• ETRI Journal
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• v.40 no.3
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• pp.355-365
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• 2018

The increase in data traffic calls for investment in mobile networks; however, the saturating revenue of mobile broadband and increasing capital expenditure are discouraging mobile operators from investing in next-generation mobile networks. Mobile network sharing is a viable solution for operators and regulators to resolve this dilemma. This research uses a difference-in-differences analysis of 33 operators (including 11 control operators) to empirically evaluate the cost reduction effect of mobile network sharing. The results indicate a reduction in overall operating expenditure and short-term capital expenditure by national roaming. This finding implies that future technology and standards development should focus on flexible network operation and maintenance, energy efficiency, and maximizing economies of scale in radio access networks. Furthermore, mobile network sharing will become more viable and relevant in a 5G network deployment as spectrum bands are likely to increase the total cost of ownership of mobile networks and technical enablers will facilitate network sharing.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.287-291
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• 2008

DWDM(dense wavelength division multiplexing)-PON technology is applied to subscriber network as the same as E-PON or G-PON. And its network components consist of OLT, ONU and RN. Legacy DWDM technologies have been applied on the long-haul part of optical network due to its excessive high cost. But many researchers have successfully devised a few methods which can considerably reduce the cost of equipment. Nowadays DWDM-PON equipment's has arrived to a level having a competitive price in comparison to E-PON or G-PON on condition of giving equal bandwidth. Recently a major domestic ISP has deployed DWDM-PON equipments in one apartment complex area in the purpose of satisfying ever-increasing bandwidth demand. The ISP increased data transmission capacity from 1 G to 16G without any additional fiber deployment. In this paper we introduce roughly three technologies of implementing DWDM-PON's optic module and related optic devices. And we also describe pre-test of vendor's DWDM-PON equipment and discuss the result. Lastly we propose some of network configurations which adopt DWDM-PON technology. By adopting DWDM-PON technology ISP can greatly save the cost of deploying broadband subscriber network.

• International Journal of Knowledge Content Development & Technology
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• v.11 no.1
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• pp.29-48
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• 2021

The paper discusses the ICT infrastructure as far as the availability of (computers, local or wide area networks, Internet connectivity and its reliability, size of the bandwidth and its optimization, etc.) in the S&T research institution. It also examined the profile of the research scientists and looked at the type of ICT infrastructure that is available for their use as well as the reliability of the Internet connectivity within these research institutions. It looked at the broadband capacities of the research institutions and the ICT capabilities in respect of the technical and managerial support back-up that are available to the research institutions. The study used the survey research method with a questionnaire as well as personal observation to gather the data. From the data gathered, it was realized that the internet connectivity and the size of the bandwidth that the R&D institutions subscribed to differed significantly. Again, the extent to which the research scientists were able to access the internet in their respective institutions depended on the quality of the local network in place. Generally, the investments in ICT were made for different management objectives, and these were meant to facilitate the generation of new knowledge as well as make measurable improvements in R&D activities.

• Journal of Communications and Networks
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• v.8 no.2
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• pp.228-233
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• 2006

Survivability is a very important requirement for the deployment of broadband networks because out of service links can affect volumes of traffic even if it is a very short time. And the data paths of broadband networks, which are critical for traffic engineering, are always necessary to be well protected. The procedure of protection or restoration for a path is initiated when failure is detected within the working path. In order to minimize the influence on transmission quality caused by the failure of links and to provide a definite time for the recovery from the failure, the protection switching time (PST) should be carefully considered in the path arrangement. Several researches have been devoted to construct the protection and restoration schemes of data paths over dense wavelength division multiplexing (DWDM) networks, however, there was rare research on the design of data paths with guaranteed protection switching time. In this paper, the PST-guaranteed scheme, which is based on the concept of short leap shared protection (SLSP), for the arrangement of data paths in DWDM networks is proposed. The proposed scheme provides an efficient procedure to determine a just-enough PST-guaranteed backup paths for a working path. In addition to selecting the PST-guaranteed path, the network cost is also considered in a heuristic manner. The experimental results demonstrate that the paths arranged by the proposed scheme can fully meet the desired PST and the required cost of the selected path is competitive with which of the shared path scheme.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.3
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• pp.264-273
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• 2005

Broadband power line communications have been receiving tremendous interest In recent years because this technology enables utilities to deploy a communication network over existing power line infrastructures. Despite the enormous potential, there is some skepticism about the technology and its commercial viability. In this paper, we investigate the performance characteristic of PLC through field test carried out in actual households. Also it addresses major field deployment aspects, such as range, coverage, the number of node for operation and maintenance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4B
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• pp.291-302
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• 2006

