Improving TCP performance in ad hoc networks using signal strength based link management

Mobility in ad hoc networks causes frequent link failures, which in turn causes packet losses. TCP attributes these packet losses to congestion. This incorrect inference results in frequent TCP retransmission time-outs and therefore a degradation in TCP performance even at light loads. We propose mechanisms that are based on signal strength measurements to alleviate such packet losses due to mobility. Our key ideas are (a) if the signal strength measurements indicate that a link failure is most likely due to a neighbor moving out of range, in reaction, facilitate the use of temporary higher transmission power to keep the link alive and, (b) if the signal strength measurements indicate that a link is likely to fail, initiate a route re-discovery proactively before the link actually fails. We make changes at the MAC and the routing layers to predict link failures and estimate if a link failure is due to mobility. We also propose a simple mechanism at the MAC layer that can help alleviat...

• Type: Journal
• Year: 2005
• Where: ADHOC
• Authors: Fabius Klemm, Zhenqiang Ye, Srikanth V. Krishnamurthy, Satish K. Tripathi
• Keywords: ADHOC 2005, Link Failures, Packet Losses, Signal Strength Measurements