ZigZag: Combating Hidden Terminals in Wireless
Networks
overview
This project presents ZigZag, an 802.11 receiver design that combats
hidden terminals. ZigZag’s core contribution is a new form of interference
cancellation that exploits asynchrony across successive
collisions. Specifically, 802.11 retransmissions, in the case of hidden
terminals, cause successive collisions. These collisions have different
interference-free stretches at their start, which ZigZag exploits to
bootstrap its decoding.
ZigZag makes no changes to the 802.11 MAC and introduces no
overhead when there are no collisions. But, when senders collide,
ZigZag attains the same throughput as if the colliding packets were
a priori scheduled in separate time slots. We build a prototype of
ZigZag in GNU Radio. In a testbed of 14 USRP nodes, ZigZag
reduces the average packet loss rate at hidden terminals from 72.6%
to about 0.7%.
papers
ZigZag Decoding: Combating Hidden Terminals in Wireless Networks,
Shyamnath Gollakota and Dina Katabi,
ACM SIGCOMM, 2008. Best Paper Award.PDF
people
Shyamnath Gollakota
Massachusetts Institute of Technology
Dina Katabi
Massachusetts Institute of Technology