Frequency overlap across wireless networks with different

radio technologies can cause severe interference and reduce

communication reliability. The circumstances are particularly

unfavorable for ZigBee networks that share the 2.4

GHz ISM band withWiFi senders capable of 10 to 100 times

higher transmission power. Our work first examines the interference

patterns between ZigBee and WiFi networks at

the bit-level granularity. Under certain conditions, ZigBee

activities can trigger a nearby WiFi transmitter to back off,

in which case the header is often the only part of the Zig-

Bee packet being corrupted. We call this the symmetric interference

regions, in comparison to the asymmetric regions

where the ZigBee signal is too weak to be detected by WiFi

senders, but WiFi activity can uniformly corrupt any bit in a

ZigBee packet. With these observations, we design BuzzBuzz

to mitigateWiFi interference through header and payload redundancy.

Multi-Headers provides header redundancy giving

ZigBee nodes multiple opportunities to detect incoming

packets. Then, TinyRS, a full-featured Reed Solomon

library for resource-constrained devices, helps decoding polluted

packet payload. On a medium-sized testbed, BuzzBuzz

improves the ZigBee network delivery rate by 70%. Furthermore,

BuzzBuzz reduces ZigBee retransmissions by a factor

of three, which increases the WiFi throughput by 10%.

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In  Proceedings of the 8th ACM Conference on Embedded Networked Sensor Systems (SenSys 2010)

Publisher  Association for Computing Machinery, Inc.
Copyright © 2007 by the Association for Computing Machinery, Inc. Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, to republish, to post on servers, or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from Publications Dept, ACM Inc., fax +1 (212) 869-0481, or permissions@acm.org. The definitive version of this paper can be found at ACM’s Digital Library --http://www.acm.org/dl/.

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