Wavelength routing-based photonic packet buffers and their applications in photonic packet switching systems (original) (raw)
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Arrayed Waveguide Grating and Re-Circulating Buffer Based Optical Packet Switch
Journal of Optical Communications
Optical packet switching has gained popularity in past decade. However, due to technical challenges all- optical switching is not implemented till date, still hybrid switching where both optical and electrical switching are used simultaneously by-passing the limitations of both the technologies. In fiber delay lines (FDLs) buffering is limited due to accumulated losses and noises, and most of the times short term storage is enough in optical switching, but in case of long term storage, re-circulating type buffer can be used, but again due to accumulation of degrading terms re-circulation count is limited therefore in case of longer duration storage, electronic buffer is better choice. In this paper, we have proposed a hybrid buffer based optical switch where both optical and electronic buffers are used for storage of contending packets, and optical buffer is re-circulating in nature. The performance of the switch is measured in terms of bit error rate (BER) and packet loss probabili...
A new wavelength-routed photonic packet buffer combining traveling delay lines with delay-line loops
Journal of Lightwave Technology, 2001
We present a new wavelength-routed photonic packet buffer that combines traveling delay lines with delay-line loops. The new packet buffer can effectively capitalize on the simplicity of traveling delay lines and the flexibility of delay-line loops. Three different packet buffering and scheduling techniques are investigated. The effectiveness of the new packet buffer is evaluated by computer simulation using a random traffic model. The simulation results show that the new packet buffer, in conjunction with the buffering and scheduling techniques, can efficiently make use of buffering spaces and, hence, substantially reduce the packet-loss probability by several orders of magnitude. Index Terms-Packet scheduling, photonic packet switching, wavelength conversion, wavelength routing, wavelength division multiplexing (WDM) packet buffer.
Journal of Lightwave Technology, 2001
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Photonic all-optical switching is widely considered as one of the technique to utilize the enormous optical bandwidth. Optical packet switching provides high speed, data rate transparency, data format transparency, efficient use of bandwidth and flexibility. To resolve the conflict during contention, packets are needed to be buffered. Due to the lack of optical RAM, fiber delay lines (FDLs) are the most suited option to buffer the packets. This paper proposes new optical packet switch architecture alongwith feedback shared buffer utilizing the advantage of WDM loop buffer memory. The loop buffer module used in this switch architecture is a new approach towards WDM buffering of packets. The mathematical modeling is done to validate the results obtained from simulation.
Inband crosstalk analysis of wavelength-routing-based photonic packet buffers
IEEE Photonics Technology Letters, 2000
Crosstalk accumulates as optical packets pass through imperfect wavelength-division-multiplexing components, resulting in performance degradation. We investigate and analyze how inband crosstalk is generated and accumulated in wavelength-routing-based photonic packet buffers (WRPPB). We show that the number of inband crosstalk elements arising from the WRPPB buffer can be approximated by a binomial distribution and examine the impact of inband crosstalk on the bit-error rate and the power penalty.
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A chip-scale optical buffer performs autonomous contention resolution for 40-byte packets with 99% packet recovery. The buffer consists of a fast, InP-based 2x2 optical switch and a silica-on-silicon low loss delay loop. The buffer is demonstrated in recirculating operation, but may be reconfigured in feed-forward operation for longer packet lengths. The recirculating buffer provides packet storage in integer multiples of the delay length of 12.86 ns up to 64.3 ns with 98% packet recovery. The buffer is used to resolve contention between two 40 Gb/s packet streams using multiple photonic chip optical buffers.
This paper presents a combined scheme for the contention resolution in optical packet switches. The scheme leads to more efficient use of the buffer space compared to the output buffering scheme. The performance of the switch is further improved by utilizing the wavelength conversion. This can be accomplished at a limited cost as the wavelength converters are udlized in the shared buffer loop, and not in the input end. The superiority of the scheme has been established through extensive simulation and analytical study and the results are encouraging, paving the way for further research in this direction.
Routing in an AWG-based optical packet switch
2003
For the next generation of the optical internet, focus is now moving from circuit switched networks, which occupy a wavelength continuously regardless of the demand at that time, towards optical packet/burst switching. By only occupying a wavelength when data is to be transmitted, a more efficient utilisation of bandwidth in optical fibres is strived for. As bandwidth in fibres keeps increasing, the bottleneck of the optical network is now moving towards the switching node, since evolution of electronic routers cannot follow the speed of bandwidth increase.