MiYoung Huh

Study, on robust billing mechanism for SIP-based internet telephony services

Nowadays, there are many Internet telephony services that support IP-IP telephony, IP-PSTN telephony or something like that. The most significant changes in Internet Telephony filed are appearance and increasing expansion of SIP protocol instead of H.323. Because H.323 protocol is TCP-based protocol, billing is so easy. However SIP protocol is UDP-friendly protocol that may cause problem with signaling loss due to the unreliability of UDP datagram. In this paper, we categorize the billing method and suggest robust billing method for SIP-based Internet Telephony.

Call management mechanism for internet phone services based on SIP

Absnuct VOW (Voice over IP) Technology is highlighted because of easy adopting the value added services related voice. In this paper, we described the architecture and its internal processing procedure of user agent system for Internet telephony services based on SIP (Session Initiation Protocol). Especially, we focused the call management mechanism for establishing the dialog within user agent system.

Basic call flow for interoperability test in the presence services based on SIP

Presence service is emerged to meet the needs of integrated service and presence service will be a core function within integrated service. IETF SIMPLE WG generates standard SIP extensions for presence service. In this paper, we described the presence service systems including internal logical function modules. We classified functions of presence service systems with itemized functions, conditions to be occurred related SIP request messages and response message for each request message. And, we also described the basic call flows for interoperability test among presence service systems based on SIP

Design considerations for user authorization in the presence services based on SIP

SIP plays an important role in VoIP service infrastructure. Presence service is emerged to meet the needs of integrated service and presence service is a core function within integrated service. IETF SIMPLE WG generates standard SIP extensions for presence service. In this paper, we described the service scenarios of presence services based on SIMPLE. We also described the construction of presence system. Especially, we described the design considerations of presence agent supporting for multiple presence packages and those of presence agent supporting for user authorization function

Hypermedia Information Retrieval System Using MHEG Coded Representation in a Networked Environment

A prototype hypermedia information retrieval system in a networked environment, is developed. For the growing importance of information sharing and interchange, the system uses the international standard, MHEG, for its multimedia information encoding and representation. The system is built in a client/server configuration having client/server communication between a server system and multiple client systems over N-ISDN. The server system stores MHEG encoded information and the client system retrieves, processes, and displays the information. For its time critical characteristics of multimedia data, the system provides functionalities to handle synchronization of transmitting data.

Design of presence agent server for SIP-based presence services

In this paper, we suggest the architecture of presence agent server system that manages presence information. The server collects presence information and distributes them to the subscriber who wants to receive presence status. When collecting and distributing the presence information, the server uses SIP protocol as main signaling protocol

A study on XCAP client system for SIP-based IMPP services

Internet users are rapidly increased and various services which use Internet are invented. IM (instant messaging) and presence service is one of them. IM and presence is looked upon as a major killer application in the field of IP telephony. In this paper, we describe about the standard technologies for SIP-based IMPP service and about XCAP (XML configuration access protocol) technologies. And then we describe service scenarios and models for SIP-based IMPP services. And finally, we suggest authorization policy and resource list manipulation mechanism using XCAP. And suggests XCAP client system. IMPP service is expecting to contribute in new service creation being integrated with various service such as conference and instant messaging services

Design of interfaces among functionalities for smart greenhouse

In order to analyse the impact of environment condition to the crop, it is necessary to accumulate the data generated by the smart greenhouse. Thus, it is important to define the standard interface and data format among functional entities within smart greenhouse to be able to use the accumulated data is meaningful. In this paper, we will describe the status of standardization in ITU-T and TTA regarding smart greenhouse briefly, and introduce the reference architecture and functional entities defined in standardization document. Additionally, we will suggest the considerations of interfaces and related information among functional entities.

Standard development considerations of common alerting service for digital signage

It is very important to provide common alerting information in the digital signage terminal. Common alerting information can be such as severe thunderstorm warning information, earthquake report information, child abduction warning, and so on. In this paper, we described the standard development considerations of common alert functionality to provide common alerting event which is produced from the alert agency to the digital signage terminal through the digital signage server.

Standardizations and considerations on P2P-based contents distribution for digital signage service

Digital signage service provides advertisement and informational content to audiences by use of electronic displays. Nowadays, the resolution of display goes higher and quality of contents is also increasingly getting higher. On distributing its contents to multiple displays, it takes much time proportional to the number of terminal and size of content. This paper proposes a method for content distribution using P2P with more considerations for digital signage service.