TRANSMISSION MEDIA

There are two type of trannsmisson media-

1- Guided media (Cable)
2- Unguided media (wireless)

Guided Media-   Guided media is a type of data transmission medium which is guided by administrator. Administrator decides a way for data transmission. Where we need to install PC we can install cable for this.

Three types of cables are used for networking-

1-  Coaxial Cable
2- Twisted Pair Cable
3- Fiber Optic Cable

Coaxial Cable- It is a copper cable which works on half duplex . It is used in linear bus topology for                                networking.It can transfer data one PCs data at a time. Now days it used for distributing TV cable connection. There is only one way of data transmission. Service providers broadcast signals and TV receiver receives signal.Coaxial cable uses BNC connector such as BNC terminator, BNC Cable connector, BNC T type connector.

It is two type - 

Thick coaxial (Thicknet/RG8)-   It is a type of coaxial cable which is used as a backbone cable in Bus topology.

Speed                               = 10mbps

Duplex                             = Half

Segment length                = 500 miter

Interferance                      = More secure transmission. It is shielded by PVC and mesh.

Crosstalk                           = Less chances of cross talk because it is shielded.





Thin Coaxial Cable (Thinnet/RG58)-  It is thinner than thick net . It is easy to install.

Speed                                =10 mbps

Duplex                              =Half

Segment lengh                  = 200 miter ( practicaly 185 miter)

Twisted Pair Cable-- 

It is most commonly used LAN cable . It is a type of cable which consist of  8 cylindrical wires. It is two type -

1-   UTP ( Unshielded Twisted Pair)  Cable- 

This types of cables don't  have shielding like STP cables. These cables have 8 wires covered with PVC and Outer jacket. These are widely used in LAN network because of some features-

1- Easy to install
2-Cheaper than other cables
3- Better speed
4- Good for full duplex star network

2-   STP ( Shielded Twisted Pair ) Cable 
 
These type of cables are same as UTP but they have shielding to protect from EMI, RFI and cross talk. They also have 8 wire and uses RJ45 connector. These are used where electrical noise is more.

Fiber Optic Cable- 

As name suggests it is made up of fiber and it's core is made up of soft glass. It uses laser or led for data transmission that is why it is known as optical cable. It provides best transmission speed and protection from internal or external interference (EMI, RFI and cross talk) . It is also unaffected by environmental issues. This type of cable is generally used for long distance because this can transmit data to a long distance without attenuation.

It is two type-

1- Single Mode Fiber
2-Multi mode  Fiber

1- Single Mode Fiber-  This type of cable is used for long distance. It uses laser for light source and can transmit one signal at a time. It uses uses always two cable , one for transmit and an other for receive. 

Multi mode Fiber optic cable-  Multi mode fibers are used for short length . These type of cables can transmit multiple signal simultaneously . They use led for light source. These are used in a LAN where are more chances of interference . Because they protect from interference. They also use two cable, one for transmission and an other for receiving. 

  
You can not identify difference  between SMF and MMF by seeing cables. You need to read on cable or packet. because both use these connectors-

SC- Subscriber connector
ST- Straight tip
SMA- Sub miniature