1.The telephone company has a fiber-optic line with time division multiplexing that runs from the United States to England and lies on the ocean floor. This fiber-optic line has reached capacity. What alternatives can the telephone company consider to increase capacity? 

2.Twenty voice signals are to be multiplexed and transmitted over twisted pair. What is the bandwidth required (in bps) if synchronous time division multiplexing is used, along with the standard analog-to-digital sampling rate, and each sample is converted into an 8-bit value? 

3.A company has two buildings that are 50 meters apart. Between the buildings is private land owned by the company. A large walk-through tunnel connects the two buildings. In one building is a collection of 30 computer workstations, and in the other building a mainframe computer. What is the best way to connect the workstations to the mainframe computer? Explain your reasoning and all the possible solutions you considered.