• The KIPS Transactions:PartC
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• v.11C no.2
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• pp.253-262
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• 2004

In this paper, a session allocation algorithm for a switch with multiple shared links is proposed. The algorithm guarantees the reserved bandwidth to each service class and keeps the delay of sessions belonging to a service class as close as possible even if the sessionsare allocated to different shared links. To support these qualities of services, a new scheduling model for multiple shared links is defined and a session allocation algorithm to decide a shared link to be allocated to a new session on the connection establishmentis developed based on the model. The proposed heuristic algorithm allocates a session to a link including the subclass with the shortest (expected) delay that subclasses of the service class the session belongs to will experience. Simulation results verify that a switch with multiple shared links hiring the proposed algorithm provides service classes with fairer bandwidth allocation and higher throughput, and guarantees reserved bandwidth better than the switch hiring other session algorithms. It also guarantees very similarservice delay to the sessions in the same service class.

• Journal of Korea Multimedia Society
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• v.7 no.7
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• pp.905-912
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• 2004

It is a study LVMPD to solve the fairness problem of inter-session shared bandwidth. Whenever congestion occurs in one session, the highest layer is dropped. Also the highest layer of other sessions in non-congestion is dropped by iner-session fairness. While there is spare bandwidth, receivers of session in non-congestion can't use bandwidth efficiently. In this paper, we proposed a distribution method to use efficiently spare bandwidth that occurred by inter-session fairness. In our method, we considered the highest layer those receivers receiving and the higher layer those receivers requesting. The sender assigns the packet-deleting priority to packets when congestion occurs in receivers, and sets layer add/drop flag when receivers of session in non-congestion request the higher layer. The switch deletes packets with packet-deleting priority and transfers packets with layer add/drop flag for session in non-congestion. Therefore receivers of session in non-congestion can add the higher layer. In experimental results, it was known that proposed algorithm use the inter-session shared bandwidth more effectively compared with already known method.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.3
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• pp.77-85
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• 2009

Execution times of tasks can be variable depend on input data. If we choose a high performance processor to satisfy the worst case execution times, the hard cost becomes high and the energy consumption also becomes large. To apply a lower performance processor, we have to utilize processor capacity maximally while overrunning tasks can not affect deadlines of other tasks. To be used for such systems, this paper presents SBP (Shared Bandwidth Partitioning) that a processor bandwidth is reserved and shared among all tasks. If a task needs more processor capacity, it can use a portion of the shared bandwidth. A simulation result shows that SBP provides better performance than previous algorithms. SBP reduces deadline miss ratio which is related to scheduling quality. And the number of context switches, which is related to system overhead, is also reduced.

• Journal of the Korea Society of Computer and Information
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• v.17 no.6
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• pp.93-100
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• 2012

In this paper we have proposed a linear time algorithm for solving the minimum sharable-bandwidth tree construction problem. The public-shared network is a user generated infrastructure on which a user can access the Internet and transfer data from any place via access points with sharable bandwidth. Recently, the idea of constructing the SVC video streaming delivery system on public-shared network has been proposed. To send video stream from the stream server to clients on public-shared network, a tree structure is constructed. The problem of constructing a tree structure to serve the video streaming requests by using minimum amount of sharable bandwidth has been shown to be NP-hard. The previously published algorithms for solving this problem are either unable to find solutions frequently or less efficient. The experimental results showed that our algorithm is excellent both in the success rate of finding solutions and in the quality of solutions.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.8
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• pp.638-651
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• 2000

When the bandwidth resources in a packet-switched network are shared among sessions by MAX-MIN flow control each session is required to transmit its data into the network subject to the MAX-MIN fair rate which is solely determined by network loadings. This passive behavior of sessions if fact can cause seri-ous QoS(Quality of Service) degradation particularly for real-time multimedia sessions such as video since the rate allocated by the network can mismatch with what is demanded by each session for its QoS. In order to alleviate this problem we extend the concept of MAX-MIN fair bandwidth allocations as follows: Individual bandwidth demands are guaranteed if the network can accommodate them and only the residual network band-width is shared in the MAX-MIN fair sense. On the other hand if sum of the individual bandwidth demands exceeds the network capacity the shortage of the bandwidth is shared by all the sessions by reducing each bandwidth guarantee by the MAX-MIN fair division of the shortage. we present a novel flow control algorithm to achieve this extended MAX-MIN fairness and show that this algorithm can be implemented by the existing ATM ABR service protocol with minor changes. We not only analyze the steady state asymptotic stability and convergence rate of the algorithm by appealing to control theories but also verify its practical performance through simulations in a variety of network scenarios.

