as far as I know it is legal, you're not allowed to cross public roads
wrong, that public road story, is how it was put into laymans terms, it is any property boundary, in fact, its even illegal to run this sort of service in an office park!
the only time a property boundary can be crossed is if 1 person owns 2 adjacent properties.
Y do u think the only people that try to provide this sort of service are powerband, and they use PowerLineCommunications for it, its not legal for anyone to provide the infrastructure except for people such as Telkom/sentech (somewhere in this also sit Eskom/transtel)
I researched this thoroughly last year, if you want more info/clarification, speak to Andries from ICASA, he will give you the full info.
This is the type of thing VANS were denied yesterday, independant building of infrastructure.
A little advice for you, in future, try discover legalities and parts of business proposals behind closed doors, and not on a public forum. If this was a legal idea, you would have given an original idea to thousands of entrepreneurs, that will become your competition.