• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.12
• /
• pp.2555-2562
• /
• 2009

The algorithm that is proposed in this paper defined a probability function to count connection process and connection-end process to apply TRW algorithm to voice network. Set threshold to evaluate the algorithm that is proposed, Based on the type of connection attack traffic changing the probability to measure the effectiveness of the algorithm, and Attack packets based on the speed of attack detection time was measured. At the result of evaluation, proposed algorithm shows that DDoS attack starts at 10 packets per a second and it detects the attack after 1.2 seconds from the start. Moreover, it shows that the algorithm detects the attack in 0.5 second if the packets were 20 per a second.

• Proceedings of the Korean Information Science Society Conference
• /
• 2003.04d
• /
• pp.277-279
• /
• 2003

본 논문에서는 편재 컴퓨팅(ubiquitous and pervasive computing) 환경에 입력 시스템으로 사용하는 센서 네트워크에서 측정한 데이터의 품질 (sampling rate and quantization depth) 을 보증하며 네트워크 트래픽 또는 소모전력과 같은 비용을 최소화하기 위한 방법으로, 휴리스틱 알고리즘에 의한 비주기적 샘플링과 신뢰성 있는 전송규약을 사용하는 비주기적 전송방식을 제안한다. 그리고 제안한 비주기적 전송방식에 핵심기술인 신뢰성 있는 전송 규약의 비용을 최적화하기 위한 방법으로 ACK방식과 NACK방식을 패킷 에러율과 동일한 라우터를 사용하는 이웃 노드의 수와 같은 네트워크 상황에 따라 상보적으로 사용하는 상보적 방식(alternative method)을 제안하고, 전체 통신규약을 설계하며, 해석을 통해 성능을 분석하고, 네트워크 상태에 따라 두 방식의 성능상의 우열이 전환되는 전환점을 유도한다. 제안하는 상보형 신뢰성 있는 전송규약은 전체 센서 네트워크에서 처리되는 패킷의 비트 수를 최소화해, 각 노드의 총 전력 소모의 20-60%를 차지하는 통신모듈의 소비 전력을 줄일 수 있어 전력소모를 크게 개선 할 수 있다. 나아가서 다양한 센서 네트워크에서 설계한 전송규약을 바탕으로 하는 제안하는 비주기적 전송방식을 활용한다면 최적의 비용으로 측정하는 데이터의 품질을 보증할 수 있다.

• Journal of Advanced Navigation Technology
• /
• v.10 no.2
• /
• pp.95-102
• /
• 2006

In this paper, we model a traffic of multiple tags operated in 2.45GHz band RTLS environment and analyze the multi-tag interference. Also, we propose a high precision location estimation algorithm of RTLS and then analyze its performance. From the results, the BER performance of RTLS degrades as the number of multi-tags increase in Gaussian noise and fading(m=15) environment. To meet the BER specification of RTLS, $10^{-5}$, we have to limit the multi-tag number to below 40. We also estimate the tag's location in $250m{\times}250m$ searching-area with enhanced TDOA scheme. It is confirmed that the 3m radius within accuracy of RTLS specification is satisfied, if the number of sub-blink receives more than 2 when available reader is 3 to 8.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.1
• /
• pp.191-197
• /
• 2012

In this paper we propose the FQSM(Fairness and QoS Supporting MAC) protocol that supports fairness and Quality of Service(QoS). The received or measured data traffics will be assigned a priority level according to its transmission urgency in the FQSM. And the load prediction algorithm is used to support the fairness between different priority traffics. For this, the buffer length values of the nodes are continuously monitored for a some period. Based on the buffer length variations for this period, the order of transmission is determined. FQSM also adapts cross-layer concept to rearrange the data transmission order in each sensor node's buffer, saves energy consumption by allowing few nodes in data transmission, and prolongs the network lifetime.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.6
• /
• pp.1121-1126
• /
• 2017

Recently, the importance of smart gateways that link these with the big data and the development of the Internet of things is getting bigger. The smart gateway includes a network function such as a router and a router, and a sensor network function that links various objects such as a sensor. As the internet market has expanded, network stability and security problems have arisen and VPN technology has been proposed as one of the ways to solve these security problems. Efficient design is needed to implement VPN in low-end smart gateway and SOHO-level Internet environment with poor line quality. In this paper, we propose the concept and principle of VPN tunneling implementation and real - time traffic shaping method according to internet line condition in the Smart Gateway that supports IOT developed based on OpenWRT, the implementation and measured performance indicators are presented.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.41 no.5
• /
• pp.133-142
• /
• 2004

