• Journal of the Korea Institute of Military Science and Technology
• /
• v.21 no.6
• /
• pp.826-841
• /
• 2018

The military satellite communication of ROK military, ANASIS is designed for analog data such as voice and streaming data. ANASIS cannot fully support ALL-IP communications due to its long propagation delay. The next generation satellite communication system is being designed to overcome the limitation. Next generation satellite communications system considers both high-speed and low-speed networks to support various operating environment. The low-speed satellite supports both broadband and narrow-band communication. This network works as the infrastructure for of wide-area internetworking over multiple AS's in the terrestrial network. It requires minimum satellite frequency and minimum power and works without PEP and router. In this paper, we propose a network operation structure to enable the inter-operation between high and low-speed satellite networks. In addition, we propose a data link protocol for low speed satellite networks.

• Journal of the Semiconductor & Display Technology
• /
• v.9 no.2
• /
• pp.7-10
• /
• 2010

In this paper, we design a modem SoC (System on Chip) for low power consumption and high speed wireless communications. Among various schemes of high speed communications, an MB-OFDM (Multi Band-Orthogonal Frequency Division Multiplexing) UWB (Ultra-Wide-Band) chip is designed. The MB-OFDM uses wide-band frequency to provide high speed data rate. Additionally, the system imposes no interference to other services. The 90nm CMOS (Complementary Metal-Oxide Semiconductor) technology is used for the SoC design. Especially, power management mode is implemented to reduce the power consumption.

• IEIE Transactions on Smart Processing and Computing
• /
• v.6 no.2
• /
• pp.133-139
• /
• 2017

Vehicles have increasingly evolved and become intelligent with convergence of information and communications technologies (ICT). Vehicle communications (VC) has become one of the major necessities for intelligent vehicles. However, VC suffers from serious security problems that hinder its commercialization. Hence, the IEEE 1609 Wireless Access Vehicular Environment (WAVE) protocol defines a security service for VC. This service includes Advanced Encryption Standard-Counter with CBC-MAC (AES-CCM) for data encryption in VC. A high-speed AES-CCM crypto module is necessary, because VC requires a fast communication rate between vehicles. In this study, we propose and implement an efficient AES-CCM hardware architecture for high-speed VC. First, we propose a 32-bit substitution table (S_Box) to reduce the AES module latency. Second, we employ key box register files to save key expansion results. Third, we save the input and processed data to internal register files for secure encryption and to secure data from external attacks. Finally, we design a parallel architecture for both cipher block chaining message authentication code (CBC-MAC) and the counter module in AES-CCM to improve performance. For implementation of the field programmable gate array (FPGA) hardware, we use a Xilinx Virtex-5 FPGA chip. The entire operation of the AES-CCM module is validated by timing simulations in Xilinx ISE at a speed of 166.2 MHz.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.705-708
• /
• 2010

Recently, HSRC (Half-Symbol-Rate-Carrier) OQPSK (Offset Quadrature Phase Shift Keying) signaling which reduces the bandwidth of transmitted signal for high-speed data communications has been introduced. Since the signal is based on QPSK modulation, it also has the characteristics of QPSK signal. This paper introduces architectures of the transceiver using differential coding to resolve the 4-phase ambiguity problem of the HSRC-QOPSK signaling for high-speed data communications. In addition, this paper proves the functionality of the transceiver with differential coding and shows the BER (bit-error-rate) performance of the transceiver by simulations.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.4
• /
• pp.454-460
• /
• 2016

Unlike conventional visible light communications (VLC) adopting photo detectors (PD), optical camera communications (OCC) employs cameras in detecting the transmitted data. Especially, the data rate of OCC can be enhanced by using the principle of rolling-shutter, which is the operating scheme of a CMOS image sensor. In this study, we consider a novel OCC system for high-speed real time video processing to transmit high speed data from LED and to acquire image utilizing rolling-shutter effect of CMOS image sensor. Also, we demonstrate the improved performance of proposed system using a test-bed.

• Proceedings of the IEEK Conference
• /
• 2002.07c
• /
• pp.1823-1826
• /
• 2002

On modern computer culture, the high quality data is required in multimedia systems. So, the technology of data compression fur data transmission is necessary now. This paper presents the pipeline architecture for the low and column address generator of 2D DCT/IDCT (Discrete Cosine Transform/Inverse Discrete Cosine Transform. In the proposed architecture, the area of hardware is reduced by using the DA (distributed arithmetic) method and applies the concepts of pipeline to the parallel architecture. As a result the designed pipeline of the low and column address generator for 2D DCT/IDCT architecture is implemented with an efficiency and high speed compared with the non-pipeline architecture.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.16 no.5
• /
• pp.1-11
• /
• 1979

Since the second half of 1960's one of the information industry's most vital, yet least-well-understood areas has evolved-Data communications/Computer communications. To successfully realize this field we have to identity and reveal a variety of fundermental characteristics of communications channels and see their high reliability as prerequisites. This paper has accumulated related data from 1973 on, systematically analyzed them and provided some basic back ground and suggestions. Error rate which is the final and external characteristics of communication lines according to channal types, communication types and speed, block length and geographical difference between test points was extensively examined as well as their frequency response and d-c characteristics. The perspective of 9600BPS high speed data communications was also discussed.

• Proceedings of the KIEE Conference
• /
• 2000.07d
• /
• pp.3121-3123
• /
• 2000

Power line communications is a topic which has been studied for many years, However. the technology has not been widely adopted for data networking in homes and small businesses due to low speed. low functionality. and other barriers. Recently. with a proper technology. it is shown that the power line infrastructure can also be served as a high-speed communications medium. This paper describes a transmission scheme for power lines that is based on orthogonal frequency division multiplex(OFDM) technique. This technique can be used for high-speed data communication over the power line. This paper also presents an adaptive tracking algorithm which allocate bits and power adaptively according to the channel characteristics. The performance of the proposed scheme has been demonstrated by some simulations with taking modeled channel conditions into account.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.12B
• /
• pp.1052-1062
• /
• 2004

Recent studies have pointed out that existing high-speed TCP protocols have a severe unfairness and TCP friendliness problem. As the congestion window achieved by a high-speed TCP connection can be quite large, there is a strong possibility that the sender will transmit a large burst of packets. As such, the current congestion control mechanisms of high-speed TCP can lead to bursty traffic flows in hi인 speed networks, with a negative impact on both TCP friendliness and RTT unfairness. The proposed solution to these problems is to evenly space the data sent into the network over an entire round-trip time. Accordingly, the current paper evaluates this approach with a high bandwidth-delay product network and shows that pacing offers better TCP friendliness and fairness without degrading the bandwidth scalability.

• Journal of the Korean Professional Engineers Association
• /
• v.24 no.1
• /
• pp.95-103
• /
• 1991

The communication transmission engineering plays the most important role in electrical communications engineering. Recently, it has been making remarkable progress as an infrastructure supporting informationaged society. Specially, the start of television conference and service of high speed digital transmission can be said it is announcing a raising curtain of high speed broad band age. Together with high speed broad band service needs a capacity as much as several or several hundred times of telephone with one circuit, various kinds of service forms are anticipated to emerge, it is anticipated to give a big impact to the way of future communications newtork. At present, telecommunication network is transforming telephone voice information by analog technology into a flexible higher system disposable of a variety of information such as pictures or data other than telephone by the introduction of digital technology. Consequently, the development of hereafter for the following respective technologies is desired.