5 research outputs found
Employing DDBPSK in optical burst switched systems to enhance throughput
We demonstrate that doubly differential decoding can demodulate phase shift keyed data much faster after the switching event of a tunable laser than usual mth power single differential decoding. This technique can significantly improve throughput of optical burst switched networks
Reduced OSNR penalty for frequency drift tolerant coherent packet switched systems using doubly differential decoding
In this paper we will demonstrate the improved BER performance of doubly differential phase shift keying in a coherent optical packet switching scenario while still retaining the benefits of high frequency offset tolerance
Optimising the efficiency of coherent optical packet switched networks
There is a continuing need to increase throughput in optical networks to satisfy the demands of internet applications. However, the non-linear Shannon capacity of
standard single mode fibre is being approached. Also, almost all of the power used in optical networks is used by electronic routers. One possible solution to deal with
both problems is to use optical packet switching. Optical packet switching uses fast switching tuneable lasers, which can change wavelength in the order of a several
nanoseconds, to dynamically vary wavelength assignments in a network, and thus achieve routing in the network without electronic routers. In addition, fast
wavelength assignment reduces waiting times, resulting in better utilization of network resources.
However, the frequency dynamics of the tuneable lasers after switching wavelengths increases the waiting times required to successfully transmit data packets. In this thesis, frequency and phase dynamics of a tuneable laser
transmitter, after a wavelength switching event, are initially characterised accurately using a novel technique. The effects that the frequency dynamics have on the transmission of coherent optical communication signals are mitigated using doubly differential decoding, a new approach proposed in this work for application in optical packet switched networks. This technique reduces the waiting times required to successfully transmit data after a wavelength switching event, and this enhances overall network efficiency and throughput. In addition, this work proposes and demonstrates the use of a least-mean squares algorithm to overcome polarisation demultiplexing issues which are present in these networks, which also decreases waiting times, increases network efficiency, and improves system robustness