  Modern communication devices are often equipped with multiple wireless
communication interfaces with diverse characteristics. This enables exploiting
a form of multi-connectivity known as interface diversity to provide path
diversity with multiple communication interfaces. Interface diversity helps to
combat the problems suffered by single-interface systems due to error bursts in
the link, which are a consequence of temporal correlation in the wireless
channel. The length of an error burst is an essential performance indicator for
cyber-physical control applications with periodic traffic, as these define the
period in which the control link is unavailable. However, the available
interfaces must be correctly orchestrated to achieve an adequate trade-off
between latency, reliability, and energy consumption. This work investigates
how the packet error statistics from different interfaces impacts the overall
latency-reliability characteristics and explores mechanisms to derive adequate
interface diversity policies. For this, we model the optimization problem as a
partially observable Markov Decision Process (POMDP), where the state of each
interface is determined by a Gilbert-Elliott model whose parameters are
estimated based on experimental measurement traces from LTE and Wi-Fi. Our
results show that the POMDP approach provides an all-round adaptable solution,
whose performance is only 0.1% below the absolute upper bound, dictated by the
optimal policy under the impractical assumption of full observability.
