Advances in photonic packet switching: an overview
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.
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TL;DR: The objective of this paper is to summarize the basic optical networking approaches, report on the WDM deployment strategies of two major US carriers, and outline the current research and development trends on WDM optical networks.
Abstract: While optical-transmission techniques have been researched for quite some time, optical "networking" studies have been conducted only over the past dozen years or so. The field has matured enormously over this time: many papers and Ph.D. dissertations have been produced, a number of prototypes and testbeds have been built, several books have been written, a large number of startups have been formed, and optical WDM technology is being deployed in the marketplace at a very rapid rate. The objective of this paper is to summarize the basic optical networking approaches, report on the WDM deployment strategies of two major US carriers, and outline the current research and development trends on WDM optical networks.
731 citations
TL;DR: An extensive overview of the current technologies and techniques concerning optical switching can be found in this paper, where the authors present an extensive survey of the optical packet switching technologies and their applications.
Abstract: The switching speeds of electronics cannot keep up with the transmission capacity offered by optics. All-optical switch fabrics play a central role in the effort to migrate the switching functions to the optical layer. Optical packet switching provides an almost arbitrary fine granularity but faces significant challenges in the processing and buffering of bits at high speeds. Generalized multiprotocol label switching seeks to eliminate the asynchronous transfer mode and synchronous optical network layers, thus implementing Internet protocol over wavelength-division multiplexing. Optical burst switching attempts to minimize the need for processing and buffering by aggregating flows of data packets into bursts. In this paper, we present an extensive overview of the current technologies and techniques concerning optical switching.
555 citations
TL;DR: In this article, advanced optical burst switching (OBS) and optical packet switching (OPS) technologies and their roles in the future photonic Internet are discussed and discussed in detail.
Abstract: This paper reviews advanced optical burst switching (OBS) and optical packet switching (OPS) technologies and discusses their roles in the future photonic Internet. Discussions include optoelectronic and optical systems technologies as well as systems integration into viable network elements (OBS and OPS routers). Optical label switching (OLS) offers a unified multiple-service platform with effective and agile utilization of the available optical bandwidth in support of voice, data, and multimedia services on the Internet Protocol. In particular, OLS routers with wavelength routing switching fabrics and parallel optical labeling allow forwarding of asynchronously arriving variable-length packets, bursts, and circuits. By exploiting contention resolution in wavelength, time, and space domains, the OLS routers can achieve high throughput without resorting to a store-and-forward method associated with large buffer requirements. Testbed demonstrations employing OLS edge routers show high-performance networking in support of multimedia and data communications applications over the photonic Internet with optical packets and bursts switched directly at the optical layer
509 citations
TL;DR: In this article, the authors present an analysis of optical buffers based on slow-light optical delay lines and show that the minimum achievable size of 1 b is approximately equal to the wavelength of light in the buffer.
Abstract: This paper presents an analysis of optical buffers based on slow-light optical delay lines. The focus of this paper is on slow-light delay lines in which the group velocity is reduced using linear processes, including electromagnetically induced transparency (EIT), population oscillations (POs), and microresonator-based photonic-crystal (PC) filters. We also consider slow-light delay lines in which the group velocity is reduced by an adiabatic process of bandwidth compression. A framework is developed for comparing these techniques and identifying fundamental physical limitations of linear slow-light technologies. It is shown that slow-light delay lines have limited capacity and delay-bandwidth product. In principle, the group velocity in slow-light delay lines can be made to approach zero. But very slow group velocity always comes at the cost of very low bandwidth or throughput. In many applications, miniaturization of the delay line is an important consideration. For all delay-line buffers, the minimum physical size of the buffer for a given number of buffered data bits is ultimately limited by the physical size of each stored bit. We show that in slow-light optical buffers, the minimum achievable size of 1 b is approximately equal to the wavelength of light in the buffer. We also compare the capabilities and limitations of a range of delay-line buffers, investigate the impact of waveguide losses on the buffer capacity, and look at the applicability of slow-light delay lines in a number of applications.
507 citations
TL;DR: A survey of two new technologies which are still in the experimental stage-optical packet switching and optical burst switching-and comment on their suitability for transporting IP traffic.
Abstract: Wavelength-division multiplexing appears to be the solution of choice for providing a faster networking infrastructure that can meet the explosive growth of the Internet. Several different technologies have been developed so far for the transfer of data over WDM. We survey two new technologies which are still in the experimental stage-optical packet switching and optical burst switching-and comment on their suitability for transporting IP traffic.
413 citations
Cites methods from "Advances in photonic packet switchi..."
...Optical burst switching is a technique for transmitting bursts of traffic through an optical transport network by setting up a connection and reserving resources end to end only for the duration of a burst....
