Photonic lattice-type self-routing switching network

Abstract

The asynchronous transfer mode (ATM) is considered as a fundamental technique in constructing the broadband ISDN. High-speed switching is required in the ATM switching equipment, which forms the core of the ATM network. Then it is desirable to apply the self-routing switching network. Various self-routing switching networks have been proposed including the Banyan network, as well as its improvements. This network is composed of the multistage connection of 2 × 2 switches. However, problems remain in such switching networks, for example, the hardware scale in the large network and the hardware reliability. This paper proposes anew a photonic lattice-type self-routing network with the following features: (1) the system has essentially a bus structure and excellent expandability; (2) by its structure, the hardware scale increases only slowly in proportion to the number of accommodated circuits. This is an advantage in the large-scale network; (3) again by its structure, it is possible to deroute the cells thereby avoiding the point of failure which improves the reliability; (4) by restricting the number of cell transfer paths to a certain number, a relatively simple routing control circuit can be employed based on the optical switching circuit; and (5) by the application of the optical switch, the transfer delay of the cell is reduced greatly.