This is a discussion paper on a very important topic that is about to become mainstream. It deals... more This is a discussion paper on a very important topic that is about to become mainstream. It deals with the issues of software engineering in concurrent systems. It introduces this topic and illustrates the arguments for a change of perspective. It underlines these arguments with two examples, an asynchronous stream-based programming model and an asynchronous thread-based virtual machine model. Both support concurrency on very different abstractions but both capture similar support for concurrency engineering.
Improving bit error rates in optical communication systems is a difficult and important problem. ... more Improving bit error rates in optical communication systems is a difficult and important problem. Error detection and correction must take place at high speed, and be extremely accurate. Also, different communication channels have different characteristics, and those characteristics may change over time. We show the feasibility of using simple artificial neural networks to address these problems, and examine the effect of using different representations of signal waveforms on the accuracy of error correction. The results we have obtained lead us to the conclusion that a machine learning system based on these principles can improve on the performance of existing error correction hardware at the speed required, whilst being able to adapt to suit the characteristics of different communication channels.
Through modelling of direct error computation, a reduction of pattern- dependent errors in a stan... more Through modelling of direct error computation, a reduction of pattern- dependent errors in a standard fiber-based transmission link at 40 Gb/s rate is demonstrated by application of a skewed data pre-encoding. The trade-off between the bit-error rate improvement and the data rate loss is examined.
Through extensive direct modelling we quantify patterning effects in a WDM RZ-DBPSK fibre link at... more Through extensive direct modelling we quantify patterning effects in a WDM RZ-DBPSK fibre link at 40 Gbit/s channel rate. We demonstrate BER improvement through skewed channel pre-encoding reducing the occurrence of the most dangerous triplets.
Summary form only given. In this paper an important new example of a system with strong and nontr... more Summary form only given. In this paper an important new example of a system with strong and nontrivial patterning effects is presented. There has been much interest lately in the implementation of the differential phase shift-keying (PSK) modulation format for long-haul and ultra long-haul fibre communications and, in particular, the differential binary PSK (DBPSK) modulation format, where data is encoded into the optical phase. The results of a direct computation of the error statistics for an SMF/DCF RZ-DBPSK 5-channel WDM RZ-DBPSK link with hybrid Raman/EDFA amplification at 40 Gbit/s per channel, with a channel separation of 100 GHz are presented. The statistics of bit triplets and quantify strong pattern-dependent ISI are obtained.
Improving bit error rates in optical communication systems is a difficult and important problem. ... more Improving bit error rates in optical communication systems is a difficult and important problem. Error detection and correction must take place at high speed, and be extremely accurate. Also, different communication channels have different characteristics, and those characteristics may change over time. We show the feasibility of using simple artificial neural networks to address these problems, and examine the effect of using different representations of signal waveforms on the accuracy of error correction. The results we have obtained lead us to the conclusion that a machine learning system based on these principles can improve on the performance of existing error correction hardware at the speed required, whilst being able to adapt to suit the characteristics of different communication channels.
Through modelling of direct error computation, a reduction of pattern- dependent errors in a stan... more Through modelling of direct error computation, a reduction of pattern- dependent errors in a standard fiber-based transmission link at 40 Gb/s rate is demonstrated by application of a skewed data pre-encoding. The trade-off between the bit-error rate improvement and the data rate loss is examined.
Through extensive direct modelling we quantify patterning effects in a WDM RZ-DBPSK fibre link at... more Through extensive direct modelling we quantify patterning effects in a WDM RZ-DBPSK fibre link at 40 Gbit/s channel rate. We demonstrate BER improvement through skewed channel pre-encoding reducing the occurrence of the most dangerous triplets.
Summary form only given. In this paper an important new example of a system with strong and nontr... more Summary form only given. In this paper an important new example of a system with strong and nontrivial patterning effects is presented. There has been much interest lately in the implementation of the differential phase shift-keying (PSK) modulation format for long-haul and ultra long-haul fibre communications and, in particular, the differential binary PSK (DBPSK) modulation format, where data is encoded into the optical phase. The results of a direct computation of the error statistics for an SMF/DCF RZ-DBPSK 5-channel WDM RZ-DBPSK link with hybrid Raman/EDFA amplification at 40 Gbit/s per channel, with a channel separation of 100 GHz are presented. The statistics of bit triplets and quantify strong pattern-dependent ISI are obtained.
Improving bit error rates in optical communication systems is a difficult and important problem. ... more Improving bit error rates in optical communication systems is a difficult and important problem. Error detection and correction must take place at high speed, and be extremely accurate. Also, different communication channels have different characteristics, and those characteristics may change over time. We show the feasibility of using simple artificial neural networks to address these problems, and examine the effect of using different representations of signal waveforms on the accuracy of error correction. The results we have obtained lead us to the conclusion that a machine learning system based on these principles can improve on the performance of existing error correction hardware at the speed required, whilst being able to adapt to suit the characteristics of different communication channels.
