• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3C
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• pp.219-227
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• 2006

In this paper, we propose a packet scheduling algorithm to maximize the required total price of the systems that is applied with a different traffic pricing criterion by the mobile service operator according to different kinds of the services. The proposed algorithm adopts a particular estimation method in scheduling using the value of pricing function, which is based on the required services and the value of SIR(signal to interference ratio) that indicate the channel condition of each user. We compare Max C/I, proportional fairness and round robin algorithm with the proposed algorithm on HSDPA in order to analyze the performance. The result shows that the proposed algorithm satisfies higher throughput and provides maximum the mobile service provider's revenue.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.5
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• pp.967-973
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• 2009

Recently, as 3rd-generation mobile communication services using high-speed data rate system are widely employed, the demand for a variety of real-time data services such as VoIP service are also increased. Unlike typical data packets, VoIP packets have delay bound and low loss rate requirement. In this paper we propose a new scheduling algorithm that schedule two deferent kinds of packets efficiently, considering the characteristics of VoIP. Basically this algorithm considers both time delay and channel condition and gives priority depending on the time delay. Simulation results show that the proposed algorithm works more efficiently than conventional algorithms.

• Proceedings of the IEEK Conference
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• 2000.06a
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• pp.229-231
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• 2000

Nowadays, the telecommunication service provider has witnessed an unprecedented growth in data traffic and the need for networking. optical fiber can provide some THz of huge bandwidth WDM technology has been an emerging issue for the efficient use of optical links. WDM uses a number of different wavelength that are assigned to each channel. The minimal number of optical transceivers and receivers should be used in a node to build an economic WDM transmission system without degrading system performance. Hence, the analysis of performance parameters such as throughput and delay is important to guarantee the WDM system performance. in this paper, the performance of a MAC protocol on a slotted WDM system that has a tunable transmitter(Txt), a tunable receiver(Rxt), and a fixed receiver(Rxf), respectively, on each node, was statistically analyzed The computer simulation validates the performance analysis.

• Journal of Communications and Networks
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• v.14 no.5
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• pp.510-517
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• 2012

This paper analyzes the performance of voice-over-Internet protocol (VoIP) services in terms of the system throughput, the packet delay, and the signaling overhead in a mobile WiMAX system with a hybrid automatic repeat request (HARQ) mechanism. Furthermore, a queueing analytical model is developed with due consideration of adaptive modulation and coding, the signaling overhead, and the retransmissions of erroneous packets. The arrival process is modeled as the sum of the arrival rate at the initial transmission queue and the retransmission queue, respectively. The service rate is calculated by taking the HARQ retransmissions into consideration. This paper also evaluates the performance of VoIP services in a mobile WiMAX system with and without persistent allocation; persistent allocation is a technique used to reduce the signaling overhead for connections with a periodic traffic pattern and a relatively fixed payload. As shown in the simulation results, the HARQ mechanism increases the system throughput as well as the signaling overhead and the packet delay.

• Journal of KIISE:Information Networking
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• v.29 no.6
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• pp.706-711
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• 2002

In this paper, we implement a diffserv-capable router on the linux system and evaluate its performance. The router supports the packet marking for the input finks that is different from the previous implementation. The edge diffserv-capable router can guarantee the performance of each class, even in a congested condition. We compare the performance of the diffserv-capable router with that of the normal router in terms of PDBs (per domain behaviors), which are defined with traffic conditioning rules and PHBs (per hop behaviors).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5B
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• pp.498-508
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• 2009

In wireless mobile environments, large bandwidth and high QoS (Quality of Service) are recently required to support the increased demands for multimedia services. LTE (Long Term Evolution) is one of the promising solutions for the next generation broadband wireless access systems. To efficiently use downlink resource and effectively support QoS, packet scheduling algorithm is one of the important features in LTE system. In this paper, we proposed DAPS (Delay-Aware Packet Scheduling) algorithm to consider QoS requirements of delays for various traffic classes as well as channel condition and fairness. To reflect delay experiences at scheduling instance, DAPS observes how queue waiting time of packet is closed to maximum allowable delay. The simulation results show that the DAPS algorithm yields better performance for delay experience by increasing the number of transmitted packets with satisfying the required delay time compared with existing scheduling algorithms.

• ETRI Journal
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• v.25 no.4
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• pp.238-246
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• 2003

This paper introduces the modeling and analysis of a discrete-time, two-phase queueing system for both exhaustive batch service and gated batch service. Packets arrive at the system according to a Bernoulli process and receive batch service in the first phase and individual services in the second phase. We derive the probability generating function (PGF) of the system size and show that it is decomposed into two PGFs, one of which is the PGF of the system size in the standard discrete-time Geo/G/1 queue without vacations. We also present the PGF of the sojourn time. Based on these PGFs, we present useful performance measures, such as the mean number of packets in the system and the mean sojourn time of a packet.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.10
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• pp.1003-1008
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• 2016

Recently hospitals have divided into many divisions, specialized the medical service, and shown organic cooperation, all to provide patients with various and high quality medical service. They have also showed improvement in information protection by introducing an information protection system to regulate the access to patients' medical and personal information. The purpose of this paper is to present a case study to implement of a limited hospital medical information system that can regulate the access to medical information. For this, a router-based virtual network applying an ACL(: Access Control List) to regulate access to information was made using a packet tracer.

• Journal of KIISE:Information Networking
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• v.35 no.5
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• pp.415-424
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• 2008

In this paper, we compare the QoS performance enhancement schemes according to the network architecture of mobile WiMAX system in order to improve the end-to-end QoS performance and propose QoS parameter mapping method and IP packet scheduling algorithm. To evaluate the end-to-end QoS performance, we implemented an end-to-end simulator of mobile WiMAX system using OPNET. Simulation results show that the proposed QoS parameter mapping scheme reduces the average delay of VoIP packet and improves uplink resource efficiency. And also, when the proposed IP packet scheduling algorithm is applied to the system, the end-to-end packet transmission delay of VoIP service can be reduced by 44-67 percent compared to FIFO and WRR scheduler.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.5 s.335
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• pp.23-28
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• 2005

Recently, new concept, NP(Network Processor) was emerged into communication systems to cope with the various service requirements from Internet users. NP is an unique promising technique to capable of implementing of the packet processing in wire-speed and providing the flexibility for supporting the newly network services, having satisfied with implementation using hardware and software respectively in past, This paper deals with the implementation techniques and evaluation results of the line card capable to do packet forwarding function with packet processing power of wire-speed and applicable to various physical interfaces. There are several interfaces of POS, Gigabit ethernet and EPON in E-OLT(EPON Optical Line Terminal) system of PATH(Photonic Access To Home) network. Therefore, the E-OLT's packet forwarding engine have to support various subscriber's interface in wire speed. Our system is implemented the subscriber's card in daughter board and the setup procedure is done by system firmware based on the module's identifier acquired from installed physical board.