Difference between Pure ALOHA and Slotted Aloha protocol?

Question

Where all these protocols are used in network and if all these network nodes are in the same category then which one is best to use ?

Answer 1

Pure ALOHA and slotted ALOHA are the two different variations of of ALOHA.

Pure ALOHA mean transmit whenever you have data. Slotted ALOHA means wait for your time to transmit i.e. time is divided into discrete intervals and each interval corresponds to a frame of data. It does not allow a system to transmit any time. Instead the system has to wait for the beginning if the next slot.

Pure ALOHA is featured with the feedback property that enables it to listen to the channel and finds out whether the frame was destroyed.

Comments

Pure ALOHA :
1. Pure ALOHA do not requried global time synchronization.

2. Pure ALOHA station can send data in continous time manner.

3. It allow the user whenever they have data..

4. Vulnerable time for the pure ALOHA is  2x Tfr.

5. The average sucessful transmission for  pure ALOHA is
G * exp(-2G).

6. The max throughput is 0.184 when G=1/2.

Slotte ALOHA :
1. the does requried the global time synchr.

2. It devide the time in slot.

3. It do not allow the user whenever they have data..

4. vulnerable time  is Tfr.

5. The average sucessful transmission for Slotted ALOHA
S =  G * exp(-G).

6.The max throughput is  .368 when G= 1.

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Wonderful :)

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thank you.