• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.93-96
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• 2002

Fair Queueing has been studied only on wired network. When it is applied to wireless netowork, the collision phenomenon makes a problem.'rho information of queue of MT cannot be transferred to fair queueing algorithm In real time easily. We propose wireless fair queueing scheduler that protects short term farirness and long term fairness. We developed it in TDMA/TDD enviroment. Our scheme also supports uplink and downlink at the same time. And it can make subframe boundary based on fair scheduling algorithm.

• ETRI Journal
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• v.22 no.3
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• pp.1-9
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• 2000

Self-Clocked Fair Queueing (SCFQ) algorithm has been considered as an attractive packet scheduling algorithm because of its implementation simplicity, but it has unbounded delay property in some input traffic conditions. In this paper, we propose a Rate Proportional SCFQ (RP-SCFQ) algorithm which is a rate proportional version of SCFQ. If any fair queueing algorithm can be categorized into the rate proportional class and input is constrained by a leaky bucket, its delay is bounded and the same as that of Weighted Fair Queueing (WFQ) which is known as an optimal fair queueing algorithm. RP-SCFQ calculates the timestamps of packets arriving during the transmission of a packet using the current value of system potential updated at every packet departing instant and uses a starting potential when it updates the system potential. By doing so, RP-SCFQ can have the rate proportional property. RP-SCFQ is appropriate for high-speed packet-switched networks since its implementation complexity is low while it guarantees the bounded delay even in the worst-case input traffic conditions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.9C
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• pp.836-841
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• 2002

Packet scheduling is an essential function to guarantee a quality of service by differentiating services in the Internet. Scheduling algorithms that have been suggested so far can be devided into Round-Robin methods and Fair Queueing methods Round-Robin methods have the advantage of high-speed processing through simple implementations, while Fair Queueing methods offer accurate services. Fair queueing algorithms, however, have problems of computational overheads and implementation complexity as their schedulers manage the states of every flow. This paper suggests a new method in which each flow performs the calculation in a distributed way to decide the service order. Our algorithm significantly reduces the scheduler's computational overheads while providing the same level of accuracy with the previous Fair Queueing algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.4C
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• pp.343-355
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• 2003

Fair bandwidth allocations at routers protect adaptive flows from non-adaptive ones and may simplify end-to end congestion control. However, traditional fair bandwidth allocation mechanisms, like Weighted Fair Queueing and Flow Random Early Drop, maintain state, manage buffera and perform packet scheduling on a per-flow basis. These mechanisms are more complex and less scalable than simple FIFO queueing when they are used in the interi or of a high-speed network. Recently, to overcome the implementation complexity problem and address the scalability and robustness, several fair bandwidth allocation mechanisms without per-flow state in the interior routers are proposed. Core-Stateless Fair Queueing and Rainbow Fair Queuing are approximates fair queueing in the core-stateless networks. In this paper, we proposed simple Layered Fair Queueing (SLFQ), another core-stateless mechanism to approximate fair bandwidth allocation without per-flow state. SLFQ use simple layered scheme for packet labeling and has simpler packet dropping algorithm than other core-stateless fair bandwidth allocation mechanisms. We presente simulations and evaluated the performance of SLFQ in comparison to other schemes. We also discussed other are as to which SLFQ is applicable.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.2A
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• pp.98-106
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• 2005

We propose a new wireless fair queueing algorithm, WFQ-R (Wireless Fair Queueing with Retransmission), which is well matched with the LLR (Link Level Retransmission) algorithm and does not require channel prediction. In the WFQ-R algorithm, the share consumed by retransmission is regarded as a debt of the retransmitted flow to the other flows. Thus, the WFQ-R algorithm achieves wireless fairness with the LLR algorithm by penalizing flows that use wireless resources without permission under the MAC layer. Through simulations, we showed that our WFQ-R algorithm maintains fairness adaptively and maximizes system throughput. Furthermore, our WFQ-R algorithm is able to achieve flow separation and compensation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.3B
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• pp.171-182
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• 2003

