Harnessing Exposed Terminals in Wireless Networks

This paper presents the design, implementation, and experimental evaluation of CMAP (Conflict Maps), a system that increases the number of successful concurrent transmissions in a wireless network, achieving higher aggregate throughput compared to networks that use carrier sense multiple access (CSMA). CMAP correctly identifies and exploits exposed terminals in which two senders are within range of one another, but each intended receiver is far enough from the other sender that the two transmissions can succeed even if done concurrently. CMAP includes a reactive channel access scheme in which nodes transmit concurrently (even if there's the possibility of a collision), then observe the loss probability to determine whether they are better off transmitting concurrently or not. Experimental results from a 50-node 802.11a testbed show that CMAP improves throughput by 2

• Type: Conference
• Year: 2008
• Where: NSDI
• Authors: Mythili Vutukuru, Kyle Jamieson, Hari Balakrishnan
• Keywords: CMAP, Computer Networks, Concurrent Transmission, NSDI 2008, Successful Concurrent Transmissions