Final answer:
Slotted ALOHA reduces collisions compared to pure ALOHA by dividing time into slots and coordinating packet transmissions to occur at the start of these slots. This structured approach lessens the probability of simultaneous transmissions, hence lowering the chance of collisions.
Step-by-step explanation:
Slotted ALOHA has lower collisions than pure ALOHA due to the structured way it manages the sending of data packets over a network. In slotted ALOHA, time is divided into discrete intervals, or slots. A node is required to wait for the beginning of the next slot to send its packet, which reduces the chance of collisions, as no two packets from different nodes will be sent at exactly the same time.
In contrast, pure ALOHA allows nodes to send packets at any time, which increases the probability of collisions because two or more nodes might transmit simultaneously. Slotted ALOHA's approach coordinates transmissions, thereby improving the efficiency of the network and reducing the likelihood of needing to retransmit data due to collisions.
In slotted ALOHA, the time is divided into discrete time slots, and each node can only transmit in its assigned time slot. This reduces the chances of collisions because nodes know exactly when they can transmit and will not interfere with each other.
On the other hand, in pure ALOHA, nodes can transmit at any time, which increases the probability of collisions. If two or more nodes transmit simultaneously, their signals will collide and result in a collision. Collisions reduce the efficiency of the network and lead to a waste of bandwidth.
Overall, slotted ALOHA improves the system's throughput by reducing collisions and increasing the efficiency of data transmission compared to pure ALOHA.