In this paper, we propose an efficient and simple fair queueing algorithm, called Minimum Possible Virtual Start Time Fair Queueing (MPSFQ), which has O(1) complexity for the virtual time computation while it has good delay and fairness properties. The key idea of MPSFQ is that it has an easy system virtual time recalibration method while it follows a rate-proportional property. MPSFQ algorithm recalibrates system virtual time to the minimum possible virtual start time of all backlogged sessions. We will show our algorithm has good delay and fairness properties by analysis.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.1
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• pp.1-8
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• 1999

In order to provide appropriate Quality of Service(QoS) guarantee to each traffic flow in intergrated service networks, an efficient traffic scheduling algorithm as well as resource reservation must be adopted in host and transit routers. In this paper, a new efficient fair queueing algorithm which adopts a linearly increasing virtual time is presented. The proposed algorithm is fair and the maximum and mean delay guaranteed of each flow are less than those of the SCFQ(self clocked fair queueing) algorithm which is one of the most promising traffic scheduling algorithm, while providing low implementation complexity as the SCFQ scheme. And, it has the better isolation provided than SCFQ, which means that each flow is much less influenced by the violating traffic flows provided its allocated bandwidth gurantee. The fairness of the proposed algorithm is proved and simulation results of maximum and mean delay presented.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.12
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• pp.1-8
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• 2003

Scheduling technology is one of the most important elements required to support the Quality of service (QoS) in the Internet and a lot of scheduling algorithms have been developed. However, most of these algorithms ire not flexible to distribute the excess bandwidth. In order to provide flexibility for distributing the excess bandwidth, we proposed excess bandwidth fair queueing (EBFQ) algorithm with relatively low complexity. In this paper, we propose the new extension to this EBFQ algorithm for the hierarchical fair queueing system. This extension can be naturally applied to the existing hierarchical algorithm and simultaneously provide the same level of fairness. Through the simulation and analysis, we verify it.

• The KIPS Transactions:PartC
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• v.12C no.5 s.101
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• pp.695-700
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• 2005

To provide the fair rate and achieve the fair bandwidth allocation, many per-flow scheduling algorithms have been proposed such as fair queueing algorithm for congestion control. But these algorithms need to maintain the state, manage buffer and schedule packets on a per-flow basis; the complexity of these functions may prevent them from being cost-effectively implemented. In this paper, therefore, to acquire cost-effectively for implementation, we propose a CS-FNE(Core Stateless FNE) algorithm that is based on FM(Flow Number Estimation), and evaluated CS-FNE scheme together with CSFQ(Core Stateless Fair Queueing), FRED(Fair Random Early Detection), RED(Random Early Detection), and DRR(Dynamic Round Robin) in several different configurations and traffic sources. Through the simulation results, we showed that CS-FNE algorithm can allocate fair bandwidth approximately than other algorithms, and CS-FNE is simpler than many per-flow basis queueing mechanisms and it can be easily implemented.

• Journal of Communications and Networks
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• v.4 no.3
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• pp.209-220
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• 2002

In this paper, we propose a hierarchical packet scheduling technique to closely approximate a hierarchical extension of the generalized processor sharing model, Hierarchical Generalized Processor Sharing (H-GPS). Our approach is to undertake the tasks of service guarantee and hierarchical link sharing in an independent manner so that each task best serves its own objective. The H-GPS model is decomposed into two separate service components: the guaranteed service component to consistently provide performance guarantees over the entire system, and the excess service component to fairly distribute spare bandwidth according to the hierarchical scheduling rule. For tight and harmonized integration of the two service components into a single packet scheduling algorithm, we introduce two novel concepts of distributed virtual time and service credit, and develop a packet version of H-GPS called Hierarchical Fair Queueing (HFQ). We demonstrate the layerindependent performance of the HFQ algorithm through simulation results.