  Small, low-cost IoT devices are typically equipped with only a single,
low-quality antenna, significantly limiting communication range and link
quality. In particular, these antennas are typically linearly polarized and
therefore susceptible to polarization mismatch, which can easily cause 10-15
dBm of link loss on communication to and from such devices. In this work, we
highlight this under-appreciated issue and propose the augmentation of IoT
deployment environments with programmable, RF-sensitive surfaces made of
metamaterials. Our smart meta-surface mitigates polarization mismatch by
rotating the polarization of signals that pass through or reflect off the
surface. We integrate our metasurface into an IoT network as LAMA, a Low-power
Lattice of Actuated Metasurface Antennas, designed for the pervasively used 2.4
GHz ISM band. We optimize LAMA's metasurface design for both low transmission
loss and low cost, to facilitate deployment at scale. We then build an
end-to-end system that actuates the metasurface structure to optimize for link
performance in real time. Our experimental prototype-based evaluation
demonstrates gains in link power of up to 15 dBm, and wireless capacity
improvements of 100 and 180 Kbit/s/Hz in through-surface and surface-reflective
scenarios, respectively, attributable to the polarization rotation properties
of LAMA'S metasurface.
