Impact of optical cross-connect architecture on the accumulation of intraband crosstalk in wavelength division multiplexing optical networks

2006 ◽  
Vol 45 (11) ◽  
pp. 115008 ◽  
Author(s):  
Ai-Hong Guan
Keyword(s):  
Optical Networks ◽  
Wavelength Division Multiplexing ◽  
Wavelength Division ◽  
Optical Cross Connect ◽  
Cross Connect

scholarly journals Reliable multicast using remote direct memory access (RDMA) over a passive optical cross-connect fabric enhanced with wavelength division multiplexing (WDM)

2019 ◽  
Vol 8 ◽  
Author(s):  
Kin-Wai Leong ◽  
Zhilong Li ◽  
Yunqu Leon Liu
Keyword(s):  
Wavelength Division Multiplexing ◽  
Direct Memory Access ◽  
Memory Access ◽  
Transport Layer ◽  
Reliable Multicast ◽  
Loss Ratio ◽  
Wavelength Division ◽  
Message Loss ◽  
Optical Cross Connect ◽  
Cross Connect

It has been well studied that reliable multicast enables consistency protocols, including Byzantine Fault Tolerant protocols, for distributed systems. However, no transport-layer reliable multicast is used today due to limitations with existing switch fabrics and transport-layer protocols. In this paper, we introduce a layer-4 (L4) transport based on remote direct memory access (RDMA) datagram to achieve reliable multicast over a shared optical medium. By connecting a cluster of networking nodes using a passive optical cross-connect fabric enhanced with wavelength division multiplexing, all messages are broadcast to all nodes. This mechanism enables consistency in a distributed system to be maintained at a low latency cost. By further utilizing RDMA datagram as the L4 protocol, we have achieved a low-enough message loss-ratio (better than one in 68 billion) to make a simple Negative Acknowledge (NACK)-based L4 multicast practical to deploy. To our knowledge, it is the first multicast architecture able to demonstrate such low message loss-ratio. Furthermore, with this reliable multicast transport, end-to-end latencies of eight microseconds or less (< 8us) have been routinely achieved using an enhanced software RDMA implementation on a variety of commodity 10G Ethernet network adapters.

A Novel Architecture of N × N Bidirectional Reconfigurable Multiwavelength Optical Cross Connect

2020 ◽  
Vol 41 (2) ◽  
pp. 133-138
Author(s):  
Manpreet Singh
Keyword(s):  
Wavelength Division Multiplexing ◽  
High Speed ◽  
Signal To Noise Ratio ◽  
Optical Amplifier ◽  
Optical Signal ◽  
Fiber Nonlinearities ◽  
Wavelength Division ◽  
Optical Cross Connect ◽  
Optical Circulator ◽  
Cross Connect

AbstractA novel architecture of N×N bidirectional-reconfigurable multiwavelength optical cross connect (B-RMOXC) based on tunable Fiber Bragg grating and optical circulator is proposed. B-RMOXC network is one of crucial network element for wavelength routing in dense wavelength division multiplexing system. This paper presents a high speed, power compensated bidirectional optical cross connect and verified the performance of bidirectionality with 0.8-nm channel spacing having bit rate of 10 Gbps at different transmission distances. Optical signal-to-noise ratio of 36.62 dB and 35.55 dB is achieved with acceptable Quality factor of 6.26 and 6.99 respectively for upstream and downstream at 60 km having input transmission power of −12 dBm. It is found that the data can be communicated bidirectionally to a distance of 60 km in the presence of fiber nonlinearities without optical amplifier.

Optical Networks Performance Optimization Based on Hybrid Configurations of Optical Fiber Amplifiers and Optical Receivers

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
I. S. Amiri ◽  
Fatma Mohammed Aref Mahmoud Houssien ◽  
Ahmed Nabih Zaki Rashed ◽  
Abd El-Naser A. Mohammed
Keyword(s):  
Optical Fiber ◽  
Optical Networks ◽  
Wavelength Division Multiplexing ◽  
Performance Optimization ◽  
Input Power ◽  
Fiber Amplifiers ◽  
Q Factor ◽  
Wavelength Division ◽  
Transmission Distance ◽  
Optical Fiber Amplifiers

AbstractThe 16-channels dense wavelength division multiplexing (DWDM) systems have been optimized by utilizing hybrid configurations of conventional optical fiber amplifiers (EDFA, RAMAN and SOA) and optical photodetectors (PIN, APD(Si) and APD(InGaAs)). The DWDM systems were implemented for 5 Gb/s channel speed using one of these configurations with 100 GHz channel spacing and 25 km amplifying section. The hybrid configurations are the combinations of (PIN + EDFA), (PIN + RAMAN), (PIN + SOA), (APD(Si) + EDFA), (APD(Si) + RAMAN), (APD(Si) + SOA), (APD(InGaAs) + EDFA), (APD(InGaAs) + RAMAN) and (APD(InGaAs) + SOA). Based on BER, Q-factor and eye diagrams, the performance was compared for these configurations under influences of various thermal noise levels of photodetectors over different fiber lengths ranging from 25 km up to 150 km. The results revealed that both APD structures give optimum performance at input power Pin = 5 dBm due to high internal avalanche gain. EDFA outperforms RAMAN and SOA amplifiers. SOA amplifier shows degraded performance because of nonlinearity effects induced. RAMAN amplifier seems to be the best alternative for long reach DWDM systems because it minimizes the effects of fiber nonlinearities. The configuration (APD(Si) + EDFA) is the most efficient and recommended to be used for transmission distance beyond 100 km due to its larger Q-factor.

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