• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.9B
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• pp.1098-1107
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• 2011

As recent integration of wire and wireless networks and the convergence of telecommunications and broadcasting, uniform and standardized by the broadcasting operators of existing stations to provide 4A(Any-time, Any-where, Any-device, Any-contents) services for the next-generation of multimedia services research is being progressed. Demand for theses next-generation multimedia services to ensure video compression coding technology, as well as mobility, ability to operation a variety of devices, characteristics and performance of user network and the status and conditiion, user preferences and context-awareness based on the technology has an interest in technical studies. In this paper, the current internet environment, SVC(Scalable Video Coding) encoded by a mixture of multicast and overlay multicast transmission technology for broadcasting services by designing and efficient multimedia broadcasting system is proposed. In addition, ACK-Aow Optimization by overlay multicast scheme existing tree-based overlay multicast, and by comparing the effectiveness of the proposed algorithm is demonstrated.

• KIPS Transactions on Software and Data Engineering
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• v.1 no.3
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• pp.169-176
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• 2012

The information delivery and transmission media(DID or PID) market is making remarkable growth as the high-speed networks are spreading and LCD/LED TVs are more and more popularized, and display devices are increasingly large and high-definition. In addition, the popularization of smart devices and the expansion of the information delivery and transmission media market make a demand for N-Screen in content service. Colleges and universities have installed and operated various types of DID to promote their schools and departments and deliver information about them, still remaining in the level of media content implementation. So, we implement and evaluate a next-generation electronic bulletin board for each department that allows for interactive N-Screen communication based on the integration of smart phone and internet. This board enhanced efficiency as supporting N-Screen, inserting and deleting the contents at real time and offering bidirectional communication.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.1A
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• pp.30-37
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• 2006

In this paper, we propose a QoS-aware efficient bandwidth re-provisioning scheme in a next generation wireless packet transport network. At the transport network layer, it classifies the traffic of the radio network layer into a real time class and a non-real time class. Using an auto-regressive time-series model and a given packet loss probability, our scheme predicts the needed bandwidth of the non-real time class at every re-provisioning interval. Our scheme increases the system capacity by releasing the unutilized bandwidth of the non-real time traffic class for the real-time traffic class while insuring a controllable upper bound on the packet loss probability of a non-real time traffic class. Through empirical evaluations using the real Internet traffic traces, our scheme is validated that it can increase the bandwidth efficiency while guaranteeing the quality of service requirements of the non-real time traffic class.

• The KIPS Transactions:PartA
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• v.9A no.3
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• pp.317-326
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• 2002

The mobile telecommunication system has been growing exponentially after 1990s due to the high population in a city and the growth of mobile user. In this time, the current mobile system mainly concentrates on the voice communication. However, in the next generation, mobile users want to get very diverse services via mobile terminal such as the Internet access, web access, multimedia communication, and etc. For this reason, the next generation system, such as the UMTS system, has to support the packet data service and it will play the major role in the system. In different from the voice service, the packet data service should store packet data in a buffer at base station before it forwards. Consequently, the performance closely related to the buffer management and its operation. However, until now, there are rare study on the buffer behavior and management. In this paper, we will observe the buffer behavior in the UMTS systems by using simulation and analyze the results. For this research, we generate packet data traffics and model the UMTS system for a simulation. Then we analyze the buffer state by a simulation and calculate the buffer overflow probability by mathematical methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6B
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• pp.544-550
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• 2006

Next-generation wireless/mobile networks are envisioned to have an IP-based infrastructure. One of the research challenges for next-generation all IP-based networks is the design of intelligent mobility management technologies that have a seamless mobility and minimal signaling overhead. Recently, HMIPv6 was proposed by the IETF for efficient mobility management. HMIPv6 reduces the amount of signaling and improves the performance of MIPv6 in terms of handover latency. However the MAP can be a single point of performance bottleneck when there are a lot of local movements. HMIPv6 can cause signaling overhead due to the unnecessary location update of idle mobile nodes. Therefore, in this paper, we propose the dynamic paging Mobile IPv6 that reduces the signaling cost of the unnecessary location updates using IP paging and organizes dynamically optimal MAP area according to user's mobility and traffic. We show performance results that are obtained from the average total location update cost and packet delivery cost.

