This paper presents the performance analysis of an optical packet switch with
a feedback delay line buffer, performed in the framework of the IST-DAVID
research project. The network operation is slotted and the case of variable
length data bursts fitted into trains of fixed size packets is considered. The
role of time and wavelength domains for congestion resolution is investigated,
showing that they must be exploited as combined tools in order to obtain good
node performance and, at the same time, optimize the optical hardware
In this paper a network architecture for all optical packet switching is presented, suitable for both long distance and metropolitan application. Overall network architecture, protocol layering, functional sub-blocks required and wavelength management are discussed with reference to the latest results obtained within the ACTS Project KEOPS (Keys in Optical Packet Switching).
This paper presents the definition of a new transfer mode suited for all optical packet switching. A preliminary format of the optical packet has been defined, consisting of a header at fix bit rate and a payload, switched transparently inside the network, able to carry whatever service and bit rate. This optical packet is inserted in a time slot of fixed time length, regardless of the link speed, in order to simplify switches operation and guaranty the network modularity. In this paper the issue of the optimal size of the time slot is addressed, with reference to access delay and traffic shaping.
The application of the IEEE 802.11 access protocol for wireless local area networks (WLAN) to an ATM wireless environment is considered with the aim to support ATM virtual connections. Two different schemes are considered to perform cell multiplexing in MAC frames. The proposed solutions are suitably discussed and evaluated by means of simulation in a multiservice environment with data and video traffic. The effect of the presence of fading in the communication channel is also taken into account.
In this paper a modeling approach to performance evaluation of a shared buffer switching element is described, based on the well-known fluid model of producers and consumers (PC fluid model). A procedure is outlined that leads to a suitable characterization of some typical parameters of the producer and consumer fluid model, making it representative of the shared buffer switch. Simulation analysis is used to investigate the relationships between the behavior of the shared buffer switching element and of the PC fluid model. In the paper it is shown that by means of a suitable fitting of one parameter characterizing the PC fluid model, it is possible to make it representative of the shared buffer in the region of interest for ATM applications. This in spite of the actual operating differences between the real system and the PC fluid model. Numerical results regarding cell loss probability performance and dimensioning of 4 by 4 and 8 by 8 switches are presented and suitably discussed.
The system design of a large (512x512) replicated banyan switch for broadband applications at 622 Mbit/s is presented and the physical limitations that arise in electronic implementation outlined. Optics seems the key to solve the problems that make all-electrical implementation impossible for high speed and large size switches. Possible solutions that adopt optics for board-to-board interconnections are here proposed and discussed for their introduction in the switch.