Upstream and downstream communication

1. Suppose N users compete using a statistical TDM system, and suppose the underlying physical transport can send K bits per second. What is the minimum and maximum data rate that an individual user can experience?

2. Of the four basic multiplexing techniques, is CDM always the best? Explain.

3. Suppose an OC-12 circuit is twenty percent the cost of an OC-48 circuit. What multiplexing technology can an ISP use to lower the cost of sending data at the OC-48 rate. Explain.

1. How does code division multiplexing work?

2. Why do service providers distinguish between upstream and downstream communication?

3. What is an access technology?

4. Telephone companies once promoted ISDN as a high-speed access technology. Why has use of ISDN declined?