Reducing Loss Rate in Slotted Optical Networks: A Lower Bound Analysis
11 Dec 2006-Vol. 6, pp 2770-2775
TL;DR: It is shown that the ingress switches can have an important role in the loss rate reduction issue in the slotted all-optical networks by balancing the traffic on the wavelength channels and the symmetric traffic transmission.
Abstract: Optical time division multiplexing can be deployed in an all-optical network to provide a finer granularity and improve the bandwidth usage. In contention-based slotted all-optical networks, transmitted traffic (referred to as slot in this paper) on the same wavelength and time-slot from different ingress switches may collide at the optical switches and therefore a number of slots will be lost. In this paper, we study various software techniques to reduce the slot loss rate at an optical switch. We prove some lemmas related to the contention avoidance issue. We show that the ingress switches can have an important role in the loss rate reduction issue in the slotted all-optical networks by balancing the traffic on the wavelength channels and the symmetric traffic transmission. We analyze for the first time the lower-bound on the slot loss rate. We show how to achieve the lower-bound on the loss rate in practice.
Citations
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TL;DR: The contention resolution and avoidance schemes proposed for bufferless OPS networks are surveyed and the Quality of Service (QoS) issue in a QoS-capable bufferlessOPS network is reviewed.
Abstract: Optical Packet Switching (OPS) is the promising switching technique to utilize the huge bandwidth offered by all-optical networks using the DWDM (Dense Wavelength Division Multiplexing) technology. However, optical packet contention is the major problem in an OPS network. Resolution and avoidance are two schemes to deal with the contention problem. A resolution scheme resolves collisions, while an avoidance scheme tries to reduce the number of potential collision events. Many OPS architectures rely on optical buffers to resolve contention. Unfortunately, optical buffering technology is still immature as it relies on bulky optical fiber delay lines. Furthermore, it requires a complex control. Therefore, a bufferless OPS network could still be the most straightforward implementation in the near future. In this article, we survey the contention resolution and avoidance schemes proposed for bufferless OPS networks. We also review the resolution and avoidance schemes that can handle the Quality of Service (QoS) issue in a QoS-capable bufferless OPS network.
95 citations
Cites background or methods from "Reducing Loss Rate in Slotted Optic..."
...b) Symmetric traffic transmission, e.g., [24, 34 ]: Here, each ingress switch (either an edge switch or a core switch) connected to a given core switch must send its traffic in a symmetric manner (i.e., with the same probability) to different output links of the given core switch....
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...The PLR for a balanced traffic load distribution is less than an unbalanced traffic load distribution [ 34 ]....
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...c) Load-balanced traffic transmission, e.g., [24, 34 ]:...
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...Controlled Traffic Transmission — We now state the contention avoidance techniques in which each ingress switch sends its traffic to OPS network in a controlled manner as follows: a) Coordinated packet transmission [ 34 ]: This technique is proposed for a slotted OPS network....
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TL;DR: A probabilistic model is proposed to dimension the number of shared FRWCs so that the same packet loss probability of a switch equipped with only sharedFRWCs is guaranteed.
Abstract: Two architectures are proposed for a wavelength-division multiplexed optical packet switch equipped with both limited-range wavelength converters (LRWCs) and shared full-range wavelength converters (FRWCs). The FRWCs are used to overcome the performance degradation in terms of packet loss probability due to the use of LRWCs only. Two different sharing strategies of the FRWCs are considered. In the first architecture, a pool of FRWCs is shared among the arriving packets. In the second one, the sharing is only partial and the packets directed to the same output share a same pool of FRWCs. A probabilistic model is proposed to dimension the number of shared FRWCs so that the same packet loss probability of a switch equipped with only shared FRWCs is guaranteed. After introducing a cost model of the converters depending on the conversion range, we show that the architectures may allow a conversion cost savings on the order of 90%.
54 citations
Proceedings Article•
01 Jan 201019 citations
01 Jan 2012
TL;DR: This article surveys the contention resolution and avoidance schemes proposed for OPS networks and reviews some contention controller propositions using neural network techniques for solving the output contention problem in OPS.
Abstract: Optical packet switching (OPS) is a promising technology for future networks. However, optical packet contention is a major problem in an OPS network. Resolution and avoidance are two schemes that can deal with the contention problem. A resolution scheme, as a reactive approach, resolves collisions, while an avoidance scheme, as a proactive approach, tries to reduce the number of potential collision events. Therefore, many contention controllers using neural networks have been proposed to control the output contention problem within a learning approach. In this article, we survey the contention resolution and avoidance schemes proposed for OPS networks. We also review some contention controller propositions using neural network techniques for solving the output contention problem in OPS.
9 citations
TL;DR: This work proposes a new slot transmission mechanism as a contention reduction scheme, called Coordinated Slot Transmission (CST), and provides loss rate performance analysis for CST under symmetric and asymmetric traffic arrivals.
6 citations
Cites background or methods from "Reducing Loss Rate in Slotted Optic..."
...In this article,we shall introduce and analyze Coordinated Slot Transmission (CST), as a newcontention reduction scheme, and extend the discussion first appeared in [30]....
