The question asks to identify statements that are not features of WDM network expansion. WDM technology is designed for rapid and efficient capacity upgrades.

Key advantages (features) of WDM expansion include adding new channels without disrupting existing traffic (B) and leveraging the existing fiber plant to increase capacity, thereby protecting the initial investment (C).

Conversely, adding more wavelengths, nodes, and equipment inherently increases the operational and management complexity of the network (A), which is a consequence or drawback, not a desirable feature. Furthermore, a primary benefit of WDM is the speed of expansion compared to laying new fiber; therefore, the statement that it "takes a long time" (D) is factually incorrect.

B. No impact on existing services during the expansion: This is a core advantage of WDM. New wavelengths are independent and can be added without affecting traffic on existing channels.

C. Maximized protection of existing investment: WDM increases the capacity of existing fiber optic cables, avoiding the high cost of installing new ones, thus protecting prior investments.

1. Huawei Certified ICT Associate - Transmission V2.0 Training Material (H31-341). Chapter 2

"WDM System Basics." This material explicitly lists the advantages of WDM technology

including "Smooth Capacity Expansion" and "Protection of Original Investment." It highlights that expansion can be achieved by adding wavelengths to existing fiber

which is a fast process that does not affect online services. This confirms B and C are features and D is false.

2. Huawei OptiX OSN 1800 V100R007C00 Product Description. Section 1.2

"Benefits." The document states that the platform supports "smooth network expansion" and "protects initial investments

" allowing for flexible

on-demand service addition. This contradicts option D and supports option C.

3. Ramaswami

R.

& Sivarajan

K. N. (2002). Optical Networks: A Practical Perspective. Morgan Kaufmann. Chapter 1

Section 1.3

"The Optical Layer

" pp. 12-14. The text describes WDM as a means for "graceful growth in capacity" on existing fiber infrastructure. It also introduces the challenges of managing a multi-wavelength network

noting the increased complexity in fault management and performance monitoring

which aligns with option A being a consequence rather than a feature.