• 한국통신학회논문지
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• 제38B권11호
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• pp.895-901
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• 2013

본 논문에서는 USN 기반 다중 프로토콜 게이트웨이 미들웨어의 설계를 제안한다. 제안된 다중 프로토콜 게이트웨이 미들웨어는 송신 메시지 형식을 정의하고, UART를 사용하여 MCU 외부 응용 프로그램에 연결을 위하여 USN 모듈 인터페이스 프로토콜을 사용하였다. 이 경우, 게이트웨이는 설정정보와 함께 지그비 모듈과의 통신 상태를 확인하고, 지그비 시리얼 PDU 형식을 설정한다. 제안된 다중 프로토콜 게이트웨이 미들웨어 실험 결과, 전력제어 및 통신제어 실험을 통해 재생 중계 장치를 사용하는 게이트웨이보다 다중 프로토콜 게이트웨이를 사용하는 통합 프로토콜 게이트웨이의 효율성을 입증하였다.

• International journal of advanced smart convergence
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• 제8권2호
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• pp.109-115
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• 2019

Currently, LPWA(Low Power Wide Area) communication technology is widely used due to the development of IoT(Internet of Things) technology. Among the LPWA technologies, LoRaWAN(Long Range Wide Area Network) is widely used in many fields due to its wide coverage, stable communication speed, and low-cost modem module prices. In particular, LoRa(Long Range) can easily construct LoRaWAN with a dedicated gateway. So many organizations are building their own LoRaWAN-based networks. The LoRaWAN Gateway receives the LoRa packet transmitted from an End-device installed in the adjacent location, converts it into the Internet protocol, and sends the packet to the final destination server. Current LoRa Gateway uses a single-hop method, and each gateway must include a communication network capable of the Internet. If it is the mobile communication(i.e., WCDMA, LTE, etc.) network, it is required to pay the internet usage fee which is installed in each gateway. If the LoRa communication is frequent, the user has to spend a lot of money. We propose an idea on how to design a multi-hop protocol which enables packet routing between gateways by analyzing the LoRaWAN communication method implemented in its existing single-hop way in this paper. For this purpose, this paper provides an analysis of the standard specification of LoRaWAN and explains what was considered when such protocol was designed. In this paper, two gateways have been placed based on the functional role so as to make the multi-hop protocol realized: (i) hopping gateway which receives packets from the end-device and forwards them to another gateway; and (ii) main gateway which finally transmits packets forwarded from the hopping gateway to the server via internet. Moreover, taking into account that LoRaWAN is wireless mobile communication, a level-based routing method is also included. If the protocol proposed by this paper is applied to the LoRaWAN network, the monthly internet fee incurred for the gateway will be reduced and the reliability of data transmission will be increased.

• 한국정보통신학회논문지
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• 제11권12호
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• pp.2265-2270
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• 2007

본 논문은 IETF와 ITU-T에서 공동으로 권고하는 미디어 게이트웨이 제어 프로토콜인 MEGACO/H.248 기반의 미디어 게이트웨이 컨트롤러와 액세스 게이트웨이의 호 처리 성능 및 기능시험 연구에 관한 내용이다. 기존 PSTN망에서 서비스되고 있는 음성 트래픽을 IP망으로 통합하는 차세대 통합네트워크의 핵심적인 구성요소로서 미디어 게이트웨이 컨트롤러와 액세스 게이트웨이의 호 처리 성능 및 기능을 시험하기 위한 효과적인 방법 및 시험 시스템 구조에 관한 연구로, 특히 시험 환경 구축을 위해 액세스 게이트웨이에 접속되는 다수의 아날로그 라인들에 대한 가상 에뮬레이션 기능과, 미디어 게이트웨이 컨트롤러와 액세스 게이트웨이 시험을 위해, 프로토콜의 상대역할을 에뮬레이션하는 시험기로 동작하는 효과적인 방안과 그 타당성을 논의한다.

• 한국통신학회논문지
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• 제26권6A호
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• pp.957-964
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• 2001

현재 국내·외적으로 VoIP 관련 시장의 지속적인 성장으로 인해 VoIP 표준 프로토콜에 대한 국제 표준화 작업과 병행하여 프로토콜 스택과 같은 소프트웨어 개발이 절실한 상황이다. 본 논문에서는 IETF RFC2705에서 제시한 MGCP 문법을 기반으로 문법 지식적 변환 기법으로 Media Gateway가 전달하는 MGCP 요청 메시지를 구조체 형태로 변화하는 엔코더와 Media Gateway Controller로부터 전달되는 구조체 형태의 응답 메시지를 텍스트 형태로 변화하는 디코더를 구현하였다. 이를 위해 BNF 형식의 MGCP 문법을 기술하여 구문 분석 동작 후 구문 트리 및 MGCP 문법으로부터 생성 가능한 모든 정보를 저장할 수 있는 구조체 형태의 헤더 파일을 자동 생성하였다.

• 융합신호처리학회논문지
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• 제10권3호
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• pp.176-180
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• 2009

This paper investigates protocol architecture for a web-sensor gateway interconnecting internet and wireless sensor network, in which Zigbee sensors are connected over the IEEE802.15.4 communication protocol standard. The web-sensor gateway is to deliver data between TCP/IP and Zigbee/IEEE802.15.4 protocols, transparently. Since the gateway provides a means to remotely control and aggregate sensor data over the internet, it needs to be designed in the view point of users and in their convenience. In accordance, the common gateway interface technology satisfying users on the web browser to efficiently manage and query the sensors in the wireless sensor networks, ubiquitously, is also introduced. Finally, a simulation prototype for the web-sensor gateway is proposed and verified using OPNET simulation tool.

