• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.5
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• pp.1027-1035
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• 2000

In this paper, we have proposed the optimum technique for wireless ATM (WATM) error control in indoor environment. As the optimum technique, the conventional concatenated FEC only is regarded as the efficient error control method for time-critical ATM traffic in AWGN, and the pilot symbol-added fading compensation with the concatenated FEC is required to optimize the WATM performance in fading environment. Also, the truncated Type- H hybrid ARQ technique will be developed for quality-critical ATM traffic in order to improve its throughput. Therefore, this paper presents the optimization of WATM performance in indoor environment by means of evaluating above techniques using theoretical analysis and simulation.

• 한국도로학회:학술대회논문집
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• 2004.02a
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• pp.107-112
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• 2004

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.1A
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• pp.1-6
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• 2003

We propose a mathematical model to analyze the performance of TD-CDMA/TDD systems in terms of call blocking probability and then find the optimum time-slot switching-point at the smallest call blocking probability considering asymmetrical traffic load distribution for various kinds of service applications.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.4
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• pp.10-17
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• 2014

This paper presents an analytical method for finding the optimum transmission range in mobile ad hoc networks(MANETs). The results are particularly useful for the operation of military networks, as the transmission range affects the traffic throughput of user & routing traffic, delay, and frequency interference. When the conditions of tactical environment are applied in our simulations and the above-mentioned performances are analyzed, we find the OLSR protocol is more excellent. Plus, we compare the results of MANETs performance when applying optimum transmission range and the default transmission range(10km), and analyze the reasonability of the calculation of optimum transmission range proposed by this paper.

• The Transactions of the Korea Information Processing Society
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• v.7 no.10
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• pp.3195-3200
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• 2000

this paper is a stucy onthe preductionof multi-media traffic flow for the realizationof optimum ATM congestion control. In ATM network it is expected that the characteristic of multi-media traffic flow is varied slowly with a time. Fjor the simulation, time-variable multi-media traffic is penerated using possion distribution(connect calls per process time).\, gamma distribution(transmission rate per a call) and exponential distribution(holding time per a call). And using back-propagation neural netwok and proposed tripple neural network, the simulation to predict generaed traffic is executed. From the result,it's capability is shown that the proposed neural network model can be used in the predictionof ATM traffic flow.

• Journal of the Korean Institute of Navigation
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• v.15 no.2
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• pp.39-47
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• 1991

As per the rapid development of world economics the marine traffic volume was increased accordingly and caused frequent disasters in human lives and natural environment in the consequence of accidents. As the result of the above they started to establish Vessel Traffic System(VTS) and separation scheme in waterway from 1960' to prevent the marin traffic accident but the problem of safety at sea appears now as neither fully defined nor sufficiently analysed. At the present, the dominant factor in establishing the strategy of marine traffic has been safety of navigation concerning only with the ship, but the risk of society derives almost wholly from the nature of cargo. To measure the degree of danger for each ship there is suggested concept of safety factor numbers denoting the level of latent danger in connection with ship and her cargo. In this paper, where the strategy of VTS is put on controlling density of safety factor for control area. it suggested algorithms how to assign the vessels and also to get optimal sequence of vessels located to a sector in the sense of minimizing the passage delay. For the formulation of problem, min max and 0-1 programming methods are applied and developed heuristic algorithm is presented with numerical example to improve the efficiency of calculation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.1
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• pp.38-55
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• 2013

Wireless network systems provide fast data transmission rates and various services to users of mobile devices such as smartphones and smart pads. Because many people use high-performance mobile devices, the use of real-time multimedia services is increasing rapidly. However, the preoccupation of resources by real-time traffic users is causing harm to other services-for example, frequent call interference, lowered service quality, and poor network performance. This paper suggests a resource allocation algorithm for effective traffic service support in a hybrid network. The main objective is to obtain an optimum value of data rates by comparing user requirements with the amount of resources that can be allocated. A new mechanism based on Adaptive-Quality of Service (QoS) and a monitoring system based on Queue-Aware are proposed. Adaptive-QoS supports effective resource control according to the type of traffic service, and the monitoring system based on Queue-Aware measures the amount of resources in order to calculate the maximum that can be allocated. We apply our algorithm to a test system and use Qualnet 4.5.1 to evaluate its performance.

• ETRI Journal
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• v.38 no.4
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• pp.622-633
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• 2016

A discontinuous reception (DRX) operation is included in the Long Term Evolution (LTE) system to achieve power saving and prolonged battery life of the user equipment. An improvement in DRX power saving usually leads to a potential increase in the packet delay. An optimum DRX configuration depends on the current traffic, which is not easy to estimate accurately, particularly for non-real-time applications. In this paper, we propose a novel way to vary the DRX cycle length, avoiding a continuous estimation of the data traffic when only non-real-time applications are running with no active real-time applications. Because a small delay in non-real-time traffic does not essentially impact the user's experience adversely, we deliberately allow a limited amount of delay in our proposal to attain a significant improvement in power saving. Our proposal also improves the delay in service resumption after a long period of inactivity. We use a stochastic analysis assuming an M/G/1 queue to validate this improvement.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.1
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• pp.153-161
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• 2022

This paper analyzes the economic effects when platform provider including CP contributes to broadband universal service and uses broadband bandwidth providing high quality network service. In this model, the contribution rate of broadband universal service is determined by ISP and platform provider sets its price of contents. The main results are as follows. First, the traffic usages is less than social optimum when the market of contents is monopoly. The sum of contribution fee and network usage rate must be less than marginal cost of network operation to get social optimum traffic. Second, the rate set by ISP is equal to social optimum when the market of contents is competitive. Third, when platform provider does not charge contents provided, ISP sets social optimum prices and the network usage rate for contents user is decreasing as advertisement revenue becomes larger. These results suggest that the platform provider should contribute to universal service funding to encourage the network investment of ISP.

• Korean Management Science Review
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• v.19 no.1
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• pp.29-38
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• 2002

Due to the rapid increase In the Internet traffic volume, ISPs are faced with the definite need of the expansion of server capacity. In order to Provide prompt services for customers and still prevent excessive facility cost, it is critical to determine the optimum level of internet server capacity. The purpose of this Paper is to provide a simple but effective strategy on the expansion of servers capacity according to the increase in internet traffic. We model an internet server as an M/G/m/m queueing system and derive an efficient method to compute the loss probability which, In turn, Is used as a basis to determine proper server capacity. The Process of estimating the traffic parameter values at each server based on log data analysis is also given. All the procedures are numerically demonstrated through the process of analyzing actual log data collected from a game company.