The ongoing convergence of AV and computing is inevitable, rooted in the dawn of digital media with the advent of the CD, and nurtured by the Internet.  Media servers, multimedia gaming consoles, HTPC, networked AV receivers, mp3 player docks, IPTV; digital entertainment is becoming as at home on computers as it is on traditional AV gear.  However, all of this crosspollination between the two often leaves entertainment stored in disparate locations so a reliable connection is required to transfer the entertainment files between devices.

There are two basic ways to go about networking devices together, wired and wireless.  Networking in the home has come to be dominated by wireless Wi-Fi methods for its apparent ease of installation.  Connections are mobile with no tethering to the wall and there is no need to pull specialized wiring through unseen and difficult to reach places in the home, just plug some transceivers into each device that needs a connection and instant network.

Wi-Fi is great for web surfing on a randomly located laptop, but it does have its drawbacks and it may not be the best choice for a home multimedia network with heavy streaming duties.

For those who find the shortcomings of Wi-Fi make it less than an ideal solution, there are other methods available that are not as onerous as pulling Ethernet cable through walls and attics by making use of existing home wiring systems.  These methods also provide connections that are more secure with better data throughput and reliability.  There is a reason that mission critical business systems and servers are primarily hardwired and not connected by Wi-Fi.

After experimenting and using a number of these alternatives, dating back to 2003, I would like to share what I know for the benefit of Audioholic’s readers who would like to gain a bit of networking know how.

Networking and Bit Rates

The discussion must start with what all the numbers mean, to define them specifically and make sure we are looking at comparable bit rate numbers from one networking standard to another.  It is a bit of a mess, and marketing, with the goal of painting a given product’s performance in the best possible light, only confuses the matter.

Quoted bit rates are not all equal, coming from different points in the transmission link, and without proper context they will suggest better or worse speeds when compared but are really apples to oranges.  Ultimately, all that matters to the end user is the data rates that they will get from using a device.  However, most networking products do not advertise this number for several reasons: because it can be extremely variable with the particulars of given network, and it can be significantly lower than idealized numbers from intermediate steps of the transmission chain.

We will start with the fastest data rates and work towards what will ultimately be seen in real world usage.

At the top is Gross bit rate, defined as the maximum number of bits that can be sent over the physical layer of a network, the bandwidth.  This includes everything that can be sent: usable data, signaling protocol, and overhead for error correction.  Providing this number to consumers will give the greatest overstatement of actual data transfer speed.

The net bit rate is the amount of useful data that can be sent absent error correction coding.  The ratio of useful information to error correction overhead is described as the code rate such that:

Gross Bit Rate · Code Rate ≥ Net Bit Rate

Throughput is the average amount of successful data delivery through a communication channel and is the net bit rate less data retransmission.  Detection of data errors between gross and net bit rate requires retransmission, which while not reducing the net bit rate per se, does increase the amount of time to get a complete transmission through a network.  Throughput can be viewed under several different circumstances:

• Maximum theoretical throughput: maximum data transmission under ideal circumstances, correlates with gross bit rate
• Maximum achievable throughput: ideal maximum with network protocol considered, correlates with net bit rate
• Peak measured throughput: maximum on realistic system over a short time period, applicable to systems under variable loading
• Maximum sustained throughput: maximum on realistic system over a longer transmission time, applicable to systems under more continuous loading

Net bit rates and maximum theoretical throughput are the numbers that are typically quoted in product marketing.  The idealized circumstances rarely occur in the real world and actual network performance will always be below these values.  Interference, network congestion, and many other factors will affect the final perceived transmission rate.

Goodput is the user perceived data rate that finally comes out of the system, the effective throughput.  Goodput is the user payload after all the vehicles used for transporting the data are removed and fits the following relationship:

Net Bit Rate ≥ Maximum Throughput ≥ Throughput ≥ Goodput

The rate of goodput is the most highly volatile number, subject to additional factors including operating system protocols and the processing performance particular to given hardware in a network.  Goodput can be empirically measured by timing file transfers of know size:

Goodput (bits/s) = (File Size (Bytes) * 8) / Transfer Time (seconds)

For an application like streamed multimedia, network goodput is the number that must be satisfied to avoid interruption, which might lead to undesirable behaviors like video frame rate stuttering.

