We obtain the error-free transmission of an 8 × 10 Gb/s signal over a 1500km G.652 fibre by means of significantly improving the quality of narrow-band chirped fibre Bragg gratings (FBGs). Asymmetric apodization is one of the powerful measures to improve the quality of gratings. Wavelength-dependent transmission performance is also observed. The experimental results indicate that the total in-band local dispersion deviation of the cascaded gratings in each channel could be a good indicator of the performance degradation tendency at different operating wavelengths, which further reveals the potential of local dispersion deviation as a performance evaluating indicator of chirped FBGs.