ISSN:1124-318X    

DOI:10.1002/ett.4460040602

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

ISSN:1124-318X    

DOI:10.1002/ett.4460040603

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

ISSN:1124-318X    

DOI:10.1002/ett.4460040604

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

ISSN:1124-318X    

DOI:10.1002/ett.4460040605

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

ISSN:1124-318X    

DOI:10.1002/ett.4460040606

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

ISSN:1124-318X    

DOI:10.1002/ett.4460040607

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractAs a result of the Synchronous Digital Hierarchy (SDH) standards, new network topologies are being introduced into existing networks. These new topologies include unidirectional and bidirectional rings in an environment which was previously dominated by point to point interconnections in meshed structures. Analysis of the traffic statistics of existing Plesiochronous Digital Hierarchy (PDH) metropolitan networks using various SDH network topologies is required in order to be able to determine optimal SDH network topologies. Existing bandwidth switching methodologies must be included in this analysis to determine the effects of these bandwidth routing methodologies. Several proposed hierarchical metropolitan optical transmission network architectures are examined in this paper in order to be able to determine strategies for the introduction of SDH capabilities into existing networks. An actual metropolitan network is used as a case study to evaluate traffic flow in several proposed hierarchical ring network topologies. These topologies include both unidirectional and bidirectional rings in three different hierarchical structures: a three level, a two level, and flat network hierarchies. The transmission requirements for these hierarchies with a central switching constraint are analyzed. The results indicate that existing centralized switching methodologies reduce the bandwidth carrying capacity advantage of bidirectional rings over unidirectional rings in hierarchical topologies.

ISSN:1124-318X    

DOI:10.1002/ett.4460040608

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe development of high performance semiconductor laser diodes has played a key role in the rapid deployment of optical fiber communications, and the realisation of advanced system concepts strongly depends on the further improvement of the laser diodes. This includes the demand for wavelength tunable single frequency laser diodes as well as the need for optoelectronic integration. The different laser structures in the 1.3 and 1.5 μ m wavelength regions, their relevant parameters and applications are described in this paper. The impact of recent progresses in the material technology on the device performance is particularly investigated. It is further shown that the availability of low‐cost, highly complex integrated optoelectronic components represents a prerequisite for the introduction of optical communication systems in the subscriber area. The photonic and optoelectronic integrated circuits presented so far for bidirectional transmission, photonic switching and optical distribution are presented and the challenges for the future development are discuss

ISSN:1124-318X    

DOI:10.1002/ett.4460040609

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractIn this work we evaluate the impairments due to laser phase noise in multichannel coherent optical systems using a heterodyne ASK modulation scheme. The effects of crosstalk due to a finite value of the channel spacing are considered in a system employing a frequency division multiplexing technique. The phase noise and the frequency spacing between adjacent channels are the fundamental parameters which determine the design criteria (e.g. the bandwidth of the intermediate frequency filters) and the performance of the receiver. The accurate statistical characterization of the filtered phase noise and of the crosstalk is the key to get accurate results: to this aim the exact moments of the random processes related to the phase noise and to the crosstalk interference are used together with a Gaussian Quadrature Rule for the evaluation of the error probability.

ISSN:1124-318X    

DOI:10.1002/ett.4460040610

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe quality objectives given in the CCITT recommendations concerning fiber optics transmission over the Synchronous Digital Hierarchy (SDH) network are difficult to achieve in high‐speed systems. Equipment imperfections often result in a Bit Error Rate (BER) floor above the recommendedBERvalue of 1CH4. In this paper we propose a simple Reed Solomon (RS) coding scheme for the Synchronous Transport Module level‐1 (STM‐1) frame which leads to a substantialBERperformance improvement over uncoded systems. The RS code proposed is a shortened one‐symbol‐correcting code. Experimental results obtained with a laboratory prototype are reported which show that this code reduces theBERfloor by four orders of

ISSN:1124-318X    

DOI:10.1002/ett.4460040611

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY