Both Pure Aloha and Slotted Aloha are Random Access Protocols.
Following are the important differences between Pure Aloha and Slotted Aloha.
|Sr. No.||Key||Pure Aloha||Slotted Aloha|
|1||Time Slot||In Pure Aloha, any station can transmit data at any time.||In Slotted Aloha, any station can transmit data only at beginning of any time slot.|
|2||Time||In Pure Aloha, time is continous and is not globally syncronized.||In Slotted Aloha, time is discrete and is globally syncronized.|
|3||Vulnerable time||Vulnerable time = 2 x Tt.||Vulnerable time = Tt.|
|4||Probability||Probability of successful transmission of data packet = G x e-2G||Probability of successful transmission of data packet = G x e-G|
|5||Maximum efficiency||Maximum efficiency = 18.4%.||Maximum efficiency = 36.8%.|
|6||Number of collisions||Does to reduces the number of collisions.||Slotted Aloha reduces the number of collisions to half thus doubles the efficiency.|