Session 2 : The types of media access method (chapter 2), continued....

The media access method, Continued....

The common media access methods are:
-Multiplexed Media Access
-Polling
-Token-Based Media Access
-Carrier Sense Multiple Access/ Collision Detection (CSMA/CD)
-Carrier Sense Multiple Access/ Collision Avoidance (CSMA/CA)
-Contention Domains

Token-Based Media Access Token-based media access is a media access method in which computers pass a special sequence of bits called a token between them.


Carrier Sense Multiple Access/Collision Detection (CSMA/CD) Carrier Sense Multiple Access/Collision Detection (CSMA/CD) is a contention-based media access method in which nodes can transmit whenever they have data to send.
They detect and manage the inevitable collisions that occur when multiple nodes transmit at once.

Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA)Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) is a contention-based media access method in which nodes can transmit whenever they have data to send.
The steps that they take to ensure media is unused are:



Contention Domain
A contention domain, also called a collision domain, is a group of nodes on a contention-based network that compete with each other for access to the media.



Let's move to session 3,  Chapter 2...

Session 2 : The types of media access method (chapter 2)

The Media Access Method

The media access method determines whether or not a particular node can place data on the network at a given time.
Two categories of media access methods are:
-Contention-based or competitive media access
-Controlled or deterministic media access

The common media access methods are:
-Multiplexed Media Access
-Polling
-Token-Based Media Access
-Carrier Sense Multiple Access/ Collision Detection (CSMA/CD)
-Carrier Sense Multiple Access/ Collision Avoidance (CSMA/CA)
-Contention Domains

Multiplexed Media Access
Multiplexing is a controlled media access method in which a central device combines the signals from multiple nodes and transmits the combined signal across the medium.
The different methods of multiplexing are:
~Time-Division Multiplexing (TDM)
~Frequency-Division Multiplexing (FDM)
A central device called as multiplexer or mux is used to manage the multiplexing process.



Polling
Polling is a controlled media access method in which a central device contacts each node in turn to see whether it has data to transmit.
Demand priority is a polling technique in which nodes signal their state—either ready to transmit or idle—to a hub.




Let's  continued to next part, session 2,Chapter 2....

Session 1 : What are all the transmission methods for communicate within the network? (chapter 2)

In this Chapter 2, you will learn to:
Identify the primary network transmission methods.
Identify the main types of media access methods.
Identify the major network signaling methods.
Identify the elements of the data addressing and delivery process.
Identify common network connection mechanisms.
Identify techniques for ensuring reliable network data delivery.

The Transmission Methods

The primary transmission mechanisms that are implemented on the networks are:
Unicast transmission
Broadcast transmission
Multicast transmission



Unicast Transmission
Unicast transmission is a transmission method in which data is transferred from a specific source address to a specific destination address.


Broadcast Transmission
Broadcast transmission is a transmission method in which data goes from a source node to all other nodes on a network.


Multicast Transmission
Multicast transmission is a transmission method in which data is sent from a server to specific nodes that are defined as members of a multicast group.




Let's move to session 2, Chapter 2....