• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.2
• /
• pp.382-389
• /
• 2009

As the use of mobile device is popularized, the needs of variable services of WiMAX technique and the importance of security is increasing. There is a problem that can be easily attacked from a malicious attack because the action is achieved connectionlessly between neighbor link establishing procedure and TEK exchange procedure in mobile WiMAX even though typical 1 hop network security technique is adapted to WiMAX for satisfying these security requirement. In this paper, security connected mechanism which safely connects neighbor link establishing procedure of WiMAX and TEK exchange procedure additional to the basic function provided by IEEE 802.16e standard to satisfy security requirement of mobile WiMAX is proposed. The proposed mechanism strengthens the function of security about SS and BS by application random number and private value which generated by SS and BS to public key of neighbor link establishing procedure and TEK exchange procedure. Also, we can prevent from inside attack like man-in-the-middle which can occur in the request of TEK through cryptographic connection of neighbor link establishing procedure and TEK exchange procedure.

• Proceedings of the IEEK Conference
• /
• 2000.11a
• /
• pp.295-298
• /
• 2000

본 논문은 ATM교환기에서 Non-ATM정합을 위한 미디어게이트웨이의 개발방안과 하드웨어, 소프트웨어 구조에 대해서 기술한다. 미디어게이트웨어의 하드웨어 구조는 ATM계층처리보드와 다중화처리보드 및 서비스보드들로 구분되며 Non-ATM을 서비스별로 처리할 수 있는 보드를 모듈당 최대 8매까지 실장 할 수 있다. 다중화처리보드는 ATM셀 MUX/DEMUX기능과 IPC송수신기능을 처리하고 서비스보드의 링크상태관리, 운용기능을 수행한다. 서비스보드의 종류는 프레임릴레이, 회선대행, AAL2 트렁킹, N-ISDN중계선 연동기능을 각각 수행한다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.14 no.6
• /
• pp.1069-1076
• /
• 2019

With the development of information and communication technology, the military's battle environment is changing greatly to network centric warfare in where weapon system is connected in a network and carries out mission by exchanging the real-time data. The core of the network centric warfare is Tactical Data Link(TDL) system, and subscribers of TDL exchange tactical information in real time through wireline, wireless and satellite network to share the battlefield situation. The amount of data sent and received through TDL inevitably increase as military's weapon systems equipped with TDL systems increase over time and the performance of communications equipment improves. This study proposes ways to improve the transmission speed and processing capacity of the TDL system by improving the Data Link Processor.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.9B
• /
• pp.1542-1550
• /
• 2000

Fiber optic link systems based on SCM scheme are widely used as efficient and economic RF signal links between base station and a central station in mobile communication networks. However, its performance can be seriously limited depending on the operational conditions of not only the optical transmission system but also the wireless link in various environments. In this paper, we propose an analytic model for performance analyses of the SCM fiber optic link for CDMA RF signal transmission in various link environments. We present optimal operational conditions taking account of the nonlinear effects of the optical transmission system, and the multiple access interference produced at the wireless link. It has been shown through the BER analyses in this paper that the selection of optical modulation index of the SCM fiber optic links can be found optimally to minimize the fiber optic link noises and intermodulation distortion due to LD.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.20 no.6
• /
• pp.43-51
• /
• 1983

A small-scale packet switching system is designed in compliance with the CCITT Recommen-dation X.25 Each switching node is controlled by a single microcomputer for all functions including terminal access control, packet-level control and link control. Basic protocol functions are successfdly implemented for the three basic hierarchical Igvels, and their results are discussed in detail.

• Journal of the Korea Society of Computer and Information
• /
• v.16 no.3
• /
• pp.75-87
• /
• 2011

Tactical Data Links are standardized radio communication data links for military armed forces and used to transmit and receive data. Because they are the core elements of achieving information superiority in a NCW environment, various kinds of TDL are used by the Korean armed forces. Operating various types of TDL is very helpful in getting more information; however, at the same time, it is hard to integrate and make them co-operate with other TDLs or C4ISR systems. In this paper, we propose a XML based messaging system to make various types of TDL interoperable in a NCW environment. For the messaging system between TDL and C4ISR systems, we define XML message processing interfaces and suggest binary XML for serialization to save transmission loads over constrained military communication bandwidth. Our experiment results show that the TDL message can be transformed into generalized XML data that is interoperable with other TDLs and binary XML serialization, and it saves parsing and transmission time.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.26 no.9A
• /
• pp.1583-1591
• /
• 2001

본 논문에서는 이동성 IP 기반 네트워크에서 효과적인 헤더압축 기법 및 압축상태 복구기법을 이용한 효율적인 비디오 트래픽 관리기법을 제안한다. 이동성 무선 링크의 대역폭은 물리매체와 무선 구간내 데이터 전송에 따른 주파수의 사용에 제약을 받는다. 또한 셀룰러 액세스 링크의 고비용과 링크손실 특성 등이 IP 기반 네트워크의 성능에 중요한 요소가 된다. 그러므로 자원을 효율적으로 사용하는 것이 필요하며, 셀 위치에 따른 메시지 교환 절차에 대하여 기술한다. 이를 위해 효율적인 헤더압축기법이 요구된다. 따라서 본 연구에서는 지금까지 제안된 기법을 분석하여, 헤더압축 및 이동호스트의 핸드오프 발생시 신속하게 압축상태를 복구하는 기법에 대한 연구를 수행하였다. 제안된 기법은 패킷손실을 줄이는 압축 컨텍스트 값을 인지하도록 하여 신속하여 압축상태로 복원되도록 하였다. 제안된 기법의 성능을 분석하기 위해서 컴퓨터 시뮬레이션을 수행하고, 그 결과에 의해서 제안된 기법의 성능이 개선됨을 입증하였다.

• Electronics and Telecommunications Trends
• /
• v.7 no.1
• /
• pp.114-120
• /
• 1992

이동 가입자에게 통신 서비스를 제공하기 위한 공중 육상이동 통신망은 SS No.7 공통선 신호망을 이용하여 이동 통신망 구성요소 (HLR, VLR, MSC 등) 들을 연결시킨다. HLR, VLR 등은 SS No.7 에서 신호점의 형태로 구현되며 이러한 신호점들은 신호 메시지 중계기능을 갖는 신호 전달점과 신호 메시지 전송기능을 갖는 신호링크를 통하여 메시지를 서로 교환한다. 신호 메시지 전송시 신호링크의 혼잡상태로 인한 트래픽 상의 문제가 발생할 수 있으며 이의 해결을 위한 트래픽 제어방법이 필요하게 된다. SS No.7은 고유의 레벨-3 트래픽 제어 방법(Congestion Control Scheme)을 이용하여 신호 링크 혼잡시 신호 메시지 발신 신호점을 제어한다.

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 1987.04a
• /
• pp.93-97
• /
• 1987

In this paper the data link control procedures for the TDX-1 ESS had been designed and implemented in accordance with the CCITT recommandation X.25 LAPB After a general discussion on intermational standards of link montrol procedures the TDX-1 data link control procedures are described in detail.

• 한국ITS학회:학술대회논문집
• /
• 2005.11a
• /
• pp.89-96
• /
• 2005