GC8802 Module

What payload can narrowband power-line communications carry ? is a question commonly asked.

The confusion arises because almost every narrowband power-line communications manufacturer quotes the maximim line data rate. Numbers like 175kbps, 250kbps are quoted and this can lead to folks thinking that is is the payload that can be carried on the power-line.

However in practice the real world payload data rate is much lower because  of the following factors :

  • 230 volts lines are noisy and in the case of OFDM the number of frequencies that can be successfully used are usually limited due to noise and interference on the power-line.
  • In Europe the industrial users are limited to using the Cenelec B and C bands (  D band is allowed specifically for fire and security systems) which in itself limits the number of frequencies that can be used
  • There is overhead due to the preamble, error correction, node addressing , RSSI information etc also transmitted. This takes up bandwidth
  • There is a trade off to be made on the byte size of the payload packets. Larger bytes are more efficient as their are fewer preambles/node addressing/RSSI  etc to be sent. However large payload bytes also result in more chance of corruption on noisy AC lines, resulting in packet loss.
  • The modulation scheme also impacts the data rate. More complex schemes result in more efficient data transmission but also increase the likelihood of data corruption on noisy AC lines.

This is just a broef summary of the issues and in the ideal world it is best to test the noise on the lines of the target site and see for yourself what the challenges are.  Using the test and evaluation boxes from companies like Gridcomm and Semitech Semiconductor will allow you to quickly see what the optimum set can be on a given set of AC lines .

Click here to get a summary of results for given sizes of payload data and modulation schemes

 

Communicating on USB , RS-232, RS-485 can be challenging in  industrial and building locations. Gridcomm manufacture a range of  power line modules. They enable users you to quickly install networking communications for USB, RS-232 and RS-485 in industrial and building environments . A key benefit of using narrowband power line  communications in industrial applications is that the 230 volts AC […]

I  work in the the industry with both Power line and Zigbee communications products. My hobby is also amateur ( ham ) radio and this got me thinking about Zigbee versus Power line and hackers.  Now this discussion is not super scientific and is my first thoughts on how hackers could attack either Zigbee or power line based systems Zigbee […]

We now are working with Adesto Technology