. OSI Model

Explain OSI model and compare it with TCP/IP

b. what are roles of each layer in OSI model?

3. What does Modulation mean? Explain types of Modulation.

A modem has 20 cps. The modem transfers data using asynchronous connection. Assume that the modem uses Extended ASCII code. What is bps (bit per second)?

5. Compare NFC (Near Field Communication) with Bluetooth in terms of meaning, advantage, and disadvantage.

You are designing an application at work that transmits data records to another building within the same city. A data record has 300 bytes in length, and your application will send one record every 0.5 seconds. Is it more efficient to use a synchronous connection or an asynchronous connection? Assume that the application uses Extended ASCII code. Explain why.