Types of Media used in Networking

Physical Media:

1.      Coaxial cables:

Ethernet based LANs using thick cable for inter-connection is referred as Thicknet. While ethernet systems using thinner coaxial cable is referred as Thinnet.

Thicknet is also referred as 10Base5 systems, where 10 means 10Mbps speed. Base means baseband and 5 denotes 500 meter max. distance between nodes/repeaters. RG-8/U cable is used as thick cable in thicknet based LAN network.

Thinnet is also referred as 10Base2, where 2 denotes 200 m max.distance between two nodes/repeaters. RG-58/U is used as thin cable in thinnet based LAN network.

BNC connectors are used, as the distance increases the signal strength is reducing.

2.      Twisted pair cables

ü  STP shielded twisted pair cable

Due to atmospheric effects like electromagnetic won’t have any effect on the signal strength. Signal efficiency is 100%.

But it is costly 

For long distance network we will use this cables

ü  UTP unshielded twisted pair cable

Normally it will effect by atmospheric electromagnetic effects. In every LAN network mostly we will use this UTP cables only.

In twisted pair cable we have different type of categories. They are:

1: Cat 1                       -           2 twisted wire pairs –about 1MHZ signals

2: Cat 2                       -           4 twisted wire pairs – upto 4MBPS – limit to 10 MHZ

3: Cat 3                       -           3 twisted wires per feet- upto 16MHZ

4: Cat 4                       -           4 twisted pairs – upto 20MHZ

5: Cat 5                       -           4 twisted pairs – upto 100MHZ

6: Cat5e                      -           4 twisted pair cables – upto 100MHZ

7: Cat6                        -           4 twisted pair - upto 250 MHZ (Became standard Cable in june 2002)

Connectors:

RJ 11 contains 2 twisted pair cables – it is used for phone connection.

RJ 45 contains 4 twisted pair cables - it is used in Ethernet connectin.

3.      Fiber optic

A technology that uses glass (or plastic) threads (fibers) to transmit data. A fiber optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated onto light waves.

• It works on the basis of  Total internal reflection

Advantages:

1. Fiber optic cables have a much greater bandwidth than metal cables. This means that they can carry more data.
2. Fiber optic cables are less susceptible than metal cables to interference.
3. Fiber optic cables are much thinner and lighter than metal wires.
4. Data can be transmitted digitally (the natural form for computer data) rather than analogically.

Modes of Fiber Optics:

1: Single mode 

2: multi-mode