• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.8
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• pp.481-490
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• 2000

This paper analyzes interference power, Erlang capacity, the number of handoff occurrences, and call blocking probability with respect to the cell radius, the soft handoff region, and the mobile's velocity in a CDMA hierarchical cellular system. The microcell cellular system has the higher Erlang capacity than the macrocell cellular system. However, the microcell cellular system, which has a high system capacity through frequency reuse has the call blocking probability higher than macrocell cellular system. Also the interference power and the call blocking probability are decreased with the operation of soft handoff. Therefore, this paper presents the optimization of soft handoff region so as to maximize system's Erlang capacity with the low the call blocking probability according to mobile's velocity in the CDMA hierarchial cellular system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.3A
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• pp.334-341
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• 2000

This paper presents an analysis of the capacity, the interference of adjacent cells of a CDMA cellular system, depending on the soft handoff region and log-normal shadowing. The optimum soft handoff region is chosen by using Erlang capacity. It is shown that when the soft handoff region increases, the Erlang capacity increase due to a reduction of the interference power of adjacent cells. But if the region is increased above a certain value, there is no improvement in the system’s capacity. Furthermore as the standard deviation of the log-normal shadowing's normal distribution factor increases, the soft handoff region has to be increased linearly to achieve the same Erlang capacity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.891-894
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• 2009

In this paper, a scheme to evaluate the number of users in a WCDMA supporting multi-rate traffic is presented through the calculations of Erlang capacity from a derived blocking probability. It is observed that voice-data Erlang capacities have an inverse linear relationship. When the $E_b/N_o$ decreases from 4 dB to 3 dB within the outage probability of 2 % and at the voice rate of 8 kbps, the results show an increase of 8 Erlang at the data rates of 15 kbps, 4 Erlang at 30 kbps, 2 Erlang at 60 kbps, and 1 Erlang at 120 kbps respectively and an increase of the Erlang capacities through a gradual decrease of the data rates from 960 kbps to 15 kbps. So this is useful for optimizing as a reference of design for the capacity in a WCDMA system.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.126-129
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• 1999

In this paper, it is assumed that a mobile radio channel is a Rayleigh distributed multipath fading channel and Erlang capacity and equivalent channel numbers are calculated for the reverse link of a imperfect power controlled DS/CDMA cellular system considering both shadowing and multipath fading. The DS/CDMA blocking probability is calculated based on a new analysis method that considers Erlang capacity and ICF(interference correction factor) using the median value of $E_{b(i)}$/ $I_{o}$ corresponding to each reverse link user. It is showed that the effect of multipath fading must not be ignored in Erlang capacity of the IS-95 DS/CDMA cellular system and the Erlang capacity is decreased according to the increase of the deviation of the imperfect power control, to the decrease of the processing gain, to the increase of the voice activity.y.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10A
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• pp.788-795
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• 2003

We analyze the performance of a truncated power controlled CDMA(code division multiple access) cellular systems with base station antenna arrays. Erlang capacity and the channel capacity which is a maximum date rate to maintain almost error free communication are analytically derived. The numerical results show there can be a substantial increase in Erlang capacity and in channel capacity by antenna arrays incorporating with the truncated power control scheme.

• Journal of Korean Society of Transportation
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• v.21 no.4
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• pp.103-111
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• 2003

This study proposes methodology deterimining a basic pedestrian crossing capacity that plays a critical role in the installation of pedestrian signal at the crosswalks. The methodology is based on the pattern of vehicle arrived at the crosswalks. Erlang distribuion is used as headway distribution that can cover the various levels of flow rate. Models using Erlang distribution are represented by Erlang parameter (K) of 1, 2, or 3 at 2-, 4-, or 6-lane roadway in both directions. In addition, this study considered the only type of road with a pedestrian refuge area in the median that is used to wait for the allowable gap provided by the flow of another direction. As a result, the pedestrian capacity decreases as flow rate increases and Erlang parameter increases for the road with the pedestrian refuge. This study develops the models to determine the pedestrian capacity under a variety of flow rates and the outcomes of this study could be used as the criteria for the determination of the installation of pedestrian signal or for the provision of pedestrian refuge in the median of road.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.327-330
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• 2007

This article discusses a capacity planning method in QoS-guaranteed IP networks such as BcN (Broadband convergence Network). Since IP based networks have been developed to transport best-effort data traffic, the introduction of multi-service component in BcN requires fundamental modifications in capacity planning and network dimensioning. In this article, we present the key issues of the capacity planning in multi-service IP networks. To provide a foundation for network dimensioning procedure, we describe a systematic approach for classification and modeling of BcN traffic based on the QoS requirements of BcN services. We propose a capacity planning framework considering data traffic and real-time streaming traffic separately. The multi-service Erlang model, an extension of the conventional Erlang B loss model, is introduced to determine required link capacity for the call based real-time streaming traffic. The application of multi-service Erlang model can provide significant improvement in network planning due to sharing of network bandwidth among the different services.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.3
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• pp.39-46
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• 1998

In the FDMA and TDMA Cellular Systems, call blocking rise when frewquence slots andtime slots are used to ther users. Otherwise, in the CDMA cellular systems, call locking arises when interference level is above 10dB according to call of other users. System capacity is defined to be Erlang capacity that is the number of users when CDMA blocking probability is 1% or 2%. Users number corresponded channel number of AMPS and TDMA cellular systems. In this paper, we proposed new reuse-fraction using square of interference poser and obtained Erlang capacity for reverse link of CDMA cellular system with bit rate $R_{b}$, 9.6kbps and 14.4kbps. As a results, Erlange capacity of CDMA system have more 20.7 and 5.5 times than AMPS and TDMA system and have more form 1 to 4 Erlang thatn Viterbi and Padovani obtaned.d.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.125-128
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• 2000

In this paper, we derive forward link Erlang capacity reflecting both outage probability and blocking probability of each traffic type in mixed traffics environment. We firstly determine the number of available virtual trunks of the forward link from a circuit switching perspective. Then, capacity sharing model and generalized Erlang model are employed to derive joint Erlang capacity of various traffics types.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.92-96
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• 2000

In this paper, we propose a call admission control(CAC) scheme fer the mixed voice/data DS-CDMA systems and analyze the Er-lang capacity under the proposed CAC scheme. Voice and data traffics require different system resources based oil their Quality of Service(QoS) requirements. In the proposed CAC scheme, some system resources are reserved exclusively for handoff calls to have high priority Over new calls. Additionally the queueing of both new and handoff data traffics that are not sensitive to delay is allowed. Ar a performance measure for the suggested CAC scheme. Erlang capacity is utilized. For the performance analysis, a four-dimensional Markov chain model is developed. Erlang capacity of a practical IS-95B type system depicts, and optimum values of system parameters such as the number of reservation channels and queue lengths are found with respect to Erlang capacity. Finally, it is observed that Erlang capacity is improved more than two times by properly selecting the system parameters with the proposed CAC scheme.