We hear a lot of comments like “if (insert your favorite powerline home networking technology here) works on powerlines it should work much better on coax.” Like a lot of marketing-speak, this really begs some investigation. Home network wires aren’t the same.
Sending signals down wires causes un-desired effects, which need to be dealt with by the technology (not to mention the external noise picked up by the wires). The effects are different for each wire. As a result, different technologies were developed to provide the highest throughput and most robust operation over each wire.
Coax and phone wires were designed for communications – they are the home network race tracks. In comparison, powerline is the dirt track. For powerline you need four wheel drive, a low gear ratio, and a heavy duty suspension. It’s a great solution for powerline but you wouldn’t want to race it at the Indy 500.
HomePNA started life as a phone wire home networking technology (an identity we have been trying to shake for years). HomePNA 3.0 is a phone wire technology. What’s often missed is that HomePNA 3.1 is new technology designed for coax – while providing backwards compatibility with HomePNA 3.0. As a result, HomePNA 3.1 products are able to operate over both coax and phone wires (probably 80 percent to 90 percent of today’s installs are over coax).
Powerline requires a very different technology. Using powerline technology on coax or phone wires in real applications brings along all the un-needed baggage that makes it work well over powerline – but hurts performance over other wires (and may have added disadvantages as well).
So, getting back to G.hn’s secret sauce – with G.hn, one chipset will operate over all wires. The trick is to design the pieces so that they can be effectively optimized for the specific media. The key is having the freedom to use “best of breed” contributions from leading home networking technology developers. It’s like designing a round peg to fit in a round hole.