Short-range, low-power off-grid data links between buildings or sensors on the property; not an internet substitute, but resilient to a wider network outage.
Note: Cost, carbon and footprint are rated against the other options for this same need, not in absolute terms.
Line-of-sight or acceptable signal path between nodes on the property
No sizing or quantities: how much a technique yields, and how much a household needs, both depend on the build and the people, so the catalogue compares options rather than dimensioning them. It carries no bill of materials and no build sequence, and it is written for an oceanic, clay-soil climate (Normandy, France). Regulatory notes are indicative and need confirming locally.