Instead of running new Ethernet cables to connect your devices to your home network then why not use your existing electrical power cables?
That is the idea behind Powerline or Homeplug networks.
Note: HomePlug is the family name for power line specifications for networking over existing home electrical wiring.
HomePlug adapters are typically used to connect non Wi-Fi equipped devices to a home network, and to extend the range of existing networks.
You normally buy homeplug adapters in pairs, and in this case all you need to do is plug them in, and they work.
However replacing faulty devices or extending an existing powerline network is a different story.
What you will Learn
In this guide we will look at powerline networking using homeplug Ethernet adapters, how it works, and how you set up a home network. You will learn:
- How powerline networking works.
- How It integrates into your existing home network.
- How to create a powerline network using homeplug adapters
- How to add and remove adapters from a network
- How various standards interoperate.
- What tools you can use.
Powerline Networking Overview
Powerline networking utilizes your existing mains electrical cable to connect devices together.
Devices like computers plug into a powerline adapter using an Ethernet cable with a UTP connector, just like they would plug into an Ethernet hub or switch.
The power line adapter then plugs into the mains, and uses the mains wiring to transmit the data.
Another power line adapter is required somewhere on the same mains cable system to extract the signal.
- No additional wiring required
- Wiring is usually hidden
- Can use Powerline adapter to power the device e.g. with pass through devices
- Fast speeds of 500Mbps are possible with new models
- Long range and not affected by thick walls and other obstacles like Wi-Fi.
Common Powerline Uses
They are often used:
- To connect devices to a home network that are out of range of the wireless router.
- To connect a device to the network that requires a high speed and reliable connection e.g. games consoles.
- To provide wireless range extension using a powerline Wi-Fi booster.
Powerline standards have evolved since the initial homeplug 1.0. It is important to be aware of the different standards because of potential inter operability issues.
The standards are:
- Homeplug 1.0 Speeds 14Mbs
- Homeplug 1.0 with Turbo Speeds 85Mbs
- Homeplug AV speeds 200Mbs speeds of 500Mbps are now available and marketed normally as AV500.
- Homeplug AV2 (latest) Maximum speed currently 1200Mbps
- HomePlug Green PHY -low power version and low speed.
See Wiki- for more detail.
You will probably face inter operability issues when you need to add another adapter to an existing network or replace a faulty adapter.
Generally homeplug 1.0 devices will only work with other homeplug 1.0 devices, and Homeplug AV,AV2 and HomePlug Green PHY will all work together, but will not work with Homeplug 1.0 devices.
- Homeplug 1.0 works with HomePlug 1.0 Turbo (85 Mbps).
- HomePlug AV can coexist on same cable with Homeplug 1.0 adapters, but will not work with homeplug 1.0.
- HomePlug AV 200 works with homeplug AV 500M but at the lower speed.
- AV,AV2 and HomePlug Green PHY are fully interoperable but at the speed of the lowest speed adapter.
How Powerline Adapters Work
Having a basic understanding of how the powerline network works is crucial to troubleshooting problems, and for building,repairing and upgrading them.
Powerline adapters share the same physical media (the mains cable).
This means that in a neighbourhood of houses that all use powerline adapters there is a potential security risk.
To overcome this powerline adapters form logical networks based on a security key or password called a NMK (Network Management Key).
This key is used to encrypt the data on the network using 128 bit AES (AV2 standard) or 56 bit DES (AV1 standard).
Creating Powerline Networks
To build a powerline network you need at least two homeplug adapters.
Normally you buy adapters in pairs, and the manufacturer will normally ship each pair with a common NMK.
This means that when you plug them into your mains socket they will establish a connection between themselves, and form a logical network.
If they don’t automatically establish a connection then you will need to intervene and manually initiate pairing.
The basic idea is that you put one of the adapters in a receptive mode where it listens for another adapter trying to establish a connection.
You then do the same with the other adapter. The two adapters should locate each other and agree a shared key.
Note: the adapters will remember this key even if they are unplugged from the mains.
Note: On Older adapters (AV1) don’t have a share/security button to initiate the paring process you may need to program each adapter with the same key using the software utility that comes with the adapter.
Some manufactures will ship adapters with a common NMK.
This means that adding adapters to an existing network is easy as the new adapters have the same NMK as the ones already on the network.
However this is a security risk and you should change the NMK from the default.
Powerline Networking Scenarios
- Creating a new powerline network.
- Replacing a broken adapter.
- Adding new adapters to an existing powerline network.
- Leaving a Network.
Creating a New Powerline Network
This assumes that you have purchased the adapters as a pair. In which case just plug them into the mains socket preferably close to each other and they should pair.
Once paired you can move them to the required location.
