• Journal of Communications and Networks
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• v.7 no.1
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• pp.76-86
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• 2005

Today's wireless access networks consist of several tiers that overlap each other. Provisioning of real time undisrupted communication to mobile users, anywhere and anytime through these heterogeneous overlay networks, is a challenging task. We extend the end-to-end approach for the handoff management in hybrid wireless data network by designing a fully mobile-controlled handoff for mobile devices equipped with dual mode interfaces. By handoff, we mean switching the communication between interfaces connected to different subnets. This mobile-controlled handoff scheme reduces the service disruption time during both horizontal and vertical handoffs and does not require any modification in the access networks. We exploit the IP diversity created by the dual interfaces in the overlapping area by simultaneously connecting to different subnets and networks. Power saving is achieved by activating both interfaces only during the handoff period. The performance evaluation of the handoff is carried out by a simple mathematical analysis. The analysis shows that with proper network engineering, exploiting the speed of mobile node and overlapping area between subnets can reduce service disruption and power consumption during handoff significantly. We believe that with more powerful network interfaces our proposal of dual interfaces can be realized.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.6
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• pp.922-928
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• 2018

Recently, various researches have been studied to support service-oriented IoT networking. This is because the IoT environment coexists with various service devices for providing the service in a certain unified area. Thus, in this network environment, an effective data delivery service is not provided in a network configuration. Also, in order to provide efficient IoT services in this network environment, new scheme is necessary to recognize services by themselves and to construct network structures for each service. In this paper, we propose a service oriented self-constructive network (SO-SCN) scheme that can construct a service-oriented network in IoT environments composed of various service devices. The proposed scheme is a method that can minimize the network overhead required for service provisioning and extend the network lifetime. Through simulation, we show that the proposed service oriented self-construction network scheme improves the performance, in terms of the number of packets generated for end-to end data transmission and the end-to-end delay.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.6
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• pp.2711-2733
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• 2018

Minimizing power consumption in bandwidth limited optical traffic grooming networks is presented as a two-objective optimization problem. Since the main objective is to route a connection, the network throughput is maximized first, and then the minimum power consumption solution is found for this maximized throughput. Both transparent IP over WDM (Tp-IPoWDM) and translucent IP over WDM (Tl-IPoWDM) network may be applied to examine such bi-objective algorithms. Simulations show that the bi-objective algorithms are more energy-efficient than the single objective algorithms where only the throughput is optimized. For a Tp-IPoWDM network, both link based ILP (LB-ILP) and path based ILP (PB-ILP) methods are formulated and solved. Simulation results show that PB-ILP can save more power than LB-ILP because PB-ILP has more path selections when lightpath lengths are limited. For a Tl-IPoWDM network, only PB-ILP is formulated and we show that the Tl-IPoWDM network consumes less energy than the Tp-IPoWDM network, especially under a sparse network topology. For both kinds of networks, it is shown that network energy efficiency can be improved by over-provisioning wavelengths, which gives the network more path choices.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.5A
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• pp.751-762
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• 2000

In the forthcoming next generation highspeed networks, the provisioning of broadband mobile multimedia services is the most important issue while an efficient network management architecture, which can manage the network resources efficiently, is essential. The next generation highspeed networks will be composed of the ATMand SDH-based transport network systems and the H-based interworking systems. The management functions of these network systems are implemented various technologies, such as TMN and SNMP. In order to integrate these network resources efficiently with heterogeneous management functions, the distributed network management architecture such as TINA is most appropriate. In this pape, we propose an interworking architecture for TINA manager and TMN agent. where the TINA-based EML subnetwork management operations mapped into the related management operations of the TMN NE agent. The proposed interworking architecture is simpler than JIDM, and the processing overhead is minimized.

• Journal of Information Processing Systems
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• v.5 no.2
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• pp.97-104
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• 2009

In this paper we propose a Differentiated Services Based Admission Control and Routing Algorithm for IPv6 (ACMRA). The basic DiffServ architecture lacks an admission control mechanism, the injection of more QoS sensitive traffic into the network can cause congestion at the core of the network. Our Differentiated Services Based Admission Control and Routing Algorithm for IPv6 combines the admission control phase with the route finding phase, and our routing protocol has been designed in a way to work alongside DiffServ based networks. The Differentiated Services Based Admission Control and Routing Algorithm for IPv6 constructs label switched paths in order to provide rigorous QoS provisioning. We have conducted extensive simulations to validate the effectiveness and efficiency of our proposed admission control and routing algorithm. Simulation Results show that the Differentiated Services Based Admission Control and Routing Algorithm for IPv6 provides an excellent packet delivery ratio, reduces the control packets' overhead, and makes use of the resources present on multiple paths to the destination network, while almost each admitted flow shows compliance with its Service Level Agreement.

