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Appendix VPIsystems—Demonstration Examples Introduction The following 12 examples have been added to demonstrate important engineering aspects of Chapter 3. The user can play with each example in real time by accessing the website http://www.vpiphotonics.com/VPIplayer.php. This particular website is maintained by VPIsystems GmbH and it is provided at no cost to the user. Any difficulties opening the website or any software improperly functioning should be addressed directly to VPIsystems GmbH, Carnotstr. 6, 10587 Berlin, Germany, Phone +49 30 398 058-0, Fax +49 30 398 058-58 Application Example 1 Title System impairments in 10 Gbps NRZ-based WDM transmissions Description This setup illustrates the impact of ASE noise and fiber nonlinearities on the performance of a 10 Gbps NRZ-based WDM system. The BER of each channel can be investigated individually. The user can adjust the number of spans (transmission length), switch off/on the fiber nonlinear- ities and modify the EDFA noise figure. Application Example 2 Title Performance of NRZ, RZ, and Duobinary modulation format in 10 Gbps transmission Description The setup compares the performance of the NRZ, RZ, and Duobinary modulation formats in a single channel 10 Gbps transmission. The BER obtained with each modulation format are displayed against the accumulated dispersion or the OSNR. The user can adjust the OSNR (respectively the accumulated dispersion) as well as the 3 dB bandwidth of the optical filter in front of the receiver. S. V. Kartalopoulos, Next Generation Intelligent Optical Networks, 257 C Springer 2008 258 Appendix: VPIsystems—Demonstration Examples Application Example 3 Title Performance comparison of NRZ, DPSK, and DQPSK in 40 Gbps transmission Description The setup investigates the performance of NRZ, DPSK, and DQPSK modulation in a single channel 40 Gbps transmission. The BER obtained with each modulation format are displayed against the accumulated dispersion or the OSNR. The user can adjust the OSNR (respectively the accumulated dispersion) as well as the 3 dB bandwidth of the optical filter in front of the receiver. Application Example 4 Title Variation of OSNR over an OADM chain Description This setup illustrates the variation of OSNR over a chain of OADMs where channels are randomly added and dropped. The OSNR is displayed over the number of passed OADM for three different random add–drop sequences. The user can specify the number of cascaded OADMs as well as their insertion loss. Application Example 5 Title EDFA transients and their control in dynamic networks Description The setup demonstrates the transient behavior of a dynamically controlled EDFA after switching off one of four WDM channels. The power control of the EDFA is achieved by adjusting the pump power with a controller. The user can adjust the feedback gain of the EDFA controller, which affects the settling time and shape of the controlled EDFA’s transient response. Application Example 6 Title Impact of the dispersion map on nonlinear impairments in 10 and 40 Gbps RZ systems Introduction 259 Description The setup illustrates the impact of the dispersion map on nonlinear impairments in single channel 10 or 40 Gbps RZ systems. Each span consists of 80 km of SSMF and a pre– and post-compensation modules. The line is considered noiseless in order to focus on the impact of nonlinear impairments. ASE is added in front of the receiver to achieve a given OSNR. An ideal DCM is placed in front of the receiver side for (partial) compensation of the dispersion accumulated in the line. The BER is displayed against the amount of residual dispersion at the receiver side. The user can adjust the OSNR as well as the amount of pre– and post-compensation per span that affect the nonlinear propagation of the signal in the line. Application Example 7 Title Reducing FWM effect using different channel spacing Description This setup illustrates the impact of four-wave mixing on the performance of WDM systems utilizing low dispersion fibers (DSF, NZDSF) and high signal powers. The BER and the magnitude of FWM products are displayed against the channel input power. The user can adjust the emission frequencies of the channels. The channel spacing can be set unequal so that the degradation due to FWM is reduced. Application Example 8 Title Influence of PMD in 40 Gbps transmission Description This setup models the random variation of the bit error rate due to polarization mode dispersion. The amount of PMD is randomly changed for each iteration. The spread of BER results demonstrates the difficulty in measuring the power penalty due to PMD. The user can adjust the modulation format (between NRZ and RZ) and the number of iterations. Application Example 9 Title Reduction of nonlinear penalties in 40 Gbps transmissions using alternate polarization modulation Description This setup demonstrates the advantages of alternate polarization modulation format over standard formats (NRZ). To apply alternating polarization between adjacent bits is an effective technique in suppressing intra-channel nonlinear distortions. The user can adjust the propagation distance and the WDM input power. 