• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.8
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• pp.25-32
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• 2011

Networks-on-chip (NoC) is emerging as a key technology to overcome severe bus traffics in ever-increasing complexity of the Multiprocessor systems-on-chip (MPSoC); however traditional electrical interconnection based NoC architecture would be faced with technical limits of bandwidth and power consumptions in the near future. In order to cope with these problems, a hybrid optical NoC architecture which use both electrical interconnects and optical interconnects together, has been widely investigated. In the hybrid optical NoCs, wormhole switching and simple deterministic X-Y routing are used for the electrical interconnections which is responsible for the setup of routing path and optical router to transmit optical data through optical interconnects. Optical NoC uses circuit switching method to send payload data by preset paths and routers. However, conventional hybrid optical NoC has a drawback that concurrent transmissions are not allowed. Therefore, performance improvement is limited. In this paper, we propose a new routing algorithm that uses circuit switching and adaptive algorithm for the electrical interconnections to transmit data using multiple paths simultaneously. We also propose an efficient method to prevent livelock problems. Experimental results show up to 60% throughput improvement compared to a hybrid optical NoC and 65% power reduction compared to an electrical NoC.

• ETRI Journal
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• v.29 no.2
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• pp.255-257
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• 2007

We propose an improved selective randomized load balancing (ISRLB) robust scheme under the hose uncertainty model for a special double-hop routing network architecture. The ISRLB architecture maintains the resilience properties of Valiant's load balancing and reduces the network cost/propagation delay in all other robust routing schemes.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.538-540
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• 2004

차세대 인터넷 어플리케이션으로서 각광받고 있는 다양한 실시간 멀티미디어 서비스들이 기존 인터넷망에서 유니케스트 라우팅 방식으로 제공되면서 사용자수의 한계와 서버의 부하 문제에 따른 여러 문제점을 안고 있다. 이로 인해 한번에 여러 사용자들에게 동일한 데이터를 보내야 하는 멀티미디어 서비스의 경우에는, 각 사용자들에게 데이터를 여러 번 전송하는 유니캐스트 라우팅(Unicaast Routing)방식에 비해 멀티캐스팅(Multicast Routing)방식으로 전송하는 것이 대역폭 활용면에서 더 효율적이다. 그러나 Multicast Routing 을 DWDM 기반의 차세대 광인터넷망에 적용하기에는 optical signal splitter의 사용으로 인한 cost의 증가와 Power Penalty 의 보상 문제 등 해결해야 할 여러가지 문제가 남아있다. 따라서 본 논문은 이러한 제한 사항을 극복하기 위해서 제한된 노드에 대해서만 optical signal splitter 를 사용하는 Virtual Source 기반의 Multicast Routing 알고리즘을 제안한다.

• ETRI Journal
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• v.43 no.1
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• pp.64-73
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• 2021

Two-dimensional torus network nodes are typically interconnected using XY routing algorithm for transmitting a packet from a source node to a destination node. In XY routing, if all the paths are used efficiently, the throughput and latency can be improved. In this paper, to utilize all the paths efficiently, we propose a novel binary optical routing algorithm (BORA) to improve the throughput and latency. The throughput is calculated according to the injection rate and number of packets received at the destination. The XY routing algorithm and proposed BORA are implemented using objective modular network testbed in C++ simulation software and the results are analyzed and compared. In this paper, the simulation results show that the network latency reduces to 50% while using the proposed algorithm; moreover, the throughput is also improved.

• Journal of Communications and Networks
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• v.18 no.4
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• pp.551-558
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• 2016

In multifiber all-optical networks, optical amplifiers are used for amplifying multiple optical signals with different wavelengths in fibers. An optical amplifier operates when any of lightpaths passes through it. Therefore, it should simultaneously amplify as many lightpaths as possible for efficiently utilizing its power. This paper proposes a dynamic lightpath establishment scheme considering the use efficiency of the optical amplifiers and the depletion of the wavelength resources in multifiber all-optical networks. The proposed scheme provides a routing and wavelength assignment strategy that reduces both the power consumption of the optical amplifiers and the blocking probability of the lightpath establishment. Through simulation experiments, we demonstrate the effectiveness of the proposed scheme.

