Over the last few decades, we witnessed notable progression in wireless 
communication. This has led to rapid emergence of heterogeneous wireless 
technologies that share the RF spectrum in an un-coordinated way. Such a 
coexistence introduces high uncertainty and complexity to the medium, 
affecting reliability and availability of wireless networks. This problem 
aggravates for technologies operating in the lightly regulated, yet crowded 
ISM bands. To address coexistence of different technologies in the scarce RF 
spectrum, provide proper interference-aware protocols, and mitigation schemes, 
we need to develop a fine understanding on the interaction patterns of these 
technologies. In this paper, we provide a thorough study of the implications 
of Cross Technology Interference (CTI) on the particularly vulnerable 
low-power IEEE 802.15.4 wireless networks. We identify the underlying 
vulnerabilities that hamper 802.15.4 ability to withstand CTI. We show that 
the uncertainty that CTI induces on the wireless channel is not completely 
stochastic; CTI exhibits distinct patterns that can be exploited by 
interference-aware protocols.