Alleviating Effects of Mobility on TCP Performance in Ad Hoc Networks Using Signal Strength Based Link Management

Mobility in ad hoc networks causes link failures, which in turn result in packet losses. TCP attributes these losses to congestion. This results in frequent TCP retransmission timeouts and 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 at light loads. 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 high power to re-establish the link and, (b) if the signal strength measurements indicate that a link is likely to fail, initiate a route rediscovery 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 that can help alleviate false link failures that occur due to congestion when the IEE...

• Type: Conference
• Year: 2003
• Where: IFIP
• Authors: Fabius Klemm, Srikanth V. Krishnamurthy, Satish K. Tripathi
• Keywords: Communications, IFIP 2003, Link Failures, Packet Losses, Signal Strength Measurements