Experimental Assessment of the Backoff Behavior of Commercial IEEE 802.11b Network Cards

— It has been observed that different IEEE 802.11 commercial cards produced by different vendors experience different performance, either when accessing alone the channel, as well as when competing against each other. These differences persist also when thorough measurement methodologies (such as RF shielding, laptop rotation, etc) are applied, and alignment of the environmental factors (same laptop models, traffic generators, etc) is carried out. This paper provides an extensive experimental characterization of the backoff operation of six commercial NIC cards. It suggests a relevant methodological approach, namely a repeatable, well defined, set of experiments, for such a characterization. Low level backoff distribution measurements are taken through a custom equipment developed in our laboratory. Our work allows to detect both a non-standard backoff behavior of some commercial cards (in terms of minimum contention window size and neglection of EIFS times), as well as potential i...

• Type: Conference
• Year: 2007
• Where: INFOCOM
• Authors: Giuseppe Bianchi, Antonio Di Stefano, Costantino Giaconia, Luca Scalia, Giovanni Terrazzino, Ilenia Tinnirello
• Keywords: Commercial Cards, Commercial Nic Cards, Communications, INFOCOM 2007, Same Laptop Models