Diagnosing Wireless Packet Losses in 802.11: Separating Collision from Weak Signal

S. Rayanchu, A. Mishra, D. Agrawal, S. Saha, S. Banerjee
2008 IEEE INFOCOM 2008 - The 27th Conference on Computer Communications  
It is well known that a packet loss in 802.11 can happen either due to collision or an insufficiently strong signal. However, discerning the exact cause of a packet loss, once it occurs, is known to be quite difficult. In this paper we take a fresh look at this problem of wireless packet loss diagnosis for 802.11-based communication and propose a promising technique called COLLIE. COLLIE performs loss diagnosis by using newly designed metrics that examine error patterns within a physical-layer
more » ... n a physical-layer symbol in order to expose statistical differences between collision and weak signal based losses. We implement COLLIE through custom driver-level modifications in Linux and evaluate its performance experimentally. Our results demonstrate that it has an accuracy ranging between 60-95% while allowing a false positive rate of upto 2%. We also demonstrate the use of COLLIE in subsequent link adaptations in both static and mobile wireless usage scenarios through measurements on regular laptops and the Netgear SPH101 Voice-over-WiFi phone. In these experiments, COLLIE led to throughput improvements of 20-60% and reduced retransmission related costs by 40% depending upon the channel conditions.
doi:10.1109/infocom.2008.124 dblp:conf/infocom/RayanchuMASB08 fatcat:fe2kragi5nc7fipyrkbkynzrrq