• Proceedings of the Korea Society for Simulation Conference
• /
• 2003.11a
• /
• pp.95-103
• /
• 2003

Event notification service is a event-based messaging middle ware service needed for various vertical domains, such as, business applications, distributed system management, and web service integration. In this paper, we investigate the architecture of an event notification service that includes a subject-based event dissemination service and a flexible message communication service. The event dissemination service is in charge of transferring events asynchronously but speedy according to the subjects of events and their environmental knowledge. It also includes content-based message filtering. The message communication service provides a common communication infrastructure supporting variety types of messages and variety of protocols. Depending on application domains and situation, we can re-configurate the communication infrastructure in order to optimize the efficiency and usability. This paper shows the performance analysis of our event notification service with various types of message formats and protocols.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.20 no.3
• /
• pp.37-41
• /
• 2020

In this paper, we propose a routing method to improve the message transmission efficiency between DTN nodes in an environment where communication infrastructure in the city is destroyed. In the situation where a certain size of communication infrastructure can not function, the message transmission process between the nodes is explained. An effective routing method for improving reliability between nodes was proposed and evaluated using DTN simulator. The routing algorithm with improved reliability in urban areas was confirmed by simulation considering the message transmission relationship between nodes on uncertain path due to the destruction of communication infrastructure. We used a routing algorithm that includes all the contact information the node has experienced in the past. In the simulation of delivering messages in a situation where the communication infrastructure was destroyed, relatively better results were obtained than the existing routing algorithm.

• Proceedings of the KIEE Conference
• /
• 2006.07a
• /
• pp.173-174
• /
• 2006

The power infrastructure defense system monitor and control a power system with parameters of a power system such as voltage, phasor angle, frequency and power flow which are measured at the same instance. For this, synchronized phasor measurement based on the GPS(Global Positioning System) is necessary. PMU(Phasor Measurement Unit) measures synchrophasor and transmits it to the power infrastructure defense system. For this communication, IEEE H37.118 defines a communication message format and measurement concept and we extend the protocol to transmit disturbance data. The synchrophasor data can be sent at various rates and there are several options for phasor information sent in the synchrophasor message. In this paper, we develop software that simulate communication between the power infrastructure defense system and PMU to annalize the traffic.

• Journal of the Korea Society of Computer and Information
• /
• v.10 no.3 s.35
• /
• pp.201-208
• /
• 2005

Event notification service is a event-based messaging middleware service needed for various vertical domains, such as, business applications, distributed system management, and web service integration. In this paper, we investigate the architecture of an event notification service that includes a subject-based event dissemination service and a flexible message communication service. The event dissemination service is in charge of transferring events asynchronously but speedy according to the subjects of events and their environmental knowledge. It also includes content-based message filtering. The message communication service provides a common communication infrastructure supporting variety types of messages and variety of protocols. Depending on application domains and situation, we can re-configurate the communication infrastructure in order to optimize the efficiency and usability. This paper shows the performance analysis of our event notification service with various types of message formats and protocols.

• The Journal of Society for e-Business Studies
• /
• v.24 no.2
• /
• pp.55-70
• /
• 2019

It is essential to consider the relationships between each component in the communication infrastructure in order to build and optimize the infrastructure. In this paper, based on the major factors to consider for the optimized communication infrastructure, we propose an enhanced MACSec-based deployment mechanism for communication infrastructure. The proposed MACSec mechanism can replace the IPSec without the additional devices and redesign of the communication infrastructure. In addition, we evaluate the performance of MACSec and IPSec in terms of the major factors such as message overhead, encryption processing, and host mobility. According to the evaluation results, we can say that MACSec is superior to IPSec with regard to mobility as well as hop delay and message overhead.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.14 no.4
• /
• pp.295-304
• /
• 2014

