• Proceedings of the IEEK Conference
• /
• 1998.10a
• /
• pp.297-300
• /
• 1998

The Phone Voting service allows subscribers to propose a voting through a telephone, and enables them to survey public opinion using telephone network. The demand on this service is growing faster and demands will be increased much more. It makes the bust traffic at the Toll SSP system on Intelligent Network because of the temporary bust traffic congestion on the Toll SSP compared to the normal call traffic. This paper will show what the problems and the causes are, and how we can solve them. The solution to these problems is an implementation of the SSP function on the Local Excange for the PV service.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1997.10a
• /
• pp.239-242
• /
• 1997

Subscriber network investment cost is a main cost element among those constituting the access charges in telephone networks. The purpose of this paper to estimate the investment cost of installing a subscriber network in a typical metropolitan area and to develop a cost modeling framework. To this aim, a metropolitan area in Seoul was investigated. The main cost elements were identified and their relationships with the cable technology, geographical characteristics, and the number of subscribers were analyzed. The findings could be used to design an enhanced cost proxy models for estimating the access charges in a multi-operator environment.

• Proceedings of the IEEK Conference
• /
• 2002.07b
• /
• pp.1109-1112
• /
• 2002

A non-coherent synchronous all-optical code-division multiple-access (CDMA) network is proposed. In this network, symmetric codes derived from prime sequence codes are used. We present the construction of symmetric codes and show that the pseudo-orthogonality of the new codes is the same as that of the original prime-sequence codes while the cardinality of the new codes is larger than that of the prime sequence codes and the modified prime codes in the same field GF(p). Therefore, an optical CDMA LAN using symmetric codes can have a larger number of potential subscribers. The new codes allow designing fully programmable serial all-optical transmitter and receiver suitable for low-loss, high-capacity, optical CDMA LANs. It is also shown that compared to systems using modified prime codes the proposed system can achieve better BER performance for low received chip optical power.

• Journal of Korea Multimedia Society
• /
• v.21 no.9
• /
• pp.1090-1098
• /
• 2018

MQTT is a lightweight messaging protocol that can be used for low power IoT devices. The MQTT basically uses single MQTT broker to indirectly share message information between publishers and subscribers. This approach has a weakness in regard to traffic overflow, connection fault, security, etc. In this paper, we propose a distributed MQTT broker architecture that solves the problems in single MQTT broker structure. The distributed MQTT broker architecture is expected to support new application services that cannot be supported by a conventional MQTT architecture. We have designed and implemented a distributed MQTT broker architecture based on the RPL protocol that has been widely used for IoT network. The experiment results show that the proposed MQTT broker architecture represents better publishing/subscribing latency and network stability than the conventional MQTT broker architecture.

• Proceedings of the Korea Society for Industrial Systems Conference
• /
• 2002.06a
• /
• pp.107-113
• /
• 2002

We have developed the MIBs for Access Gateway which is for diverse subscribers to access the core network at the NGN. We organized the subscriber and network interface Information such as xDSL, ATN, PSTN, MIBs, and so on. The MIBs are managed by EMS.

• ETRI Journal
• /
• v.19 no.3
• /
• pp.98-115
• /
• 1997

The architecture of the CDMA mobile system (CMS) is developed based on three function groups - service resource, service control, and service management groups. In this paper, the CMS architecture is discussed from the point of view of implementing these functions. The variable length packets are used for transmission. The synchronization clock signals are derived form the GPS receiver. The open loop and closed loop techniques are used for the power control. The internationally accepted signaling and network protocols are employed. The call control for the primary services in designed to provide efficient mobile telecommunication services. The softer handoff is implemented in one card. The mobile assisted handoff and the network assisted handoff are employed in the soft and hard handoffs. The authentication is based on the secret data which includes random numbers. The management functions, which include the location management, resource management, cell boundary management and OAM management, are implemented to warrant the system efficiency, maximum capacity and high reliability. The architecture ensures that the CMS is flexible and expandable to provide subscribers with economic and efficient system configuration. The dynamic power control, adaptive channel allocation. and dynamic cell boundary management are recommended for future work.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.6 no.3
• /
• pp.433-438
• /
• 2011

The purpose of this paper is to define WiFi LDT(Location Determination Technology) and Service available for mobile wireless network. This paper introduces positioning technology such as Basic Technology Element and QoS(Quality of Service) etc. of WPS(WiFi Positioning System) for mobile wireless network. The LDT and wireless positioning technology in order to determine the position of terminal when mobile based positioning service is provided, and by providing service with postioning technology, it will not only provide convenience to the users or subscribers but also contribute to the activation of LBS(Location Based Services) industries.

• Electronics and Telecommunications Trends
• /
• v.34 no.1
• /
• pp.36-48
• /
• 2019

Recently, competition among global mobile operators has focused on the commercialization of 5G for the first time. Apart from protecting the privacy of subscribers and the confidentiality and integrity of communication, protecting the network against various cyber attacks is also important to ensure that high-quality mobile services operate safely. In this study, we examine the security vulnerabilities with respect to mobile communication environments using previous and current LTEs. We also investigate whether existing vulnerabilities can be effectively protected and identify security issues that need to be considered in the approaching 5G environment.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.5 s.347
• /
• pp.59-67
• /
• 2006

We demonstrate bidirectional long-reach 35-channel dense wavelength division multiplexing-passive optical network(DWDM-PON) based on wavelength-locked Fabry-Perot laser diodes (F-P LDs). The mode control of F-P LD enhances output power at decreased the required injection power. We show packet-loss-free transmission in all 70 channels at 125 Mb/s per channel line rate through 70 km of single mode fiber without optical amplifier The DWDM-PON can consolidate a metro network into an access network by bypassing the central offices within its reach. The proposed DWDM-PON can accommodate about 80 subscribers with an EDFA-based broadband light source. Further expansion up to 100 subscribers is possible with a semiconductor-based BLS.

• Journal of Advanced Navigation Technology
• /
• v.13 no.2
• /
• pp.172-177
• /
• 2009

Mugunghwa Satellite N0.1 is fired after operation was 13 years. The establishment of communication satellites, as well as Internet service backbone network the country, including satellite broadcasting services to provide multimedia services to general users and contribute to have a big role. High-speed Internet Access Network was expanded and satellite Internet subscribers Access Network rapidly decreasing, but it also a difficult situation, satellite communications network is still important as a component is located. Launched the first communication satellite to be launched and operated several commercial communications satellite, but satellite communications services and the pace of the system is in place. In this paper VSAT, satellite communications service to provide a service based on the status and problems of the status of operating system and will present alternative policies to solve.