Analogue data signal.PM does not involve in

Analogue Transmission

It
uses a continuous signal which differs in amplitude or phase. It is a method
for transmitting image, signal, video or voice data. The transmission can take
place via fiber optic cable or twisted pair cable.

There
are 3 types of analogue transmission:

1. Frequency
modulation(FM)

In the
communication process, FM is the data in a carrier wave by varying the instant
frequency

 

2. Amplitude
Modulation(AM)

It is used
in communication process to transmit data through radio carrier wave. In this
modulation it differs instant amplitude of a carrier signal with the instant
amplitude of a message signal.

 

3. Phase
Modulation(PM)

It is used
to carry both analogue & digital signals. The phase is varied but,
amplitude if signal is kept constant to carry the data signal.PM does not
involve in any channel noise.

 

 

 

 

 

Encryption

Encryption
involves applying mathematical function by using a key value that can be only
read by sender & intended receiver.

There
are 2 encryption methods:

            
 1. Symmetric key encryption

              2. Asymmetric key encryption

 

 

Token Ring LANS

It
is a local area network (LAN) topology where nodes are arranged in a ring
topology, it uses a different network known as token passing. It allows network
adapters to transfer data on the media. It prevents collision between two nodes
that needs to send data at the same time.

HOW IT WORKS

·        
A
token circulates inside the token ring

·        
To
send data ,a node inserts data & destination address  inside an empty token

·        
The
token is investigated by a successive node

·        
The
destination node copies data & return to source with the source address

·        
When
source receives data, it verifies & copies data which is received and empty
the token

·        
Empty
token is now changed to circulation process in token ring continuously

Advantages

.  Easy to troubleshoot
& correction of cable failures

.  Traffic can be prioritized

. Easy
to implement & install

 

 Ethernet LANS

Ethernet
is a computer Network topology commonly used in local area network. It is
defined as 802.3 in IEEE standard. Ethernet is a way that is used to connect
computers to a network .Ethernet uses star topology, it undertake a shared
medium where multiple devices on each segment of the network connected in star
topology via ethernet.