• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.6
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• pp.547-553
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• 2019

Presence server should process massive SIP subscription request messages and massive presence event notifications from presence resources in real time. Therefore multiple servers architecture is needed for presence service system. In this paper, an architecture of multiple servers presence service system using SIP based CCMP control messages for lowering presence server load level has been presented. In this system, each presence server exchanges current load status using CCMP control messages, and total system load according to variance of users number and amount of presence resources has been effectively distributed processed. The CCMP control messages has been optimally designed to control presence servers, and exchange procedures of these control messages between presence servers has been also presented and the performance of the proposed multiple servers presence service system has been analysed by experiments. The result shows that average presence subscription processing time reduced from 40.8% to 69.2% and average presence notification processing time reduced from 29.4% to 62.7%.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.585-588
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• 2005

The Presence Agent Server receives user's presence information via PUBLISH request message and let subscribers to know that information. IMPP client has a functions for PUA(presence user agent) as a base operational entity. In some circumstance, the client has both pua and pa logical entities. However presence agent server has take part only of PA. In this paper, we describes the design and implementation that contains modules based configurations and approaches for presence agent server. Also, we describe how we handle each events and database API instruction set.

• The Journal of the Korea Contents Association
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• v.7 no.3
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• pp.34-41
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• 2007

The presence service which provides user's presence information by subscription and notification is one of SIP(session initiation protocol) extension services, and it is used importantly in VoIP(Voice over IP) and Instant Messaging service. In this paper, we propose a new method in which users can combine and control presence service and call processing services in various ways by extending call processing language, and only changed parts of the presence information are published instead of full presence information document. Each user registers full presence information document with his own call processing script during the first publication to a presence server. The presence server executes these call processing scripts, so it can provide various services with combination of presence service and call processing services during the presence subscriptions and notifications. Afterwards, users publish only changed parts of the presence information and the presence server notify only these changed parts to watchers. Therefore the efficiency of the overall system can be improved. The performance of our proposed model is evaluated by experiments.

• 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.

• 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 Information Science Society Conference
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• 2003.04d
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• pp.214-216
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• 2003

SIP(Session Initiation Protocol)는 사용자간에 멀티미디어 세션을 생성, 수정, 종료를 위한 응용계층의 시그널링 프로토콜로써 확장성이 뛰어나 여러 인터넷 응용분야에 적용이 가능하다. SIP를 이용한 확장 서비스의 하나인 Presence 서비스는 사용자들간에 현재 위치의 변화에 따른 최신 정보를 제공함으로써 VoIP(Voice over IP), 인스턴트 메시징(Instant Messaging) 등 Presence 정보를 기반으로 하는 여러 응용 서비스와 연계하여 활용이 가능하다. Presence 서비스에서의 Watcher 정보는 특정한 자원(resource)에 대한 모든 등록(subscription) 상태를 의미하며 이 상태는 동적(dynamic)으로 변화하게 된다. 따라서 사용자는 이러한 변화되는 상태를 알기 위하여 watcher 정보에 등록할 필요가 생긴다. 따라서 본 논문에서는 SIP 기반의 Presence 시스템에서 동적으로 변화하는 사용자들의 등록 상태를 알려주는 Watcher 정보 서비스를 구현하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.1131-1134
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• 2006

프리젠스(Presence) 서비스는 SIP(Session Initiation Protocol) 확장 서비스의 하나로서 사용자들 사이에 현재 위치의 정보나 온라인 정보 등과 같은 통신 상태의 변화를 등록(Subscription)과 Notification을 통해서 제공한다. 이때 프리젠스 정보가 변화될 때마다 전체 프리젠스 문서를 이용하여 업데이트하는 기존의 Publication 및 Notification 방식을 사용할 경우 프리젠스 정보 전송에 상당한 오버헤드가 발생한다. 이를 해결하기 위해 본 논문에서는 부분 Publication 및 Notification 방식을 사용하여 변화되는 최신 프리젠스 정보만으로 구성된 부분 프리젠스 문서를 메시지 바디에 포함시켜 전달하도록 함으로써 기존의 방식에 비해 효율적인 프리젠스 관련 정보 전송이 가능한 새로운 프리젠스 서비스를 구현하였다.

• The Journal of the Korea Contents Association
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• v.8 no.1
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• pp.152-159
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• 2008

In this paper, we have studied a new method in which multimedia message can be processed effectively in SIP(Session Initiation Protocol)-based Instant Messaging service. Total system is composed of multimedia message server, presence server and user system. To provide effectively message informations such as number of messages stored in the multimedia message server, waiting status and message types to users, we have proposed a new method which can be a substitute for message waiting indication event package. In our proposed method, when changes of messages status informations occur, these informations are sent to the presence server, and can be transferred as a separate tag within notification message. The presence server processes subscription requests and notifications, and efficiency can be improved as it provides both message status informations and several communication status informations such as on-line status to service users. Partial publication is used in our system to improve data transfer efficiency more between user system and the presence server. The performance of our proposed model is evaluated by experiments measuring multimedia message transfer speed and server processing time.

• 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.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.