Frequently Asked Questions
In order to get as close to NLOS as possible it is important to observe the rules of propagation and try to get enough height in the gateway antenna to avoid the first Fresnel zone as much as possible. The mathematics defining the Fresnel zone are beyond the scope of this FAQ, however, as guidance, for an ISD of 4km, the antenna height should be 16m above the ground (and trees). With enough antenna height and an open landscape performance in the region of 10-30m have been observed.
With the early trial data, Semtech is recommending a 1.5km ISD in most urban cases as a guideline. There is, however, no substitute for detailed network planning and the coverage target should be four gateways. Targeting a configuration giving a four gateway redundancy means that in most cases, the sensor will be in coverage of all four, and in almost all cases will have the required minimum of three.