With the increasing deployment of mobile devices and the advent of broadband wireless access systems such as WiBro, WiMAX, and HSDPA, an efficient IP mobility management protocol becomes one of the most important technical issues for the successful deployment of the broadband wireless data networking service. IETF has proposed the Mobile IPv6(MIPv6) as the basic mobilitymanagement protocol for IPv6 networks. To enhance the performance of the basic MIPv6, researchers have been actively working on HMIPv6 and FMIPv6 protocols. In this paper, we propose a new mobility management protocol, HIMIPv6 (Highly Integrated MIPv6), which tightly integrates the hierarchical mobility management mechanism of the HMIPv6 and the proactive handover support of the FMIPv6 to enhance the handover performance especially for the cellular networking environment with high frequent handover activities. We have performed extensive simulation study using ns-2 and the results show that the proposed HIMIPv6 outperforms MIPv6, FMIPv6 and HMIPv6 in terms of signaling overhead, service interruption and packet lost during handovers.

• 한국정보통신설비학회:학술대회논문집
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• 2002.08a
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• pp.110-113
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• 2002

FS-VDSL은 B-PON과 VDSL을 이용하여 가입자에게 디지털TV, VOD, 초고속인터넷, 전화 등을 총 망라한 Full Service를 제공하기 위해 필요한 모든 망구조 및 프로토콜에 대해서 규정한다. FS-VDSL의 전신은 FSAN xDSL working group이며, FSAN에서 정의한 B-PON을 기본적인 액세스망으로 정의하고 있다. 본 논문에서는 End-to-end Full Service 제공을 위하여 FS-VDSL에서 솔루션으로 제시하고 있는 하이브리드 코어망, B-PON 및 VDSL 액세스망, Ethernet 홈네트워크를 포함하는 End-to-end 망구조 및 각각의 프로토콜에 대하여 살펴본다. 또한 Full Service의 핵심인 영상서비스 수용을 위하여 효율적인 비디오 트래픽 전달이 가능한 비디오 인켑슐레이션 프로토콜 및 DBTV 채널변경 프로토콜 등에 대하여 살펴보고, FS-VDSL에서 제시하는 방안을 이용한 KT의 브로드밴드 망구축 적용성에 대해 살펴본다.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.43-46
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• 2006

IEEE 802.16 WirelessMAN aiming to broadband wireless access (BWA) is evolving to 4G mobile communication system through the standardization of IEEE 802.16e supporting mobility on existing fixed WirelessMAN system. It is necessary for hand-over to provide seamless data service while MS (Mobile Station) moves to another BS (Base Station). Because the performance of handover affects packet loss or delay of any communications, it must consider low latency handover mechanism in packet based network. In this paper, we describes handover scheme of IEEE 802.16e with the cell edge interference problem and shows the way to solve the problem in frequency reuse one deployment. Our scheme reduces the handover latency and packet loss probability.

• Journal of the Korea Computer Industry Society
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• v.9 no.2
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• pp.77-82
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• 2008

The diversity reception and the equal gain combining technique are applied to the compensation of the distortion of channel, which occurs in transmission of data at rapid speed. DSSS BPSK system which has the receiving structure with the compensation algorithm is formed on the diversity branch, and the characteristics of the system are evaluated at the view point of the average bit error rate due to the SNR. In addition, the multi-tap update algorithm which is superior for the data compensation is suggested. Moreover, using the American Joint Technical Committee PCS RF channel characterization and system deployment model standard, the suggested multi-tap update algorithm is compared and analyzed with the view-point of the average bit error rate and convergence speed for evaluating the realistic efficiency of the system.

• Journal of the Optical Society of Korea
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• v.12 no.4
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• pp.326-336
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• 2008

A WDM-PON has been considered as an ultimate solution for access networks. However, there were many technical and practical issues for commercial deployment. These issues were solved with wavelength locked F-P LD and the WDM-PONs employing this optical source were commercialized. These WDM-PON systems have been deployed in Korea, Europe, and US. We reviewed wavelength locking technology and WDM-PON achievements. When we inject spectrum sliced broadband light into an F-P LD, the multimode output is changed to a quasi single mode. Then, we can use the single mode light for WDM signal transmission. The broad spectral gain of the semiconductor gain medium enables a color-free operation of WDM-PON, i.e., an identical ONT can be used for each user. The wavelength locking properties depend on many parameters, especially alignment of injection wavelength to a lasing mode, passband profile of AWG and front facet reflectivity of F-P LD. However, these dependencies can be reduced by proper design of the laser and the injection bandwidth. Thus, WDM-PON systems have been achieved with color-free operation.