• Journal of Internet Computing and Services
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• v.5 no.6
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• pp.11-20
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• 2004

Proportional Fair (PF) share policy has been adopted as a downlink scheduling scheme in CDMA2000 l×EV-DO standard. Although It offers optimal performance in aggregate throughput conditioned on equal time share among users, it cannot provide a bandwidth guarantee and a strict delay bound. which is essential requirements of real-time (RT) applications. In this study, we propose a new scheduling policy that provides quality-of-service (QoS) guarantees to a variety of traffic types demanding diverse service requirements. In our policy data traffic is categorized Into three classes, depending on sensitivity of Its performance to delay or throughput. And the primary components of our policy, namely, Proportional Fair (PF), Weighted Fair Queuing (WFQ), and delay-based prioritized scheme are intelligently combined to satisfy QoS requirements of each traffic type. In our policy all the traffic categories run on the PF policy as a basis. However the level of emphasis on each of those ingredient policies is changed in an adaptive manner by taking into account the channel conditions and QoS requirements. Such flexibility of our proposed policy leads to offering QoS guarantees effectively and. at the same time, maximizing the throughput. Simulations are used to verify the performance of the proposed scheduling policy. Experimental results show that our proposal can provide guaranteed throughput and maximum delay bound more efficiently compared to other policies.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.4
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• pp.84-91
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• 2011

Recently, WBAN(Wireless Body Area Network) which has progressed standardization based on IEEE 802.15.6 standardization is a network for the purpose of the short-range wireless communications within around 3 meters from the inner or outer human body. Effective QoS control technique and data efficient management in limited bandwidth such as audio and video are important elements in terms of users and loads in short-range wireless networks. In this paper, for high-speed WBAN IEEE 802.15.6 standard, the dynamic allocation to give an efficient bandwidth management and weighted fair queueing algorithm have been proposed through the adjustment of the super-frame about limited data and Quality of Service (QoS) based on the queuing algorithm. Weighted Fair Queueing(WFQ) Algorithm represents the robust performance about elements to qualitative aspects as well as maintaining fairness and maximization of system performance. The performance results show that the dynamic allocation expanded transmission bandwidth five times and the weighted fair queueing increased maximum 24.3 % throughput and also resolved delay bound problem.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.499-501
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• 2004

현재 IPv6에서 이동 통신에 끊김 없는 서비스를 제공하기 위해 Mobile IPv6에 관한 많은 연구가 이루어지고 있다. FMIPv6는 핸드오버 절차를 간소화시켜서 빠른 속도의 핸드오버와 데이터 전송이 가능하며 SIP나 VoIP 및 무선 인터넷 동영상 서비스와 같은 경우에 많이 사용될 것으로 예상되지만 패킷 손실의 문제점을 지니고 있다. 본 논문은 FMIPv6에서 핸드오버시 발생하는 패킷 손실을 줄이기 위하여 라우터에서 사용하는 여러 패킷 관리 스케줄링 기법 중 WFQ기법을 사용한 트래픽 관리 메커니즘을 설계하고 평가하였다.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.06a
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• pp.219-222
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• 2001

본 연구의 내용은 실시간 서비스 트래픽, 즉 보장형 서비스를 위한 스케줄링 알고리즘들에 대한 성능분석에 대한 연구이다. 특히 실시간 데이터 전송의 경우, 작은 지연 시간을 요구하면서 안정된 QoS를 요구하고 있다. 기존에 알려진 FQ, WFQ, WF2Q, Virtual Clock 스케줄링 알고리즘들을 사용해서 대기 큐의 수학적 모델이 아닌 시뮬레이션 도구를 사용해서, 지연에 민감한 보장형 서비스 트래픽에 대한 시간 복잡도, 공정성, 처리율 측면으로 성능을 분석하였다.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.11b
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• pp.786-789
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• 2003

현재 IPv6에서 이동 통신에 끊김 없는 서비스를 제공하기 위해 Mobile IPv6에 관한 많은 연구가 이루어지고 있다. FMIPv6는 핸드오버 절차를 간소화시켜서 빠른 속도의 핸드오버와 데이터전송이 가능하며 SIP나 VoIP 및 무선 인터넷 동영상 서비스와 같은 경우에 많이 사용될 것으로 예상되지만 패킷 손실의 문제점을 지니고 있다. 본 논문은 FMIPv6에서 핸드오버시 발생하는 패킷 손실을 줄이기 위하여 라우터에서 사용하는 여러 패킷 관리 스케줄링 기법 중 WFQ기법을 사용한 트래픽 관리 메커니즘을 설계하였다.

