Imagine, after a long day of work and battling traffic, entering your home and heading straight to the bedroom to start unwinding. As you change out of regular work clothes you decide you'd like to pop in some smooth jazz you recently downloaded, to help your mind empty of phone calls, emails and colleagues. The problem, however, is that the specific music you want is located on a machine in the family room. Then realizing you recently hooked up a home network, you press a few buttons on your new digital media adapter and instantly the music joins you as you dress.
Then, you head to your master bathroom where you hope to splash some clean water on your face to invigorate yourself after the grime of working in the city. As you walk over, you press a few more buttons and the flat-panel above your Jacuzzi tub lights up with the evening entertainment program.
As you head towards the kitchen from your bedroom you press a few more buttons and think ” why did it take me so long to get my home connected. This article explores the growing trend for audio/video home networking, the motivation for it and the considerations in implementing it.
Home networking involves connecting very different consumer electronic and data devices for convenient, if not ubiquitous, access to information and entertainment content. The connection of these disparate devices is evolving with a variety of connection schemes and electronic services being proposed. The ideal home network will allow users to have access to one or more audio/video resources from any room inside/outside the house, or alternatively supply access to one or more audio/video resources from anywhere on the property.
An example of the former case would be using digital media adapters attached to your televisions to view the sporting event of your choice as you move to different regions of the property. An example of the latter case might be supplying audio/video from a digital video recorder in the basement to viewers in the kitchen preparing dinner. Ultimately, the entire home is conveniently orchestrated by the homeowner to operate as dictated.
The Home Environment
What are the technical challenges to have non-stop, user controlled audio/visual stimulation everywhere within a home? To answer that, we need some idea of what the home environment could contain in the not too distant future. For those who enjoy the more futuristic view, there are some interesting visions put forth that predict an information/entertainment rich environment with full access from any room in the house, with bathroom mirrors doubling as flat-panel displays to watch CNN while shaving (hopefully with an electric razor), to panoramic kitchenette windows which double as projection screens, to the more conventional dedicated home theatre. These ideas are probably a little too futuristic, not to mention expensive, for most of us.
So for those who have a shorter timeline for the home of the future, you don't have to look very far to see that things are about to change in a dramatic way. Digital entertainment products like video games, CDs and DVDs will soon be joined by new digital display technologies like plasma, LCD and LCoS projection TVs and services like HDTV and video-on-demand (VOD). These new products/services and the linkage between audio/video sources and display systems are the driving force for home networking.
Below we have a list of new and existing digital products that are candidates for home networking. The recurring theme in these products is that they are bandwidth hungry. That is, they process large amounts of digital information in performing their functions. This, of course, is not a surprise since they're mostly video devices.
Candidates for Home Networking
High-Definition Televisions (HDTV)
Digital Video Cameras
Personal Digital Assistants (PDA)
High Speed Internet Connections
Personal Video Recorders (PVR)
Digital Audio Systems (CD/MP3)
The networking requirements for the home will depend on how many devices might connect together at any time. It also depends on the bandwidth consumed by the products in performing their functions. How the equipment is used, is up to each individual, but the bandwidth is product defined. Listed below are the bandwidth requirements for some of the functions of these products.
|Playback||Size (15 titles)||Size (74 min. audio)|
|CD||1.4 Mbps||700 MB|
|MP3||128 Kbps||75 MB|
|SDTV MPEG-2||4 – 8 Mbps|
|HDTV MPEG-2||20 – 24 Mbps|
|HDTV MPEG-4||12 Mbps|
|DVD MPEG-2||6 – 10 Mbps||4.5 – 8.5 GB|
|DV Camcorder||27 Mbps|
|MicroMV Camcorder||12 Mbps|
|Digital Camera (3Mpxl)||1.4 MB/file|
|Interactive Gaming||76.8 Mbps|
|Video Conferencing||188 Mbps|
There are four major issues facing implementation of the home network. Unfortunately, some of these issues will only be worked out with time and market acceptance but need be mentioned anyway. The four issues are: Bandwidth, Connectivity, Structure and Security.
As the tables above show, many of these products and services are large bandwidth consumers. There are, however, a number advances coming down the road that will help resolve the potential bandwidth contention in the highly trafficked home network.
The first one is video compression. The tables above list the current state of the art standards for most applications of video. The list, however, is not comprehensive and there are some new standards, like Windows Media 9 (WM9) that purports to provide a 3X improvement over MPEG-2 and 2X over MPEG-4. Another new standard for compression, H.264, will allow HDTV to be streamed at 4 Mbps or less. This type of compression will dramatically reduce the bandwidth demands of many the networked devices listed above.
Under the category of connectivity there are two major categories, hard-wired and wireless. The possibilities for wired solutions include cable, which is capable of high bandwidths, and HomePlug, which is more limited in bandwidth. The HomePlug industry claims a bandwidth of 14 Mbps, but one 6-month field test found at www.broadbandhomecentral.com found an average of 3.8 Mbps throughput. There was a recent report that the HomePlug association is working on the HomePlug AV spec which may offer throughput in excess of 50Mbps range. The advantage of HomePlug is that it uses existing wiring in your house. On the other hand, cable could be very expensive and disruptive to install in a discrete manner.
