computer network

Aloha:

A shared communication system like ALOHA requires a method of handling collisions that occur when two or more systems attempt to transmit on the channel at the same time. In the ALOHA system, a node transmits whenever data is available to send. If another node transmits at the same time, a collision occurs, and the frames that were transmitted are lost. However, a node can listen to broadcasts on the medium, even its own, and determine whether the frames were transmitted.  

  

 

Pure aloha:

send any data ,any time
                          Transmission time=Tt 
                          vulnerable time= 2*Tt  

vulnerable time means if in this period if other is there then collision will be there.

    Load factor =λ*Tslot

   efficiancy(η) = G × e −2G 

 ηmax=18.4%