• The Journal of Korean Institute of Next Generation Computing
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• v.14 no.6
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• pp.75-86
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• 2018

The DDS (Data Distribution Service) specification defines a discovery method for finding participants and endpoints in a DDS network. The standard discovery mechanism uses the multicast protocol and finds all the endpoints in the network. Because of using multicasting, discovery may fail in a network with different segments. Other problems include that memory space wastes due to storing information of all the endpoints. The Topic Name Service (TNS) solves these problems by unicasting only the endpoints, which are required for communication. However, an extra delay time is inevitable in components of TNS, i.e, a front-end server, topic name servers, and a terminal server. In this paper, we analyze the performance of TNS. Delay times in the servers of TNS and time required to receive endpoint information are measured. Time to finish discovery and number of receiving endpoints compare with the standard discovery method.

• Journal of Broadcast Engineering
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• v.13 no.2
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• pp.245-250
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• 2008

Efficient service discovery mechanism is a crucial feature for the usability of a wireless ad-hoc network. A wireless ad-hoc network is a temporal network formed by a collection of wireless mobile nodes without the aid of any existing network infrastructure or centralized administration. We propose an efficient service discovery mechanism using non-disjoint multi-path routing protocol for a wireless ad-hoc network. Our scheme has advantages of not only multi-path routing protocol but also cross-layer service discovery. By simulation, we showed that faster route recovery is possible by maintaining multiple routing paths in each node, and the route maintenance overhead can be reduced by limiting the number of multiple routing paths and by maintaining link/node non-disjoint multi-path.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.64-75
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• 2007

Service discovery protocols is software components to find specific services or resources on network. The SLP defined by IETF protocol is a framework for automatic service discovery on IP based networks. Automatic service discovery is an important component on ubiquitous computing environment. This paper proposes a service discovery architecture named as SLPA(Service Location Protocol based on AMAAM). AMAAM(Mobility Agent Advertisement Mechanism) is an aggregation-based Mobile IP implementation in MANET. In SLPA, the role of the directory agent is assigned to the mobility agent in AMAAM. The mobility agent periodically beacons an advertisement message which contains both the advertisement of the directory agent in SLP and the advertisement of the mobility agent in Mobile IP. For evaluating the functional correctness of SLPA and the overhead of maintaining a service directory of SLPA. We simulate SLPA using ns-2 and analyze the overhead of control overheads for the aggregation. Through the simulation experiments we show the functional correctness of the proposed architecture and analyze the performance results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9B
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• pp.947-954
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• 2009

In mobile ad hoc networks, service discovery to search for an available service is an important issue. In this paper, we propose an efficient service discovery protocol that is combined a dht-based service discovery scheme and a P2P caching-based information spreading scheme. Proposed scheme store key information in hashed zone and search services using it's information. To search quickly a service, it use its physical neighbors information which collected by 1-hop hello message between a node and its physical neighbors. We do not use a central look up server and do not rely on flooding. Hence, it uniquely balanced all node's load in mobile ad hoc networks and reduced the number of messages exchanged, network load and response time. The simulation results show that our protocol outperforms DHT-based and flooding protocols.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.205-208
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• 2011

In recent years, the user interest has increased for DDS (Data Distribution Service) which is a data centric middleware based on publish-subscribe communication as the demands for real-time data exchange in distributed systems have been growing rapidly. To reflect these needs, many vendors and research groups provide their DDS middleware. However, there has been a problem with interoperability between DDS middlewares because of a lack of common communication rules such as the message exchange and the discovery manner. For this reason, OMG defines RTPS (Real-Time Publish-Subscribe) specification which is the standard network protocol used to exchange data between different implementations of DDS. In this paper, we analyze and design the SDP (Simple Discovery Protocol) of RTPS which enable DDS middleware to provide interoperable discovery mechanism.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.292-294
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• 2004

향후 세상의 모습을 그려볼 때 흔히들 유비쿼터스 시대를 언급한다. 이를 위해서는 다양한 서비스 공급자들과 사용자들이 서로 네트워크로 묶여 있어야 하며, 이때의 네트워크는 선이 없는 무선 환경이고, 국소 지역을 커버하는 Ad-hoc망이 기본 네트워크 망이 될 것이다. 이러한 네트워크로 이루어진 다양한 장소, 임의의 시간에 존재하는 다수의 서비스들 중에서 원하는 서비스를 찾는 일을 service discovery라고 하며, 이를 위해서 기존의 wired 망에서는 네트워크 계층 위에서 이를 수행하는 작업이 이루어져 왔다. 본 논문에서는 service discovery 실행을 별도의 에이전트나 응용 레벨에 두지 않고, 이를 Ad-hoc 라우팅 계층에서 수행 함으로써 오버헤드 트래픽이 줄어들고, 응답 시간이 짧아지는 성능 향상이 있음을 제시하고 있다. E한 동적/부분 caching 기법에 대해서도 제시하고 있다. 아울러 다양한 사용자의 기호(User Preference)를 표현하고, 이를 바탕으로 서비스를 검색하기 위한 새로운 서비스 표현/검색 모델을 제시하였다. 실제로 이러한 service discovery 기능을 Ad-hoc 라우팅 계층에서 처리하도록 하는 Ad-hoc 라우팅 데몬을 구현하고, 테스트 베드를 구축하여 동작 시킴으로써 실제 상황에서도 얼마나 효율적인가를 구체적으로 제시하고 있다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.856-859
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• 2005

There are various clients, information appliances, sensors in a home network environments. These devices can dynamically join a network, convey its capabilities, and learn about the presence and capabilities of other devices- all automatically. Most of a home network middleware provide the protocols that discovery devices and services. In this paper we look about service discovery protocol and security that is offered in Jini, UPnP, SLP, Bluetooth.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.558-561
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• 2004

Currently, most IP multicasting applications are implemented based on Any-Source Multicast (ASM) model that supports many to many multicast services. However, it is known that current ASM-based multicast architecture has several deployment problems such as address allocation, lack of access control, and inefficient handling of well-known multicast sources. Source-Specific Multicast (SSM) working group in IETF proposed SSM architecture to overcome the weaknesses of ASM architecture. The architecture of SSM is based on one to many multicast services. Also, in order to provide SSM service, Multicast Listener Discovery Version 2 (MLDv2) protocol should be supported. In this paper, we introduce the architecture of SSM protocol and multicast group management protocol. After that, we present the architecture and implementation of IPv6 SSM and MLDv2 protocols in Linux systems.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1545-1549
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• 2005

According as computer is supplied in a lot of homes and offices and Internet use increases, various service based on the Internet. Including wireless PDA in the future, many devices such as Internet telephone, TV, refrigerator and oven will be connected on the Internet and Internet address exhaustion will be raised to serious problem gradually. Today, the IPv4 address exhaustion problem has been solved partially using NAT (Network Address Translation) however, the transition to next Generation Internet will be accelerated because of advantages such as mobility, security service, QoS, and abundant IP addresses. In IPv6, all hosts are designed to create and set their address automatically without manager's intervention using Neighbor Discovery Protocol. But, when an IPv6 host sets its address automatically, there are serious security vulnerabilities. In this paper, we analysis security vulnerabilities in auto-configuration and provide security requirements for secure auto-configuration.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.296-296
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• 2006