Many modern network systems have Quality of Service protocols built in to prioritize traffic and minimize transmission problems for lag sensitive applications.  Services like IPTV make use of such systems to provide uninterrupted video streams.  QoS can prioritize video traffic, but for someone looking to stream personal video files through a home network, the network still must have the capacity to successfully transmit enough data to satisfy the demand placed upon it by the video plus any other likely, simultaneous uses.

Jargon used throughout various sources of real world performance numbers for networking gear are inconsistent, coming from marketing, product reviews, and actual, credible scientific testing.  Terms like typical throughput are the most likely correlation for goodput, as mentioned above, but vary for the specifics of each network.  Ultimately, most of the product testing is scientifically informal and reviewers are not measuring internal data rates, they are simply measuring what comes out at the end, what a user might actually see.  This is not necessarily the same number one will get after installing it in their own home, but it should be similar in all but the worst of circumstances.

Home Theater Bandwidth and Network Sizing

Next, we should discuss what kind of bandwidth would be required to shunt A/V signals around a network for home theater purposes.  Obviously, there are varying levels of quality, but the necessary bandwidth to stream A/V content will of course depend upon native resolution and the amount of compression as well as software specifics such as file types and codecs.

To give the reader an idea of the amount of bandwidth required by high definition media, we will look at various methods by which video can currently be delivered:

Various A/V Bit Rates

From low quality flash video to high-end video sources, higher resolution and lower compression quickly add to increase bandwidth.  Broadcast HDTV bandwidth will need a minimum of 20 Mbits/s per stream.  Any video that approaches the current gold standard for video quality, Blu-ray, will require a bandwidth of 48 Mbits/s just for the actual A/V signal in addition to necessary signal protocol overhead.  These numbers represent the required goodput for streaming through a networked A/V system in real time without problems.

One complication in the above is the common practice with cable television and other paid, non-terrestrial service providers to squeeze in additional subchannels into each 6 MHz designated ATSC channel width, which are remapped to virtual channels in a manor transparent to subscribers.

Common Digital Subchannel Schemes

From the table above we can see that digital television bit rates can vary widely, and there is every reason to believe that some carriers will and do push to squeeze in as many subchannels as they can.  However, accommodation for contingencies requires that the maximum bit rate be used as the basis for selecting an appropriate network technology when sizing it for throughput.

The final issue to consider when sizing network capacity for streaming multimedia is what other network/internet connectivity must be maintained for simultaneous use.  Add up the numbers for all the different uses that need to be accommodated, and keep in mine, sizing only 20 Mbits/s to stream to a single HDTV is great if no one else in the house intends on surfing the net and downloading files at the same time.

The Cons of Wireless

For all its convenience, Wi-Fi does have some distinct drawbacks, and we will have a look at these issues to form a clear picture of the pros and cons of alternative networking methods:

• Security
• Transmission rate
• Reliability

A significant problem for Wi-Fi is security, which requires proper network configuration to maintain, but neglect does not preclude using the network.  It’s all too common to get the network running but leave it wide open to connection by anyone within broadcast range, a potential security hole into any personal information stored on the network.  Improperly configured Wi-Fi is not only wide open but it will broadcast the open connection SSID to all within earshot if not disabled.  Disabling SSID broadcast is a first step, but it not an actual method of security, a proper encryption method is needed, but they are not all equally secure.  Older decryption methods such as WEP are easily hacked, and even the more recent WPA can be cracked by brute force.  Using the newer, more secure standard WPA2 is recommended but every networked device must support compatible standards, potentially forcing either upgrades or dependence on the lowest common denominator security protocol supported by all the devices.

