• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.608-611
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• 2005

The existing wired emergency call such as 119, 112 have its own location information to serving immediate rescue service. For the case of wireless emergency call by mobile phone, the location information should be provided by wireless network. This paper describes the network architecture and protocol for mobile emergency service referring TIAlEWJ-SID-036-A with reviews about technical issues, legacy factors and related researches. The mobile emergency service is divided into mobile emergency rescue service and mobile emergency alert service. The network reference model for mobile emergency rescue service is released in KOREA. In this paper, the interfaces between elements of the network reference model, and service scenarios, message flows are defined. Supplement to mobile emergency rescue service, the network reference model, interfaces and message flows for mobile emergency alert service are developed. The protocol is described by DID, and the proposed works are on processing for domestic standard of TTA.

• The Journal of the Acoustical Society of Korea
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• v.28 no.3E
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• pp.99-108
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• 2009

In this paper, we suggest criteria for objective measurement of speech quality in mobile VoIP (Voice over Internet Protocol) services over wireless mobile internet such as mobile WiMAX networks. This is the case that voice communication service is available under other networks. When mobile VoIP service users in the mobile internet network based on packet call up PSTN and mobile network users, but there have not been relevant quality indexes and quality standards for evaluating speech quality of mobile VoIP. In addition, there are many factors influencing on the speech quality in packet network. Especially, if the degraded speech with packet loss transfers to the other network users through the handover, voice communication quality is significantly deteriorated by the transformation of speech codecs. In this paper, we eventually adopt the Gilbert-Elliot channel model to characterize packet network and assess the voice quality through the objective speech quality method of ITU-T P. 862. 1 MOS-LQO for the various call scenario from mobile VoIP service user to PSTN and mobile network users under various packet loss rates in the transmission channel environments. Our simulation results show that transformation of speech codecs results in the degraded speech quality for different transmission channel environments when mobile VoIP service users call up PSTN and mobile network users.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.4
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• pp.83-94
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• 2010

Mobile network infrastructure is being completed with the development of hardware and software for mobile devices. Network in mobile devices has evolved for telematics that is expanded much more than its existing concept. Telematics is compound word that is formed from the words "telecommunication" and "informatics". It means that telematics performs control and monitoring service with using mobile device resources. These services provide their services for users' requests through wired or wireless network from mobile devices and server that offers contents and network service collects management information of mobile devices. Map service is one of the preferred services for many telematics users. However, mobile map service has a limit between traffic and information sharing. Therefore it is very important to supply their information for both service provider and terminal user. In this paper, we design a new interactive sketch map using routes and information on the space to be applied effectively, and provide an extended document format that is defined to an extensible and dynamic clustering scheme to have portability map service for mobile device.

• Journal of the Korea Computer Industry Society
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• v.6 no.2
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• pp.345-354
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• 2005

Mobile grid can provide the grid service to grid users regardless of space and time. There are many restrictions to use grid service in mobile environment such as battery power of mobile device, movement pattern of mobile device etc. So it is difficult to apply the grid technologies of wired network to wireless network environments. Therefore, to provide the mobile grid service, we suggested the mobile grid architecture using ad-hoc network. Also we showed that hybrid routing protocol is efficient for mobile grid service by considering the battery power of mobile device and simulations of evaluating the delay time of three routing protocols using NS-2. We will study the methods of resource allocations and network reliability to provide the mobile grid service.

• 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 the Korea Society for Simulation
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• v.13 no.2
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• pp.65-73
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• 2004

The capability to provide the network service must survive even if a significant network system element is disrupted. To sustain the network service under the system failure, network survivability mechanisms minimizing the impact of failures are needed. Also, since the mobile network has its unique characteristic, the survivability scheme for the vulnerability of the mobile network is required. This paper proposes a survivability scheme to support the reliable service of the wireless access point level (BS-base station system). By the survivability scheme, the mobile network can use an overlap BS of the cellular network architecture after a BS system failure. We analyze the performance of the proposed scheme using Markov model. Also, a computer simulation is used for the scheme analysis. The proposed scheme shows that the service of the mobile network can be provided under the BS system failure.

• Journal of Communications and Networks
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• v.17 no.2
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• pp.110-117
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• 2015

In mobile social network, it is a critical challenge to select an optimal set of devices to supply high quality service constantly under dynamic network topology and the limit of device capacity in mobile ad-hoc network (MANET). In this paper, a multi-devices composition and maintenance problem is proposed with ubiquitous service model and network model. In addition, a multi-devices composition and maintenance approach with dynamic planning is proposed to deal with this problem, consisting of service discovery, service composition, service monitor and service recover. At last, the simulation is implemented with OPNET and MATLAB and the result shows this mechanism is better applied to support complex ubiquitous service.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.335-338
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• 2004

In this paper, we present a perspective of the next generation mobile communication services and its characteristics. As a preliminary research work on the next generation mobile communications and services, we exploit the next generation mobile services [1]. We define the next generation mobile services as strata of services consisting of three different service levels, the service areas, the service functionalities, and the service technologies. We derive these service levels by means of the scenario based analysis. Finally, we propose a conceptual network architecture that can support the next generation mobile services by placing network functions and service elements within the network.

• The KIPS Transactions:PartC
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• v.19C no.1
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• pp.29-38
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• 2012

Due to rapid spread of smart phones and SNS(Social Network Service), using of Internet applications has increased and taking up bandwidth more than 3G network's capacity recently. This caused reduction of speed and service quality, and occurred strong needs that backbone network company to increasing investment costs. Also a great rise of mobile network users causing identity management problems on mobile service provider through mobile network. This paper proposes advanced IDM3G[1] - to solve user ID management and security problems on mobile internet application services over 3G network and more - authentication management protocol. $I^2DM$ protocol breakup loads which made by existing IDM3G protocol's mutual authentication via mobile operator, via sending some parts to internet application service provider, enhancing mobile and ID management of service provider and network load and process load from information handling and numbers of transmitting packets, to suggest more optimized protocol against further demanding of 3G mobile network.

• Journal of Information Technology Services
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• v.11 no.2
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• pp.339-353
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• 2012

Mobile communication technology is advancing forward to deliver more connected devices and richer content and applications. The number of subscriptions continues to grow along with an explosive increase in the mobile data traffic demand. Thereby, it creates a significant network capacity shortage concerns for mobile network operators. In order to address this problem, it is essential to increase the network capacity at a low additional cost. The device-to-device (D2D) communication based proximity service is believed to have a promising future mobile communication technology that is capable to create new mobile service opportunities and offload traffic to the eNB. In addition, it is also required to develop new mobile communication services and its business models not only to accommodate the increasing mobile traffic demand but also to foster profitability of mobile business service providers such as the network providers, contents providers and platform providers. In this article, we first analyze current mobile business eco-system in the context of CPNT based value chain. Then, propose service development framework and business model creation methodologies for the device-to-device communication based services in the beyond LTE/LTE-Advanced systems.