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Comtrend PowerGrid 902 Powerline Ethernet Adapters review



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Comtrend PowerGrid 902 Powerline Ethernet Adapters
  • Comtrend PowerGrid 902 Powerline Ethernet Adapters
  • Comtrend PowerGrid 902 Powerline Ethernet Adapters
  • Comtrend PowerGrid 902 Powerline Ethernet Adapters
  • Comtrend PowerGrid 902 Powerline Ethernet Adapters
  • Comtrend PowerGrid 902 Powerline Ethernet Adapters
  • Comtrend PowerGrid 902 Powerline Ethernet Adapters
  • Comtrend PowerGrid 902 Powerline Ethernet Adapters
  • Comtrend PowerGrid 902 Powerline Ethernet Adapters
  • Comtrend PowerGrid 902 Powerline Ethernet Adapters


Our Score:


Subscribers to BT's Vision IPTV service will no doubt be quite familiar with Comtrend's PowerGrid 902 Powerline adapters as you get a pair of these thrown in when you sign up. There's one very good reason why these are supplied as they are designed to be extremely easy to set up so reducing the likelihood of a support call.

All you do is plug them in to a standard wall socket and let them create an Ethernet network by hitching a ride on your existing premises electrical cabling. These chunky units score over a number of other Powerline solutions as they incorporate a pass through socket so you can plug other devices or even power strips into them. However, don't connect them to anti-surge equipped power strips with EMI/RFI filters as these can affect operations.

We can see why BT uses these adapters as they are, indeed, remarkably easy to install and use. One of the units is designated as an Access Point (AP) and this effectively acts as a bridge between other PowerGrid adapters and your main network and Internet connection. You simply plug the first one in and connect it directly to your Internet router or modem where it defaults to accepting an IP address from a DHCP server.

The first unit needs to be configured as an AP and to do this you press the reset button until the AP/Standby LED flashes. Thirty seconds later and we had our first adapter ready to go. Only one AP is allowed to exist on the Powerline network and all other adapters are configured as EPs (End Points). The next adapter is then plugged in next to your PC or other network device. Timing is everything now as on the AP you reset the configuration again and whilst its AP light is flashing you reset the second adapter.

This process only took a few minutes and with both adapters now talking to each other our test PC received an IP address plus Internet access from our router where the AP adapter was connected. Three status LEDs are provided showing whether the adapter is an AP, the status and activity for the Ethernet connection and the speed of the connection. To save power you can press the standby button and the unit will switch itself off.

Communications between adapters are secure as all traffic is encrypted using 3DES or the stronger 128-bit or 256-bit military grade AES standards. As with initial installation, there's nothing you need do here as all key generation and exchanges are handled automatically during the setup phase. If you do add further adapters, you go through the same process of resetting the AP and following with this procedure on each new unit.


March 11, 2009, 9:00 am

Talk about false advertising, the 200mbps their on about is the physical connection to the network card. 100mbps upload and 100mbps download. I doubt it would reach that speed, even if plugged in right next to each other in a double adapter. Maybe you should try that to see if it reaches anywhere near that speed.


March 11, 2009, 12:50 pm

I've got a similar setup at home and it's incredibly useful for kit that doesn't come with wireless access. I already had a hub hanging around so adding something like this to my network gave me a quick (well, quick enough) link to let a 360 and PC access the net quite happily without any of the setup quirks or potential security issues of adding another wireless bridge. Not a solution for everyone but for those who either can't or don't want to use wireless they work very well (just check everything's on one fuse board!)


March 11, 2009, 1:17 pm

Any comments regarding how these compare with the Solwise equivalents that you have previously reviewed?


March 11, 2009, 1:21 pm

Any word on when those Belkin AV+ units are coming to the UK? You know, the one with 3 ports at the bottom. Been waiting for those to show up (a TR review would be great)


March 11, 2009, 1:49 pm


Right next to each other is even worse. They don't actually use the mains cabling as a direct connection; instead they use it as a big aerial to transmit a wireless signal.

That's why it works even if you put it on a different ring main.

It still worries me though, putting that much RF into a power circuit used for sensitive devices (PC, TV, BD player etc.).


March 11, 2009, 2:05 pm

This is a standard practice for these sort of adapters; they all advertise 200Mbps but use 100Mbps Ethernet adapters and result in much lower real world performance. I think the best we've obtained from devices like these is around 60Mbps, which is enough to stream HD video.


March 11, 2009, 2:22 pm

Sorry commented when only one comment had been approved. So my above comment was in response to Justin.


In all honesty all these devices (which are rated at the same speed) use the same circuitry so the only differentiators are the design and software, neither of which I would care about.


Solwise already do a triple port version though it is of the slower 85Mbps standard. We find this version of the standard can actually give real world performance of around 45Mbps.


Huh? What utter tosh. These devices do nothing of the sort. They very much do use the wiring directly and being closer is better. The reason they might work across ring mains is because ring mains aren't electrically isolated from each other - these things can theoretically work between houses but in real life the signal breaks down too much.


March 11, 2009, 3:05 pm

The speed isn't that bad to be honest - 32-38 Mbps is more than fast enough to share an ADSL broadband connection without bottlenecking, and for LAN gaming, streaming audio and video (maybe not high bandwidth HD) and transferring all but the largest files at reasonable pace. Yes you'd get better performance by hard wiring CAT 5 all round your house, but that's a slightly bigger job than plugging in a pair of these.

It is significantly faster than the real maximum throughput seen on most so-called "54 Mbps" 802.11g wireless networks, and in a house with decent wiring the signal should hopefully reach further with less drop in speed than Wi-Fi. And to cap it all, they're a breeze to install.


March 11, 2009, 7:45 pm

I have a couple of the 85Mbps Solwise plugs and a Solwise ethernet + Wireless plug and I absolutely love 'em. So easy to install, brilliant, consistent results and I never have any problems streaming HD content over 100ft away. Highly recommended...if you've got good, solid house wiring - great for a block of flats too.


March 11, 2009, 8:49 pm

I got these like many others with my BT vision package. I am very impressed and find them a godsend compared to my previous set-up.

I have a studio at the end of my garden and I used to use a wireless network to get internet access down there. It was never a perfect set-up, even with wifi boosters etc..

since using the powerline, I now have my router in the front room sharing the telephone line for the SKY box, I plug my BT vision directly into the router and the other LAN connection goes into the powerline. I simply turn on the power in the studio and within seconds Im ready to go.

The speed is very similar to what I get up in the house. My studio connection consists of 1 laptop, 1 PC and an XBOX, the power line in the studio can host all of these by connecting to an Ethernet hub/switch to it.

In conclusion, the powerline is a great solution.


March 11, 2009, 9:59 pm

Laugh if you want, but I have an old Netgear XE102 Homeplug setup, with a blistering transfer rate of 14Mbps. I find it fine for web surfing!


March 12, 2009, 6:42 pm

Ed, thanks. The point i was trying to make was that 100Mbps Ethernet Adapters are actually 200Mbps when in full duplex mode, ie you can transmit and recieve at 100Mbps at the same time, so their not actually lying, they are just using the ethernet connection statistics to say what you connect to the individual point via lan cable at, knowing full well that you will never reach the full 100Mbps upload and 100Mbps download at the same time. That said I do think that this is a very good product, and very reliable technology. Much better than wireless, as in my experience it is much more stable a connection than wireless, just wish that companies would be more honest with their connection statistics.

Steve Redway

May 1, 2009, 12:36 am

Power Line Adapters (PLAs) whilst seemingly a good solution to home

networking are essentially a very poor technology. They pollute the

radio spectrum, interfere with your neighbours radio (preventing

reception of Short Wave broadcasts) and do not adhere to the European

EMC directives.

They rely upon your internal house wiring to pass signals between

units. Unfortunately, your house wiring is a good ariel and these

signals go far beyond your house, many 100s of yards and in some cases

get into external telephone lines and street wiring and have even been

known to radiate from lamp posts. The units effectively become the

same as an illegal radio transmitter.

The government and OFCOM know the problems regarding PLAs and will

respond when complaints are made by your neighbours, by removing the

devices, so please ensure that the retailer has a sale or return

policy. In a lot of cases involving BT, this translates to BT

replacing the PLAs with CAT5 cabling.

Home networking has a perfectly good wireless system based on the IEEE

802.11 standard (see http://en.wikipedia.org/wik.... This

is commonly called WiFi and operates at frequencies (2.4GHz) that do

not interfere with other equipment. It is legal, adheres to all

European EMC directives and allows you to transfer your broadband and

gaming system throughout the house.

There are campaigns afoot both at local and governmental level to have

PLAs removed from the shops and banned. Australia has already taken

steps to ban PLA devices.

So in reality, they are not such a good idea after all.


May 11, 2009, 8:25 pm

Steve Redway :

Power Line Adapters (PLAs) whilst seemingly a good solution to home

networking are essentially a very poor technology : I believe that the 50mbps (real world usage) I manage to get from my powerline adaptors demonstrates that this technology is very far from poor. I get 4 times the performance I had from my old 802.11g network.

Unfortunately, your house wiring is a good ariel and these

signals go far beyond your house, many 100s of yards and in some cases

get into external telephone lines and street wiring and have even been

known to radiate from lamp posts : Whilst maybe true, maybe not - As the signals are encrypted why would this worry me? I cannot comment on the legality but the hundreds of thousands of these devices that are currently being used in the UK demonstrate that perhaps the legality issue that you raise isn't quite the issue you make it out to be.

In a lot of cases involving BT, this translates to BT replacing the PLAs with CAT5 cabling : So why do BT still sell them? and can you quantify this please? I find it hard to believe BT have replaced many (if any?) houses powerline installations with CAT5.

