The lambda-scheduler: A multiwavelength scheduling switch

Citation
Jp. Lang et al., The lambda-scheduler: A multiwavelength scheduling switch, J LIGHTW T, 18(8), 2000, pp. 1049-1063
Citations number
27
Categorie Soggetti
Optics & Acoustics
Journal title
JOURNAL OF LIGHTWAVE TECHNOLOGY
ISSN journal
07338724 → ACNP
Volume
18
Issue
8
Year of publication
2000
Pages
1049 - 1063
Database
ISI
SICI code
0733-8724(200008)18:8<1049:TLAMSS>2.0.ZU;2-4
Abstract
We propose a new multiwavelength almost all-optical switch architecture cal led the lambda-scheduler that uses wavelength division multiplexing (WDM) i nternally to fold the switch architecture in both the space and time domain s to reduce the hardware complexity and to improve the signal characteristi cs through the switch. The lambda-scheduler preserves the packet order for a given input-output pair, is consistent with virtual circuit switching, an d when combined with appropriate connection and flow control protocols, pro vides lossless communication for bursty (or nonconstant rate) traffic, prov ided the traffic satisfies certain smoothness properties. The lambda-schedu ler uses novel scheduling and wavelength assignment algorithms, in conjunct ion with a series of feed-forward delay blocks, to avoid packet collisions within the switch or at the switch outputs. We present two implementations of the lambda-scheduler when the number of internal wavelengths k equal the number of inputs (and outputs) N to the switch. in the compressed lambda-s cheduler, the N internal wavelengths are used to fold the architecture in t he time domain, which reduces the total number of delay blocks for the swit ch by 2N log N, In the collapsed lambda-scheduler, the N internal wavelengt hs are used to fold the architecture in the space domain, which reduces the number of delay blocks and total fiber length used for delays by a factor of N, We examine the insertion loss for both lambda-scheduler implementatio ns and discuss the tradeoffs between the reduction in overall component cou nt and the improvement in the signal characteristics.