This is not new. The first attempt was by a company called MetriCom. They had the same idea but had too may obstacles in their way. They had to get permission from all the major power companies and phone companies to use their poles. Eventually, they just have up. That is what I recall with a few specifics missing.
I lived in the Bay Area when MetriCom was active. The big issues were:
1. MetriCom was expensive.
2. MetriCom was not very fast--speeds comparable to, but slower than, dial up modems.
3. MetriCom required an external modem the size of a small brick.
These were the specifics that killed MetriCom. I thought about subscribing, but the cost and disadvantages above persuaded me not to.
... They had the same idea but had too may obstacles in their way. They had to get permission from all the major power companies and phone companies to use their poles ...
Not sure why this would be a big problem. In areas where cable is not underground it all runs along power and phone poles.
In fact, many times a power pole has all three on it, power, phone, and cable.
As we said, Below Power, Above Phone.
I had a wireless modem from that company. The mesh network radios were hung off street lights in my area. The service quality was much better than dialup modem service. It was wonderful for about 5 weeks. They went bankrupt. An attempt to resuscitate the company was attempted in the Denver, CO area, but the San Diego service never returned.