Home networking has a perfectly good wireless system based on the IEEE

802.11 standard (see http://en.wikipedia.org/wik... : 802.11g (which was the best avaiable when i constructed my network) was woefully inadaquete when streaming HD video, Powerline does it fantastically. A brief trial of 802.11N has shown it to be just about satisfactory, however as soon as other traffic goes over the network i get frequent stuttering /buffering of video.

Australia has already taken steps to ban PLA devices : I do not live in australia.


November 6, 2009, 5:10 pm

Hello, Can you help me with a question please? If I connect 1 Comtrend PLA to my modem (sfr-neufbox .. I live in France and these have just become available here)and I plug the other in downstairs, having configured them both as you describe; will I be able to connect my Linksys WRT54GL router to the EP and configure the Linksys as an access point to extend my wifi network? We live in an old stone house and the wifi won't reach from one end to the other, despite the modem being at the highest point I can get it!

Thanks in advance - any suggestions gratefully received.


April 13, 2010, 11:12 am

Powerline adapters cause chronic radio interference and came to market in the UK via a loophole in the law. Many 'battles' have appeared across the web between radio users, enthusiasts, EMC Engineers and users of PLT products, & the fact remains that PLT / PLN / PLC in its current format does not comply with the essential requirements of the EMC Directive: 2004/108/EC and therefore the UK Electromagnetic Compatibility Regulations (2006) - which states that devices MUST NOT prevent radio equipment from operating as intended.

Current Powerline adapters do not and cannot comply with EN 55022 for Conducted Emissions; all Powerline products which have been subjected to lab tests thus far, have failed the limits set by international agreement by a huge margin. The adapters belong to two main categories governed by the ‘alliances’ of various manufacturers and principally comprise the HomePlug Powerline Alliance (HPA), the Universal Powerline Association (UPA) and more recently with the advent of gigabit PLT, the HD-PLC Alliance.

On the HPA website, careful browsing allows one to locate a pdf intended for internal use which is a presentation entitled, "HomePlug Executive Seminar, Setting Standards In Motion". Page four of this document is titled:

"EMC Issue with EN 55022" here the HPA state the products do not comply:-

“Safety, immunity and harmonics are correct but almost all PLC devices pass over the CISPR 22 class A, B limits SO FAILED THE TEST and we could not generate (directly) the DoC (Declaration of Conformity) needed for Europe."

The text which follows this explains how to circumvent this embarrassing problem!

If you currently use one of these products in the UK, you may receive a visit from OFCOM should a complaint be registered about radio interference in your locality. These devices can cause terrible problems and have been observed over 1km from the installation. Calculations based on the extensive work undertaken by NATO indicate that there is now significant and increasing risk of disruption to Civil Air safety radio systems. Let us hope YOU aren’t on one of those planes...

At a meeting in March 2010 at the House of Commons, attended by Adrian Sanders (MP), Clive Corrie (Ofcom), Colin Richards (RSGB) and Alan Warner (EMCIA) Ofcom admitted there is a problem and are looking at the Wireless Telegraphy Act to include interference from networks.

Many PLT manufacturers used non-legitimate documentation as the basis for their Declaration of Conformity, citing CISPR/I/89/CD for a technical construction file reference. This document was acrimoniously withdrawn from the IEC's website in 2003 having been discredited. Also, this document was a Committee Draft (signified by the suffix CD) and was thus never a Standard which could be (nor should have been) referenced.

As an engineer, I strongly discourage the continued use of these products and in particular, for those who are relying upon the technology to achieve a home or small business network, there is a realistic chance you may be required to ditch the devices and make other arrangements, at your own cost and with no possibility of recompense.

BT have discovered to their significant cost, the perils of using these adapters as part of their BT Vision product (IPTV), where, in cases complaints have been made, BT had to replace the equipment with a hard-wired network or expensive Ruckus Wi-Fi.

Read the truth about Powerline products with test results from highly accredited laboratories at http://plt.g7cnf.me.uk/

John Berry

April 23, 2010, 11:23 pm

As this review is well over 12 months old I thought a little light need to be shed on the current Comtrend PowerGrid 902 Powerline Ethernet Adapters.

The latest versions are the 3rd generation versions which came out in march 2010.

Maybe a re-review of these would assist and also maybe get a bit better recommendation as these are superb.

PLEASE NOTE: these DO NOT work with any other Powerline/Homeplug versions that you see on the web/other websites as they are only compatible with all other DS2 powerline adapters.

hope this helps

steve bithell

December 29, 2010, 1:19 am

hi experiencing problems with trying to get two comtrend plugs to see each other ?

had them on differing electric household circuits told they needed to be on the same circuit but even with a house full of wires can get them to see each other

im trying to connect a kryptview a 780 box to my broadband connection any ideas

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