• Journal of Korea Multimedia Society
• /
• v.18 no.2
• /
• pp.189-198
• /
• 2015

Despite the fact that traffic engineering techniques have been comprehensively utilized in the past to enhance the performance of communication networks, the distinctive characteristics of Software Defined Networking (SDN) demand new traffic engineering techniques for better traffic control and management. Considering the behavior of traffic, large flows normally carry out transfers of large blocks of data and are naturally packet latency insensitive. However, small flows are often latency-sensitive. Without intelligent traffic engineering, these small flows may be blocked in the same queue behind megabytes of file transfer traffic. So it is very important to identify large flows for different applications. In the scope of this paper, we present an approach to detect large flows in real-time without even a short delay. After the detection of large flows, the next problem is how to control these large flows effectively and prevent network jam. In order to address this issue, we propose an approach in which when the controller is enabled, the large flow is mitigated the moment it hits the predefined threshold value in the control application. This real-time detection, marking, and controlling of large flows will assure an optimize usage of an overall network.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.3
• /
• pp.534-539
• /
• 2005

The key in wireless sensor networks, which consist of a number of sensor nodes, is an energy efficiency. Many routing protocols have been proposed for prolonging network lifetime and reducing traffic in wireless sensor networks. Wireless sensor networks usually use wireless ad-hoc network protocols for routing, but these protocols are not well-suited for wireless sensor networks due to many reasons. In this paper, RM-flooding protocol is proposed for reducing routing overhead occurred when packet flooding. The nodes using this routing protocol can consume the limited energy effectively, and exchange information with remote nodes usulg information receiving from multipath. So, RM-flooding prolongs the network's lifetime.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2003.10a
• /
• pp.908-911
• /
• 2003

In this study, the security system (Firewall and IDS) was installed in high speed information network and analyzed for a change in the speed of data transfer and the possibility of invasion. The selection of appropriate system, efficient detection and protection and surveillance method were suggested and analyzed. In order to do experiments, an experimental model was comprized to analyze the parameters that was affected by the detection and protection system in network. This will give a standard how much we can pull up the security system maintaining the network speed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2003.10a
• /
• pp.916-919
• /
• 2003

Reliable multicast data transmission in a 1:N environment needs more sophisticated error control mechanism than that of in 1:1 environment due to ACK implosion and duplicated retransmission. Although there have been many related research on error control in reliable multicast, real implemented protocols are rare. As one of the reliable multicast transport protocols, ECTP is selected as an international standard reliable multicast protocol by ITU-T and ISO and implemented on RedHat 7.2 machine by us. In this paper, we evaluate the performance of the error control mechanism in the respect of throughput and generated control packet numbers with a real implementation code. From the results, it is concluded that the suitable values of error control parameters can be obtained from the local group size and network environments.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.6C
• /
• pp.615-623
• /
• 2003

This paper presents effective quality-of-service renegotiating schemes for streaming video. The conventional network supporting quality-of-service generally allows a negotiation at call setup. However, it is not efficient for the video application since the compressed video traffic is statistically non-stationary. Thus, we consider the network supporting quality-of-service renegotiations during the data transmission, and study effective quality-of-service renegotiating schemes for streaming video. Simple token bucket model, whose parameters are token filling rate and token bucket size, is adopted for the video traffic model. The renegotiating time instants and the parameters are determined by analyzing the statistical information of compressed video traffic. In this paper, two renegotiating approaches, i.e. fixed renegotiating interval case and variable renegotiating interval case, are examined. Finally, the experimental results are provided to show the performance of the proposed schemes.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.10
• /
• pp.4574-4577
• /
• 2011

In this paper, In this paper, analyzed structure of home networking used in USN(Ubiquitous Sensor Network) and embedded systems for home automation was implemented on the Android operating system. Developed a system for building a home network using wireless communication, so it is possible to minimize the difficulty of installation. Home automation system has built based on pre-defined ID according electronic components that make a house. In addition, a data structure suitable for home automation was defined and developing application programs based on Android OS according to packet structure, embedded system for home automation was developed.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.19 no.9
• /
• pp.1824-1837
• /
• 1994

