• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.3
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• pp.519-525
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• 2014

In this paper, we show a scheme to directly access DLNA network with the 3G/4G communication module of a smartphone in home or office environment. By exploiting this scheme, end users can use DLNA service more conveniently regardless of the type of activated communication module in a smartphone. For the implementation of this scheme, we use a femtocell that is a basestation with small coverage. A problem caused by the IP address hierarch discrepancy between the IP address of 3G/4G module of smartphone and those of local network nodes is resolved by deploying local IP address scheme. The processing of multicasting packet, that is required in DLNA service, is enabled by using IP tunneling scheme. As a result, end user can access DLNA network regardless of the type of activated wireless communication module. We validate the design result by implementing it on a commercial WCDMA femtocell.

• Journal of Satellite, Information and Communications
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• v.6 no.2
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• pp.51-59
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• 2011

To support seamless IPTV services in IP-based wireless network, delay or interruption time must be minimized because noticeable interruption will make IPTV service users unhappy. A number of protocols have been proposed for solving mobility problem. However effective seamless handover mechanism to support mobile IPTV services yet to be solved. Mobile WiMAX offers a wireless solution in the access networks that can support IPTV services. Goal of this paper is to identify some reasons of delay time during handover process in an IPv6 capable Mobile WiMAX and to perform handover delay of some optimization scenarios given by existing standardization and proposed improvement.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.2
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• pp.165-179
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• 2005

Close collaboration among businesses is required in B2B EC environment. Furthermore, emergency requests or critical information among businesses should be processed in an immediate mode. Most current systems, however, due to firewalls for the systems' security and autonomy, can not handle these requirements appropriately, but handle them in an ad hoc manner In this paper a method of timely collaboration among businesses and an active functionality component to support it in B2B EC environment are proposed. Since the active functionality component supports high level ECA rule patterns and event-based immediate processing, system administrators and programmers can easily program and maintain the timely collaboration independently to the application logic. The proposed active functionality component uses HTTP protocol to be applied through firewalls and is designed using a commercial DBMS for practical purpose.

• Journal of Advanced Navigation Technology
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• v.23 no.5
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• pp.333-338
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• 2019

Satellite communication is not used by many people like mobile communication, but it is a necessary technology for public service and communication services, such as providing the Internet in military, disaster, remote education and medical services, island areas, and infrastructure vulnerable areas. However, most communication modems have problems with two-way communication with server as IP addresses are assigned to floating IP that change every time they communicate with the network. In this paper, we used the Raspberry Pi as the controller of the terminal device to communicate the network through the satellite modem and the PPP protocol, and to solve the problem of the modem with the floating IP, we used the text message function of the satellite modem. Through this process, two-way data links using the Thuraya geostationary orbit satellite were implemented.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.5
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• pp.87-98
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• 2007

AAA protocol is an information protection technology which systematically provides authentication, authorization and accounting function not only in the existing wire network but also in the rapidly developing wireless network, various services and protocol. Nowadays, standardization of the various application services is in progress with the purpose of AAA standardization fer the mobile user in the wireless network. And various researches are being conducted fur using AAA in the roaming service and mobile IPv6 network between heterogeneous networks. In this paper uses OTP and ID-based ticket for user authentication in the mobile device under the ubiquitous environment, and service is seamlessly provided even though the mobile device moves from the home network to the foreign network. In addition, with the ticket renewed from the foreign network, the overhead of the home authentication server can be reduced, and provides anonymity of service through the anonymity ID.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.6
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• pp.37-47
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• 2009

In VANET, each vehicle can obtain traffic information from other vehicles or infrastructure, and they frequently exchange life-critical safety message. Therefore, it is necessary among vehicles to establish a secure channel for keeping the driver's safe and protecting the channel against several attack challenges. TSVC is a representative scheme which needs low communication and computation to be performed. But, there is a delay when verifying the messages because it is designed based on TESLA. Thus, it is not acceptable to use TSVC for sending the time-critical messages. In this paper, we propose a novel message authentication scheme which reduces a delay for the verification of messages. Therefore, the proposed scheme can be suitable to transmitting time-critical messages. Furthermore, the scheme supports to privacy preservation and can robust against DoS attacks.

