• Journal of Korea Multimedia Society
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• v.11 no.3
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• pp.398-403
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• 2008

Data broadcasting is a mechanism to transmit information to clients in simplex transmission environments. In this mechanism, server transmits to repeat all information to all users and users use a necessary data when the data is transmitted. Therefore users are waiting the necessary data until the data is transmitted. It is important to reduce user's waiting time. Server schedules the data to reduce waiting time. In this paper, we study efficient data scheduling algorithm. The result shows that the performance of the proposed method is increased 13 percent compared to the method considering only request frequency.

• Journal of the Korea Society of Computer and Information
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• v.12 no.2 s.46
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• pp.111-121
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• 2007

In mobile computing environments, data broadcasting is widely used to resolve the problem of limited power and bandwidth of mobile equipments. However, the previous broadcast scheduling methods can be inefficient in the environment where the user requests change dynamically since they are based on static data requests. Moreover, a high-priority user can wait long for infrequently requested data because they never consider the priority of listeners. In this paper, we propose a new broadcast scheduling method that reflects dynamic changes of user requests using user profiles. It also reflects user priorities to reduce the access time of high-priority users. We evaluate the performance of the proposed method through simulation.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.9
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• pp.433-444
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• 2005

In video-on-demand(VOD) systems, a broadcast-based scheduling mechanism is known to be a very efficient technique for disseminating popular videos to very large client populations. The main motivations of broadcasting scheduling mechanisms are that they scale up extremely well and they have very modest bandwidth requirements. This paper proposes a new dynamic broadcasting scheduling mechanism, named FDBS (fast dynamic broadcasting scheme), and proves its correctness. This paper also evaluates the performance of FDBS on the basis of a simulation approach. The simulation results indicate that FDBS shows a superior performance over UD, CBHD, and NPB in terms of the average response time with very reasonable bandwidth requirements.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.5
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• pp.131-140
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• 2018

A broadcast scheduling scheme is an essential technique to improve the performance of data broadcast systems. This paper explores the problem of data broadcast over multiple channels to reduce query response time, and proposes a new hybrid data broadcast scheduling scheme named HDAMA. The proposed scheme employs the strategy that combines the advantages of push-based broadcast and pull-based broadcast. HDAMA could enhance the performance of query response time since it is capable of controlling the influence of access probability properly reflecting the characteristics of multi-data queries and broadcasting pull data items relatively on time. Simulation is performed to evaluate the performance of the proposed scheme. The simulation results show that the performance of HDAMA is superior to other schemes in terms of the average response time.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.06a
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• pp.319-320
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• 2011

본 논문에서는 초중등학교의 조회 및 실내 집체 교육은 내용과 수준에 따라 학년별로 서로 다른 내용의 방송을 동시에 실시할 필요성이 요구되고 있다. 그러나 현재 사용 중인 방송 설비는 일방적으로 같은 내용의 방송을 전달하고 있고, 서로 다른 내용의 방송을 위하여 별도의 라인을 설비해야하는 번거로움과 비용부담을 안고 있다. 또한, 큰 건물의 재난 방송 시스템도 장소와 위치에 따라 서로 다른 내용의 방송을 동시에 실시해야 하는 필요성이 제기되고 있다. 즉, 위치에 따라 비상탈출 안내 방송을 실시하고 상황변화에 따라 장소에 맞는 방송을 전달하기 위한 시스템이 필요하다. 따라서 본 논문에서는 인터넷 망을 이용하여 미리 계획된 스케줄에 따라 동시에 청취자에 맞는 맞춤형 방송을 실시할 수 있는 인터넷 스케줄링 방송 시스템의 임베디드 시스템을 개발한다.

• Journal of Internet Computing and Services
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• v.15 no.2
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• pp.33-39
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• 2014

How to transfer spatial data from server to client in wireless broadcasting environment is shown as following: A server arranges data information that client wants and transfers data by one-dimensional array for broadcasting cycle. Client listens data transferred by the server and returns resulted value only to server. Recently number of users using location-based services is increasing alongside number of objects, and data volume is changing into large amount. Large volume of data in wireless broadcasting environment may increase query time of client. Therefore, we propose Client based Data Scheduling (CDS) for efficient data scheduling in wireless broadcasting environment. CDS divides map and then calculates total sum of objects for each grid by considering number of objects and data size within divided grids. It carries out data scheduling by applying hot-cold method considering total data size of objects for each grid and number of client. It's proved that CDS reduces average query processing time for client compared to existing method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.86-89
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• 2002

Recently, video conferencing, Web-casting service, and network sane service which use multicast-based service are popular in Internet. In order to support the broadband Internet services efficiently, more communication bandwidth are needed. The WDM single-hop broadcast network topology is coming into the spotlight in next-generation access networks area. In this paper, the new multicast scheduling algorithm, PGM, is proposed and is evaluated through the computer simulation. The PGM method shows the better performance comparing with existing multicast scheduling algorithm.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.386-388
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• 2008

무선 데이터 방송 시스템은 다수의 이동 클라이언트 들에게 효율적으로 데이터를 전달하는 방법이다. 최근까지 이동 클라이언트들의 평균 접근 시간을 줄이기 위한 스케줄링 기법과 튜닝시간을 줄이기 위한 색인 기법에 대한 많은 연구가 진행되고 있다. 본 논문에서 우리는 실제 기기를 사용하여 기존의 색인 기법과 스케줄링 기법을 활용한 무선데이터 방송시스템을 구현하였다. 또한 구현한 무선 방송 시스템에서 키워드 탐색 질의 처리시, 기존의 색인 기법과 스케줄링 기법의 성능을 평가 하였다.

• Journal of KIISE:Databases
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• v.37 no.2
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• pp.121-126
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• 2010

This paper proposes an efficient index scheduling technique for kNN query processing in multiple wireless broadcast channel environment. Previous works have to wait for the next cycle if the required child nodes of the same parent node are allocated in the same time slot on multiple channel. Our proposed method computes the access frequencies of each node of R tree at the server before the generation of the R-tree index broadcast schedule. If they have high frequencies, we allocate them serially on the single channel. If they have low frequencies, we allocate them in parallel on the multiple channels. As a result, we can reduce the index node access conflicts and the long broadcast cycle. The performance evaluation shows that our scheme gives the better performance than the existing schemes.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.5
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• pp.61-69
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• 2021

On-demand broadcast is an effective data dissemination technique in mobile computing environments. This paper explores the issues for scheduling multi-data queries in on-demand broadcast environments, and proposes a new broadcast scheduling scheme named CASS. The proposed scheme prioritizes queries by reflecting the characteristics of multi-data queries, and selects the data that has not been broadcast in the query for the longest time as the broadcast data according to the query priority. Simulation is performed to evaluate the performance of CASS. The simulation results show that the proposed scheme outperforms other schemes in terms of the average response time since it can show highly desirable characteristics in the aspects of query data adjacency and data conflict rate.