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...Since the increase in the number of empty slots on each wavelength decreases slot loss rate [30], the maximum slot loss rate happens when E = 0....
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References
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TL;DR: Some of the critical issues involved in designing and implementing all-optical packet-switched networks are presented.
Abstract: The current fast-growing Internet traffic is demanding more and more network capacity every day. The concept of wavelength-division multiplexing has provided us an opportunity to multiply network capacity. Current optical switching technologies allow us to rapidly deliver the enormous bandwidth of WDM networks. Photonic packet switching offers high-speed, data rate/format transparency, and configurability, which are some of the important characteristics needed in future networks supporting different forms of data. In this article we present some of the critical issues involved in designing and implementing all-optical packet-switched networks.
637 citations
TL;DR: In this article, the authors present a comprehensive study of contention resolution schemes in a multi-wavelength optical packet-switched network, which include contention resolution in wavelength, time, and space dimensions.
Abstract: This paper presents a comprehensive study of contention-resolution schemes in a multiwavelength optical packet-switched network. This investigation aims to provide a unified study of a network of optical routers, which include contention resolution in wavelength, time, and space dimensions. Specifically, we show: 1) how to accommodate all three dimensions of contention resolution in an integrated optical router; 2) how the performance of the three dimensions compare with one another; and 3) how various combinational schemes can be designed and how they perform. With the representative architectures and network topologies studied in this paper, the simulation experiment results capture the characteristics of different contention-resolution schemes, and they quantify the upper-bound average offered transmitter load for these schemes. The combinational contention resolution schemes are shown to effectively resolve packet contention and achieve good network performance under light to intermediate load.
325 citations
"Reducing Loss Rate in Slotted Optic..." refers methods in this paper
...Optical buffering, deflection routing and wavelength conversion are the basic contention resolution techniques [3]....
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TL;DR: The consortium, funded by ARPA, has three main goals: investigating networking issues involved in optical contention resolution, constructing an experimental contention-resolution optical (CRO) device, and building a packet-switched optical network prototype employing a CRO and novel signaling/synchronization techniques.
Abstract: The implementation of optical packet-switched networks requires that the problems of resource contention, signalling and local and global synchronization be resolved. A possible optical solution to resource contention is based on the use of switching matrices suitably connected with optical delay lines. Signalling could be dealt with using subcarrier multiplexing of packet headers. Synchronization could take advantage of clock tone multiplexing techniques, digital processing for ultra-fast clock recovery, and new distributed techniques for global packet-slot alignment. To explore the practical feasibility and effectiveness of these key techniques, a consortium was formed among the University of Massachusetts, Stanford University, and GTE Laboratories. The consortium, funded by ARPA, has three main goals: investigating networking issues involved in optical contention resolution (University of Massachusetts), constructing an experimental contention-resolution optical (CRO) device (GTE Laboratories), and building a packet-switched optical network prototype employing a CRO and novel signaling/synchronization techniques (Stanford University). This paper describes the details of the project and provides an overview of the main results obtained so far.
301 citations
"Reducing Loss Rate in Slotted Optic..." refers background in this paper
...Optical buffers require bulky and expensive optical fiber delay lines [4, 5]....
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TL;DR: In this article, a detailed traffic analysis of optical packet switch design is performed, where special consideration is given to the complexity of the optical buffering and the overall switch block structure.
Abstract: A detailed traffic analysis of optical packet switch design is performed. Special consideration is given to the complexity of the optical buffering and the overall switch block structure is considered in general. Wavelength converters are shown to improve the traffic performance of the switch blocks for both random and bursty traffic. Furthermore, the traffic performance of switch blocks with add-drop switches has been assessed in a Shufflenetwork showing the advantage of having converters at the inlets. Finally, the aspect of synchronization is discussed through a proposal to operate the packet switch block asynchronously, i.e. without packet alignment at the input.
223 citations
"Reducing Loss Rate in Slotted Optic..." refers background in this paper
...Optical buffers require bulky and expensive optical fiber delay lines [4, 5]. Wavelength converters (WC) can also reduce the traffic loss [ 6 , 7], but they are expensive....
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01 Dec 2003
TL;DR: This paper proposes two dynamic congestion-based load balanced routing techniques to avoid congestion and shows that the proposed contention avoidance techniques improve the network utilization and reduce the packet loss probability.
Abstract: In optical burst-switched networks, data loss may occur when bursts contend for network resources. There have been several proposed solutions to resolve contentions in order to minimize loss. These localized contention resolution techniques react to contention, but do not address the more fundamental problem of congestion. Hence, there is a need for network level contention avoidance using load balanced routing techniques in order to minimize the loss. In this paper, we propose two dynamic congestion-based load balanced routing techniques to avoid congestion. Our simulation results show that the proposed contention avoidance techniques improve the network utilization and reduce the packet loss probability.
125 citations
"Reducing Loss Rate in Slotted Optic..." refers methods in this paper
...[8] in OBS; 2) Employing a feedback-based mechanism to minimize the loss, e....
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