• ETRI Journal
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• v.25 no.5
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• pp.369-378
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• 2003

Using the general switch management protocol on a multi-protocol label switching network, we present an efficient method for handling handovers. The proposed method directly changes an established path into a new path for supporting a handover. Our investigation reveals the effects of the proposed scheme and demonstrates that this method significantly reduces signaling costs and delays.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1220-1222
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• 2002

The railway signaling system consists of several vital computerized equipments. Now the project for development of signaling system for the next-generation high-speed train is progressed according to the consortium. The developing signaling system by this project, kTCS(Korean Train Control System), is composed of kTCS-CTC, kTCS-IXL, kTCS-ATC and etc. The KTCS signaling has to be operated as a integrated system by interface between each signaling. To achieve these, communication protocols between each signaling have to be designed and message codes are defined. In this paper the configuration of integrated kTCS system and designed communication protocol is presented.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.4
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• pp.64-73
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• 2003

There are many economic and operational reasons to integrate fire alarm signaling system with other building automation system Integration of this requires open network with the standard communication protocol and careful design practices. The important point for this is also the development of intelligent control modules for replacing the conventional zone adapter in fire system. Therefore, this paper proposes an new conceptual design of the open distributed fire alarm signaling system for the integration of BAS and a new intelligent control modules with LonTalk protocol. Newly proposed additions to LonWorks network make it very well suited for integrating fire systems with other building automation systems. Additionally, it is very important that best design practices, test procedures and building codes need to be modernized to accommodate integrated building systems.

• Journal of KIISE:Information Networking
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• v.28 no.3
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• pp.377-388
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• 2001

An approach for testing multi-protocol Implementation Under Test (IUT) with a single test suite has been proposed in[1]. this paper proposes an algorithm called Multi-protocol Test Method (MPTM) for automatic test case generation based on that approach. With the MPTM, a multi-protocol IUT consisting of two protocol layers is modeled as two Finite State Machines (FSMs), and the relationships between the transitions of the two FSMs are defined as a set of transition relationships pre-execution and carried-by. The proposed algorithm is implemented and applied to a simplified TCP/IP and B-ISDN Signaling/SSCOP. MPTM is able to test the multi-protocol IUT even though the interfaces between the protocol layers are not exposed. It results in that the proposed MPTM allows the same test coverage as conventional test methods even with fewer numbers of test cases.

• Journal of Internet Computing and Services
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• v.10 no.6
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• pp.27-36
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• 2009

PSTN (public switched telephone network) provides voice communication service, whereas IP network provides data oriented service, and we can use IP network for multimedia transport service (e.g. voice over IP service) with economic price. In this paper, we propose RoIP (robot on IP) service scenario, signaling call flow, and implementation to provide home automation and monitoring service for remote site users. In our scheme, we used a extended SIP (session initiation protocol) for signaling protocol between remote site users and home robots. For our bearer transport control, we implemented H.263 video codec over RTP (real-time transport protocol) and additionally DTMF (dual tone multi-frequency) transport for robot actuator control. We implemented our scheme on home robots and experimented with KTF operator network, and it shows good communication quality (average MOS = 9.15) and flexible robot controls.

• Journal of Communications and Networks
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• v.7 no.4
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• pp.509-524
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• 2005

Due to the strict requirements of emerging applications, per-flow admission control is gaining increasing importance. One way to implement per-flow admission control is using an on­path resource reservation protocol, where the admission decision is made hop-by-hop after a new flow request arrives at the network boundary. The next-steps in signaling (NSIS) working group of the Internet engineering task force (IETF) is standardising such an on-path signaling protocol. One of the reservation methods considered by NSIS is reduced-state mode, which, suiting the differentiated service (DiffServ) concept, only allows per-class states in interior nodes of a domain. Although there are clear benefits of not dealing with per-flow states in interior nodes-like scalability and low complexity-, without per-flow states the handling of re-routed flows, e.g., after a failure, is a demanding and highly non-trivial task. To be applied in carrier-grade networks, the protocol needs to be resilient in this situation. In this article, we will explain the consequences of a route failover to resource reservation protocols: Severe congestion and incorrect admission decisions due to outdated reservation states. We will set requirements that handling solutions need to fulfill, and we propose extensions to reduced-state protocols accordingly. We show with a set of simulated scenarios that with the given solutions reduced-state protocols can handle re-routed flows practically as fast and robust as stateful protocols.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.147-148
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• 2007

BICC protocol is a relay protocol adaptable to ATM and IP based core networks compared to ISUP protocol to TDM networks. Using BICC protocol, multi-rate bearer traffic such as voice and video can flow in the relay core networks. BICC protocol is standardized as WCDMA circuit switching networks in 3GPP Release 4. Thus KTF is now operating core networks using BICC protocol. In this paper, we describe the background and characteristics of BICC protocol. We also provide the status of KTF WCDMA core networks using BICC. To show the efficiency of BICC protocol an analytical simulation is given in which the results can be expected by intuitive observation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.7
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• pp.1030-1040
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• 2018

In Distributed Mobility Management (DMM) protocol, the mobility functions are distributed to network edge closer to mobile users. DMM protocol has some advantages of low-cost traffic delivery, optimized routing path, high scalability. However, it needs many mobile anchors to exchange signaling messages and it results in a high signaling cost. Thus, previous works suggested the hybrid DMM protocol to reduce the high signaling cost for long-live sessions and this paper extends a hybrid scheme to the NEMO environment. The mobile routers are installed at vehicles and can move together with several mobile devices. So we can define the high-mobility property for mobile routers and suggest the hybrid scheme using this property. According to the high-mobility property of mobile routers, we can distribute the mobile anchors or allocate a centralized mobile anchor. In this paper, we mathematically analyze the performance of the proposed NEMO-enabled hybrid DMM protocol and show superior performance.

• Journal of Korea Multimedia Society
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• v.20 no.11
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• pp.1768-1775
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• 2017

The SIP(Session Initiation Protocol) is an application layer call signaling protocol which can create, modify and terminate the session of user, and provides various services in combination with numerous existing protocols. However, most of cryptosystems for SIP cannot prevent quantum computing attack because they have used ECC(Elliptic Curve Cryptosystem). In this paper, we propose a NTRU based authentication and key distribution protocol for SIP in order to protect quantum computing attacks. The proposed protocol can prevent various attacks such as quantum computing attack, server spoofing attack, man-in-the middle attack and impersonation attack anonymity, and our protocol can provide user's anonymity.

• ETRI Journal
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• v.26 no.2
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• pp.181-184
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• 2004

For communication between heterogeneous conference systems, it is important to build a conference control protocol independent from signaling protocols. We simulate an XML-based conference control that is under consideration as a standard mechanism. We describe the framework and operations for easy implementation in heterogeneous conference systems. The simulation results show that the proposed control protocol provides a consistent service for an increasing number of conferences and participants in small to mid-size centralized conferencing.