Zigzag decoding: combating hidden terminals in wireless networks

By Shyamnath Gollakota, Dina Katabi. 2008

663 citations recorded by the source corpus.

This paper 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%.

Subfields: Computer Networks and Communications

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Citations in the corpus

Over-the-air Function Computation in Sensor Networks (2016, background): “his can improve spectrum efﬁciency and data latency. (b) Collision Decoding: Our work is motivated by recentwireless trendsadvocatingconcurrenttransmissionsand collision decoding. Systems like ZigZag [15], Buzz [25], Caraoke [2], and compressive sensing [4, 6], treat wireless collisions as a code an”
AirSync: Enabling Distributed Multiuser MIMO With Full Spatial Multiplexing (2012, methodology): “We placed a third RF front-end on the secondary sender and conﬁgured it in receive mode.”
Interference alignment and cancellation (2009, background): “The subtraction step of interference cancellation is widely studied and has been shown to work in practical implementations [ 4 , 14 , 18 ].”
Whole-home gesture recognition using wireless signals (2013, background): “that, similar to communication systems [10], this correlat ion works even in the presence of interfering users, since their motion is uncorrelated with the preamble’s alternating sequence of positive and negative Doppler shifts.”
Cross-layer wireless bit rate adaptation (2009, background): “We note that if the PHY uses some form of interference cancellation [9, 7], then the interference detection strategy remains the same, though the fraction of time interference-related losses occur may be lower.”
Practical, real-time, full duplex wireless (2011, background): “Implementing DC for a full duplex radio, however, is more challenging than other uses of digital cancellation, such as successive interference cancellation (SIC) [8] and ZigZag decoding [7].”
Multi-Person Localization via RF Body Reflections (2015, methodology): “In the communications community, we refer to such techniques as successive interference cancellation, and they have been used in a large number of applications such as ZigZag [12], VBLAST [37], and full duplex [6].”
Achieving single channel, full duplex wireless communication (2010, background): “Categories and Subject Descriptors C.2.1 [Computer-Communication Networks]: Network Architecture and Design—Wireless communication General Terms Design, Performance”
Efficient and reliable low-power backscatter networks (2012, background): “ZigZag decoding requires an offset between colliding messages [21], which is inefficient given the short messages in backscatter systems.”
MIDU: enabling MIMO full duplex (2012, methodology): “This remaining SI is due to the presence of multi-path components in our environment which can be suppressed by employin g conventional digital cancellation techniques [10, 11, 12] .”
Enabling Practical Backscatter Communication for On-body Sensors (2016, methodology): “Other recent work use signal processing techniques over the analog signal to minimize interference [17, 18, 21, 29, 33].”
Full-Duplex Wireless Communications: Challenges, Solutions, and Future Research Directions (2016, methodology): “In theory, the employment of the RF/analog cancellation module is not mandatory, if the FD radio is capable of performing a perfect SI leakage-path estimation at the RAs, the reconstructed digital samples of the SI signal may be readily subtracted from the low-power received samples, for example by ”