Statistics on home telephone-based computer networks and HF

I have personally tested telephone-wiring computer based networks. They emit awful noise - which is not a surprise since they operate right across the 40 meter band.

Two months after home telephone based computer networking products were introduced early this year, they achieved a 24% marketshare (as of last May - source was CNet News). Industry market researchers, depending on who you read, say that 50% to 70% of all home computer networks will be based on the telephone wiring based model.

Unfortunately I do not have the exact estimates and sources in my hands as I write this from memory - so, from memory, I believe we are now at about 30 million homes having 2 or more computers in the home. I saw an estimate that guessed out just a few years (2004?) that just over half of all homes would have 2 or more computers. Other reports have shown that most users who have 2 or more computer will choose to network them together within something like 6 months of acquiring the 2nd system. Further, there are a lot of new products coming out soon that tie together all sorts of consumer electronics into home networks, making it easier to send your cable or satellite TV signals to multiple TVs, to route audio from a stereo to other speaker locations, and much more.

So, let's assume that in 2004 there are approximately 60 million homes (half of homes in U.S.) with 2 or more computers, and 50% of them (using the lower of the estimates) or 30 million have a telephone based home network. That works out to 1 out of every 4 homes. In reality, the installation of home networks is not going to be uniformly distributed because wealthier areas are more likely to have multiple computers than poor areas. Further, I would hypothesize that the demographics of ham operators are more likely to place them in neighborhoods with computer owners. Regardless, using the estimate of 1 in 4 homes down the street having HF noise generators is going to be a serious problem.

The facts:
a. multiple PCs in homes are occuring; this is a fact and its growing explosively. Numerous new non-PC products will be forthcoming that leverage home network technology to distribute information around the home.
b. once multiple PCs are installed, there is a huge desire to network them together. This is a fact.
c. a huge driving force behind multiple PCs is the Internet, followed by (slow) deployments of fast Internet access (which is a big driver of home networks).
c. the fastest growing home networking technology is now based upon home telephone wiring and spews emissions across the HF band. In about 2 months, this technology went from 0% market share to 24% marketshare! It is unknown, of course, where this will go in the future. It could increase or decrease. Some argue that home users will opt for wireless networks instead of wired networks. Also, version 2 of the spec *may* make things better since in version 2 there will be some attenuation on the digital signals occuring in the Amateur HF allocations. It is critical that we address this interference problem BEFORE there are 30 million installations.

The trend is overwhelmingly pointing to an HF noise problem that is far, far more troubling than anything we have ever dealt with in the past. It cannot be taken out with a noise blanker or DSP. You can hear a sample of what it sounds like via a link off of the RFI information page, linked to from our front page.

Intel, Microsoft, AT&T, Compaq and other manufacturers have invested directly in the companies who are building this technology. Version 2 of the home phone networking spec is nearing finalization and will utilize a broader swath of spectrum somewhere in the 2 to 30 Mhz range.

There are major market forces pushing home telephone line based networking into all kinds of dwelling units. Please read the material on the RFI page to better understand this situation.

Ed, KF7VY