Just cellular transmission. The tiny slice of bandwidth that our federal government "gave" the cellular providers must be reused--thus the need for cells. This means that RF engineers, (can you hear me now?) must design systems to deal with extreme interference issues. Even using digital CDMA technology, there is a limited number of calls that can be carried on the tiny slices of bandwith that Clinton's administration busted up the 1900 MHz range into but that is an argument for another day.
"This means that RF engineers, (can you hear me now?) must design systems to deal with extreme interference issues. Even using digital "
What good is any of this if a disaster knocks out cell towers? How good was cell service in the path of Katrina? huh? I would say it was ZERO!
I will freely admit that I don't know a lot about the effects of BPL on the bands above VHF. From what I know, the harmful interference is most pronounced at HF and drops off at higher frequencies. Cell phone companies don't want anything to do with HF, they want the higher frequencies. I'm not quite sure what cellular spectrum has to do with BPL, unless you are just saying to take it all away from the hams.
The thing that fries me about BPL is that it is licensed under Part 15 rules, which basically states that it must not cause harmful interference with any other licensed service and that it must accept any interference from other licensed services. Because the BPL industry had some buddies in the FCC like Michael Powell, it appeared that the FCC looked the other way when it came to harmful interference to other services. BTW, hams aren't the only ones affected by BPL interference, the miliary still uses a lot of HF communication as well.
If the BPL industry could prove that they had a system which caused no harmful interference to licensed services, then I would have no problem with it. However, I am doubtful about that. When you send RF through unshieled cable strung up high in the air, it's going to act like an antenna and radiate.
One other point for all of those so gung-ho for BPL. Theoretically, someone could setup a receiver to demodulate the BPL signals leaked by powerlines and read the Internet traffic. Would you want someone to have open access (with no practical way to stop them) to anything you send and receive over the Internet, such as personal and financial information?