For those who do choose to go the wireless route, Ars Technica has a good article on securing a wireless network:

• Ars Technica: The ABCs of Securing Your Wireless Network

Data transmission is another potential limit for using wireless for transferring high bit rate digital A/V signals.  Theoretical data transmission rates of a wireless connection are always lower than the contemporary wired solutions.  Wi-Fi equipment vendors are also reluctant to advertise that typical real world throughputs are only 20% to 50% of the maximum, preferring to advertise the theoretical maximum rate:

Wi-Fi Performance and Standards

For wireless transmission, the difference in maximum theoretical rate and actual rate are due to protocol overhead and error correction/retransmission.  Anything that causes signal attenuation, distance and physical obstructions, will increase overhead for error correction, slowing useable data rates as a function of the signal to noise ratio with higher bit rate transmissions being more susceptible to noise.  Keep in mind that the typical data rates above are generalized and they will vary with the particulars of any given installation.

Currently, the fastest available Wi-Fi solution is a moving target, the draft IEEE 802.11n standard, which has not been officially adopted and currently is at draft 2.0.  While products are available that use the draft standards, there is no guarantee that devices based on either draft 1.0 or 2.0 will be completely compatible with the final standard.  Some incompatible devices may only require a firmware upgrade, but some will be physically incompatible with the final standard due to hardware differences.

Ethernet bit rates also drop due to signal attenuation decreasing signal to noise ratio, but typical throughputs hover around the 70% range and tests at conducted at Los Alamos of the latest 10 Gigabit Ethernet standard achieved throughputs in excess of 7 Gbits/s, consistent with that mark.  Based on an approximate 70% net bit rate we have the following:

Ethernet Standards and Performance

Then there are also problems with connection reliability, uneven coverage, and signal interference that can lead to intermittent connections, and further reduction in data rates.  While indoor Wi-Fi ranges typically still exceed the dimensions of most dwellings, it is reduced not just by the presence of floors and walls but also by the relative angle of the obstructions to the signal path.  When devices are separated by an obstruction at a shallow angle the apparent thickness of the obstruction is greater and may cause a loss in range and data rate great enough to leave the extremities of a home without usable signal.  Also, a significant number of other devices operate in the 2.4 GHz Wi-Fi band that can cause interference and congestion: cordless phones, baby monitors, microwave ovens, and Bluetooth, not to mention the neighbor's Wi-Fi network.  Interference produces signal masking where relative signal strengths are similar, decreasing the signal to noise ratio, and increasing data reception errors.  So, sit down and watch a favorite movie streamed from a media server and pop some popcorn; have fun.

Based on the throughput capacities provided here and the throughput demands provided in the section above, any Wi-Fi standard below draft n will likely run into capacity trouble just to stream a single HD channel and allows minimal to no overhead for any other network transmissions or internet connections.  However, higher bit rate Wi-Fi solutions such as draft n are also be more sensitive to interference and other less than ideal conditions.  Ethernet solutions have the necessary throughput to not bog down or overload the entire network to run HD video, but unless a home is pre-wired, building such a network will be a painful endeavor. 

Ethernet over Existing Wiring

Ethernet is ubiquitous: one will be hard pressed to buy a computer at present that does not have an 8P8C (improperly but commonly referred to as RJ-45) modular connector jack built into the machine and PCI based add in adaptor cards are plentiful and cheap for older machines.  The ubiquity is so widespread that it is also the standard connection for the majority of internet/network enabled AV gear.  Ultimately, even if one uses Wi-Fi for the network, it has to be converted back to an Ethernet protocol before any device can be plugged in.

Numerous options that use existing home wiring systems to interface with Ethernet are available at present.  If one just happens to have some telephone lines, coaxial cable, or even standard electrical wiring running through their home, they can make use of these options very easily with the appropriate hardware.

• HomePNA Alliance
• Multimedia Over Coax Alliance
• Home Plug Powerline Alliance
• Universal Powerline Association
• High Definition Power Line Communication Alliance

The various methods for repurposing existing home wiring as a network involve embedding, or piggybacking, another signal onto the primary transmission in the wiring that operates at non-interfering frequencies.  Each home wiring network technology runs its signal at frequencies above those that the primary wiring system uses but they will not always be cross-compatible with other technologies that also make secondary use of existing wiring.