• The KIPS Transactions:PartC
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• v.9C no.4
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• pp.581-588
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• 2002

In this paper, we newly propose the optical CDMA routing scheme for the radio access network. At the radio base station (RBS), the received radio signals are multiplied by the PN codes and converted to the CDMA radio signals. In the next optical CDMAS are performed and multiplxed by using the PN codes which are the addresses of the routing mobile switching center (MSC). At the MSC, the CDMA radio signals are routined to another MSC by the CDM receiver at the routing node. In the case MSC is equal to the desired MSC, the radio signal is correlated by the two-layerd spectrum despreading at a time. Finally we theoretically analyze the signal-to-interference and noise power ratio of regenerated signal and the routing error probability and show the availability of proposed scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.1
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• pp.66-74
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• 1994

Gradient projection (GP) technique is applied for solving the optical routing problem (ORP) in high speed packet switched networks. The ORP minimizing average network packet loss probability is non-convex due to packet losses at intermediate switching nodes and its routing solution cannot be directly sought by the GP algorithm. Thus the non-convex ORP is transformed into a convex problem called the reduced-ORP (R-ORP) for which the GP algorithm can be used to obtain a routing solution. Through simulations, the routing solution of the R-ORP is shown to be a good approximation to that of the original ORP. Theoretical upper bound of difference between two (ORP and R-ORP) routing solutions is also derived.

• The KIPS Transactions:PartC
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• v.10C no.4
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• pp.447-454
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• 2003

Optical burst switching (OBS) has been proposed to reduce the use of fiber delay lines (FDLs) and to realize the optical switching paradigm of the next-generation ail optical networks. The OBS can provide improvements over wavelength routing in terms of bandwidth efficiency and core network scalability via statistical multiplexing of bursts. Recently, another challenging issue is how to upport quality of service (QoS) in the optical burst switching networks. In this paper, we propose a deflection routing scheme to guarantee the QoS for the OBS networks to detour lower priority burst forward to the deflection routing path when congested. A big advantage of the proposed scheme is the simplicity of QoS provision, that comes from the simple QoS provisioning algorithm. Also, the QoS provisioning scheme be able to make efficient networks by fairly traffic distributing with the reduce of the use of FDLs at core routers. The QoS provisioning scheme has been verified to reliably guarantee the QoS of priority 0, 1, 2 burst and to efficiently utilize network resources by computer simulations using OPNET As results, the end-to-end delay of high priority burst is improved, and the network efficiency is also improved.

• Journal of Communications and Networks
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• v.9 no.4
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• pp.377-382
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• 2007

This paper presents a new enhanced dynamic and multilayer protection(DMP) routing scheme that considers cooperation between packet and wavelength switching domain in order to minimize the resource consumption. The paper describes the architecture of the multilayer network scenario and compares the proposed algorithm with other routing mechanisms applying protection at the IP/multi-protocol label switching(MPLS) layer or at the optical layer. Simulation results show that DMP reduces the number of optical-electrical-optical(o-e-o) operations and makes an efficient use of the network resources compared to non-multilayer proposals.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2382-2392
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• 2014

In this paper, a new data frame structure for wavelength routing in optical ring access network(ORAN) is designed and the functions of each field in the frame are defined. In addition, the IP packet transmission to the network layer corresponding to the newly proposed structure of the protocol stack is newly presented. Tha data transmission protocol design techniques of ORAN was proposed. IP packet and broadcasting packet transmission within the sub-network, and the IP packet transmission to other sub-network was shown through the process illustration. In the process, the encapsulation and framing process of the wavelength information to routing has been described in detail. And each step takes place in a packet transfer process is demonstrated. A ring type optical access network protocol is not yet research field. ORAN data transfer protocol to send/receive module structure of a subscriber node and a control node of the two rings which analyzed the results are shown. The high-speed Internet solution is proposed that by using wavelength routing the packet transport protocol for ORAN is designed.