• The KIPS Transactions:PartC
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• v.11C no.6 s.95
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• pp.807-814
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• 2004

This paper researches and evaluates a bandwidth reallocation mechanism for efficient DiffServ QoS support in MPLS networks by monitoring the network traffic status and reallocating unused bandwidth. While the Differentiated Services in MPLS Networks architecture provides QoS management through the RSVP resource reservation, this mechanism is based on a static provisioning of resource. But this approach can lead to waste bandwidth in some service classes or, leave some service classes' resource starved. This paper presents the bandwidth reallocation dynamically based on network traffic status for bandwidth usage maximization.

• International Journal of Advanced Culture Technology
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• v.2 no.1
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• pp.1-13
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• 2014

In next-generation wireless networks, provisioning of IP-based network architecture and seamless transmission services are very important issues for mobile nodes. For this reason, a mobility management mechanism to support global roaming is highly regarded. These technologies bring a broader life by using a global roaming account through the connection of multiple devices or technology to mobile users; they also provide real-time multimedia services. This paper presents a comprehensive performance analysis of fast handover for hierarchical mobile IPv6 (F-HMIPv6), hierarchical mobile IPv6 (HMIPv6), Proxy Mobile IPv6 (PMIPv6), and fast Proxy Mobile IPv6 (FPMIPv6) using the fluid-flow model and random-walk model. As a result, the location update cost of the PMIPv6 and FPMIPv6 is better than that of HMIPv6 and F-HMIPv6. These results suggest that the network-based mobility management technology is superior to the hierarchical mobility management technology in the mobility environment.

• Journal of Communications and Networks
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• v.13 no.3
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• pp.286-297
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• 2011

A novel converged optical network unit (ONU)-base station (BS) architecture has been contemplated for next-generation optical-wireless networks. It has been demonstrated through high quality studies that data traffic carried by both wired and wireless networks exhibit self-similar and long range dependent characteristics; attributes that classical teletraffic theory based on simplistic Poisson models fail to capture. Therefore, in order to apprehend the proposed converged architecture and to reinforce the provisioning of tightly bound quality of service (QoS) parameters to end-users, we substantiate the analysis of the QoS behavior of the ONU-BS under self-similar and long range dependent traffic conditions using custom queuing which is a common queuing discipline. This paper extends our previous work on priority queuing and brings novelty in terms of presenting performance analysis of the converged ONU-BS under realistic traffic load conditions. Further, the presented analysis can be used as a network planning and optimization tool to select the most robust and appropriate queuing discipline for the ONU-BS relevant to the QoS requirements of different applications.

• The KIPS Transactions:PartC
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• v.12C no.2 s.98
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• pp.289-300
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• 2005

This paper proposed an analytical framework to compare and model the policy-based network management; centralized and distributed typed model. Policy-based network is introduced in various application fields, and a policy framework can offer different processing performance according to application. Therefore, we evaluated the performance and extensibility of each PBNM model when we apply the policy process to the models. The evaluated measurement metrics are policy provisioning time, traffic occurrence amount, PDP processing rate, and global conflict detection in qualitative simulation. The results show that the suitable structure is required according to the analysis for the careful application characteristics, when PBNM is adopted. The modeling framework presented in this paper is intended to quantify the merits and demerits among the currently suggested PBNM models.

• Journal of Information Processing Systems
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• v.15 no.2
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• pp.440-448
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• 2019

The Internet of Things (IoT) is one of the main enablers for situation awareness needed in accomplishing smart cities. IoT devices, especially for monitoring purposes, have stringent timing requirements which may not be met by cloud computing. This deficiency of cloud computing can be overcome by fog computing for which fog nodes are placed close to IoT devices. Because of low capabilities of fog nodes compared to cloud data centers, fog nodes may not be deployed with all the services required by IoT devices. Thus, in this article, we focus on the issue of fog service placement and present the recent research trends in this issue. Most of the literature on fog service placement deals with determining an appropriate fog node satisfying the various requirements like delay from the perspective of one or more service requests. In this article, we aim to effectively place fog services in accordance with the pre-obtained service demands, which may have been collected during the prior time interval, instead of on-demand service placement for one or more service requests. The concept of the logical fog network is newly presented for the sake of the scalability of fog service placement in a large-scale smart city. The logical fog network is formed in a tree topology rooted at the cloud data center. Based on the logical fog network, a service placement approach is proposed so that services can be placed on fog nodes in a resource-effective way.