If they don’t pair then use the pairing procedure below, but you may also want to consult the documentation that came with the adapters.
- Press the security or NMK button on adapter A for less than 3 seconds and the power LED should flash
- Within one minute Press the security or NMK button on adapter B for less than 3 seconds and the power LED should flash.
- Both power LEDs should stop flashing and stay illuminated for a successful connection.
If pairing is unsuccessful then see troubleshooting section.
Replacing a Broken Adapter
If one of you adapters goes faulty then you can replace it. However you should be aware of the following.
- Homeplug 1.0 works with HomePlug 1.0 Turbo (85 Mbps) but not with Homeplug AV1 or AV2 adapters. Therefore if you have the older adaptors then consider replacing both adapters with new ones.
- If you Have Homeplug AV1 adapters then try to replace the broken one with one of the same speed, and from the same manufacturer when possible. However it is not crucial as devices from different manufactures should work together.
- A Homeplug AV1 200Mbps adapter paired with a Homeplug AV1 500Mbps adapter will run at the lower speed.
Adding new Adapters to an Existing Powerline Network
Adapters must be added one at a time and the pairing process carried out each time.
For example to add two new adapters C and D to an existing network with adapters A and B then proceed as follows:
- Pair adapter C with either Adapter A or B but not both.
- Pair adapter D with either Adapter A or B or C.
- The Logical network now consists of adapters A,B,C,D
Note: pairing procedure covered above:
Leaving a Network.
To remove an adapter from an existing network then press the security/NMK button for 10 seconds while still plugged it.
The adapter will generate a new random password which places it outside the existing logical network.
Things to try
- If they don’t pair you can try resetting both devices by pressing the security/NMK button for 10 seconds and then try again.
- You can also use the the utility that came with your adapters to set the key on the adapters. See using the Powerline utility.
Extending Wi-Fi Coverage
Homeplug adapters can also come with built in wireless access points which allows you to easily and quickly provide Wi-Fi coverage in other locations
Using The Powerline Software Utility
You should receive a DVD with your adapter containing software that you can use to mange your powerline adapters.
If not you should be able to download the software online.
I use TP-link adaptrrs and there are two utilities available.
The tpPLC.exe utility shows a nice powerlink map whereas the powerline scan .exe utility is for configuring individual adapters.
The tpPLC.exe utility lets you add devices,set device names,turn off leds,set new security password all through a nice GUI.
However the best feature is the network map which shows you all of the discovered adapters and the line speeds and an example is shown below.
Just like WiFi there are published speeds for each powerline standard. These speeds are theoretical maximum speeds and you will no get them in practise.
The line speed you get is determined by the cabling in your home/office and the distance between adapters.
In addition because all powerline adapters share the same medium (mains cable) the number of devices that are connected also affects the throughput speed.
If you look at my diagram taken form my network you can see that the maximum line speed is much less than the theoretical speed and that distance also plays a role.
A good rule of thumb is to half the theoretical line speed so for a 600Mbps adapter expect around 300Mbps.
There is an interesting table on this forum page showing live test results for adapters under different load conditions.
However generally the speed for even the low speed av200 adapters is much quicker than the Internet connection speeds (15-100Mbps).
Line Speeds and Throughput Speeds
The line speed is the actual bit rate on the line. However because this line is shared by other devices the speed of each device (throughput) is less than the line speed.
So as a crude example if two device were sending on a 300Mbit/s line then each device would have a throughput speed of 150Mbps.
Measuring Throughput Speeds
These are very difficult to measure as they work by transferring data between two computers at either end of the connection.
A common utility is LANSpeedTest by Totusoft which is a simple free and powerful tool for measuring Local Area Network (LAN) speeds.
It is not really for non technical users as it is not easy to setup.
A lot of people try to measure using an Internet speed checker but that measures your overall connection speed which is limited by the slowest link in the chain which is normally the Internet connection itself.
Buying Adapters Quick Note
When purchasing high speed adpaters e.g AV 500 and above check the speed of the Ethernet port as many older adapters used 100Mbps Ethernet.
So even though the line speed was 300Mbps the actual speed out was limited by the Ethernet port.
Newer devices usually use 1Gbps Ethernet but check.
Powerline/Homeplug networks are very good way of extending your home network without running cables, and for connecting devices that need a fast and reliable connection.
Speeds are usually much better than Wi-Fi and much more reliable.
PLC Power Line Communication
NMK Network Membership Key
AVLN – Logical network of AV adaptors
TP link Setup Video – The procedure is used for all makes of adaptor
Resources and references:
- Build a Home Network
- See How to Wire your Home Network
- How to Setup and Configure your Home Router
- solorwise manual
- Homeplug AV White paper
- Netgear support-adding an adapter
- TP Link- how to pair adapters