Improving the Collision Avoidance of the CSMA/CA Medium Access Control Protocol

In this work we present two approaches to improve the “Collision Avoidance” mechanism of the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol. Our first approach : the “Uniform Law with Doubling Interval CSMA/CA (ULDI_CSMA/CA)” uses a uniform law in an interval of values I=[a, b] to calculate the random starting time when stations wish to send data. In addition to that, after the occurrence of a collision, the concerned stations will calculate their new random starting time by doubling the previous interval I, in order to reduce collisions. Our second approach : the “Poisson Law with Doubling its Parameter CSMA/CA (PLDP_CSMA/CA)” uses a Poisson probability law to calculate the random starting time when stations wish to send data. Secondly, after the occurrence of a collision, the concerned stations will calculate their new random starting time by doubling the parameter μ of the Poisson law, in order to reduce the collisions. Simulations using our simulation tool, show that both ULDI_CSMA/CA and PLDP_CSMA/CA approaches reduce better the number of collisions occurrences than the CSMA/CA protocol. Key-Words: Medium Access Control (MAC) protocols, CSMA/CA, Local Area Networks (LAN), Collisions.