Logitech homeplug - is it real?

[Jskid]

I'm having trouble getting my head around Logitech's Homeplug technology. From the ads it sounds like ones plugs it into an electrical outlet and the rest of the electrical outlets in the building are on the network. How can this possibly work considering any time an electrical appliance is turned on or off it would create noise on the network?

 

[cliffordcooley]

There is less noise in a home electrical circuit than there is in radio frequencies. A power line network would have less noise to contend with than a wireless network.

There are filters used to filter out unwanted frequencies and stray noise. Not to mention the uses of error detection to catch problems in data transmissions. Upon any detected errors the data is sent again.

 

[Jskid]

Is the data transferred by modulating the voltage or current? Wouldn't this be harmful to other appliance plugged in?

 

[cliffordcooley]

AC current usually operates at 50 or 60 Hertz, depending on where you live. The network frequencies are so high and the voltage of the network signal so small, there would be very little difference in the power supplied to any appliances.

The home electronics has little to fear as well. In fact any appliance that uses a DC power supply would never see the network signal because the power supply by nature would practically kill any signals other than the specified DC voltage. There would have to be filters placed within the power supply to capture the network signal in order to keep it alive.

 

[LookinAround]

I played around with Netgear's powerline ethernet last year. For more info, also see Powerline networking question

In my case, it was pretty easy to run cable between the rooms so I ended up not using it.

/* Edit */
Also see Anyone else tried Powerline ethernet yet? Here's my results

 

[Mr. PLC]

The standard for Power Line Communications at 200Mbps is the HomePlug AV std. It operates at 2 to 30 MHz. the std just uses the electrical copper as the transport for voice video and data. If there is noise at a specific frequency between the 2-30MHz spectrum it will avoid sending data across those frequencies. If you take into consideration the noise and overhead of the PLC protocol your looking at a realistic throughput of apprx 75 to 90Mbps. There is also 128 bit encryption built into the std. It's easy to use and works well.

 

[mevans336]

The standard for Power Line Communications at 200Mbps is the HomePlug AV std. It operates at 2 to 30 MHz. the std just uses the electrical copper as the transport for voice video and data. If there is noise at a specific frequency between the 2-30MHz spectrum it will avoid sending data across those frequencies. If you take into consideration the noise and overhead of the PLC protocol your looking at a realistic throughput of apprx 75 to 90Mbps. There is also 128 bit encryption built into the std. It's easy to use and works well.

Unless you have a GFCI breaker in between the two devices, which in the US are required in all bedrooms and bathrooms for construction after 2007. My devices see about 80Mbps of throughput, but trying to go from a bedroom to the living room (and hence, through a GFCI breaker) drops the throughput to a couple of Mbps.

MoCA adapters are about the same price and if you have GFCI breakers, are probably a better choice.

http://forums.smallnetbuilder.com/showthread.php?t=5607

 

[Jskid]

I'm not familiar with the jargon when it comes to electronics but would devices such as UPS interfere with the transfer of data?

 

[cliffordcooley]

I'm not familiar with the jargon when it comes to electronics but would devices such as UPS interfere with the transfer of data?

Yes, that is one of the properties a UPS has to offer. A UPS will eliminate any signal/noise other than the power signal to insure you have a clean power source for your equipment.

Think of a UPS in these terms. A UPS consist of three main parts.

• DC Power Supply
• Battery
• AC Inverter

During the process of converting voltage from AC to DC and then back to AC, the only output signal is the one created during the final stage. The battery is used primarily as power storage, so the UPS still works during power outages.