Preparing for IPTV - Ethernet-over Powerline Delivery (1/11/2006)

By James Ferguson, ZyXEL Communications UK

A recent report from Informa Telecoms and Media forecasts the rapid growth of Internet Protocol Television (IPTV) to become the dominant TV technology in 36 million homes by 2011. More immediately, the report forecasts 4.8 million IPTV households by the end of 2006 - nearly double the 2005 figure of 2.5 million. Part of its appeal will be that it can provide viewing on demand, allowing consumers to watch episodes of their favourite soap, the latest blockbuster movie and sport's greatest moments, back to back.
There are two methods of delivering television over broadband: IPTV and WebTV. Both do the same job, but there are fundamental differences between the two. WebTV uses the Internet to broadcast, and so is prone to transmission delays, and packet loss resulting in screen jitter, delay and poor definition. As a result, WebTV may be fine if you want to check the news in a small window on a PC screen, but it is not suitable for the home television viewing experience. IPTV, on the other hand, is controlled by the ISP, giving it better definition and no screen interruptions. For this reason, IPTV is predicted to have much greater growth, and any system integrators, builders or architects wanting to take advantage of this opportunity will need to understand the impact of this technology on the property market and what consumers will want in the new digital home.
IPTV with interactive functions and real time information on the screen
IPTV offers television on demand, a service which is more secure, provides a more convenient means of entertainment than hiring DVDs or going to the cinema, and represents the final piece in the jigsaw for 'triple play' services, providing consumers with video, voice and data delivered through one cable. Over the past decade, successful competing in the triple play market has become the Holy Grail for telecommunication companies striving to offer consumers a range of services at an affordable cost, without sacrificing performance in terms of speed and bandwidth.
Connecting the IPTV set-top box
The problem for the consumer is how to connect an IPTV set-top box to a broadband router. Easy enough, I hear you say, as IPTV set-top boxes include Ethernet ports. But consider that the router is traditionally located in the study next to the PC. The challenge now becomes how to get an Ethernet network to a set-top box on a TV. There are currently no set standards in home networking in place, so many homes use an array of arbitrary technologies to network, most of which will struggle to deliver broadband to the IPTV set-top box. For example, a wireless network is prone to interference, lacks adequate security and is notoriously unstable, and so is unsuitable for this task.
Wiring the home up with CAT-5 cable is another option, as it is by far the fastest method of delivering online connectivity around the home. However, this solution isn't practical as it costly to install and requires careful planning during the building of the home to ensure enough cabling is installed behind walls. Once the walls are sealed, ongoing maintenance is difficult, The alternative is to have unsightly cabling running around the home, which is equally less than ideal.
Ethernet-over powerline
New developments in Ethernet-over powerline technology however, could be the ideal solution. The one thing all homes have in common is a copper-based network which is used in the home's electrical circuits. This is ideal for delivering IPTV because it forms part of the basic infrastructure of any home and is always present. In addition, it is also a cost-effective, hassle-free and stable method of delivery. It provides system integrators, builders and architects with the best return on investment as it requires no maintenance, and tracking any faults to the adaptor or set-top box is simple and straight forward.
Ethernet-over powerline may not be the fastest method of delivering IPTV, but the technology does provide multiple access points across the home without the need to run unsightly and disruptive cabling. CAT-5 cabling on the other hand, while attractive for new builds or massive renovation projects, does restrict future owners from changing the interior layout of the property unless the cables are re-laid. Therefore, while LAN networks may be included in new homes to increase overall value, the investment would ultimately be wasted if at some point home buyers have to replace the network with alternative technologies. In contrast, powerline Ethernet adaptors provide home users with a high degree of autonomy and flexibility in creating LAN access points around the home. They are simply 'plug and play' devices that can be deployed by anyone, provided sufficient power outlets are placed around the home with this technology in mind.
How it works
Ethernet-over powerline works by taking an Ethernet network signal and passing it over a normal household power circuit. There is a range of Ethernet-over powerline products on the market, with most providing a maximum throughput of 85Mb/s - enough for three high-definition MPEG-4 video streams or one MPEG-2 high-definition video stream. Each adaptor has an Ethernet socket on it which can be used to attach a standard CAT-5 network cable.
The ZyXEL PL-100 85Mb/s Powerline Ethernet adapter
Ethernet-over powerline is easy to install and use by even the most technologically challenged. An Ethernet-over powerline local area network (LAN) is easily created by plugging an Ethernet-to-powerline adaptor into the broadband router and by plugging in a second adaptor into the set-top box. This LAN can be accessed across the home by further devices by adding additional adaptors. Unavoidably, using the home power circuit to create a home LAN will result in a certain level of interference generated by the electrical current. However, this is the lesser of two evils when you consider the problems associated with wireless technology - at least Ethernet-over powerline is stable.
Diagram showing Ethernet-over powerline adapters in use around the home
The IPTV future
As consumers develop greater expectations from technology, they are turning away from traditional media. As a result, we can expect to see the penetration of IPTV quite literally change the face of the current television distribution model. With this in mind, system integrators, builders and architects need to be ready to adapt the technology they integrate into their new building projects in order to meet the demands of this growing market and reap the rewards.
The Zyxel Powerline Homeplug Ethernet-over powerline adapters deliver the broadband connection directly to the lounge from the router located in the study
The IPTV model combines both continuous digital streaming and on-demand services such as being able to watch the latest movies whenever the consumer wants. As a result, there will be a definite need for throughput to be improved. The industry is already responding, with several 200Mb/s Ethernet-over powerline adaptors recently being launched and additional manufacturers set to release similar products over the coming months.
Conclusion
Since its introduction, powerline-over Ethernet technology has changed, developed and matured to the point where it is now both stable and standardised. Ethernet-over powerline is the most efficient and cost-effective method of distributing multimedia content around the home. It is proven, well understood, easy to install and use, and does not require extra unsightly cables. It has the bandwidth, stability and capacity to distribute a number of different video streams, making it the ideal technology to distribute IPTV around the home.
James Ferguson is Product Manager for ZyXEL Communications UK Ltd, the UK subsidiary of one of the world's leading broadband access solutions specialists.