An Efficient Metropolitan WDM Ring Architecture for a Slotted Transmission Technique (original) (raw)
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A slotted access control protocol for metropolitan WDM ring networks
Optical Fiber Technology, 2009
ABSTRACT In this study we focus on the serious scalability problems that many access protocols for WDM ring networks introduce due to the use of a dedicated wavelength per access node for either transmission or reception. We propose an efficient slotted MAC protocol suitable for WDM ring metropolitan area networks. The proposed network architecture employs a separate wavelength for control information exchange prior to the data packet transmission. Each access node is equipped with a pair of tunable transceivers for data communication and a pair of fixed tuned transceivers for control information exchange. Also, each access node includes a set of fixed delay lines for synchronization reasons; to keep the data packets, while the control information is processed. An efficient access algorithm is applied to avoid both the data wavelengths and the receiver collisions. In our protocol, each access node is capable of transmitting and receiving over any of the data wavelengths, facing the scalability issues. Two different slot reuse schemes are assumed: the source and the destination stripping schemes. For both schemes, performance measures evaluation is provided via an analytic model. The analytical results are validated by a discrete event simulation model that uses Poisson traffic sources. Simulation results show that the proposed protocol manages efficient bandwidth utilization, especially under high load. Also, comparative simulation results prove that our protocol achieves significant performance improvement as compared with other WDMA protocols which restrict transmission over a dedicated data wavelength. Finally, performance measures evaluation is explored for diverse numbers of buffer size, access nodes and data wavelengths.
Journal of Optical Networking, 2004
A system of slotted interconnected rings employing a combination of wavelength-division multiple access (WDMA) with time-division multiple access (TDMA) can serve a metropolitan area without electro-optical conversion and buffering of payload except at system entry points. The multiple rings overcome the power budget limitations of the single ring extending the reach of the system to even the largest metropolitan areas, the WDM dimension provides flexibility and ease of evolution, and the TDMA dimension offers the efficiency of multiplexing gain particularly under bursty traffic. The system control information is transferred on a dedicated wavelength and is processed in the electrical domain at the ring nodes and the hub, which interconnects the rings. The algorithms control the access to each ring and the scheduling of slots among the rings, based on explicit reservations, to adapt efficiently to the fluctuating offered load. We present the design and hardware implementation of the access control algorithms for such a system built in the framework of the Information Society Technologies (IST) project DAVID (data and voice over DWDM).
2010 17th IEEE Workshop on Local & Metropolitan Area Networks (LANMAN), 2010
In this paper, an efficient traffic allocation technique and a slotted delay-sensitive WDMA protocol suitable for ring metropolitan area networks is proposed. Our purpose is to improve the limited bandwidth utilization that many WDMA protocols for MANs introduce, especially at high loads. This is achieved by: 1) applying an access algorithm to avoid data wavelengths and receiver collisions, and 2) introducing a multiple buffer architecture at each node with an effective buffer selection for transmission scheme that combines the priority criteria of receiver collisions avoidance and packet age. Thus, we obtain not only dropping probability and delay reduction, but also significant throughput enhancement. The required number of buffers per node to maximize throughput is investigated. Performance evaluation is provided by a discrete event simulation model based on self-similar traffic. Comparative results prove that the proposed architecture manages efficient bandwidth utilization as compared with other WDMA protocols, especially under high loads.
CWDM Metropolitan Multiple-Access Ring Network Based on Optical Packet Witching
Photonic Network Communications, 2006
We present a novel CWDM metropolitan multipleaccess ring network based on optical switching of packets according to their wavelength. Each node within the MAN is identified by a combination of wavelength and numerical address. Hence, nodes are able to drop packets presenting a particular wavelength and numerical address, but can insert packets in any wavelength into the ring. This configuration allows wavelength sharing, as several nodes are identified by the same wavelength (but different numerical addresses), and simplifies switching requirements since the set of numerical addresses is reduced. We analyze the viability and scalability of such a network, determining the number of nodes supported by the network under different traffic scenarios and wavelength resources. The impact of switching time on network performance is also analyzed in order to determine which switching technology should be employed when implementing the network.
