COMPARATIVE-EVALUATION OF PHOTONIC ATM SWITCH ARCHITECTURES

In this paper, we discuss configurations of photonic ATM (Asynchronous Transfer Mode) switches and their advantages in terms of the number o f optical switching devices to be implemented on the system, the numbe r of wavelengths, throughput, broadcast function etc. In particular, w e focus on photonic ATM switch architectures which can be built in the near future; that is, with presently available optical and electrical devices. For example, we assume the optical devices such as optical g ate switches with 40 dB on/off ratio. In this context, we evaluate 17 types of photonic ATM switches; they are 6 types of input buffer type switches, 6 types of output buffer type switches, 4 types of shared bu ffer switches, and 1 proposed type. From our evaluation, for cell swit ching, wavelength division switching technologies are desirable compar ed with space division switching technologies in the sense that the fo rmer enables us to build a photonic ATM switch with the less number of optical gate switches. Furthermore, we propose a switch architecture equipped with optical delay line buffers on outputs and electric buffe rs on inputs. We show that our switch architecture is superior in the number of required optical gate switch elements under the given condit ions.