  The main building block of Internet of Things (IoT) ecosystem is providing
low-cost scalable connectivity for the radio/compute-constrained devices. This
connectivity could be realized over the licensed spectrum like Narrowband-IoT
(NBIoT) networks, or over the unlicensed spectrum like NBIoT-Unlicensed, SigFox
and LoRa networks. In this paper, performance of IoT communications utilizing
the unlicensed band, e.g. the 863-870 MHz in the Europe, in indoor use-cases
like smart home, is investigated. More specifically, we focus on two scenarios
for channel access management: i) coordinated access, where the activity
patterns of gateways and sensors are coordinated with neighbors, and ii)
uncoordinated access, in which each gateway and its associated nodes work
independently from the neighbor ones. We further investigate a distributed
coordination scheme in which, devices learn to coordinate their activity
patterns leveraging tools from reinforcement learning. Closed-form expressions
for capacity of the system, in terms of the number of sustained connections per
gateway fulfilling a minimum quality of service (QoS) constraint are derived,
and are further evaluated using simulations. Furthermore, delay-reliability and
inter network interference-intra network collision performance tradeoffs
offered by coordination are figured out. The simulation results highlight the
impact of system and traffic parameters on the performance tradeoffs and
characterize performance regions in which coordinated scheme outperforms the
uncoordinated one, and vice versa. For example, for a packet loss requirement
of 1%, the number of connected devices could be doubled by coordination.
