Jaekyoung Ahn

A dynamic competition analysis on the Korean mobile phone market using competitive diffusion model

The purpose of this paper is to estimate the demand function of mobile phone subscription in Korea, with an explicit consideration of market competition effects, and to empirically clarify the dynamic competitive relationship between the cellular and PCS services. The demand function was estimated using the Lotka-Volterra model, a famous competitive diffusion model. In addition, the characteristics of the dynamic competitive relationship in the Korean mobile phone market are empirically examined, including the existence of an equilibrium point and its stability with the estimated demand function. The results show that competitive relationship in the Korean mobile phone market exhibits a kind of commensalisms, in which the PCS market benefits from the existence of the cellular market, while the number of cellular subscribers is hardly affected by the PCS market. Furthermore, it is shown that the competition between the cellular and PCS services has a dynamic equilibrium point that is partially stable.

Forecasting service parts demand for a discontinued product

Stochastic demand forecasting methods for service parts of a discontinued product are proposed. The identified four major factors are the number of product sales, the discard rate of the product, the failure rate of the service part, and the replacement probability of the failed part. During a given period, typically a year, the number of failed service parts is estimated using the first three factors, and then the demand for those service parts is obtained with the use of the last factor. A stochastic model is derived to estimate the demand in a certain prediction interval, and the closed-form solutions in the case of a constant failure rate are provided. An approximate model is proposed to render actual computation possible when the part failure time is not distributed exponentially. Numerical data from the automotive industry are used to validate the model.

Integrated/hybrid satellite and terrestrial networks for satellite IMT-Advanced services

This paper addresses key features of the satellite component of IMT-Advanced systems, including candidate system architectures, service scenarios, and candidate radio interfaces. We consider integrated/hybrid satellite and terrestrial networks as an efficient means to meet the main service requirements of the satellite component. As satellite bandwidth is a very scarce resource, efficient frequency reuse techniques will play an important role in the successful deployment of the service. For this reason, we propose an efficient frequency reuse technique, designed for an integrated satellite system to support IMT-Advanced services. In the proposed scheme, satellite and terrestrial components effectively share the same bandwidth. Copyright

Is HAPS viable for the next-generation telecommunication platform in Korea?

HAPS is a promising technology capable of providing broadband multimedia services as an alternative to the satellite communication system or terrestrial network. In this study, economic aspects of HAPS service are analyzed, HAPS services are defined, and revenues from the defined services are forecasted assuming nine scenarios. Capital expenditure as well as operating expenditure is estimated. To evaluate the profitability of HAPS service, the net present value (NPV), payback period, and the internal rate of return (IRR) are calculated. The results show that HAPS is economically justifiable in all the scenarios. Assuming that ARPU for the service is

A study on economic evaluation of IMT-Advanced satellite services in Korea

35 per month in the average scenario, NPV is calculated as

Factors affecting companies’ telecommunication service selection strategy

2964 million, IRR becomes 31.9%, and payback occurs in 2017, which implies that HAPS service is profitable in Korea. In addition, the results of the sensitivity analysis show that the results are fairly robust.

A Competitive Analysis on the Network Infrastructures of Wibro Service in Korea

The objective of this paper is to assess the economic feasibilities of International Mobile Telecommunication (IMT)-advanced satellite services in Korea. IMT-Advanced systems allow mobile services that are able to have an always-on access to a wide range of broadcasting and telecommunication networks including advanced mobile service with transparent devices. In this paper, economic aspects of a Fill-in Service and a Two-way S-DMB Service are analyzed; Revenues from the defined services are forecasted and capital expenditure as well as operating expenditure is estimated. To evaluate the profitability of IMT-advanced satellite services, the net present value (NPV), the internal rate of return (IRR) and economic spill-over effects are calculated. The results show that IMT-advanced satellite service is economically justifiable.