Communication media or communication channels are the paths through which data transfers from one computer to another. These channels connect senders and receivers, allowing them to transmit data. Examples include twisted-pair wire, coaxial cable, fiber optic cable, and microwave.
When data is sent from a source to a destination, it travels through a communication channel. This channel has three main characteristics: bandwidth, attenuation, and propagation delay. As signals move through the channel, they may lose quality, so they need to be strengthened at certain points. Various transmission lines establish these channels, including two-wire lines, co-axial cables, microwave radio, optical fibers, and satellites.
Types of Communication Channel
There are two main types of communication channels:
1. Guided Media
Guided media uses a physical path to send data. It needs an actual wire to connect devices. It’s also known as bounded media.
There are different types of guided media:
Twisted pair cable
This is the most common type of communication medium. It’s made of copper and has two wires twisted together to reduce noise. Noise is an electrical disturbance that can make communication worse. Twisted pair cables are often used in local telephone systems.
They’re good for short-distance digital data communication and are sometimes called wire pairs. They can send 9600 bits per second over a distance of 100 meters.
Coaxial Cable
A coaxial cable has a copper wire core covered by insulating material. This insulated wire is then protected by a copper mesh shield. This shield keeps out electromagnetic waves that could interfere with the signal. It’s the same kind of cable used for television. Coaxial cables usually have between 4 and 22 coaxial units called tubes.
Coaxial cables are used for long-distance telephone lines and local area networks. They cost more than twisted pair cables.
Fiber Optics Cable
Fiber optic cables send data through tiny tubes as pulses of light. A typical fiber optic cable has a very thin strand of glass called the core. These strands are as thin as human hair. The core is where the light travels through the fiber.
Around the core is a layer of glass called cladding. It reflects light into the core. The cladding is protected by a plastic coating called a jacket. Internet service providers and cable TV companies use fiber optics in their networks.
2. Unguided Media
In unguided media communication devices communicate with each other through air or space using broadcast radio signals, infrared signals, and microwave signals. It’s also known as unbounded media.
There are different types of unguided media used in communication:
Microwave
Microwaves are radio waves that allow for high-speed transmission. They can carry both voice and data. Data is sent through the air from one microwave station to another, similar to a radio signal.
Microwaves use line-of-sight transmission. This means the signals travel in a straight line and can’t bend. Because of this, microwave stations or antennas are usually put on tall towers or buildings. These stations are typically 20 to 30 miles apart.
Each station gets the signal from the previous one and sends it to the next. This is how data moves from place to place.
Communication Satellite
A communication satellite is like a space station. It receives microwave signals from Earth stations, makes these signals stronger, and sends them back to Earth. Communication satellites orbit about 22,300 miles above the Earth.
These satellites can transfer data very quickly. When a signal goes from an Earth station to the satellite, it’s called an uplink. When the signal comes back from the satellite to an Earth station, it’s called a downlink.
Mobile Communication
Mobile communication uses a radio-based network. It sends data to and from mobile computers. In mobile communication, a computer can connect to the network through either wired ports or wireless connections.
