• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.12
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• pp.46-58
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• 2003

The recent Internet is changing from its best-effort service and needs the network structure and traffic engineering, which can support various applications requiring differentiated traffic processing and high quality of service. The extension of the Internet from wired to wireless system generating location-dependent and burst errors make more difficult to support a good service with the existing packet scheduling algorithm. In this paper, we propose a wireless diffserv packet scheduling (WDSPS) algorithm that can provide reliable service in the differentiated wireless internet service network. The proposed scheduling algorithm solves the HOL(head of line) blocking problems of class queue occurred in wireless network, supports the differentiated service for each class which is defined in differentiated service networks and makes possible the gradual and efficient service compensation not only among classes but also among flows to prevent the monopoly of one class or one flow. Through simulations, we show that our proposed WDSPS scheduling algorithm can provide the required QoS differentiation between classes and enhance the service throughput in various wireless network conditions.

• Journal of information and communication convergence engineering
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• v.10 no.2
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• pp.117-122
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• 2012

We propose a hybrid multiple access (HMA) for uplink orthogonal frequency division multiple access (OFDMA) systems, which combines two resource sharing schemes: a scheduling-based resource allocation (SBRA) scheme and a contentionbased resource allocation (CBRA) scheme. The SBRA scheme is appropriate for non-real time high data rate traffic, and, CBRA is appropriate for near-real time low/medium data rate traffic. Thus, the proposed HMA scheme supports various types of traffic. As a CBRA scheme, our proposed random frequency hopping (RFH)-OFDMA scheme was presented. Simulation results show that the proposed HMA yields the best performance among various resource allocation schemes for uplink OFDMA systems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.2
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• pp.733-750
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• 2019

Software Defined Networking (SDN) is a new network paradigm, allowing administrators to manage networks through central controllers by separating control plane from data plane. So, one or more controllers must locate outside switches. However, this separation may cause delay problems between controllers and switches. In this paper, we therefore propose a Priority-based Scheduling policy for OpenFlow (PSO) to reduce the delay of some significant traffic. Our PSO is based on packet prioritization mechanisms in both OpenFlow switches and controllers. In addition, we have prototyped and experimented on PSO using a network simulator (ns-3). From the experimental results, PSO has demonstrated low delay for targeted traffic in the out-of-brand control network. The targeted traffic can acquire forwarding rules with lower delay under network congestion in control links (with normalized load > 0.8), comparing to traditional OpenFlow. Furthermore, PSO is helpful in the in-band control network to prioritize OpenFlow messages over data packets.

• The Transactions of the Korea Information Processing Society
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• v.7 no.11S
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• pp.3684-3693
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• 2000

In this paper, performance of a nonblocking high speed packet switch with switching capacity m which adopts a dynamic priority control function (DPCF) of a threshold- based Bernoulli priority jump (TBPJ) scheme is considered. Each input queue has two separate buffers with different sizes for two classes of traffics, delay-sensitive and loss-sensitive traffics, and adopts a TBPJ scheme that is a general state-dependent Bernoulli scheduling scheme. Under the TBP] scheme, a head packet of the delay-sensitive traffic buffer goes into the loss -sensitive traffic buffer with Hernoulli probability p according to systems states that represent the buffer thresholds and the number of packets waiting for scheduling. Performance analysis shows that TBPJ scheme obtains large performance build-up for the delay-sensitive traffic without performance degradation for the loss-sensitive traffic. In addition to, TBP] scheme shows better performance than that of HOL scheme.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.9
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• pp.4108-4122
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• 2016

To address challenges of an unprecedented growth in mobile data traffic, the ultra-dense network deployment is a cost efficient solution to off-load the traffic over other small cells. However, the real traffic is often much lower than the peak-hour traffic and certain small cells are superfluous, which will not only introduce extra energy consumption, but also impose extra interference onto the radio environment. In this paper, an elastic energy efficient cell management scheme is proposed based on flow scheduling among multi-layer ultra-dense cells by a SDN controller. A significant power saving was achieved by a cell-level energy manager. The scheme is elastic for energy saving, adaptive to the dynamic traffic distribution in the office or campus environment. In the end, the performance is evaluated and demonstrated. The results show substantial improvements over the conventional method in terms of the number of active BSs, the handover times, and the switches of BSs.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.75-78
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• 1998

In this paper, we propose a new cell discarding and scheduling scheme which reduce cell loss rate by measuring, in real time, the number of discarded cells in the queuing system with a different loss priority for each class of service such that each class of service meets its cell loss rate requirements and reduce average delay rate for the traffic that is sensitive in cell delay in output buffer of the ATM switch. Throughout the computer simulation, the existing scheduling scheme and proposed scheme are compared with respect to cell loss rate and average delay time.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.85-88
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• 2002

Maintaining a proper level of cell lead, system throughput can be maximized by a transmission rate control over the uplink in DS/CDMA cellular system to support integrated services of real-time and delay-tolerant traffic. We find that the cell load-based rate control scheme can be further enhanced by taking the varying channel condition into account In conjunction with some fair scheduling algorithm. Our simulation results show that the proposed scheme outperforms the original cell load-based rate control with the round-robin sharing scheduling scheme.

• Journal of the Korea Society of Computer and Information
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• v.25 no.1
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• pp.21-27
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• 2020

In this paper, a hybrid scheduling algorithm is proposed for CMS(Combat Management System) to improve QoS(Quality of Service) based on DWDRR(Dynamic Weighted Deficit Round Robin) and priority-based scheduling method. The main proposed scheme, DWDRR is method of packet transmission through giving weight by traffic of queue and priority. To demonstrate an usefulness of proposed algorithm through simulation, efficiency in special section of the proposed algorithm is proved. Therefore, We propose hybrid algorithm between existing algorithm and proposed algorithm. Also, to prevent frequent scheme conversion, a hysteresis method is applied. The proposed algorithm shows lower packet loss rate and delay in the same traffic than existing algorithm.

• Journal of Korea Multimedia Society
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• v.13 no.11
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• pp.1667-1676
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• 2010

In this paper, we propose a packet scheduling algorithm that assigns different number of HS-PDSCH(High Speed Primary Downlink Shared Channel) to the service user according to the received signal to interference ratio of CPICH(Common Pilot Channel) and to the traffic characteristics. Assigned channel number is determined by the signal to interference ratio level from CPICH. The highest signal to interference ratio user gets the number of channels based on the signal to interference ratio table and the remained channels are assigned to the other level users. Therefore the proposed scheme can provide the similar maximum service throughput and higher fairness than existing scheduling algorithm. Simulation results show that our algorithm can provide the similar maximum service throughput and higher fairness than MAX C/I algorithm and can also support the higher service throughput than proportional fairness scheme.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.4
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• pp.436-442
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• 2006

It is important matter that inflect well allocated frequency resource in cellular network and is still more serious element in environment that provide multimedia services. Also, that do that make job scheduling how base station system or terminal according to this service request is important constituent that evaluate performance of whole system. channel allocation according to service kind causes big effect to whole system when hand off gets up in cellular network. This paper describes model and algorithm that increase two elements that is frequency allocation and job scheduling that consider multimedia service traffic special quality by emphasis that do mapping present in CDMA cellular system.