What is the difference between 1 persistent and nonpersistent csma

In this protocol, if the medium is identified as being clear after listening to it, an additional randomly selected time is waited before transmitting, thus reducing the number of collisions.

This deals with a scenario where there are two stations, A and B, which are out of range of each other, and a third station, C, within both their ranges and to whom both wish to transmit.

It will therefore identify the medium as clear and commence transmission, causing interference in the confluence zone between both stations. Currently, the IEEE Within this department he works as a software developer.

Your email address will not be published. Submit Comment. Leave an answer. Featured image Select file Browse. Click here to cancel reply. About Gianna. Previous question Next question. At the time when a collision occurs the station has to wait for random time for channel to be idle and to start all again.

In the case of an idle channel, it will send frames immediately to that channel. In case when channel is found busy, it will wait for a fixed amount of time and again sense for state of station to be idle or busy. In this method, station does not immediately sense for channel for only purpose of capturing it when it detects end of previous transmission. This method reduces the chances of a collision but reduces efficiency of network. Skip to content. Message do not need to be ACKed.

When 2 or more nodes are waiting for the current transmission to end using 1-persistent CSMA , their transmissions will surely collide when the current transmission ends So I'll just wait until this fellow is done and then take my turn". Performs very well in lightly loaded systems - I. Performance will suck at heavy load There will be an excessive number of collisions. When 2 or more nodes are waiting for the current transmission to end using p -persistent CSMA , they will only collide when: 2 or more nodes pick a random number that is less than p.

The p-persistent CSMA is designed to avoid the collision problem in 1-persistent CSMA By picking a random number , the system tries to ensure that at most 1 node will transmit.