• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.10
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• pp.888-893
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• 2012

Quality of Service (QoS) provisioning is an important issue in the design of next generation wireless network. In visible light communication (VLC) networks, link switching is a solution to maintain or improve the quality of communication. In this paper, we propose a novel link switching scheme using the location of mobile nodes (MNs). The current serving transmitter uses location history of the MN to find out which neighbor transmitter the MN is approaching. This neighbor transmitter is chosen to inform the MN as the next serving transmitter. The simulation results show that our proposed scheme gains better performance than non-predictive link switching scheme.

• Asia pacific journal of information systems
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• v.30 no.1
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• pp.94-119
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• 2020

Digital platforms characterized by network effects enable provisioning of various types of services and provide a mechanism for linking producers and consumers. Identifying the key Quality of Service attributes of such platforms is vital for their continued success and growth. In this paper, a set of quality attributes for platforms is first extracted from different extant quality models. Then actual user feedback data from three platform providers are analysed and mapped against the set of quality attributes to determine the key attributes that are relevant. These findings are corroborated with qualitative data from interviews of different stakeholders. The results show that service quality characteristics are important to the success of platforms. Functional characteristics of platforms assume importance where the digital contributions of the platform is higher. Apart from these, 'fitness for use' as a major determinant of quality is also important in digital platforms.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.2
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• pp.473-494
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• 2020

To provide a guaranteed Quality of Service (QoS) to real-time traffic in High-Speed Downlink Packet Access (HSDPA) core network, we proposed an enhanced mechanism. For an enhanced QoS, a Class-Based Low Latency Fair Queueing (CBLLFQ) packet scheduling algorithm is introduced in this work. Packet classification, metering, queuing, and scheduling using differentiated services (DiffServ) environment was the points in focus. To classify different types of real-time voice and multimedia traffic, the QoS provisioning mechanisms use different DiffServ code points (DSCP).The proposed algorithm is based on traffic classes which efficiently require the guarantee of services and specified level of fairness. In CBLLFQ, a mapping criterion and an efficient queuing mechanism for voice, video and other traffic in separate queues are used. It is proved, that the algorithm enhances the throughput and fairness along with a reduction in the delay and packet loss factors for smooth and worst traffic conditions. The results calculated through simulation show that the proposed calculations meet the QoS prerequisites efficiently.

• Journal of Communications and Networks
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• v.3 no.4
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• pp.297-306
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• 2001

In the last couple of years service management has gained more and more momentum in the research community. Nowadays, as complexity of IT-services is increasing, these services are usually composed of interdependent, layered services hosted by various providers. Therefore, a strong cooperation of providers involved in service provisioning is needed, especially regarding their management processes and systems. One important step is to establish a common understanding about service-related terms in order to be able to specify service functionality and the resulting management tasks. Additionally, means to analyze and identify the necessary actors and the corresponding inter- and intra-organizational relationships are needed. This paper presents an extended version of the MNM service model which provides a generic model defining commonly needed service-related terms, concepts and structuring rules in a general and unambiguous way. Furthermore, we demonstrate the application of the MNM service model by modeling a riser help desk service based on a concrete scenario. The experience gained from modeling is used to discuss the benefits of service modeling in general.

• Journal of Korean Society of Rural Planning
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• v.24 no.3
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• pp.63-71
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• 2018

The comparison of demand and supply is needed for efficient ecosystem services planning. However, the gap between them cannot be analyzed as existing studies mainly dealt with only the supply of ecosystem services. This study compares the demand and supply of ecosystem services in Shiheung using environmental complaints and urban planning by semantic network analysis. As a result, 'air' and 'water' quality are magnified in demand, 'energy' and 'water' are crucial in supply. This result presents that citizen ask for the improvement of air quality in regulation services, although local government has plans for energy support in provisioning services. Periodic ecosystem services demand and supply monitoring will be the base of effective ecosystem services planning, which reduce insufficiency and surplus.

