The five pillars of home networking, explained
Value, Mobility, Ease of Installation, High Performance, High Reliability
A home network is multi-functional and multi dimensional if it is to work well and provide value to the consumer. It must provide mobility, or access to the Internet anywhere and anytime. Tablets and smartphones, as well as laptops among other devices, should be able to connect seamlessly and without effort. As these devices are portable in nature, wireless connectivity is the obvious choice.
However, sometimes mobility is hindered because wireless connectivity is obstructed by thick walls, interference or too many devices on the network, thus impacting coverage. If so, a supporting or complementary connectivity mechanism should be available. Power line technology can be very useful as outlets are located in every room throughout the house.
A home network should be easy to use and install. It should not require a technician every time a home network upgrade is needed. Though wireless networks are easy to use and relatively easy to install, products integrating power line technology are essentially plug and play.
And last, but not least, a home network must offer both high performance and high reliability. The two are separate but related, and joined at the hip. Basically, the network has to go fast ALL the time. There should be a guarantee of minimal performance. Coaxial cabling for instance, was designed for video and has virtually unlimited bandwidth providing the speed and reliability essential to a well-functioning, home networking environment.
These five elemental pillars of a comprehensive home network are dependent on the choice of medium itself, wired or wireless, as well as supporting technologies. I suggest additional variables to consider include interoperability vs. compatibility, actual vs. theoretical data rates, and a suggestion as to how to think about cost.
It should be noted that security is an ongoing issue. So while exceedingly important, it is not presented as a core element as it as much a function of medium and technology, as it is digital rights management, the pay TV or network service provider, and one’s own protective schemes. Certainly, one should always add security measures to remove the threat of disruption and unauthorized intrusion.
Wired or wireless?
Home networking using wireless (represented by the Wi-Fi® Alliance) technology offers a significant benefit in mobility. The user can receive content and send content any where in the house. However, high definition video can be challenging due to building materials and interference with other devices. Also, wireless is a shared medium meaning the more the devices on the network, the less bandwidth there is to go around. This can affect performance and hinder distribution of HD video around the home, and prohibit Internet access anywhere and anytime.
Wired alternatives, power line or coax for example, tend to be more stable and generally provide the reliability required for HDTV, ultra HD, multi-room DVR and gaming, HD streaming, and maybe most importantly, Internet access everywhere in the home.
So what is the best wire?
Bandwidth Consuming Applications (courtesy of Comcast Corporation)
Power line or coax?
There are really only two wires already resident in the home to consider and they are power line (represented by HomePlug® Power Line Alliance) and coax (represented by the Multimedia over Coax Alliance, MoCA®). Phone lines, despite the move to cell phones, are still in use but are an especially poor medium for video and should not be considered.
A fundamental benefit of power line is its ubiquity throughout the home. Outlets are in every room including the closet, garage and patio. It is more than adequate for voice, data and home automation. Networks using this medium however, rely on a very low operating frequency and can be affected by commonly used electronics such as microwave ovens, vacuum cleaners and DECT phones. Thus it is not consider a stable medium as signals or noise can be detected from anywhere in the house. This interference leads to a loss in performance and reliability, which is essential for HD video and overall network performance and reliability.
Devices using power line technology are, however, very easy to use. Basically, plug one wire into the socket and the other into the computer. Voila. Instant connection. It just works.
Except when it doesn’t.
Power line effectiveness can also be a function of the age of the wiring, and does not always work on a strip cord.
Coax on the other hand, was designed for video and is found where the homeowner is most likely to watch TV. More than 90 percent of all homes in the US have coax already installed. There are no new wires and no holes to punch into walls.
Coax is inherently secure as it is a shielded medium. It is not nearly as prevalent as power line, but coaxial outlets are generally found where you watch TV.
The best medium for consuming video is already in the house.
Cat5/6 (Ethernet) is a viable medium as well. Speeds of Gigabit and more are realizable and it is secure. However, it is not an incumbent wire. It is a new wire every time, adding substantial cost. It will more than adequately do the job but coax is already in the house saving considerable expense.
