| Technical Details I'm a ham and I support this form of BPL. This BPL is an application of a phenomenon called G-line discovered by Georg Goubau in the early 1950's or so. A page describing G-line is here : »www.amasci.com/tesla/tmistk.html (scroll down about 1/3 of the way down the page).
There's one big problem with G-line, it requires a dielectric (i.e. plastic, rubber, etc.) on the line the microwaves are propagating on. Most power lines are not insulated and changing out the lines would be a pain and costly. G-line also requires that the power cables be fairly straight or at least have gentle bends, otherwise the radio frequency energy floats off into space. The coupling "funnels" (for lack of a better term) that are required may be a bit difficult to install on a live line as well. If they get this to work, though, they stand to make a pile of money with a non-interfering technology.
This technology is much different than the lower frequency BPL that threatens HF bands (1-30Mhz) and lower VHF (30-80Mhz).
Goody
K3NG |
| There's two other items I'd like to add. This could have the potential to interfere with existing UNII band operations such as wireless ISPs (WISPs) and 802.11a wireless LANs. However, all of these devices are on equal regulatory footing as they operate under Part 15 rules. Something to consider, though, is the nature of 5 Ghz signals. They do not propagate like HF signals that the low speed BPL uses. This is microwave frequencies, so it propagates much more like light - in straight waves, or line-of-sight. So any radiated emissions could be expected to be stopped or severely attenuated by vegetation and buildings in short order. I'd suspect that indoor wireless LANs could easily overcome any emissions from such a system, and wireless ISPs using directional antennas would not have problems.
The other item is more a thought or question. As I mentioned, I'm uncertain they can get this to work due to the nature of G-line. I'm curious if they are perhaps using this as a lossy radiating type system with the "drops" to the houses actually being wireless an not conducted via the power line into the house. I haven't seen any details on this or how they're dealing with the limitations of G-line, but this may be a workable solution.
This, folks, is innovation. Someone at Corridor did their homework and found a nearly forgotten phenomenon with no applications and developed a much better mousetrap. I wish them luck. If they get a working trial system, the investors will be lining up... |
