What are the sub-systems in telecom infrastructure

What are the sub-systems in telecom infrastructure: - Once identified, what type of power supplies are needed and what are their power levels? - How are the sub-systems different from wireless and wireline systems? - Explain the typical power architectures used in each of these sub-systems - What are brick modules, remote radio units? Are they part of the telecom infrastructure? Explain and expand on these sub-systems