Author’s antidote: In my old house, which was a new house, the power line adapter worked great. I used it instead of the wireless. But in my new house, which is an old house, the power line adapter does not work at all.
Home Networking Technology Standards (Actual vs. theoretical data rates)
Essentially there are two ways to measure performance but only one that matters. One is the theoretical data rate, previously referenced, which is never realized even in pristine lab settings, which most homes probably are not. This is a case of what is promised is not what is delivered.
The other is the actual, or net, data rate. This number is not always advertised on the package, though it might be found in the brochure inside the box. It is the only performance metric that should be used when comparing various home networking remedies.
If for instance, the packaging states that the product inside is capable of a 200 Mbps (Megabytes per second) data rate for instance, it is the theoretical rate not the actual rate. If the actual or net data rate is 200 Mbps, the vendor will state it as such. If the number shown is presented without clarification or definition, than assume it is a theoretical rate.
Pay TV operators for instance, design their network based on actual, not theoretical, data rates. So should the consumer. The performance demands on any given home network increase over time with the addition of devices (portable and stationary), usage models, applications (especially video), home construction, wiring, et al.
The consumer is often seduced into thinking that more is better, when in fact more can be less.
Performance vs. reliability
High performance is great but so is reliability. The network must not only go fast, it must go fast all the time with no buffering or lag.
Unreliable performance, no matter how high the data rate promised, is still insufficient for a satisfactory home networking experience and thus not a solution. What is required is high performance AND reliability for consistent delivery of content such as video.
Many home networking technology standards are capable of high performance but not all can guarantee reliability. Some are challenged by nearby interference or the shared medium nature of the technology. Or the technology itself does not have the built in mechanisms that govern reliable packet delivery or Quality of Service (QoS).
Unreliable performance is likely to hinder the time it takes to download a movie and/or inhibit Internet access from the upstairs bedroom or another room in the back of the house.
An analogy is if you drop a call on your cell phone, you can redial and finish the conversation. Annoying, but the task is completed. Not so with video. Glitches, artifacts and latencies, all disrupt the movie/program and the experience is unacceptable.
Interoperability vs. compatibility
These terms are often used interchangeably but they are not the same. Again, caveat emptor.
Compatibility generally means coexistence. This means that two technologies, products or services can reside or work within the same device without interfering with each other’s operation. Interoperability means each succeeding version of a networking specification can interact with the one previous.
Interoperability includes backward compatibility. Compatibility does not always mean backward interoperable.
Think of it as living in the same neighborhood (compatibility) and having them over for a BBQ (interoperability).
If the device is truly backward interoperable with the previous version, the vendor will promote that fact and list it as a benefit on the box. If the word used is compatible, however, than it probably isn’t interoperable.
Interoperability is essential for a technology to be a true standard as it assures consumers that their current investment is protected as next-generation versions of a product line can be added later while preserving the use of the existing equipment.
And then there is Cost
Cost is a tricky and elusive issue and includes the purchase cost, operating cost and maintenance cost. There is also the cost of lost productivity from down time.
Trying to limit the upfront spend on equipment, may actually be more costly in the long run as more time and money might be spent trying to get the network to work properly.
Cheaper is always more expensive in the long run.
Solution or alternative?
To sum up, a complete and comprehensive home network is probably a combination of wireless and wired. Take into account the usage model and applications to be deployed, and then determine the appropriate underlying technology standards.
There are really only three standards or solutions to consider, Wi-Fi, HomePlug and MoCA. These are the only three that when combined meet all the requirements of a comprehensive and productive home network.
The reality is you will still need a wire.
About Rob Gelphman
Rob Gelphman is the VP of Marketing and Member Relations for the Multimedia over Coax Alliance, MoCA®. MoCA technology works over the coaxial cabling already in the home. MoCA is used by pay TV operators worldwide. Products integrating MoCA technology are available in retail. More information is available at www.mocaisinyourhouse.com and www.moca4installers.com.