It is actually worthwhile to mention that bandwidth is an ambiguous specification. It is common for technology to provide a specification for bandwidth, which is the actual number of bits per second. What is actually relevant though, is the throughput, which is the number of useable bits per second. The difference is related to amount of overhead information included in the bit stream required to successfully transmit the desired information.
In the wireless category there is an alphabet soup of standards that are available and in some sense competing. They are, at best, only partially compatible and sometimes not compatible at all. In addition, there are custom wireless solutions that are vendor specific but offer enhanced performance. However, a clear near-term downside to wireless is the number of standards and the fact that it is an industry in transition. This will change over time as one or more standards become dominant.
Two wireless standards worthy of note are 802.11a, b, g (also known as Wi-Fi) and 802.15.3a (also known as Ultra Wideband [UWB]). These two standards, by the way are not compatible, because of differing frequency bands and modulation schemes. Their bandwidths (not throughputs) range from11 Mbps to 54 Mbps for the 802.11 series of standards to 100 Mbps to 500 Mbps for the 802.15.3a standard. The 802.11n, the next generation 802.11 specification, is in discussion and it has a requirement to deliver 100 Mbps (throughput). In addition to bandwidth there is also a difference in the physical range these two standards will transmit.
Physical range is another issue to consider in setting up a personal network with wireless connectivity. The reason is that RF waves do not propagate well through walls. The impact of walls is that the data throughput gets reduced. Put enough walls (or floors) in between communicating devices and there is no connection at all. For a large or complex property with multiple audio/visual devices, placement of some type of repeater in the house will likely be required.
In an effort to ensure interoperability the Wi-Fi alliance has a program which provides a listing of Wi-Fi CERTIFIEDTM products. An example of products that are Wi-Fi certified include Wi-Fi adapters in digital media devices. These digital media devices are early evidence of the growing demand for wireless solutions like Wi-Fi for media applications. As compression improves over time, so will the availability of inexpensive products with Wi-Fi adaptors.
The benefit of wireless is that it is portable, can be hidden, is inexpensive and is reasonably wide band. The ability to be hidden inside the housing of a product also eliminates a potential unsightly connection to a $5,000, work of art, flat panel television. Potential downsides to wireless include security, setup and administration. This leads us to our last two topics Structure and Security.
Structure is a non-issue if you're living alone, own a small property, have few devices to connect or are not a technophile by nature. However, setup and administration could be an issue if there is a complex network (lots of video/computer toys in the house) or a physically large or complex property. For example, manufacturers of several video products are planning on increasing the sophistication of specific products to act as a video server. This means in the future the set top box, DVD player, PC may offer capabilities to act as a video server. How the network is set up will depend on what products the user owns and the manner in which they are used.
Security could be a complex problem as there may be one system to protect against Internet intruders and separate systems for parental controls on cable or satellite based input. If deploying a wireless network in the house, there may be another layer of security. Wireless security can be an issue, for if not secured properly neighbors may be viewing broadcasts right along with you. New, more secure encryption systems will be available for 802.11 wireless technologies some time next year.
Many of the other complexities will be resolved with operating system improvements or special purpose software products.
The emergent home network is still a complex subject that involves some new and evolving technologies including compression, wireless, system management and security. Technical issues notwithstanding, the reality of readily available video and audio at spectacular levels of quality is inevitable. Wi-Fi and/or UWB may provide convenient solutions for unwired homes or work to complement networks in wired homes. Endpoint products are available or soon will be made available, especially as the service providers start rolling their products out to consumers. Ultimately, continuous access, with the homeowner in complete control of audio/video running into and out of the home will be a reality.
About the Authors
Kenneth Lowe – Vice President, Strategic Marketing, Sigma Designs, Inc. Mr. Lowe joined the Company in May 2000 as Vice President, Marketing and was promoted to Vice President, Business Development in January 2001; he currently serves as the Vice President of Strategic Marketing. Prior to joining the Company, Mr. Lowe served as the Director of Multimedia Marketing for Cadence Design Systems. Prior to 1995, Mr. Lowe founded his own technology company, Performix, and also held various marketing management positions at Sierra Semiconductor, Chrontel and Dataquest. In the late 1980's, Mr. Lowe served as Product Marketing Director of Sigma Designs.
David Fealkoff ” Director of Product Development, Display Products, Sigma Designs, Inc. Mr. Fealkoff joined the Company in November 2001 in his current position of Director of Product Development. Prior to joining the Company, for 12 years, Mr. Fealkoff served as President of a consulting firm specializing in embedded systems and database management. From 1975 to 1989, Mr. Fealkoff worked in the microwaves and RF business primarily in sales and marketing management. He was co-founder of Magnum Microwave Corporation and served as Vice President of Marketing and Sales from 1980 to 1986. Mr. Fealkoff has a B.S.E. in Physics from the University of Michigan and an M.S.E.E. from Stanford University.