1. What is Data Communication?
Data Communication is the transmission of data and information from one place to another through a transmission medium.
Key Idea: Data Communication needs a transmission medium, without it, data cannot travel from source to receiver.
2. Basic Elements of Data Communication
Every data communication process needs four basic elements:
- Data Source, the place or device where data originates
- Data, the information that is transmitted
- Transmission Medium, the path used to carry data from the source to the receiver
- Receiver, the person or device that receives the data
Communication Flow
Key Idea: Remember the flow order, Data Source → Data → Transmission Medium → Receiver.
3. Data Transmission Modes
A transmission mode describes the direction in which data travels between two devices. There are three modes.
Simplex Mode
Data travels in one direction only.
Example: Television BroadcastingKey Idea: One-way only.
Half-Duplex Mode
Data travels in both directions, but not at the same time.
Example: Walkie-TalkieKey Idea: Both ways, one at a time.
Full-Duplex Mode
Data travels in both directions at the same time.
Example: Telephone ConversationKey Idea: Both ways, simultaneously.
Summary
- Data Communication, sending data from a source to a receiver through a medium
- Four elements: Data Source, Data, Transmission Medium, Receiver
- Simplex, one way (TV broadcasting)
- Half-Duplex, both ways, one at a time (Walkie-talkie)
- Full-Duplex, both ways, at the same time (Telephone)
Remember: Simplex, one way. Half-Duplex, both ways, one at a time. Full-Duplex, both ways, same time.