Communication infrastructure supports wide variety of mobile services such as photo and file sharing, location tracking, social network services and instant messaging. However, instances like power-loss and natural disasters disrupt these communication infrastructures unable to render support to these mobile services. Delay-tolerant networks (DTNs) offer a solution to these problems at hand. By utilizing mobility and opportunistic contacts among mobile devices, a plausible communication network can be establish and enable support to mobile applications. This paper presents an energy-efficient, reliable message delivery routing scheme with message prioritization rules for DTN. It uses the context information of nodes (mobile devices) such as the contact history (location and time of contact), speed/velocity, moving direction to determine the best forwarders among nodes in the network. The remaining energy of the nodes is also used to determine the message types a node can deliver successfully. The simulation results show that proposed approach outperforms Epidemic and Prophet routing schemes in terms of delivery ratio, overhead ratio, delivered messages per types and remaining energy.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.5 no.2
• /
• pp.440-456
• /
• 2011

In this paper, we introduce a novel Public Key Infrastructure (PKI) based message authentication scheme that takes advantage of temporal and spatial uniqueness in physical layer channel responses for each transmission pair in vehicular communication networks. The proposed scheme aims at achieving fast authentication and minimizing the packet transmission overhead without compromising the security requirements, in which most messages can be authenticated through an extreme fast physical-layer authentication mechanism. We will demonstrate that the proposed secure authentication scheme can achieve very short message delay and reduced communication overhead through extensive analysis and simulation.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.5 no.4
• /
• pp.243-253
• /
• 2010

Multihop data delivery in vehicular ad hoc networks (VANETs) suffers from the fact that vehicles are highly mobile and inter-vehicle links are frequently disconnected. In such networks, for efficient multihop routing of road safety information (e.g. road accident and emergency message) to the area of interest, reliable communication and fast delivery with minimum delay are mandatory. In this paper, we propose a multihop vehicle-to-infrastructure routing protocol named Vertex-Based Predictive Greedy Routing (VPGR), which predicts a sequence of valid vertices (or junctions) from a source vehicle to fixed infrastructure (or a roadside unit) in the area of interest and, then, forwards data to the fixed infrastructure through the sequence of vertices in urban environments. The well known predictive directional greedy routing mechanism is used for data forwarding phase in VPGR. The proposed VPGR leverages the geographic position, velocity, direction and acceleration of vehicles for both the calculation of a sequence of valid vertices and the predictive directional greedy routing. Simulation results show significant performance improvement compared to conventional routing protocols in terms of packet delivery ratio, end-to-end delay and routing overhead.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.11 no.6
• /
• pp.215-221
• /
• 2011

Communication infrastructure of wireless sensor networks significantly tends to depend on application requirements. Gossip communication is becoming one of the promising solutions for addressing its scalability problems in providing information propagation functionality based on the P (publish)/S (subscribe) paradigm. In particular, despite the importance of both guaranteeing message delivery order required and supporting overlapping groups in sensor networks, there exist little research works on development of gossip-style dissemination protocols to satisfy all these requirements. In this paper, we present the latest causal information transmission protocol between publishers and subscribers for overlapping groups. In this protocol, sensor leaders as publishers might guarantee consistently causally ordered message delivery among themselves by aggregating causality information. On the other hand, only the latest causal information piggybacked on each multicast message is transmitted from publishers to subscribers through gossip-style dissemination. Its scalability feature might be highly suitable for the area of the applications requiring only the minimum meaningful information.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.6
• /
• pp.3280-3298
• /
• 2019

Vehicular ad-hoc networks (VANETs) have become increasingly significant in intelligent transportation systems, they play a great role in improving traffic safety and efficiency. In the deployment of intelligent VANETs, intelligent vehicles can efficiently exchange important or urgent traffic information and make driving decisions. Meanwhile, secure data communication and vehicle's identity privacy have been highlighted. To cope with these security issues, in this paper, we construct an efficient anonymous authentication scheme with secure communication in intelligent VANETs. Combing the ElGamal encryption technique with a modified Schnorr signature technique, the proposed scheme provides secure anonymous authentication process for encrypted message in the vehicle-to-infrastructure communication model, and achieves identity privacy, forward security, and reply attack resistance simultaneously. Moreover, except the trusted authority (TA), any outside entity cannot trace the real identity of an intelligent vehicle. The proposed scheme is designed on an identity-based system, which can remove the costs of establishing public key infrastructure (PKI) and certificates management. Compared with existing authentication schemes, the proposed scheme is much more practical in intelligent VANETs.