Smart antennas include a broad variety of antenna technologies ranging
from the simple switched beams to the sophisticated digital adaptive arrays.
While beam-forming antennas are good candidates for operation in strong
line of sight (LOS) environments, it is the multiple input multiple
output (MIMO) technology that is best suited for multipath environments.
In fact, the MIMO links exploit the multipath induced rich scattering to
provide high spectral efficiencies. The focus of this work is to identify
the various characteristics and tradeoffs of MIMO links that can be
leveraged by routing layer protocols in rich multipath environments to
improve their performance. To this end, we propose a routing protocol
called MIR for ad-hoc networks with MIMO links, that leverages the
various characteristics of MIMO links in its mechanisms to improve the network performance. We show
the effectiveness of the components of the proposed protocol by evaluating
its performance through ns2 simulations for a variety of network
conditions.