• Journal of the Korea Society of Computer and Information
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• v.16 no.10
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• pp.73-81
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• 2011

The WBAN(Wireless Body Area Network) technology is a short distance wireless network which provides each device's interactive communication by connecting devices inside and outside of body located within 3 meters. Standardization on the physical layer, data link layer, network layer and application layer is in progress by IEEE 802.15.6 TG BAN. The The WBAN servides consists of both medical and non-medical applications. The medical application service uses the sensor that transfer the periodic traffic and have different data rates. It uses GTS method to guarantee QoS. In this paper, a new method is proposed, which are suitable design for MAC Protocol. Firstly, MAC frame structure and a primitive based on the WBAN are proposed. Secondly, we proposed the GTS algorithm improved the channel utilization based on the WFQ(Weighted Fair Queuing). The proposed scheduling method is improved channel utilization compared with i-Game(Round Robin scheduling method).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11C
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• pp.10-23
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• 2001

It is difficult to satisfy the QoS(Quality of Service) guarantee which is required by real-time application services only with the Best-Effort(BE) service adopted in the current Internet. Therefore, worldwide research is being made on the method of QoS provisioning. Among them, the QoS guarantee mechanism using the Diffserv(Differentiated Service) was discussed in this paper. First we analyzed how the DiffServ performance was affected by traffic models. For this, we performed the research for the random, bursts, and self-similar traffic modeling method. We then designed and implemented an OPNET simulator, and performed the simulation 7d performance evaluation for diverse input parameters. Based on the results of performance evaluation, it was confirmed that QoS guarantee is possible for the EF(Expedited Forwarding) class with the DiffServ function under every environments considered and the service separation between EF and BE(Best Effort) classes is also possible. We also analyzed the performance variation and dynamic behavior of DiffServ mechanism based on the resource allocation between E? and BE classes in WFQ(Weighted Fair Queueing).

• Journal of the Korea Society of Computer and Information
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• v.16 no.11
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• pp.45-56
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• 2011

WBAN is short range wireless communication technology which is consists of several small devices close to, attached to or implanted into the human body. WBAN is classified into between medical and non-medical by applications based on technology and medical data with periodic characteristics is used the GTS method for transmitting data to guarantee the QoS. In this paper we proposed algorithm that resolve lack of GTSs while data transmit GTS method in superframe structure of WBAN. Coordinator dynamically allocates GTSs according to the data rate of devices and make devices share GTSs when lack of GTSs. We compared delay bounds, throughput for performance evaluation of the proposed algorithm. In other words, we proposed algorithm adaptive WFQ scheduling that GTS allocation support differential data rate in environments of WBAN. The experiment results show the throughput increased and the maximum delay decreased compared with Round Robin scheduling.

• ETRI Journal
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• v.25 no.6
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• pp.475-488
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• 2003

In this paper, we propose an efficient and simple fair queuing algorithm, called new starting potential fair queuing (NSPFQ), which has O(1) complexity for virtual time computation and also has good delay and fairness properties. NSPFQ introduces a simpler virtual time recalibration method as it follows a rate-proportional property. The NSPFQ algorithm recalibrates the system virtual time to the minimum virtual start time among all possible virtual start times for head-of-line packets in backlogged sessions. Through analysis and simulation, we show that the proposed algorithm has good delay and fairness properties. We also propose a hardware implementation framework for the scheduling algorithm.

• Journal of the Korea Society of Computer and Information
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• v.10 no.6 s.38
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• pp.261-268
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• 2005

Recently, Many People have studied in Mobile Ipv6 to provide seamless service. FMIPv6 is designed to reduce the procedure of handover and will be used SIP, VoIP and Mobile Internet moving picture service. But, If mobile node moves fast, it will happen to packet loss and interruption problem in handover procedure. So, In this paper, designed and evaluated traffic control mechanism using WFQ scheduling to reduce the packet loss that occurred to handover procedure.