• Journal of KIISE:Information Networking
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• v.33 no.3
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• pp.257-268
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• 2006

In this paper, we have designed and implemented mobile instant messenger which has extensible presence service capability. Most previous work on instant messaging system has some limitation with regard to interoperability and extensibility. To solve these problems, we have employed the presence service architecture of IETF. In order to provide extensible presence capability in the wireless mobile communication, we have employed the presence service attributes which are defined in OMA's IMPS architecture. In particular, we have designed and implemented the presence service libraries for manipulating the presence information in response to user's requirement. finally, we have developed the wireless E-mail service, employing the presence service architecture, to verity the extensibility.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.11
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• pp.2678-2684
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• 2014

In this paper a new message control method that can reduce server load and network traffic in XMPP/SIP presence service system has been proposed. This presence service system can process both XMPP(Extensible Massaging and Presence Protocol) based presence information and SIP(Session Initiation Protocol) based presence information. A new XMPP stanza architecture with added elements for presence stanza and IQ stanza has been designed, and a new presence information data processing method which can reduce size of SIP notification message and SIP PUBLISH message has been suggested. Furthermore a messages exchanging procedure that can transfer presence information between XMPP domain and SIP domain has been also suggested. The performance of the proposed system has been analysed by simulation.

• The Journal of the Korea Contents Association
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• v.5 no.2
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• pp.257-266
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• 2005

As developing of the internet and computer technology, more interests are gathered to the conference service which provides capability of multi-party real-time visual conference. In this paper, we have designed and implemented a SIP-based visual conference system which includes Presence service. The elements of this conference system are user system, which has conference UA(User Agent) capability, presence seuer and conference server. For the presence service, we have adapted publication method which uses SIP PUBLISH message, and with this service various status informations of users are easily acquired. Also invitations and involvements to the conference are easily made through this service. For the conference server which controls establishment and management of multi-party connections, we have included conference event package. This package provides dynamically changing conference informations and users informations through SIP subscription and notification functions.

• Digital Contents
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• no.9 s.100
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• pp.88-89
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• 2001

우리가 흔희 친구목록이라고 부르는 버디 리스트는 사용자가 온라인 상태에 있는지, 통신이 가능한지를 확인해주는 기능으로 야후, AOL, 마이크로소프트와 같은 서비스업자들이 제공하는 인스턴트 메시징 서비스의 부가 기능으로서 잘 알려져 있다. 그러나 사용자의 온라인/오프라인 상태, 통신 가능 여부 등에 대한 정보를 실시간으로 확인케 해주는 presence기능이 결코 인스턴트 메시징 만의 전유물은 아니다는 점을 간과해서는 안될 것 같다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.5
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• pp.514-520
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• 2018

Presence service provides various information about users such as locations, status of on/offline and network access methods, and number of presence resources required by each users increases largely in mobile environment. Therefore an effective method which can reduce load of presence servers is needed. In this paper, a large scale distributed presence service system which can distribute effectively total presence system load of presence servers using message control session has been presented. This large scale distributed presence service system provides various presence information for massive volumes of users. In this study, a new message control session architecture which can dynamically distribute loads of the presence servers to multiple servers has been presented, and a new presence information data architecture for controlling load of the presence servers has been designed. In this architecture, each presence server can exchange current load level in real time to get variance of the total system load change according to user numbers, and can distribute system load to maintain load level of each server evenly. The performance of the proposed large scale distributed presence service system has been analysed by experiments. The results has been showed that average presence resource subscription processing time reduced from 42.6% to 73.6%, and average presence notification processing time reduced from 37.6% to 64.8%.

• Journal of the Korea Society of Computer and Information
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• v.14 no.9
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• pp.67-74
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• 2009

The presence informations of users of Instant Messaging System In SIP(Session Initiation Protocol) environment are obtained by presence server, and message waiting indication event package is used to provide various message informations stored in the message server. In this paper, I have proposed a new method in which Extended CPL(Call Processing Language) has been applied to presence service to provide various functions to the users. A user of Instant Messaging System subscribes presence information and CPL scripts which describe his requirements, and presence server executes CPL scripts when instant messaging service is subscribed and notifies presence informations. Several CPL operation tags are added, and therefore various services which combine presence service and call processing can be provided in this system. Furthermore a new method has been proposed in which message server and presence server correlate in Instant Messaging System. When changes of message status informations occur, message server send these informations to the presence server, and presence server provides both presence informations and message status informations in extended format. As this method can be a substitute for message waiting indication event package, the system operating efficiency can be increased. The performance of this proposed system is evaluated by experiments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.5
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• pp.1144-1150
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• 2015

Presence information provides various informations about users such as on-line status, current location, network connection method and connection address, and there are two kinds of presence information, SIP(Session Initiation Protocol) based presence information and XMPP(Extensible Massaging and Presence Protocol) based presence information. In this paper, a multiple server architecture that can handle these two kinds of presence information has been proposed. In this architecture, severs are added dynamically according to number of users to provide system scalability, and load of each server can be effectively controlled. In this system, a new XMPP stanza architecture and presence information data format are designed for load control. Furthermore message exchanging procedures between servers and users for dynamic server control has been also suggested. The performance of the proposed system has been analysed by simulation.

• Journal of the Korea Society of Computer and Information
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• v.15 no.12
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• pp.67-73
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• 2010

In SIP(Session Initiation Protocol) environment, the presence event notification operation makes presence service user to recognize presence information status changes of the other party. In conventional method, the user should send each SIP SUBSCRIBE message containing the address of the other party to the presence server. Furthermore each presence subscription requires refresh messages, and the amount of notification messages from the other party becomes large. These facts increases network traffic and the load of presence server. In this paper, to solve these problems a new presence list service has been suggested. It uses a presence list consists of URI of the other party and make it possible to subscribe by using one SUBSCRIBE message. So this method decreases the amount of SUBSCRIBE messages and refresh messages, and it also decreases the amount processing event notification messages from the subscribed the other party. And to increase the efficiency, a presence filtering method which enables to include some parts of selected presence information into the notification message body has been also suggested. The implemented system can reduce SIP message related network traffic and message processing time of the presence server. The performance of this proposed system has been evaluated by experiments, and the results showed decreasing of server processing time.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.923-926
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• 2005

We explain the Presence Model defined in IETF IMPP WG. We also roughly explain the standards defined methods and behaviors among components for services according to presence model. We especially explain the XCAP technology which is defined authorization rules related subscription and notification of presence information and describe the design considerations of PA server for presence service.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.575-578
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• 2005

인터넷 사용자의 급격한 증가로 인하여 인터넷 서비스 보급이 대중화됨에 따라 인터넷을 이용한 다양한 부가 서비스들이 창출되고 있다. 이러한 흐름에 발맞추어 VoIP(Voce over IP) 표준기술들이 최근 몇 년간 주요 이슈가 되고 있다. VoIP 서비스가 시장성 있는 기술로서 각광을 받게 되면서, VoIP 서비스를 위한 시스널링 프로토콜인 SIP(Session Initiation Protocol)가 기존의 H.323을 대체하는 기술로서 주목 받고 있다. 또한 SIP를 이용한 다양한 부가 서비스들도 함께 관심이 집중되고 있으며, 그중에서도 SIP를 이용한 프레즌스 서비스에 많은 관심을 보이고 있다. 본고에서는 현재 IETF를 중심으로 진행되고 있는 SIP 기반 프레즌스 부가 서비스에 대한 표준 기술 및 주요 이슈에 대해 소개하고자 한다.