• Spatial Information Research
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• v.17 no.2
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• pp.171-181
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• 2009

In Web2.0 environment, with advanced platform technologies, global vendors such as Google, Microsoft and Yahoo provide competitive geospatial services based on global map and satellite image. But the relatively low level of platform technologies has not rapidly increased the land information and geospatial service markets in Korea. For the ubiquitous next generation Internet, as a one of the R&D projects by Korean Land Spatialization Group, the project for platform technologies has being made to provide customized land information and geospatial service. The platform technologies can be categorized for streamming, mashup and geosearch. More specifically, the 2D/3D Hybird streamming engine, mashup engine for u-GIS service and next generation search engine for land information have being developed. In this context, the strategies for efficient development and use of geoweb platform technologies are required. This study surveys the present geospatial products and services using of platform technologies to propose the strategies for efficient development and use of platform technologies. The strategies for efficient development and use of platform technologies can be proposed focusing on target market and each of platform technologies.

• The Journal of the Korea institute of electronic communication sciences
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• v.1 no.1
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• pp.70-80
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• 2006

The large portion of communication service areas move from a legacy wire-line voice service to mobile data service. For the purpose of satisfaction on market need, many communication systems should be installed and upgraded based on a mobile wide-band transmission facility. Recently, large part of communication service is based on internet protocol by packet switch techniques and required new technologies such as multimedia processing, QoS achievement, and mobility managememobile communication network such as IS-95A/B and CDMA2000-1X. In this paper, I analyzed the network architecture and service provision methods. in CDMA2000-1X nt. In korea, a CDMA communication technique is standardized for digital mobile communication systems. By using the analysed results, I will extract an efficient method for network evolution and a core technique for next generation mobile communication network.

• The Journal of the Korea Contents Association
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• v.8 no.9
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• pp.42-54
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• 2008

In recent years, embedded systems have been expanding their application domains from traditional embedded systems such as military weapons, robots, satellites and digital convergence systems such as celluar phones, PMP(Portable Multimedia Player), PDAs(Personal Digital Assistants) to Next Generation Personal Computers(NGPCs) such as eating PCs, wearable computers. The NGPCs are network-based, human-centric digital information devices diverged from the traditional PCs used mainly for document writing, internet searching and database management. Wearable computers with battery capacity and memory size limitations have to use real-time operating systems with small footprints and low power management techniques to provide user's QoS in spite of hardware constraints. In this paper, we have designed and implemented a low-power RTOS (called eRTOS) for wearable computers. The implemented eRTOS has 18KB footprints and the dynamic power management and the device power management schemes are adapted in it. Experimental results with wearable computer applications show that the low power techniques could save energy up to 47 %.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.747-749
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• 2005

The popularity of web services within the IT industry continues to grow as the next generation web technologies. Web services are self-contained, self-describing, modular applications that can be published, located, and invoked across the Web. Web services will be core technology for e-business in the Web. IPv6 is sometimes also called the Next Generation Internet Protocol and is a new version of IP which is designed to be an evolutionary step from IPv4. In this paper, we define problems for adapting web services to IPv6 Environment. This paper survey and explain consideration issues that include standards, components, coexistence of IPv6 and IPv4, etc.

• Journal of the Korea Society of Computer and Information
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• v.27 no.9
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• pp.113-120
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• 2022

In this paper, we analyze the feasibility of the IP spoofing attack exploiting null security algorithms in 5G networks based on 3GPP standard specifications. According to 3GPP standard specifications, the initial Registration Request message is not protected by encryption and integrity. The IP spoofing attack exploits the vulnerability that allows a malicious gNB (next generation Node B) to modify the contents of the initial Registration Request message of a victim UE (User Equipment) before forwarding it to AMF (Access and Mobility Management Function). If the attack succeeds, the victim UE is disconnected from the 5G network and a malicious UE gets Internet services, while the 5G operator will charge the victim UE. In this paper, we analyze the feasibility of the IP spoofing attack by analyzing whether each signaling message composing the attack conforms to the 3GPP Rel-17 standard specifications. As a result of the analysis, it is determined that the IP spoofing attack is not feasible in the 5G system implemented according to the 3GPP Rel-17 standard specifications.