• Journal of the Korea Society of Computer and Information
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• v.20 no.4
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• pp.87-93
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• 2015

Recently, an idea has been suggested in which members construct the network by sharing their surplus bandwidth of their own access point. This kind of network is called public-shared network. As an application, SVC video streaming delivery system on public-shared network has been proposed. To send video stream from the stream server to clients, a tree structure is constructed where the root is a stream server, internal nodes are sharable access points, and leafs are clients. The previous researches have focused on constructing the minimal sharable-bandwidth tree which can serve all video streaming requests using the minimal sharable bandwidth. In this paper, we have shown that the problem of constructing a tree structure with given sharable access points to serve maximal video streaming requests is NP-hard. We also have developed an efficient heuristic algorithm for this problem and evaluated experimentally our algorithm.

• The KIPS Transactions:PartA
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• v.9A no.2
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• pp.147-162
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• 2002

Multi-processor system with fast I/O devices improves processing performance and reduces the bottleneck by I/O concentration. In the system, the Performance influenced by shared memory used for exchanging data between processors varies with configuration and utilization. This paper suggests a prediction model for buffer and shared memory optimization under interrupt recognition method using mailbox. Ethernet (IEEE 802.3) packets are used as the input of system and the amount of utilized memory is measured for different network bandwidth and burstiness. Some empirical studies show that the amount of buffer and shared memory varies with packet concentration rate as well as I/O bandwidth. And the studies also show the correlation between two memories.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.12
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• pp.1168-1173
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• 2012

In this paper, we propose a protection architecture of passive optical network (PON) system by using two optical line terminals (OLTs). Using this scheme, the network can sustain services to access area and restores normal operation in faulty conditions. Unlike existing systems, the proposed one increases the efficiency of the system by operating both OLTs using different wavelengths in normal condition. During protection mode, a Shared-bandwidth allocation scheme is employed to maximize the utilization efficiency. Performance analysis shows that the proposed scheme can provide reliability to Ethernet-based PON system very efficiently.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11a
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• pp.89-92
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• 2003

대규모 네트워크 망인 인터넷을 통한 실시간 멀티미디어 데이터 전송에 있어 다양한 수신자들의 요구를 충족시키기 위해 공유 대역폭(shared bandwidth)을 공정하게 사용해야 한다. 그러나, 공유 대역폭을 공정하게만 사용하기 때문에 혼잡이 발생할 경우 가용대역폭(available bandwidth)을 효율적으로 사용할 수 있는 기법이 필요하게 되었다. 이에 본 논문에서는 최상위 레이어의 손실률에 따른 패킷에 우선순위(priority)를 부여하여 패킷(Packet)을 선택 제거함으로써 혼잡이 발생하지 않는 세션에서는 공유 대역폭을 보다 효율적으로 사용할 수 있는 알고리즘을 제안한다. 실험결과, 제안하는 알고리즘이 기존기법 보다 공유 대역폭을 효율적으로 사용할 수 있었다.

• Journal of Convergence Society for SMB
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• v.6 no.4
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• pp.17-23
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• 2016

With the advance of ICT, the Internet has been creating new services in various fields. However, due to the architectural problem of the Internet, it may inhibit the development of network architectures and various services. Network virtualization is being investigated as an alternative to overcome the architectural problem of the Internet and a virtual network resource allocation algorithm is a very important issue. In this paper, we propose a multiple path resource allocation algorithm with shared backup bandwidth in order to overcome single link failure. It will be improved survivability of the virtual networks. Through our experiments, we confirmed that the multi-path creation time of the proposed algorithm has about 50% performance improvement than previous works.