## Homework 1: due on Jan 27

• What are the three important characteristics of a periodic signal?

• What is the relationship between a signal's spectrum and its bandwidth?

• The frequency of a digital signal is 2000 Hz. What is its information capacity in bits per second?

• An agency needs to connect several departmental LANs. The interconnection will be made using a LAN to which departmental LANs are connected. The interconnection LAN must operate at 100Mbps. The medium will be run through elevator shafts and a machine room, so signal distortion is a concern. What medium would you recommend? Justify your answer.

• Suppose a file of 10,000 characters is to be sent over a line at 2400 bps.

• calculate the overhead in bits and time in using asynchronous communication. Assume 1 start and stop bit, and 8 bits to send the character itself for each character.

• calculate the overhead in bits and time using synchronous communication. Assume that the data are sent in frames. Each frame consists of 1000 characters=8000 bits, and an overhead of 48 bits per frame.

• what would the answers to parts a and b be for a file of 100,000 characters?

• what would the answers to parts a and b be for the original file of 10,000 characters except at a data rate of 9600bps?