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MEDIUM ACCESS CONTROL LAYER - Coggle Diagram
MEDIUM ACCESS CONTROL LAYER
Random Access Techniques:
CSMA/CD (Collision Detection)
Used in Ethernet.
Station listens for collisions while transmitting.
If a collision is detected, stop transmission, send a jam signal, and retry after a random backoff time.
CSMA/CA (Collision Avoidance)
Used in Wi-Fi.
Instead of detecting collisions, it tries to avoid them using:
Backoff timers , RTS/CTS signals (Request to Send / Clear to Send)
CSMA (Carrier Sense Multiple Access)
Before sending, a station listens to the channel.
Improves efficiency compared to ALOHA.
Controlled Access Techniques:
Reservation:Nodes request transmission slots in advance, and the system schedules when each node can send data
Polling:A central controller asks each node in turn if it wants to send data, allowing controlled access.
Token Passing .A special token circulates among nodes, and only the node holding the token can transmit, preventing collisions.
Channelization:
BDMA(Broadband Division Multiple Access)
BDMA divides the total bandwidth into separate frequency bands, assigning each user a unique band to communicate simultaneously. This prevents interference by separating users in the frequency domain.
CDMA(Code Division Multiple Acess
Used in mobile networks, military communications. In CDMA, users share the same frequency with unique codes
FDMA(Frequency Division Multiple Access)
Used in radio broadcasting and satellite communication.
In FDMA, each user gets a unique frequency band.
Ethernet:
Standard ethernet:
It is a family of wired networking technologies defined by the IEEE 802.3 standard, supporting data transmission over various media at speeds ranging from 10 Mbps to multi-gigabit rates.
Fast Ethernet :
It is an Ethernet standard (IEEE 802.3u) that provides
100 Mbps
data transfer over twisted-pair (100BASE-TX) or fiber-optic (100BASE-FX) cables.
Giga bit ethernet:
It is an Ethernet standard (IEEE 802.3ab/802.3z) that supports
1 Gbps (1000 Mbps)
data transfer over copper (1000BASE-T) or fiber (1000BASE-SX/LX) cables. !)