• Journal of Internet Computing and Services
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• v.19 no.2
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• pp.33-41
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• 2018

In recent years, technology is rapidly changing to support new service consumption and distribution models in multimedia service systems and hybrid delivery of media services is a key factor for enabling next generation multimedia services. This phenomenon can lead to rapidly increasing network traffic and ultimately has a direct and aggravating effect on the user's quality of service (QOS). To address the issue, we propose a novel system architecture to provide smart hybrid media services efficiently. The architecture is designed to apply the software-defined networking (SDN) method, detect changes in traffic, and combine the data, including user data, service features, and computation node status, to provide a service schedule that is suitable for the current state. To this end, the proposed architecture is based on 2-level scheduling, where Level-1 scheduling is responsible for the best network path and a computation node for processing the user request, whereas Level-2 scheduling deals with individual service requests that arrived at the computation node. This paper describes the overall concept of the architecture, as well as the functions of each component. In addition, this paper describes potential scenarios that demonstrate how this architecture could provide services more efficiently than current media-service architectures.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.2
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• pp.193-204
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• 2010

Since Wireless Multimedia Sensor Network(WMSN) needs to process various multimedia data such as audio, image and video data as well as scalar data, it requires a mechanism that can support Quality of Service(QoS) to handle efficiently. This paper classifies traffic in WMSN as periodic monitoring traffic, event traffic, multimedia traffic and query-based traffic, proposes marking algorithm and queue management mechanism that guarantee differentiated QoS in terms of delay, energy efficiency and credibility on each traffic and conduct performance analysis with simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4B
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• pp.202-209
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• 2005

In this paper, a dynamic TCP-friendly rate control (TFRC) is proposed to adjust the coding rates according to the channel characteristics of the wireless-to-wired network consisting of wireless first-hop channel. To avoid the throughput degradation of multimedia flows traveling through wireless lint the proposed rate control system employs a new wireless loss differentiation algorithm (LDA) using packet loss statistics. This method can produce the TCP-friendly rates while sharing the backbone bandwidth with TCP flows over the wireless-to-wired network. Experimental results show that the proposed rate control system can eliminate the effect of wireless losses in flow control of TFRC and substantially reduce the abrupt quality degradation of the video streaming caused by the unreliable wireless link status.

• The KIPS Transactions:PartC
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• v.12C no.6 s.102
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• pp.817-826
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• 2005

BcN(Broadband convergence Network) is being developed in order to support a variety of network applications, with enhanced capabilities of QoS(Quality of Service) provisioning and security, and IPv6. In a high-speed network environment such as BcN, it if more likely for the network resources to be exposed to various intrusion activities. The propagation speed of intrusion is alto expected to be much faster than in the existing Internet In this paper, we present a multi-domain security management framework which my be used for a global intrusion detection at multiple domains of BcN and describe its characteristics. For the performance evaluation, we first present test results for the security node and compare with other products. Then we design and Implement an OPNET simulator for the proposed framework, and present some simulation results. In the simulation model, we focus on the performance of alert information in the security overlay network.

• KIISE Transactions on Computing Practices
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• v.21 no.1
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• pp.1-12
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• 2015

To realize futuristic services with agility, the role of the experimental facility (i.e., testbed) based on integrated resources has become important, so that developers can flexibly utilize the dynamic provisioning power of software-defined networking and cloud computing. Following this trend, an OpenFlow-based SDN testbed environment, denoted as OF@TEIN, connects multiple sites with unique SmartX Racks (i.e., virtualization-enabled converged resources). In this paper, in order to automate the multi-point L2 (i.e., Ethernet) inter-connection of OpenFlow islands, we introduce an automated tool to configure the required Network Virtualization using Generic Routing Encapsulation (NVGRE) tunneling. With the proposed automation tool, the operators can efficiently and quickly manage network inter-connections among multiple OpenFlow sites, while letting developers to control their own traffic flows for service realization experiments.