Coarse wavelength division multiplexing (CWDM) applications were expanded to include use in large metropolitan networks, utilizing wavelengths in what band?

Coarse Wavelength Division Multiplexing (CWDM) is a technology that allows for the transmission of multiple signals over a single optical fiber by using different wavelengths of light. CWDM typically takes advantage of uncooled lasers and operates in the range of wavelengths that falls within the E-band.

The E-band generally refers to the wavelength range of approximately 1295 nm to 1330 nm, which is well-suited for CWDM applications. This band provides a set of standard wavelengths that can be used in large metropolitan area networks (MANs), allowing for efficient data transmission with minimal wavelength spacing.

This application is significant in metropolitan networks where capacity demands are high, making CWDM a practical and cost-effective solution for expanding bandwidth without needing to lay new fiber. Using wavelengths in the E-band helps facilitate the simultaneous transmission of multiple channels, increasing overall network efficiency.

In contrast, alternatives like the C-band and L-band refer to other wavelengths that are commonly used in Dense Wavelength Division Multiplexing (DWDM) systems or other optical networking technologies but are not the standard band associated specifically with CWDM expansion in metropolitan networks. The CX-band is less commonly referenced and does not align with standard wavelength ranges associated with CWDM technologies.