This is a discussion paper on a very important topic that is about to become mainstream. It deals... more This is a discussion paper on a very important topic that is about to become mainstream. It deals with the issues of software engineering in concurrent systems. It introduces this topic and illustrates the arguments for a change of perspective. It underlines these arguments with two examples, an asynchronous stream-based programming model and an asynchronous thread-based virtual machine model. Both support concurrency on very different abstractions but both capture similar support for concurrency engineering.
Improving bit error rates in optical communication systems is a difficult and important problem. ... more Improving bit error rates in optical communication systems is a difficult and important problem. Error detection and correction must take place at high speed, and be extremely accurate. Also, different communication channels have different characteristics, and those characteristics may change over time. We show the feasibility of using simple artificial neural networks to address these problems, and examine the effect of using different representations of signal waveforms on the accuracy of error correction. The results we have obtained lead us to the conclusion that a machine learning system based on these principles can improve on the performance of existing error correction hardware at the speed required, whilst being able to adapt to suit the characteristics of different communication channels.
Through modelling of direct error computation, a reduction of pattern- dependent errors in a stan... more Through modelling of direct error computation, a reduction of pattern- dependent errors in a standard fiber-based transmission link at 40 Gb/s rate is demonstrated by application of a skewed data pre-encoding. The trade-off between the bit-error rate improvement and the data rate loss is examined.
Through extensive direct modelling we quantify patterning effects in a WDM RZ-DBPSK fibre link at... more Through extensive direct modelling we quantify patterning effects in a WDM RZ-DBPSK fibre link at 40 Gbit/s channel rate. We demonstrate BER improvement through skewed channel pre-encoding reducing the occurrence of the most dangerous triplets.
Summary form only given. In this paper an important new example of a system with strong and nontr... more Summary form only given. In this paper an important new example of a system with strong and nontrivial patterning effects is presented. There has been much interest lately in the implementation of the differential phase shift-keying (PSK) modulation format for long-haul and ultra long-haul fibre communications and, in particular, the differential binary PSK (DBPSK) modulation format, where data is encoded into the optical phase. The results of a direct computation of the error statistics for an SMF/DCF RZ-DBPSK 5-channel WDM RZ-DBPSK link with hybrid Raman/EDFA amplification at 40 Gbit/s per channel, with a channel separation of 100 GHz are presented. The statistics of bit triplets and quantify strong pattern-dependent ISI are obtained.
Improving bit error rates in optical communication systems is a difficult and important problem. ... more Improving bit error rates in optical communication systems is a difficult and important problem. Error detection and correction must take place at high speed, and be extremely accurate. Also, different communication channels have different characteristics, and those characteristics may change over time. We show the feasibility of using simple artificial neural networks to address these problems, and examine the effect of using different representations of signal waveforms on the accuracy of error correction. The results we have obtained lead us to the conclusion that a machine learning system based on these principles can improve on the performance of existing error correction hardware at the speed required, whilst being able to adapt to suit the characteristics of different communication channels.
Through modelling of direct error computation, a reduction of pattern- dependent errors in a stan... more Through modelling of direct error computation, a reduction of pattern- dependent errors in a standard fiber-based transmission link at 40 Gb/s rate is demonstrated by application of a skewed data pre-encoding. The trade-off between the bit-error rate improvement and the data rate loss is examined.
Through extensive direct modelling we quantify patterning effects in a WDM RZ-DBPSK fibre link at... more Through extensive direct modelling we quantify patterning effects in a WDM RZ-DBPSK fibre link at 40 Gbit/s channel rate. We demonstrate BER improvement through skewed channel pre-encoding reducing the occurrence of the most dangerous triplets.
Summary form only given. In this paper an important new example of a system with strong and nontr... more Summary form only given. In this paper an important new example of a system with strong and nontrivial patterning effects is presented. There has been much interest lately in the implementation of the differential phase shift-keying (PSK) modulation format for long-haul and ultra long-haul fibre communications and, in particular, the differential binary PSK (DBPSK) modulation format, where data is encoded into the optical phase. The results of a direct computation of the error statistics for an SMF/DCF RZ-DBPSK 5-channel WDM RZ-DBPSK link with hybrid Raman/EDFA amplification at 40 Gbit/s per channel, with a channel separation of 100 GHz are presented. The statistics of bit triplets and quantify strong pattern-dependent ISI are obtained.
Improving bit error rates in optical communication systems is a difficult and important problem. ... more Improving bit error rates in optical communication systems is a difficult and important problem. Error detection and correction must take place at high speed, and be extremely accurate. Also, different communication channels have different characteristics, and those characteristics may change over time. We show the feasibility of using simple artificial neural networks to address these problems, and examine the effect of using different representations of signal waveforms on the accuracy of error correction. The results we have obtained lead us to the conclusion that a machine learning system based on these principles can improve on the performance of existing error correction hardware at the speed required, whilst being able to adapt to suit the characteristics of different communication channels.
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