How does TDMA increase the network capacity over what FDMA can provide?

a) It allows each frequency channel to service multiple users by dividing the channel into smaller frequencies.

b) It allows each frequency channel to service multiple users by separating them in time.

c) It allows for interoperability of different standards.

d) It allows some users to text rather than call, thereby increasing the number that can use the network simultaneously.

Which of the following statements about CDMA is FALSE?

a) Users are undistinguished in both time and frequency; rather, links are assigned different codes.

b) The spreading code typically changes much slower (e.g., has a lower frequency) than the data signal.

c) It reduces the frequency reuse factor to 1.

d) To avoid interference, the spreading codes would need to be perfectly orthogonal to one another.

Suppose a phone is currently transmitting at 10 mW. By the time it gets to the cell tower, it has diminished to 2 mW. If the tower wants to receive at 5 mW, what would the TPC algorithm tell the phone to switch its transmit power to?

a) 5 mW

b) 20 mW

c) 25 mW

d) 100 mW

As opposed to TPC, what parameter is DPC concerned with equalizing?

a) Received power levels

b) Interference

c) Signal to Interference Ratio

d) Distance

Suppose a phone is currently transmitting at 10 mW. The receiver measures an SIR of 5, whereas the desired SIR for this link is 10. What would the DPC algorithm dictate the phones next step to be?

a) Decrease its transmit power to 5 mW.

b) Decrease its SIR to 1.

c) Increase its transmit power to 20 mW.

d) Increase its SIR to 10.

Which of the following statements is FALSE?

a) Each transmitter poses a negative externality on the others, in the form of added interference.

b) The cell towers process of continually passing the measured SIR back to each transmitter for them to use in adjusting their transmit powers is known as negative feedback.

c) Once each link matches the measured and desired SIRs, the DPC algorithm has reached equilibrium.

d) None of the above.

For a given cellular system, which of the following is NOT an advantage of CDMA over TDMA?

a) It has a higher capacity.

b) It leads to longer battery life for the transmitters.

c) Its power control algorithm, DPC, only needs to be run for one iteration.

d) It leads to smoother transitions between towers, through the soft handoff.