We present analysis of different modulation formats using actual Polarization Mode Dispersion (PMD) data of deployed
fiber links in the metro area in Kuala Lumpur, Malaysia. Simulations have been conducted for comparing the
performance of Non-Return-to-Zero (NRZ), Return-to-Zero (RZ), Carrier-Suppressed Return-to-Zero (CSRZ), Phase
Shaped Binary Transmission (PSBT) and Differential Quadrature Phase Shift Keying (DQPSK) modulation formats for
possible future upgrade to 40Gbps from an existing 10Gbps DWDM system. The performance in terms of BER is
presented to illustrate the limitations attributed to PMD based on current existing network configurations.