Barceló Vicens, JaumeBellalta, BorisCano Bastidas, CristinaSfairopoulou, AnnaOliver Riera, MiquelVerma, Kshitiz2016-02-162016-02-162011Barcelo J, Bellalta B, Cano C, Sfairopoulou A, Oliver M, Verma K. Towards a collision-free WLAN: dynamic parameter adjustment in CSMA/E2CA. EURASIP Journal on Wireless Communications and Networking. 2011;2011(708617):1-11. DOI: 10.1155/2011/708617.1687-1472http://hdl.handle.net/10230/25840Carrier sense multiple access with enhanced collision avoidance (CSMA/ECA) is a distributed MAC protocol that allows collisionfree/naccess to the medium in WLANs. The only difference between CSMA/ECA and the well-known CSMA/CA is that the former/nuses a deterministic backoff after successful transmissions. Collision-free operation is reached after a transient state during which/nsome collisions may occur. This paper shows that the duration of the transient state can be shortened by appropriately setting the/ncontention parameters. Standard absorbing Markov chain theory is used to describe the behaviour of the system in the transient/nstate and to predict the expected number of slots to reach the collision-free operation. The paper also introduces CSMA/E2CA,/nin which a deterministic backoff is used two consecutive times after a successful transmission. CSMA/E2CA converges quicker to/ncollision-free operation and delivers higher performance than CSMA/ECA, specially in harsh wireless scenarios with high frameerror/nrates. The last part of the paper addresses scenarios with a large number of contenders. We suggest dynamic parameter/nadjustment techniques to accommodate a varying (and potentially high) number of contenders. The effectiveness of these/nadjustments in preventing collisions is validated by means of simulationapplication/pdfeng© 2011 Jaume Barcelo et al. This is an open access article distributed under the Creative Commons Attribution License,/nwhich permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.info:eu-repo/semantics/articlehttp://dx.doi.org/10.1155/2011/708617WLANMACContention protocolinfo:eu-repo/semantics/openAccess