The biggest advantage has to be ubiquity, I think. Power lines are required regardless, are already distributed throughout buildings, so wouldn't it be great if they could be used for data as well as power for your device.

The drawbacks have to do with the high carrier frequency required for data communications, and the suboptimal design of power systems when you want them to effectively transport these high frequency signals, including attenuation and noise levels.

For instance, power transformers are typically quite poor at transferring frequencies much above 50 or 60 Hz, so that means that in homes fed by two different phases of a 230 VAC feed, you won't necessarily get coverage between all of the wall plugs. And impulse noise can seriously degrade your high frequency comms too, especially from devices like those triac light dimmers, or wideband noise from electric motors, or noise from switching power supplies. So at best, you will experience packet loss greater than most competing technologies, and also data rates that aren't all that impressive anymore.

Here's a good paper on the subject, and on designs that are workable.

http://www.viste.com/LON/tools/PowerLine/pwrlinetutoral.pdf

The biggest advantage has to be ubiquity, I think. Power lines are required regardless, are already distributed throughout buildings, so wouldn't it be great if they could be used for data as well as power for your device.

The drawbacks have to do with the high carrier frequency required for data communications, and the suboptimal design of power systems when you want them to effectively transport these high frequency signals, including attenuation and noise levels.

For instance, power transformers are typically quite poor at transferring frequencies much above 50 or 60 Hz, so that means that in homes fed by two different phases of a 230 VAC feed, you won't necessarily get coverage between all of the wall plugs. And impulse noise can seriously degrade your high frequency comms too, especially from devices like those triac light dimmers, or wideband noise from electric motors, or noise from switching power supplies. So at best, you will experience packet loss greater than most competing technologies, and also data rates that aren't all that impressive anymore.

Here's a good paper on the subject, and on designs that are workable.

http://www.viste.com/LON/tools/PowerLine/pwrlinetutoral.pdf

hi

Possible disadbantage maybe that it can only transmit during the 0 crossing of the AC transmission. Meaning that it is limited in frequcy of transmition.

It works by have burst of data sent at 120 Hz on an acitve AC input signal (carrier wave). There must be some kind of decoding device in direct contact with the power that can pick the signal up make sense of it.

The biggest advantage has to be ubiquity, I think. Power lines are required regardless, are already distributed throughout buildings, so wouldn't it be great if they could be used for data as well as power for your device.

The drawbacks have to do with the high carrier frequency required for data communications, and the suboptimal design of power systems when you want them to effectively transport these high frequency signals, including attenuation and noise levels.

For instance, power transformers are typically quite poor at transferring frequencies much above 50 or 60 Hz, so that means that in homes fed by two different phases of a 230 VAC feed, you won't necessarily get coverage between all of the wall plugs. And impulse noise can seriously degrade your high frequency comms too, especially from devices like those triac light dimmers, or wideband noise from electric motors, or noise from switching power supplies. So at best, you will experience packet loss greater than most competing technologies, and also data rates that aren't all that impressive anymore.

Here's a good paper on the subject, and on designs that are workable.

http://www.viste.com/LON/tools/PowerLine/pwrlinetutoral.pdf

Visit the website

www.exp-math.uni-essen.de/~vinck/.../PLC-encyclopy-ferrera-atal.pdf

Advantages are already mentioned in previous answers, so I will skip this part. However, the main disadvantage of using PLC in distribution systems (as suggested in advanced metering infrastructure in Iran known as FAHAM) is improper performance especially in long distances and in high noise environment. The problem is that international standards (such as CENELEC in Europe and FCC in US) limit the allowed frequency range for PLC (less than 100 KHz or 500 KHz). Thus, we cannot use the full potential of power lines for PLC. Given this limited frequency, alongside with highly noisy state of power lines and high attenuation rate of power lines, we cannot always obtain satisfying performance from even well-known PLC standards (such as PRIME, G3 and Meters&More etc) 

Failure of can affect performance of the other.

Can we use PLC for data communication in the power fail condition?

If Line voltage is not present how can we send data as there is no zero crossing?