One of the linchpins is a repeater on Hales Track, near Mangamahu, which provides back-up transmission to the usual route through Wanganui and ensures the system cannot fail.
The company has a repeater on the Bastia Hill water tower and can hook Wanganui city people up to wireless broadband. But Mr Watts doesn't recommend that.
He said the wireless network would get faster as technology changed, but could never equal the speed of light through tiny glass tubes - the technology that drives ultrafast broadband.
The wireless broadband he is offering works better than having the same data bounced around by satellite - the only other option for isolated rural people.
"It's exponentially faster and cheaper, and it's a good solution when there's no other solution."
Rural people hooking up with InSPire pay a connection cost of $150. After that a standard 5Mbit speed and 20 gigabytes of data a month costs $70. The download speed is guaranteed to be no slower than 1Mbit, Mr Watts said.
"You can stream YouTube, and watch TVNZ On Demand."
He can add a telephone connection, using Voice Over internet Protocol (VOIP), for an additional cost.
It hasn't been as challenging to provide coverage in the hilly Whanganui hinterland as it looks, Mr Watts said.
"It's amazing what a pair of legs and a quadbike and a pair of binoculars can work out."
Lately, Google Earth has speeded up the search for good repeater sites. Mr Watts finds the likeliest hills online, then checks them out on foot. Each repeater can send a signal 25km, provided it has a line of sight to the receiver.
InSPire Net got the Government contract to provide broadband to the region's 10 most remote schools - Orautoha, Ngamatapouri, Kakatahi, Aberfeldy, Upokongaro, Ngamatea, Mangamahu, Pukeokahu, Taoroa and Te Wainui a Rua. That gave it a head-start, which it has used to the max. Any repeater installed can be used to provide broadband to other households within line of sight, and also to send a signal to a neighbouring repeater.
Only the Te Wainui a Rua school at Ranana now remains to be connected, and Mr Watts is working on a repeater that will also connect up all the houses down the Whanganui River as far as Parikino.
"There are 32 houses, and 23 that want to connect."
He's open to putting up new repeaters, wherever there are 10 people who will sign up to connect for a year or more. He can recoup the cost of the repeater within four years.
He doesn't advertise, and finds word of mouth brings him more than enough new business.
Mr Watts started InSPire Net in a garage in 1998, and it has grown quickly.
It now has a substantial office in Palmerston North and 32 staff, and provides services nationwide, including ultrafast broadband where that is available.
Since 2005 the business has been building wireless broadband mainly in rural Manawatu, Tararua and Horowhenua, and it was InSPire that put the repeater on the hill near the coastal Rangitikei settlement of Koitiata.