  This paper studies a specific low-power wireless technology capable of
reaching a long range, namely LoRa. Such a technology can be used by different
applications in cities involving many transmitting devices while requiring
loose communication constrains. We focus on electricity grids, where LoRa
end-devices are smart-meters that send the average power demanded by their
respective households during a given period. The successfully decoded data by
the LoRa gateway are used by an aggregator to reconstruct the daily households'
profiles. We show how the interference from concurrent transmissions from both
LoRa and non-LoRa devices negatively affect the communication outage
probability and the link effective bit-rate. Besides, we use actual electricity
consumption data to compare time-based and event-based sampling strategies,
showing the advantages of the latter. We then employ this analysis to assess
the gateway range that achieves an average outage probability that leads to a
signal reconstruction with a given requirement. We also discuss that, although
the proposed analysis focuses on electricity metering, it can be easily
extended to any other smart city application with similar requirements, like
water metering or traffic monitoring.