This study introduces the scalability problem of many WDMA protocols for ring networks. We present a slotted access protocol and a scalable network architecture suitable for WDM ring metropolitan area networks. Each node is equipped with a pair of tunable transceivers to communicate exploiting all the fiber data wavelengths. Also, each node uses a pair of fixed tuned transceivers to exchange control information over a separate control wavelength. The proposed protocol efficiently utilizes the available bandwidth applying a simple access algorithm to avoid both the data channels and the receiver collisions. Performance measures evaluation is provided through analysis. Also, a discrete event simulation model is developed that uses both poisson and pareto traffic sources, giving more realistic performance measures evaluation. Comparative simulation results show that the proposed protocol and network architecture achieve significant performance improvement as compared with the study of ...
Optik - International Journal for Light and Electron Optics, 2013
ABSTRACT In this paper we study a slotted WDM ring network architecture with a suitable access protocol that avoids both data channels collisions and destination conflicts and decreases the packets dropping probability. Our intention is to increase throughput and to decrease transmission delay. The key idea of this paper is the exploitation of a number of buffers at each access node, in conjunction with the appropriate allocation of the incoming traffic among them and the effective decision algorithm for the appropriate buffer selection for transmission. Simulation results approximate the necessary number of buffers at each access node that maximizes the fiber bandwidth utilization.
IEEE Journal on Selected Areas in Communications, 1990
A dynamic time-wavelength division multiaccess protocol (DT-WDMA) is proposed for metropolitan-sized multichannel optical networks employing fixed wavelength transmitters and tunable optical receivers. Control information is sent over a dedicated signaling channel and data are sent over channels owned by the transmitters. Time is divided into slots on each channel and slots on the control channel are further split into mini-slots. Fixed time-division multiaccess is used within each slot on the control channel. Transmitters indicate their intention to transmit a packet by transmitting the destination address during their appropriate mini-slot in the control channel and then transmit their packet in the next slot on their data channel. Receivers listen to the control channel and tune to the appropriate channel to receive packets addressed to them. A common but distributed arbitration algorithm is used to resolve conflicts when packets from many transmitters contend for the same receiver. Each receiver executes the same deterministic algorithm to choose one of the contending packets.
Efficient QoS support in a slotted multihop WDM metro ring
IEEE Journal on Selected Areas in Communications, 2002
In this paper, a novel distributed access protocol for a slotted wavelength-division-multiplexing (WDM) metro ring employing all-optical packet switching and supporting quality-of-service (QoS) classes is presented and analyzed. Since we assume that there are more nodes than available wavelengths in the network, we obtain a scalable multihop WDM ring as underlying network architecture. By dividing each channel into several time slots and further applying destination release and slot reuse, data packets can be efficiently transmitted and received in a statistically multiplexed manner. In our architecture, each node is equipped with one tunable transmitter and one fixed-tuned receiver. Furthermore, as we generally consider so-called a posteriori access strategies, different packet selection schemes are proposed and compared. An analytical model based on the semi-Markov process methodology is developed to quantify the performance of one of these schemes. As a key element of the protocol, an efficient QoS support access mechanism is proposed and its performance is evaluated. The new QoS control scheme adopts a frame-based slot reservation strategy including connection setup and termination, which only slightly increases the signaling and node processing overhead. Thus, an efficient hybrid protocol combining connectionless and connection-oriented packet transmissions is proposed. Index Terms-All-optical ring networks, medium access control (MAC) protocols, quality-of-service (QoS) support, semi-Markov analysis, wavelength-division multiplexing (WDM).
Analysis of metropolitan ring network based on optical packet switching
Here, we present a metropolitan multiple-access ring network based on optical switching over wavelength division multiplexing. An access point to connect local area networks to the metropolitan ring whose key component is an optical switch is introduced. Several simulations have been performed to study the performance of this network that show its viability for a particular set of standard conditions. Several parameters such as packet latency, traffic load or number of access points per wavelength have been analysed to establish the limitations of this architecture.