Nonpersistent CSMA a station wishing to transmit listens to the medium and obeys the following rules 1. If medium is idle, transmit; otherwise, go to step 2 2. If medium is busy, wait an amount of time drawn from a probability distribution and repeat step 1 The use of random delays reduces probability of collisions Consider two stations become ready to transmit at about the same time while another transmission is in progress If both stations delay the same amount of time before retrying both will attempt to transmit at same time>collision Drawback: Capacity is wasted because medium will generally remain idle following the end of a transmission even if there are one or more stations waiting to transmit. 1010 Nonpersistent CSMA • A station wishing to transmit listens to the medium and obeys the following rules: 1. If medium is idle, transmit; otherwise, go to step 2 2. If medium is busy, wait an amount of time drawn from a probability distribution and repeat step 1 • The use of random delays reduces probability of collisions — Consider two stations become ready to transmit at about the same time while another transmission is in progress — If both stations delay the same amount of time before retrying, both will attempt to transmit at same time → collision • Drawback: — Capacity is wasted because medium will generally remain idle following the end of a transmission, even if there are one or more stations waiting to transmit