Pure ALOHA vs. Slotted ALOHA: Speed, Efficiency, and Collision Rates Explained
Pure ALOHA lets stations transmit any time they have data; Slotted ALOHA forces them to wait for the next synchronized time slot.
Students cramming for exams often swap the two, because both sound like “send when ready.” The twist: one method lets chaos reign, the other slices that chaos into neat slices—like choosing between a free-for-all buffet and a timed lunch bell.
Key Differences
Pure ALOHA’s throughput peaks near 18 % under heavy load; Slotted ALOHA doubles that by aligning packets to slots. Collisions drop from random overlaps to slot-only clashes, making Slotted more predictable and faster in busy networks.
Which One Should You Choose?
Need simplicity and minimal hardware? Pick Pure ALOHA. Want higher speed and fewer crashes in crowded traffic? Go Slotted ALOHA. Most modern systems favor Slotted for its cleaner, slot-aligned efficiency.
Can Pure ALOHA ever outperform Slotted?
Only at ultra-light traffic where slot waiting wastes time; otherwise, Slotted wins.
Do Wi-Fi and 5G use either?
No, they evolved past both, but Slotted ALOHA inspired early MAC layer designs.