21. What are the different types of transmission medium ?
There are two types of transmission media, namely guided and unguided. Guided transmission media are cables like twisted pair cables, coaxial cables, and fiber optic cables. Unguided transmission media are wireless, such as infrared, radio waves, and microwaves.
22. What are the different spread spectrum techniques ?
In telecommunication and radio communication, spread-spectrum techniques are methods by which a signal (e.g., an electrical, electromagnetic, or acoustic signal) generated with a particular bandwidth is deliberately spread in the frequency domain, resulting in a signal with a wider bandwidth.
23. What are the different transmission modes ?
Transmission Mode defines the direction of the flow of information between two communication devices i.e. it tells the direction of signal flow between the two devices.
24. Explain different types of topologies ?
In networking, topology refers to the layout of a computer network. Physical topology means the placement of the elements of the network, including the location of the devices or the layout of the cables. Logical topology maps the flow of data, regardless of the physical layout.There are four categories: Star topology, Bus topology, Ring topology and Mesh topology.
25. Explain about different types of connections ?