  In wireless communication, heterogeneous technologies such as WiFi, ZigBee
and BlueTooth operate in the same ISM band.With the exponential growth in the
number of wireless devices, the ISM band becomes more and more crowded. These
heterogeneous devices have to compete with each other to access spectrum
resources, generating cross-technology interference (CTI). Since CTI may
destroy wireless communication, this field is facing an urgent and challenging
need to investigate spectrum efficiency under CTI. In this paper, we introduce
a novel framework to address this problem from two aspects. On the one hand,
from the perspective of each communication technology itself, we propose novel
channel/link models to capture the channel/link status under CTI. On the other
hand, we investigate spectrum efficiency from the perspective by taking all
heterogeneous technologies as a whole and building crosstechnology
communication among them. The capability of direct communication among
heterogeneous devices brings great opportunities to harmoniously sharing the
spectrum with collaboration rather than competition.
