Abstract

Wavelength-division multiplexing (WDM) can potentially enable higher capacity and functionality in high-speed optical networks by providing simultaneous transmission of many wavelengths and by providing wavelength-dependent routing paths. [1] As in all networks, it is imperative to ensure high throughput and efficiency in the switching process. Consequently, outputport contention, in which data packets on two input ports request to be routed to the same output port, must be rapidly resolved and the data packets must be sent to their appropriate destination ports. [2] In a WDM network, the problem is both compounded and made easier due to the wavelength-dependent paths and the multiple wavelengths allowed per port. One the one hand, the difficulty arises since each fiber input port may have many different wavelengths which must be compared to all the wavelengths on the other input ports to determine and resolve contention. On the other hand, multiple wavelengths allows for a natural solution to contention, that being all-optical wavelength shifting of one data packet onto a free wavelength at the contended output port. Previous work has resolved a collision between 2 packets located on different wavelengths by separating the wavelengths and delaying one by a packet time, requiring a free packet time slot.[3]

© 1996 Optical Society of America