High-performance switchless WDM network using multiple free spectral ranges of an arrayed-waveguide grating

In this paper, we report on a scalable and reliable switchless wavelength division multiplexing (WDM) network that is based on an arrayed-waveguide grating (AWG). All wavelengths are used for data transmission and signaling is done in-band. Each node at the network periphery is equipped with a single tunable transceiver for data and a broadband light source for control while the network itself is completely passive. Broadcasting is realized by spectrally slicing the broadband signal. The proposed random distributed medium access protocol is reservation based and schedules variably sized data packets on a first-come-first-served and first-fit basis without resulting collisions. The protocol supports both packet and circuit switching and allows for multicasting. The degree of concurrency is significantly increased by using multiple free spectral ranges (FSRs) of the AWG, spatially reusing wavelengths and transmitting data and control informations simultaneously by means of code division multiplexing. Our analytical results demonstrate that exploiting multiple FSRs of an AWG significantly improves the throughput-delay performance of the network.