• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.12
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• pp.99-108
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• 2014

WBAN(Wireless Body Area Network) is network to support medical and non-medical services. It is susceptible to loss and delay of data. WBAN is required to satisfy many kinds of demands such as a variety of data rate and a data priority for providing various service. In this paper scheduling algorithm, considering a data priority and transmission delay time, is proposed to improve service quality of WBAN. The proposed algorithm operates by allocating a channel to a flow with longer transmission delay. When a packet, in a queue of herb, is left within a certain period, the packet is assigned a channel and transmitted according to a data priority. Through the comparison with other existing scheduling algorithms, it is confirmed that QoS is improved due to higher arrival probability of medical data and less delay time in the proposed algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.1B
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• pp.11-17
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• 2003

In this paper, we presented the dynamic random access channel allocation method under the priority based scheduling policy in order to improve the system performance of HIPERLAN/2 standardized by ETSI According to the scheduling policy, AP scheduler primarily allocates the resource to the collision MT This scheduling policy bring about decreasing the transmission delay of collision MT Dynamic RCH(random access channel) allocation method decreases the collision probability by increasing the number of RCH slots in case of low traffic. While it increases the maximum throughput by increasing the number of the data transmission slots in case of high traffic Therefore dynamic allocation method of RCH slots decreases the scheduling delay and increases the throughput When we evaluate the performance of presented method based on standards, we saw that the presented method improve the performance of the MAC protocol in terms of throughput and transmission delay.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.11
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• pp.2607-2612
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• 2014

In this paper, we propose a distributed user scheduling with transmit power control based on the amount of interference inflicted to other BSs in multi-cell uplink networks. Assuming that the channel reciprocity time-division duplexing(TDD) system is used, the channel state information (CSI) can be obtained at each user from pilot signals from other BSs. The amount of generating interference to other BSs will be calculated at each user. Especially, in this paper, we propose the threshold-based transmit power control, in which a user decrease its transmit power if its generating interference to other BSs is larger than a predetermined threshold. Simulation results show that the proposed technique significantly outperforms the existing user scheduling algorithms.

• The KIPS Transactions:PartC
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• v.16C no.4
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• pp.477-486
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• 2009

This paper proposes a dynamic bandwidth allocation (DBA) algorithm with adaptive maximum transmission window (DBA-AMTW) to increase channel utilization in Ethernet passive optical networks (EPONs). A polling mechanism in EPON determines channel utilization and puts constraints on DBA algorithm and scheduling. DBA algorithms based on interleaved polling with stop (IPS) allocate transmission windows to optical network units (ONU) considering requests of all ONUs. However channel idle time when any ONU does not transmit packets decreases channel utilization. Proposed DBA-AMTW improves efficiency of a network and allocates transmission windows effectively by appropriate DBA computation from REPORT messages of all ONUs. An adaptive maximum transmission window for each ONU determined by a DBA computation in the previous scheduling cycle. Simulation results show that the proposed DBA algorithm improves performance of throughput and average delay time.

• Journal of Korea Multimedia Society
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• v.10 no.6
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• pp.745-753
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• 2007

The wireless medium is known to be time-varying which could affect and result to a poor network's performance. As a solution, an opportunistic scheduling and power control algorithm based on IEEE 802.11 MAC protocol is proposed in this paper. The algorithm opportunistically exploits the channel condition for better network performance. Convex optimization problems were also formulated i.e. the overall transmission power of the system is minimized and the "net-utility" of he system is maximized. We have proven that an optimal transmission power vector may exist, satisfying the maximum power and SINR constraints at all receivers, thereby minimizing overall transmission power and maximizing net-utility of the system.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.261-266
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• 2007

UMTS release 5 에서 소개된 HSDPA 를 위해 도입된 새로운 기술 Adaptive Modulation and Coding, Hybrid Automatic Repeal reQuest, Fast Packet Scheduling 에 대해 알아보고 여기서 key role 이 되는 Fast Packet Scheduling 알고리즘 가운데 대표적인 세 가지 Round Robin(RR), Promotional Fairness(PF), Maximum Channel Quality Index(Max CQI) 알고리즘의 성능을 시스템 수율과 공평성의 관점에서 분석해보았다. 시스템 수율에서는 Max CQI, PF. RR 알고리즘 순이었으며 공평성 측면에서는 RR, PF Max CQI 알고리즘 순으로 나타났다. 같은 시스템, 같은 망 구조 내에서라면 알고리즘을 최적화하여 QoS와 성능을 극대화할 수 있도록 지속적인 연구가 필요하다.

• Journal of the Korea Society of Computer and Information
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• v.7 no.2
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• pp.40-45
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• 2002

In this paper, we deals with scheduling problem for data-path synthesis in high-level synthesis. We proposed a new method to optimize interconnection cost for operator allocation. Especially, we focus to optimize for buses to transfer data channel and register to restore operation result. Also we take account ILP formulation in order to get optimal scheduling result. To verify the effectiveness of this study, we select 5th Digital Wave Filter. The experimental result show that purposed method was better then the general methods.

• ETRI Journal
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• v.29 no.1
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• pp.120-123
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• 2007

In this letter, we address the problem of resource allocation with efficiency and quality of service (QoS) support in uplink for a wireless CDMA network supporting real-time (RT) and non-realtime (NRT) communication services. For RT and NRT users, there are different QoS requirements. We introduce and describe a new scheme, namely, traffic aided uplink opportunistic scheduling (TAUOS). While guaranteeing the different QoS requirements, TAUOS exploits the channel condition to improve system throughput. In TAUOS, the cross-layer information, file size information, is used to improve fairness for NRT users. Extensive simulation results show that our scheme can achieve high system throughput in uplink wireless CDMA systems, while guaranteeing QoS requirements.

• International Journal of Computer Science & Network Security
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• v.22 no.4
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• pp.351-357
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• 2022

LTE (Long-Term Evolution, sometimes known as 4G LTE) is a wireless high-speed data communication technology for mobile phones and data terminals. The Packet Scheduler (PS) is an important component in improving network performance. Physical Resource Blocks (PRBs) are assigned to associated User Equipment by the packet scheduler (UEs). The primary contribution of this study is a comparison of the eNodeB throughput between a suggested method and the Round Robin (RR) Algorithm. The RR Algorithm distributes PRBs among all associated UEs without taking channel circumstances into account. In this research, we present a new scheduling method that takes into account the number of PRBs and associated UEs and produces higher throughput than the RR algorithm.

• Annual Conference of KIPS
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• 2007.05a
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• pp.1310-1312
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• 2007

Throughput improvement problem in wireless mesh network can be alleviated by equipped mesh router with multiple radios tuned into orthogonal channels. However, some links on the same channel also can be activated concurrently if the Signal-to-Noise and Interference Ratio (SNIR) at their receiver endpoints is not lower than the threshold. We propose a greedy algorithm to investigate the problem of how to schedule a set of feasible transmission under physical interference model by using the spatial time-division multiple-access (STDMA) scheme. We also consider the fairness in scheduling to prevent some border nodes from starvation. We evaluate our algorithms through extensive simulation and the results show that our algorithms can achieve better aggregate throughput and fairness performance than 802.11 standard.