Experimental evaluation of optimal CSMA

Abstract—By ‘optimal CSMA’ we denote a promising approach to maximize throughput-based utility in wireless networks without message passing or synchronization among nodes. Despite the theoretical guarantees on the performance of these protocols, their evaluation in real networking scenarios has been preliminary. In this paper, we propose a methodical approach for the first comprehensive evaluation of optimal CSMA, via experimentation with a custom implementation. Example findings include; 1) hidden terminals with symmetric channels can drive the protocol to a state of extreme contention aggressiveness due to the low service received by flows. Since increasing aggressiveness does not mitigate collisions but actually aggravates them, optimal CSMA enters a positive-feedback loop eventually reaching a deadlock state of total flow starvation; 2) however, the use of RTS/CTS in such scenarios can reduce collisions to lower levels, restoring throughput and preventing an excessive con...

• Type: Journal
• Year: 2011
• Where: INFOCOM
• Authors: Bruno Nardelli, Jinsung Lee, Kangwook Lee, Yung Yi, Song Chong, Edward W. Knightly, Mung Chiang
• Keywords: Communications, Implementation Example, INFOCOM 2011, Networking Scenarios, Positive Feedback Loop