Could someone let me know the difference between ALOHA, R-ALOHA and Polling multiple access schemes? I tried surfing the net for definitions but I couldn't find a site with clear, concise definitions (especially Polling).
using pure ALOHA: you don't divide the channel, when you have packet you send it immediately..
when you use slotted ALOHA you divide the channel to slots in time, and every node can try to send their packet only at beginning of slots,,, of course collosion can be, but overlap can't