• Journal of Internet of Things and Convergence
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• v.8 no.4
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• pp.1-7
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• 2022

As the number of IoT devices increases, power management of the cluster head, which acts as a gateway between the cluster and sink nodes in the IoT network, becomes crucial. Particularly when the cluster head is a mobile wireless terminal, the power consumption of the IoT network must be minimized over its lifetime. In addition, the delay of information transmission in the IoT network is one of the primary metrics for rapid information collecting in the IoT network. In this paper, we propose a low-power buffer management algorithm that takes into account the information transmission delay in an IoT network. By forwarding or skipping received packets utilizing deep Q learning employed in deep reinforcement learning methods, the suggested method is able to reduce power consumption while decreasing transmission delay level. The proposed approach is demonstrated to reduce power consumption and to improve delay relative to the existing buffer management technique used as a comparison in slotted ALOHA protocol.

• Journal of the Korea Society of Computer and Information
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• v.14 no.8
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• pp.59-64
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• 2009

This paper is intended to study how well the routing protocol supplied in wireless mesh networks can evade interference path along the applied routing metric. Wireless mesh networks, unlike existing network techniques, has the characteristics that node movement is less and energy effect is limited. Therefore. this type of network requires path configuring technique to reflect such network characteristics and new routing metric to determine proper path. Routing metric proposed recently is designed to produce link quality accurately, but it configures path not considering the traffic situation of adjacent nodes. Thus. this technique has the problems of reduced transfer rate and delay between terminals occurring due to frequent traffic chaos by the interference of adjacent nodes. Therefore, this paper proposes metric that configures routing path by finding like metric that can transfer data effectively by considering the traffic situation of adjacent nodes. We confirmed through simulation that the proposed routing metric reduces the delay between terminals via the path that evades the traffic interference of adjacent node.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.8
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• pp.1620-1625
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• 2004

To advance fisheries, we set developmental directions of fishery information by grasping present situations and analyzing maritime & fisheries issues. We promote various policies through effective systematical information data bases, based on both control and utilization of oceanic resources. For these puposes, it is imperative that we set up fisheries communication networks. There are satellite assisted informational networks to assist fishing vessels with their marine based movements. However, there's no hope for poorly equipped fishermen to adopt this network because of extravagant network call charges. So we think that using existing SSB communication system is the best plan. We organize fishery communication network by HF SSB communication which doesn't have operational costs. We build wireless transmitting and receiving stations that are basic systems of informnation, and equip wireless data communication systems by the use of wireless communication network protocols in coastal stations. It is necessary that a fish boat has a terminal device for wireless data communication. In this research we can conclude that if we transmit the location of a fishing boat in-real time through GPS channels then we propose that some methods be formulated to able terminal devices on fishing boats to collect various types of information, such as meteorological and oceanic conditions.

• Journal of KIISE:Information Networking
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• v.34 no.1
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• pp.1-15
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• 2007

Increase in the wireless mobile network users brings the issue of mobility management into the Virtual Private Network (VPN) services. We propose a provider edge (PE)-based provider provisioned mobile VPN mechanism, which enables efficient communication between a mobile VPN user and one or more correspondents located in different VPN sites. The proposed mechanism not only reduces the IPSec tunnel overhead at the mobile user node to the minimum, but also enables the traffic to be delivered through optimized paths among the (mobile) VPN users without incurring significant extra IPSec tunnel overhead regardless of the user's locations. The proposed architecture and protocols are based on the BGP/MPLS VPN technology that is defined in RFC24547. A service provider platform entity named PPVPN Network Server (PNS) is defined in order to extend the BGP/MPLS VPN service to the mobile users. Compared to the user- and CE-based mobile VPN mechanisms, the proposed mechanism requires less overhead with respect to the IPSec tunnel management. The simulation results also show that it outperforms the existing mobile VPN mechanisms with respect to the handoff latency and/or the end-to-end packet delay.