full on business. Nearly all of the equipment types are out of the original manufacturers (OEM) repair & support agreement and it takes a lot
of innovation to build the solutions to repair down to component level on legacy networks. In some cases the original manufacturers do not exist any more and neither do the spare components needed for the repairs.
However successful the innovations may be they all start with the idea. As many engineers will tell you, some of the best solutions were first realised on pieces of scrap paper or as in the above network diagram of a simplified Siemens Fastlink SHDSL testbed, on a piece of cleaning tissue.
Wikipedia defines innovation as;
"from the Latin word innovatus, which is the noun form of innovare "to renew or change," stemming from in-"into" + novus-"new"