• Journal of Communications and Networks
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• 제13권6호
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• pp.583-590
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• 2011

Full-mesh IPSec tunnels pass through a black ("unsecure") network (B-NET) to any red ("secure") networks (RNETs). These are needed in military environments, because they enable dynamically changing R-NETs to be reached from a BNET. A dynamically reconfiguring security policy database (SPD) is very difficult to manage, since the R-NETs are mobile. This paper proposes advertisement process technologies in association with the tunnel gateway's protocol that sends 'hello' and 'prefix advertisement (ADV)' packets periodically to a multicast IP address to solve mobility and security issues. We focus on the tunnel gateway's security policy (SP) adaptation protocol that enables R-NETs to adapt to mobile environments and allows them to renew services rapidly soon after their redeployment. The prefix ADV process enables tunnel gateways to gather information associated with the dynamic changes of prefixes and the tunnel gateway's status (that is, 'down'/restart). Finally, we observe two different types of performance results. First, we explore the effects of different levels of R-NET movements on SP adaptation latency. Next, we derive the other SP adaptation latency. This can suffer from dynamic deployments of tunnel gateways, during which the protocol data traffic associated with the prefix ADV protocol data unit is expected to be severe, especially when a certain tunnel gateway restarts.

• 대한임베디드공학회논문지
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• 제5권4호
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• pp.217-224
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• 2010

Nowadays, people perform their tasks anywhere anytime using their mobile devices. For this reason, data synchronization (DS) between mobile devices and a central server has become one of the most essential technologies in mobile environments. Currently, several mobile DS protocols are proposed and used. However, the existing DS protocols cannot guarantee interoperability between them. To solve the problem, an embedded DS gateway has been developed in our previous study. The gateway runs on a Windows Mobile-based emulator. It converts data on a mobile device into common data specified by OMA DS standard protocol and vice versa. The embedded gateway has been built to support the OMA DS standard protocol. In order to verify that the embedded gateway conforms to the OMA DS standard protocol, two kinds of OMA conformance tests have to be conducted - interoperability test with an OMA DS-based server and conformance test with SCTS (SyncML Conformance Test Suit). In this paper, some parts of the gateway previously built are modified and the modified gateway is installed on a Windows Mobile-based smart phone. And the interoperability test and the conformance test with the SCTS are conducted. The results of the tests show that the embedded DS gateway operates properly on the Windows Mobile-based smart phone and that the gateway passes the tests, verifying its conformity to the OMA DS standard protocol. In addition, DS performance tests show that DS delay times between a real smart phone and a DS server increase gently as the number of DS data increases. In other words, the embedded DS gateway built in this paper can be used for a real smart phone at a reasonable performance cost.

• 한국통신학회논문지
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• 제19권7호
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• pp.1346-1363
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• 1994

패킷 음성 프로토콜은 지금까지 많이 연구되고 구현되어왔다. 하지만 음성통신을 위한 근거리 통신망과 사설교환기사이의 연동에 대한 연구는 아직 많은 편은 아니다. 본 논문에서는 근거리 통신망과 기존의 사설교환기사이의 음성통신을 위한 게이트웨이를 설계하고 구현하였다. 구현한 게이트웨이의 프로토콜은 CCITT의 G.764 패킷 음성 프로토콜을 수정. 사용하였다. 연동을 위한 하드웨어 시스템을 구현하였으며, 이는 전화선과의 인터페이스 부분, 음성처리부분, PC 인터페이스 부분 및 제어부분, 그리고 DTMF(Dual Tone Multiple Frequency) 접속부분으로 나누어진다. 그리고 소프트웨어는 근거리 통신망 접속용 네트웍카드를 구동하는 패킷 드라이버를 이용하기위한 인터페이스 부분과 게이트웨이를 구동하는 드라이버, 그리고 프로토콜 처리부분으로 구성되어있다.

• Journal of Communications and Networks
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• 제17권2호
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• pp.118-125
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• 2015

In this paper, we propose a method to reduce mobile social network services (SNSs) traffic using a mobile integrated SNS gateway (MISG) to improve network communication performance between the mobile client and SNS servers. The gateway connects the client and SNS servers using the contents adapter and the web service adapter and helps to improve communication performance using its cache engine. An integrated SNS application, the user's client, communicates with the gateway server using integrated SNS protocol. In addition, the gateway can alert the client to new SNS contents because of the broker server implemented by the message queuing telemetry transport protocol. We design and develop the modules of the gateway server and the integrated SNS application. We then measure the performance of MISG in terms of content response time and describe the result of the experiment.

• 제어로봇시스템학회논문지
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• 제8권5호
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• pp.434-437
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• 2002

A small size and light-weight DSP board is newly designed for a real time multi-distributed control system that overcomes constraints on time and space. There are a variety of protocols for a real-time distributed control system. In this research, we selected CAN for the multi distributed control, which was developed by the BOSCH in the early 1980's. If CAN and Internet are connected together, the system attains the characteristics of a distributed control system and a remote control system simultaneously. To build such a system. The TCP/IP-CAN Gateway which converts a CAN protocol to TCP/IP protocol and vice verse, was designed. Moreover, the system is required to be small and light-weighted for the high mobility and cost effectiveness. The equipment in remote place has a TCP/IP-CAN Gateway on itself to be able to communicate with another systems. The received commands in the remote site are converted from TCP/IP protocol to CAN protocol by the TCP/IP-CAN Gateway in real time. A simulation system consists of a TCP/IP-CAN Gateway in remote place and a command PC to be connected to Ethernet.