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References
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Book•
01 Jan 1997TL;DR: A comprehensive explanation of the newest developments in optical networks in the MCGRAW-HILL COMPUTER COMMUNICATIONS series.
Abstract: A comprehensive explanation of the newest developments in optical networks in the MCGRAW-HILL COMPUTER COMMUNICATIONS series. Case studies and research projects at AT&T, Fujitsu, and NTT are considered in order to provide the reader with hands-on information which can be applied in practice.
852 citations
"Advances in photonic packet switchi..." refers background in this paper
...In multihop networks, where informat ion from a source node to a destination node may be routed through intermediate nodes [8], only a portion of the network capacity is used for newly generated traf fic....
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11 Aug 1997
TL;DR: This work investigates a high speed protocol called Just-Enough-Time (JET) based on a tell-and-go (TAG) protocol that can efficiently utilize the bandwidth, reduce the latency and provide data transparency.
Abstract: We investigate a high speed protocol called Just-Enough-Time (JET) based on a tell-and-go (TAG) protocol It is suitable for bursty traffic where the duration of each burst is neither long enough to warrant circuit switching nor short enough to fit in a packet The proposed JET protocol can efficiently utilize the bandwidth, reduce the latency and provide data transparency
322 citations
"Advances in photonic packet switchi..." refers background in this paper
...It is also possible to implement quality of service (QoS) by manipulating the offset time between the control packet and the data burst [16, 17]....
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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
"Advances in photonic packet switchi..." refers background in this paper
...[5] I. Chlamtac et al., “CORD: Contention Resolution by Delay Lines,” IEEE JSAC, vol. 14, June 1996, pp. 1014–29....
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...There are various designs for optical buffering, for example, the s taggering switch [4]; switched fiber delay lines (SDL) such as contention resolution by delay lines (CORD) [5]; and switch with large optical buffers (SLOB) [6]....
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TL;DR: A photonic packet switching testbed is detailed which will allow the ideas developed within WASPNET to be tested in practice, permitting the practical problems of their implementation to be determined.
Abstract: WASPNET is an EPSRC-funded collaboration between three British Universities: the University of Strathclyde, Essex University, and Bristol University, supported by a number of industrial institutions. The project which is investigating a novel packet-based optical WDM transport network-involves determining the management, systems, and devices ramifications of a new network control scheme, SCWP, which is flexible and simplifies optical hardware requirements. The principal objective of the project is to understand the advantages and potential of optical packet switching compared to the conventional electronic approach. Several schemes for packet header implementation are described, using subcarrier multiplexing, separate wave lengths, and serial transmission. A novel node design is introduced, based on wavelength router devices, which reduce loss, hence reducing booster amplifier gain and concomitant ASE noise. The fabrication of these devices, and also wavelength converters, are described. A photonic packet switching testbed is detailed which will allow the ideas developed within WASPNET to be tested in practice, permitting the practical problems of their implementation to be determined.
294 citations
"Advances in photonic packet switchi..." refers background in this paper
...[14] D. K. Hunter et a l. , “WASPNET: A Wavelength Switched Packet Network,” IEEE Commun....
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...WASPNET [14] is another research collaboration between three British universities....
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TL;DR: In this paper, an architectural concept is discussed and justified mathematically that relies on cascading many small switches to form a bigger switch with a larger buffer depth, providing an economical and feasible hardware solution.
Abstract: Recently, optical packet switch architectures, composed of devices such as optical switches, fiber delay lines, and passive couplers, have been proposed to overcome the electromagnetic interference (EMI), pinout and interconnection problems that would be encountered in future large electronic switch cores. However, attaining the buffer size (buffer depth) in optical packet switches required in practice is a major problem; in this paper, a new solution is presented. An architectural concept is discussed and justified mathematically that relies on cascading many small switches to form a bigger switch with a larger buffer depth. The number of cascaded switches is proportional to the logarithm of the buffer depth, providing an economical and feasible hardware solution. Packet loss performance, control and buffer dimensioning are considered. The optical performance is also modeled, demonstrating the feasibility of buffer depths of several thousand, as required for bursty traffic.
207 citations
"Advances in photonic packet switchi..." refers background in this paper
...[6] D. K. Hunter et al., “SLOB: A Switch with Large Optical Buffers for Packet Switching,” J. Lightwave Tech., vol. 16, Oct. 1998, pp. 1725–36....
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...There are various designs for optical buffering, for example, the s taggering switch [4]; switched fiber delay lines (SDL) such as contention resolution by delay lines (CORD) [5]; and switch with large optical buffers (SLOB) [6]....
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