU-R WP4C and active response to protect terrestrial IMT are necessary to protect domestic radio resources and secure additional frequencies reflecting satellite service use plans.

• Journal of Information Technology Services
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• v.14 no.2
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• pp.111-128
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• 2015

In this paper, we examined the effects of emotional and individual variables on flow in the usage of mobile application. We selected four relevant emotional and individual factors such as positive affect, negative affect, addiction and habituation. We also attempted to figure out the moderating role of communication in the effect of positive affect, negative affect, and addiction on the flow. For empirical analysis, we surveyed real users of mobile application and applied PLS (Partial Least Square) methodology for SEM (Structural Equation Modeling). As a result, we found that positive affect, addiction, and habituation have significant and positive impact on the flow. Furthermore, we also found that the moderating effects of communication on the relationships between positive/negative affect and communication are significant. Our findings provide important theoretical grounds for the effects of human behavior and emotion on the flow of mobile applications. Lastly, we also suggest significant managerial implications for the development mobile applications industry.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.5
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• pp.353-358
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• 2018

We herein analyze the service traffic characteristics and spectrum of the 5G mobile communication and suggest the effective 5G network deployment method for 5G mobile communication services. The data rates of the 5G mobile communication are from several kbps (voice and IoT) up to 1 Gbps (hologram, among others). The 5G mobile communication services show the diverse cell coverage environments owing to the use of diverse service data rates and multiple spectrum bands. To effectively support the 5G mobile communication services, the network deployment requires the optimization of the service coverages for new service environments and multiple spectrum bands. Considering the 5G spectrum bandwidth debated at present, if the 5G services of 100 Mbps can be supported in the 200 m cell edge using the 3.5 GHz spectrum bands, the 5G services of the 1 Gbps hologram and 500-Mbps 4k UHD can be supported in the cell edges of 50 m and 100 m using the 28 GHz spectrum bands. Therefore, the 5G services can be supported effectively by the 5G network deployment using spectrum portfolio configurations to match the diverse 5G services and multiple bands.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.12
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• pp.455-462
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• 2014

In recent years, various services in mobile environments due to the growth of mobile devices and related techniques like wireless networks. Furthermore, as the increasing communication traffic in cellular networks has become a new significant issue, many studies for device-to-device(D2D) communication and D2D-based cooperative services have been performed recently. In this paper, we design a smart agent system for D2D-based cooperative services and propose a dynamic service binding method based on service ontology. We classify roles of mobile devices for cooperative services by defining three types of smart agents, and construct a knowledge base in order to describe properties of 'service' unit. The proposed knowledge model, D2D cooperative service ontology, can enable a autonomous cooperative services between mobile devices by binding a requested service to the appropriate member device according to the real-time context in mobile environments.