Write a 200- to 300-word response to the each following questions:
Question 1: What is the nature of digital signals, binary, and other multilevel signal types? What are the advantages of digital signals over analog signals? Cover noise suppression in your explanation.
Qustion 2: Explain digital multiplexing, the digital T(X), and SONET hierarchy. Explain the differences between the American and European systems.
Question 3: Explain digital services such as Integrated Services Digital Network, Switched Multimegabit Data System, and Switch 56.