Broadband ISDN will support advanced communication services such as multimedia conference, VOD and electronic news service. Because many of these advanced services require multimedia data delivery, future communication networks must have flexible and efficient multiparty communications capabilities. In this paper we propose a new multicasting method which uses packer filtering capabilities both in a physical network and in a logical network layers. This new scheme has potential to reduce the transmission and packet processing overheads of multicast communications. For the new multicasting method, we develop a group matching algorithm which finds a suitable set of groups that covers multiple target hosts. We show the application of the multicasting method and the group matching algorithm with two simple examoles.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.11
• /
• pp.4644-4661
• /
• 2015

Wireless sensor networks are often organized in the form of clusters leading to the new framework of WSN called cluster or hierarchical WSN where each cluster head is responsible for its own cluster and its members. These hierarchical WSN are prone to various routing layer attacks such as Black hole, Gray hole, Sybil, Wormhole, Flooding etc. These routing layer attacks try to spoof, falsify or drop the packets during the packet routing process. They may even flood the network with unwanted data packets. If one cluster head is captured and made malicious, the entire cluster member nodes beneath the cluster get affected. On the other hand if the cluster member nodes are malicious, due to the broadcast wireless communication between all the source nodes it can disrupt the entire cluster functions. Thereby a scheme which can detect both the malicious cluster member and cluster head is the current need. Abnormal energy consumption of nodes is used to identify the malicious activity. To serve this purpose a learning based energy prediction algorithm is proposed. Thus a two level energy prediction based intrusion detection scheme to detect the malicious cluster head and cluster member is proposed and simulations were carried out using NS2-Mannasim framework. Simulation results achieved good detection ratio and less false positive.

• International Journal of Highway Engineering
• /
• v.17 no.5
• /
• pp.75-82
• /
• 2015

PURPOSES : In link matching using vehicular trajectory in a car navigation system, it is technically difficult to match the location of the subject vehicle with a link on an electronic map in the vehicle on a grade separation highway segment consisting of an elevated highway and atgrade highway, because of the overlap of geometric lines of the two highways. This study was initiated to propose a link matching algorithm using the characteristics of vehicular movement of the subject vehicle. METHODS : The selected test site is the highway segment between Jeong-reung IC and Gil-eum IC where the Inner Circulation Road and Jeong-reung-ro run together. To evaluate the proposed algorithm, this study collected the raw packet data of vehicles that drove on the test site. In a simulation environment, link matching was performed using an existing algorithm as well as the proposed algorithm. RESULTS: It was clearly found that the characteristics of vehicular movements are different on the two highways. CONCLUSIONS: The proposed algorithm outperformed the existing algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.6 no.4
• /
• pp.1223-1247
• /
• 2012

The need for securing Wireless Sensor Networks (WSNs) is essential especially in mission critical fields such as military and medical applications. Security techniques that are used to secure any network depend on the security requirements that should be achieved to protect the network from different types of attacks. Furthermore, the characteristics of wireless networks should be taken into consideration when applying security techniques to these networks. In this paper, energy efficient Security Model for Tree-based Routing protocols (SMTR) is proposed. In SMTR, different attacks that could face any tree-based routing protocol in WSNs are studied to design a security reference model that achieves authentication and data integrity using either Message Authentication Code (MAC) or Digital Signature (DS) techniques. The SMTR communication and processing costs are mathematically analyzed. Moreover, SMTR evaluation is performed by firstly, evaluating several MAC and DS techniques by applying them to tree-based routing protocol and assess their efficiency in terms of their power requirements. Secondly, the results of this assessment are utilized to evaluate SMTR phases in terms of energy saving, packet delivery success ratio and network life time.