260 Appendix: VPIsystems—Demonstration Examples Application Example 10 Title Multi-pump Raman optimization Description Flat Raman gain is achieved over C and L bands by adjusting pump wavelengths and powers. The Raman gain and noise figure are displayed over the wavelength. Raman amplification between the pumps can be observed in an OSA. The user can modify the wavelength and power of the pumps and observe the changes in the Raman gain. Application Example 11 Title 10G–40G upgrade using Raman amplifier Description This setup demonstrates the benefits of Raman amplification allowing an upgrade from 10 s to 40 Gbps. Distributed Raman amplification is achieved by backward pumping the transmission fiber from the receiver terminal end. The user can change the bit rate from 10 to 40 Gbps and adjust the Raman pump power. Application Example 12 Title MLSE versus classical receiver performance Description This setup demonstrates the advantage of the Viterbi-MLSE receiver over classical receiver in the presence of intersymbol interferences. The BER of a 10 Gbps NRZ signal is displayed for a constant OSNR against the amount of residual dispersion for both receivers. The user can adjust the OSNR as well as the length of the sequences and the number of states used for Viterbi-MLSE detection. Acronyms 10Base-T: 10 Mbps over twisted pair 100Base-T: 100 Mbps over twisted pair 1000Base-T: 1,000 Mbps over twisted pair 2B1Q: two bits to one quaternary 2f-BLSR: two-fiber bidirectional line switched ring 3R: re-amplification, reshaping, and retiming 4B/5B: four bit to five bit coding 4f-BLSR: four-fiber bidirectional line switched ring 8B/10B: eight bit to ten bit coding AAL: ATM adaptation layer ABR: available bit rate ADC: analog to digital conversion ADM: add-drop multiplexer ADPCM: adaptive differential pulse code modulation ADSL: asymmetric digital subscriber line AES: advanced encryption standard AIS: alarm indication signal ALP: application layer protocol AM: administration module; amplitude modulation AMI: alternate mark inversion AON: all-optical network AP: access point APD: avalanche photodetector APDU: application protocol data unit; authentic protocol data unit API: access point identifier APON: ATM-based broadband PON APS: automatic protection switching ARM: access resource management ASE: amplified spontaneous emission ASIC: application-specific integrated circuit ASK: amplitude shift keying ATM: asynchronous transfer mode AU: administrative unit AU-n: administrative unit, level n AUG: administrative unit group AUG-N: administrative unit group-N B8ZS: bipolar with eight-zero substitution B: B channel (ISDN) BB: broadband BBER: background block error ratio BBO: beta-barium borate BCD: binary coded decimal 261 262 Acronyms BDI: backward defect indication BDI-O: backward defect indication overhead BDI-P: backward defect indication payload BEI: backward error indication BER: bit error rate; basic encoding rules BI: backward indication B-ISDN: broadband integrated services digital network BIP-8: bit interleaved parity 8 field BITS: building information timing supply BML: business management layer bps: bits per second BPSR: bidirectional path-switching ring BRI: basic rate interface BSHR: bidirectional shelf-healing ring BSHR/2: 2 fiber bidirectional shelf-healing ring BSHR/4: 4 fiber bidirectional shelf-healing ring C-n: container-level n; n = 11, 12, 2, 3, or 4 CAC: connection admission control CAM: content addressable memory CAP: carrierless amplitude phase CAS: channel associated signaling CBR: constant bit rate CCAMP: common control and management plane CDMA: code division multiple access CELP: code excited linear prediction CEPT-n: conference of European posts and telecommunications-level n (see E1) CIT: craft interface terminal CLEC: competitive local exchange carrier CLP: cell loss priority CLR: cell loss rate CM: communications module; connection management; connection monitoring CMI: coded mark inversion CMIP: common management information protocol CMISE: common management information service element CMIS/P: common management information service/protocol CMT: coupled-mode theory CNM: customer network management CO: central office CODEC: COder–DECoder COP: connection-oriented protocol COPS: common open policy service CORBA: common object request broker architecture COT: central office terminal CP: customer premises CPE: customer premises equipment CPN: calling party’s number;
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