Recently, the growth of Internet and a variety of multimedia services through Internet increasingly demands high-speed packet transmission, the new routing function, and QoS guarantee on conventional routers. Thus, a new switching mechanical called the MPLS(Multi-Protocol Label Switching), was proposed by IETF(Internet Engineering Task Force) as a solution to meet these demands. In addition the deployment of MPLS network supporting Differentiated Services is required. In this paper, we propose the architecture of the MPLS switch supporting Differentiated Services in the MPLS-based network. The traffic conditioner consists of a classifier, a meter, and a marker. The VOQ-PHB module, which combines input Queue with each PHB queue, is implemented to utilize the resources efficiently. It employs the Priority-iSLIP scheduling algorithm to support high-speed switching. We have designed and verified the new and fast hardware architecture of VOQ-PHB and the traffic conditioner for QoS and high-speed switching using NS-2 simulator. In addition, the proposed architecture is modeled in VHDL, synthesized and verified by the VSS analyzer from SYNOPSYS. Finally, to justify the validity of the hardware architecture, the proposed architecture is placed and routed using Apollo tool.

• KIISE Transactions on Computing Practices
• /
• v.23 no.5
• /
• pp.310-315
• /
• 2017

In a centralized control structure, the software defined network controller manages all openflow enabled switched in a data plane and controls the telecommunication between all hosts. In addition, the network manager can easily deploy the network function to the application layer with a software defined network controller. For this reason, many methods for network management using a software defined network concept have been proposed. The main policies for network management are related to traffic Quality of Service and resource management. In order to provide Quality of Service and load distribution for network users, we propose an efficient routing method using a naive bayesian algorithm and transmission delay estimation module. In this method, the forwarding path is decided by flow class and estimated transmission delay result in the software defined network controller. With this method, the load on the network node can be distributed to improve overall network performance. The network user also gets better dynamic Quality of Service.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.9
• /
• pp.1906-1914
• /
• 2012

In this paper, relative service differentiation in JET based optical burst-switched networks with deflection routing is presented. It differs from conventional schemes in that it tries to make the loss rate of high class bursts as low as possible while maintaining the desired proportional ratio between the high class bursts and low class bursts. Strategies applied to it are dynamic wavelength allocation and the preemption which are combined to deflection routing. With dynamic wavelength allocation, the number of wavelengths allocated to high class bursts are dynamically changed. Preemption which gives more preference to high class bursts is also applied to decrease its loss rate. To lower the loss rate, deflection routing is applied for any kind of traffic. With those strategies, the suggested scheme shows desired properties that the loss rate of high class traffic is as lowered as possible. A queueing model for the scheme is developed to approximate loss ratio and the numerical results show that the proposed scheme provisions relative service differentiation.

• Convergence Security Journal
• /
• v.17 no.4
• /
• pp.11-16
• /
• 2017

MANET composed of only mobile node is applied to various environments because of its advantage which can construct network quickly in emergency situation. However, many routing vulnerabilities are exposed due to the dynamic topology and link failures by the movement of nodes. It can significantly degrade network performance. In this paper, we propose a secure routing protocol based on trust model. The domain-based network structure is used for efficient trust evaluation and management of nodes in the proposed technique. The reliability evaluation of nodes was performed by the discard ratio of control packet and data packet of the nodes. The abnormal nodes are detected by performing traffic check and inspecting of nodes on a path that generates excessive traffic in order to increase the efficiency of routing. It is confirmed through experiments of the proposed technique that data transmission is performed securely even if an attack exists on the path.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.3
• /
• pp.567-574
• /
• 2013

Recently, many researches on P2P overlay network-based multimedia streaming services have been actively performed because of their high scalability and cost-efficiency advantages. However, P2P overlay networks also have the shortcoming of generating higher traffic owing to their unicast-based one-to-many multimedia deliveries. In order to reduce the traffic generated by the P2P streaming overlay network, we propose an ISP and locality-based parent node discovery method and check its feasibility through an implementation of a prototype streaming system. The measurement of RTTs and hop counts for random nodes having different ISPs and localities shows the proposed method to be able to shorten about 32% RTTs and about 17% Hop counts.