Nik's Technology Blog

Travels through programming, networks, and computers

HomePlug Networking Incompatibilities

It seems HomePlug certified powerline networking components aren't as interoperable as it would first appear.  I've been using Devolo Homeplug dLAN 200 desk units for a number of years now and they have been trouble free and constantly out perform wireless networking in terms of speed.  I recently bought another Devolo dLAN 200 unit to expand my network to enable streaming video to a Windows Media Extender.

I assumed it would be a case of just connecting it to the mains and using the Devolo dLAN configuration wizard to set all the units up with a new encryped password.  I soon realised that this wasn't the case.
The dLAN configuration wizard didn't even detect the new unit on the mains network.  After looking through the manual for a while scatching my head searching for a non-existant troubleshooting guide, I spotted a paragraph that mentioned that older Devolo products using firmware 1.x need their firmware upgraded in order to work with newer models.

Upgrading the firmware has now made all my dLAN 200 HomePlug certified devices compatible!  Thank God for standards Smile

Powerline Networking Now Fast Enough For Streaming HD Content

I've decided to give up waiting for the 802.11n standard to be ratified. When you spend hard earned cash on a piece of kit, you want to have some confidence that it will work in a year or so. Most of the high-end routers on sale today use a proprietary pre-802.11n or draft 802.11n, which may or may not be compatible with devices that meet the standard, when the IEEE pull their finger out.

What is Powerline networking?

Powerline networking has been around for sometime. Essentially it uses your electrical mains wiring as the media to send data over as if it were category 5 cable. You simply plug a box into the wall socket, which converts these signals that multiplex over the mains wiring to Ethernet. Typically you'd have one next to your router, which connects to your routers Ethernet socket, and the other in the room where your computer is located.

Advantages of Powerline over Wireless networking?

One of the main advantages of Powerline networking over Wi-Fi is that there are no dead spots where you can't get a good connection. As long as you are near a mains outlet, you can have a connection; Albeit with an Ethernet cable connected to the wall.

The latest batch of Powerline networking kits are sporting theoretical speeds of up to 200Mbps! Although in practice, overhead in the system, mains wiring and the 100Base-T outputs limit this maximum throughput; However, I have been getting speeds of over 100Mbps along my mains wiring, easily more than 802.11g, and more reliable too.

Installation does not require software drivers, it literally is a case of plugging them into the wall sockets, and connecting up the Ethernet cables and turning them on. This also means out-of-the-box Linux, Vista and OSX support! They'll also work with games machines and media extenders, or any other piece of kit that has an Ethernet port.

I purchased the Devolo HomePlug dLAN 200 AVDesk Starter Kit, which comes with two HomePlug adapters. They include Quality of Service for uninterrupted Internet TV and IP telephony circuitry, and they were given a "best buy" from PC Pro magazine.

There are other manufacturers who produce Powerline networking equipment, like Netgear's HD Powerline adapters, but after reading this review in PC Pro I decided to opt for the devices that conform to the Powerline AV standard.

Media Center Extender - Network Congestion

Media Extenders are particularly useful for streaming video to your TV. Here in the UK the only available Media Extenders you can purchase come in the form of an Xbox 360.

I have been using my Xbox 360 to stream movies stored on my main Media Center PC to my living room over a wireless network (802.11g).

Occasionally I get a "Network Congestion" message appear in the top-right-hand corner, which comes accompanied with a small amount of picture judder/stutter. It's still highly watchable, just a little annoying. Information is available to help you improve your wireless performance; however the crux of the issue is the wireless standards. The Xbox wireless networking adapter supports the following WLAN standards 802.11a, 802.11b and 802.11g. The 802.11n standard has not been ratified by the IEEE yet, but when it comes around it will improve the throughput of data.

The Xbox 360 wireless networking adapter doesn't support any draft version of the 802.11n standard however, so we are stuck with 802.11a,b,g, unless we run an ethernet cable from the router to the Xbox, but that kind of defeats the object, doesn't it?

Microsoft recommends the following:

  • Only have 1 wireless route between your PC -> Router -> Media Extender
  • Use 802.11a standard as it works at 5GHz compared to the congested 2.4GHz channel
  • Use a router designed for Windows XP Media Center Edition

I fairly certain 802.11a is not legal in the UK, can anyone confirm this?

Where does Apple TV leave the Xbox 360?

Apple have just released Apple TV, essentially a device used to wirelessly bridge the gap between iTunes on your computer (Mac, PC) and your TV set in your living room.

Apple added video downloads to the iTunes service a while back, by getting several Hollywood studios on-board. These videos have so far only be available to watch on your computer screen or on your iPod video. Apple TV aims to fix this, by allowing your iTunes library to be wirelessly streamed to your HDTV.

Xbox 360's Media Capabilities

Microsoft on the other hand have similar strategies on invading peoples' living rooms with digital content, theirs though, is in the form of the Xbox 360, which as well as being a high definition games machine is also a very capable Media Center Extender.

As a Media Center Extender it wirelessly streams content from Windows Media Center, or Windows Vista (Home Premium and Ultimate editions) computers. If you don't have a Media Center edition of Windows you can still stream your music, pictures and just recently WMV videos too from the Xbox console using Windows Media Connect.

So How Do Apple TV and Xbox 360 Compare?

Ok, here's a matrix comparision table between Apple TV and the Xbox 360, so you can make your own mind up.

Feature
Apple TV
Xbox 360
HD Games Machine
No
Yes
Stream Audio
Yes
Yes
Stream Video
Yes
Yes
Stream Photos
Yes
Yes
Component Video
Yes
Yes
HDMI
Yes
No
Audio Out
Yes (optical and RCA analogue)
Yes (optical and RCA analogue)
Ethernet connection
Yes
Yes
Wireless capabilities
Yes (built-in) (pre-n)
Yes (sold separately) (a, b, g)
HD Resolution capabilities
1080i, 720p, 576p, or 480p 1080p, 1080i, 720p, 480i,480p
DVD player
No
Yes
HD DVD player
No
Yes (sold separately)
iTunes compatibility
Yes
No
Remote control
Yes
Yes (sold separately)
HD drive
40GB
20GB (premium package only, not needed for streaming)
Video formats supported
H.264 and protected H.264 (from iTunes Store): Up to 5 Mbps, Progressive Main Profile (CAVLC) with AAC-LC audio up to 160 Kbps (maximum resolution: 1280 by 720 pixels at 24 fps, 960 by 540 pixels at 30 fps

iTunes Store purchased video: 320 by 240 pixels or 640 by 480 pixels

MPEG-4: Up to 3 Mbps, Simple Profile with AAC-LC audio up to 160 Kbps (maximum resolution: 720 by 432 pixels at 30 fps)
WMV only, although a Windows 3rd party app called Transcode360 will allow most other formats to be streamed
Audio formats supported
AAC, protected AAC (from iTunes Store), MP3, MP3 VBR, Apple Lossless, AIFF, WAV MP3, WMA, un-encoded AAC, CD, DVD audio