• Journal of Broadcast Engineering
• /
• v.10 no.2
• /
• pp.190-201
• /
• 2005

MPEG-21 has identified the need fur Event Reporting in its vision for an interoperable multimedia framework. Event Reporting is required within the MPEG-21 multimedia framework in order to provide a standardized means for sharing information about Events amongst Peers and Users. Such Events relate to Digital Items and/or Peers that interact with them. Arising from an each Event, there is the opportunity to describe what occurred. However, there are a number of difficulties in providing an accurate report about an Event. Different observers of the Event may have vastly different perspectives, needs, and focuses. They may emphasize certain elements to the detriment of others, or they may describe an Event in a way that others may find confusing. In this paper, we design how to express Event Reporting message structure and system architecture in compliance with ISO/IEC 21000-15. And we implement the system for MPEG-21 Event Reporting service.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.4A
• /
• pp.385-392
• /
• 2006

It is widely accepted that high user densities in mobile multimedia environments can only be achieved with micro- and pico-cell. The smaller cell size causes frequent handovers between cells, and decreases permissible handover processing delay. This may result in the handover failure, in addition to the loss of some packets during the handover. In these cases, re-transmission is needed in order to compensate errors, which in turn triggers a rapid degradation of throughput. In this paper, we propose a new handover scheme for the next generation mobile communication systems, in which the handover setup process is done in advance before a handover request by predicting the handover cell based on mobile terminal's current position and moving direction. Simulation is performed in order to analyze the handover failure rate and packet loss rate. Simulation results show that our proposed method provides a better performance than the conventional method.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.13 no.1
• /
• pp.107-112
• /
• 2018

Recently, there are many real life applications that uses drones. There are various applications such as the aerial shot with the drones for the broadcasting service or drone racing competition and so on. Specifically, they patrol for the traffic enforcement on a highway. The police department use the 'Spot Mobility' method which float the drones for 30 minute period. However, this method is inefficient for the wide area with small numbers of enforcement. Therefore, a wireless network system consists of drones to patrol on the highway systematically is required. In this paper, the most efficient routing protocol will be selected for the MANET drone network by applying various routing protocols. To accomplish this, the drone patrol network system with routing protocols are designed and simulated in OPNET simulator.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.19 no.1
• /
• pp.71-77
• /
• 2013

Smart work has been gaining more popularity recently. Smart work means that employees perform their works anytime and anywhere as utilizing the information and communication technology. It can be divided into four categories; the mobile office, the home office, the work-at-center and the tele-cooperation. Among them, the mobile office based on tablet personal computers(PCs) or smart phones, employees can exchange information with tablet PCs or smart phones via mobile radio communication networks and portable terminals. Smart devices such as tablet PCs and smart phones help to access intranet system for requests, approvals, information search whenever employees need. This mobile office system for real-time HSE managing can contribute to improve the productivity and work efficiency in a shipyard. In this study, the main goal is to design the specialized mobile application for the HSE management system on the shipbuilding industry. The mobile application including 10 functions is designed based on ooCBD(object-oriented Component Based Development) methodology.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.17 no.2
• /
• pp.99-113
• /
• 1992

In general, TDMA and FDMA have been used for multiple access communication methods. Recently. However, ALOHA and CSMA protocols came to exist as new schemes for VSAT data networks and LANs, respectively. These schemes are proven to be effective for packet switched communication systems that has bursty traffic but packet collisions. In this paper we analyze capture statistics arising from fading channels in packet radio communication systems in the context of ALOHA protocol. We derive general results of the exact form of capture probabilities and present numerical data for wide range of fading parameters. Since the capture probabilities are found to approach zero when the number of transmitted signals become larger, we are able to determine the achievable channel throughput by a least squares fitting of an exponential-type function to the probabilities.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.1B
• /
• pp.95-105
• /
• 2010

IEEE 802.15.4 is the one of the protocols for radio communication in a personal area network. Since it aims to provide low cost and low power communication for ubiquitous communication, it requires high level of optimization in implementation. Recently, there have been many studies on the performance evaluation of IEEE 802.15.4 MAC protocol. According to the results of the studies, it is tendency that the transceiver is implemented to SoC type. On the implementation, the specific functions of MAC like CSMA-CA and MAC frame handling is designed to hardwired functions. In this paper, we implemented the protocol with hardwired low MAC (HL-MAC) and its state machine for the optimization from the physical layer and MAC layer. it has the characteristics of the small code size and the enhanced power consumption.

• Convergence Security Journal
• /
• v.11 no.3
• /
• pp.39-46
• /
• 2011

Smart environment of health information technology, u-Healthcare architecture, ad-hoc networking and wireless communications environment are major factors that increase vulnerability of u-healthcare information systems. Traffic domain is the concept of network route that identifies the u-Healthcare information systems area as the traffic passing and security technologies application. The criterion of division is an area requiring the application of security technology. u-Healthcare information system domains are derived from the intranet section. the public switched network infrastructure, and networking sectors. Domains of health information systems are separated by domain vulnerability reason. In this study, domain-specific security vulnerability assessment system based on the USN in u-Healthcare system is derived. The model used in this study suggests how to establish more effective measurement USN-based health information network security vulnerability which has been vague until now.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.7 no.6
• /
• pp.1479-1485
• /
• 2012

The parking management system can increase driver's convenience with detailed parking information service in the parking lot. At the same time, parking management system consumes non-negligible electrical energy with large amount of sensors, displays and control modules. With the increase in the demand for green and sustainable building design all over the world, it becomes a meaningful issue for parking management system to reduce operating power. This paper presents the preliminary design and estimated results of a parking management system which is optimized to reduce the power consumption mainly on detectors and displays. The system design is based on pre-developed wireless parking detectors, Park Tile and Park Disk. The system has a number of parking space detectors, vehicle count detectors, information displays, guidance terminals and other control units. We have performed system architecture design, communication network design, parking information service scenario planning, battery life regulation and at last operating power estimation. The estimated operating power was 0.93KW per parking-slot, which is 20% of traditional systems. The estimated annual maintenance cost was 18% of traditional systems.

• Convergence Security Journal
• /
• v.13 no.4
• /
• pp.11-17
• /
• 2013

All u-Health system has security vulnerabilities. This vulnerability locally(local) or network(network) is on the potential risk. Smart environment of health information technology, Ad-hoc networking, wireless communication environments, u-health are major factor to increase the security vulnerability. u-health care information systems user terminal domain interval, interval public network infrastructure, networking section, the intranet are divided into sections. Health information systems by separating domain specific reason to assess vulnerability vulnerability countermeasure for each domain are different. u-Healthcare System 5 layers of security risk assessment system for domain-specific security vulnerability diagnosis system designed to take the security measures are needed. If you use this proposed model that has been conducted so far vaguely USN-based health information network security vulnerabilities diagnostic measures can be done more systematically provide a model.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.1A
• /
• pp.17-24
• /
• 2003

Access network is one of the most critical components of telecommunication networks. Essentially it provides the final connection through to the subscriber and at the same it is usually the most expensive component in terms of capital investment and ongoing cost of maintenance and repair In recent, various access technologies with broadband have been developed and also are emerging newly Comparing fixed access networks, the concrete concept as well as the scope of mobile access networks or parts has not been defined yet although it is caused by peculiarities of mobile network with mobility-guarantee technology, use of RF resource, fixed-exchange and transport networks This article examines the characteristics and detailed functions of BTS, BSC, MSC and other components in CDMA mobile network under the IS-95 A/B and cdma 2000-1x standards comparing the ITU's access network functional model From the systematic and functional perspectives, futhermore, an alternative definition for access parts of mobile network is proposed.