  Developing ways to affordably deliver broadband connectivity is one of the
major issues of our time. In challenging deployment locations with irregular
terrain, traditional Clear-Line-Of-Sight (CLOS) wireless links can be
uneconomical to deploy, as the number of required towers make infrastructure
investment unviable. With new research focusing on developing wireless
diffractive backhaul technologies to provide Non-Line-Of-Sight (NLOS) links,
this paper evaluates the engineering-economic implications. A Three-Dimensional
(3D) techno-economic assessment framework is developed, utilizing a combination
of remote sensing and viewshed geospatial techniques, in order to quantify the
impact of different wireless backhaul strategies. This framework is applied to
assess both Clear-Line-Of-Sight and diffractive Non-Line-Of-Sight strategies
for deployment in Peru, as well as the islands of Kalimantan and Papua, in
Indonesia. The results find that a hybrid strategy combining the use of
Clear-Line-Of-Sight and diffractive Non-Line-Of-Sight links produces a 9-45
percent cost-efficiency saving, relative to only using traditional
Clear-Line-Of-Sight wireless backhaul links.