Home Wiring Primary Operating Frequencies

The primary advantage of using a wired system is higher typical throughput than is available with wireless and more reliable connections.  The latest iterations of these alternate schemes have been pushed by triple play television service providers and most, if not all, have QoS mechanisms built into the specifications to provide seamless service.  The other advantage is security: anyone looking for unauthorized access to a wired network will have to physically access the network wires to tap them and not just merely be in range.

The primary disadvantage is hardware availability.  Wi-Fi is plentiful and available everywhere, as close as the local Walmart.  Most of these alternate solutions are not as readily available at brick and mortar stores at present, but with a bit of looking on the Internet, they can be found and are many are manufactured by the same companies familiar to the Wi-Fi scene.

HomePNA, MoCA, HomePlug, UPA Systems

The first option is one I have familiarity with, having used it back as far as 2003 when it was the Home Phoneline Networking Alliance. The standard, in version 2.0 at the time with a maximum throughput of 10 Mbits/s, was fast enough for sharing an Internet connection and some PC gaming, but not fast enough for HD streaming duties, not that there was much of that to do back then. Adapters were available both as usb dongles sold by DSL providers and as third party internal PCI computer cards of which I typically adopted the later.

HomePNA is a non-profit industry association with the goal of standardizing home networking using existing wiring.  The current standard, HPNA 3.1, has a maximum throughput of 320 Mbits/s and a range of 300 meters over phone wiring or 1000+ meters over coaxial wiring.  With a QoS mechanism written into the specification to prioritize network transmission and reduce data collisions, HPNA typically achieves about 90% of maximum throughput.  With it roots in phone wiring, HPNA has become something of the standard of choice for telecom based triple play IPTV systems such as AT&T U-verse.  The current network running through my house is mixed, using an HPNA coax connection into the gateway and to the IPTV receivers but is also distributed at the gateway to an Ethernet backbone between floors for networking other devices and computers with several supplemental HomePlug Turbo connections (as described below).

Up through the HPNA 3.0 specification, the standard covered networking over phone lines but the most recent revision to HPNA 3.1 includes coaxial cable networking.  HomePNA operates at frequencies above voice, DSL, and ISDN on phone and coaxial wire, but below those used for broadcast TV and direct broadcast satellite (DBS) TV on coaxial wiring to avoid interference.  Cable based IP standard DOCSIS overlaps with HPNA frequencies, making the two incompatible for home networking on coaxial.  Supported by a wide array of companies, HPNA 3.1 is also the current home networking standard for phone line and coaxial cable networking recommended by the International Telecommunication Union, Telecommunication Standardization Sector (ITU-T) under Recommendation G.9954 (01/07): Home networking transceivers - Enhanced physical, media access, and link layer specifications.

To use HPNA, a gateway and/or bridges will be required with gateways typically supplied as part of an ISP service.  HPNA also can be set up without an ISP gateway simply by connecting at least two bridges, one at the central network node or primary Internet service connection, and one to any outlying node.  From the bridges, any Ethernet enabled device can be connected directly to the bridge or the bridge can be connected to a switch to allow multiple connections.  Network setup is as simple as plugging the bridges into the appropriate wire, phone or coax, and plugging in an Ethernet cable with no software or drivers to set up on any of the connected machines.

HPNA products such as bridges, IPTV set top boxes, and gateways are available from a number of member companies listed on the HPNA website.  While most of the gear would come with a particular service provider, bridges can be used on any compatible home network and look to be around $80 or less at street prices. 

MoCA

The Multimedia over Coax Alliance is another standards group that looks to make use of existing wiring commonly found in most homes.  The latest standard is MoCA 1.1 that pushes 175 Mbits/s over existing home coaxial wiring at frequencies around 1 GHz.

Also supported by an array of companies, some overlapping with the HPNA group, MoCA has been incorporated in recommendations by the Digital Living Network Alliance, a cross industry group that includes consumer electronics, computing, and electronics to promote cross communication.  As evidenced by the member company list, MoCA tends to be the preferred standard of cable based TV triple play providers.

Generally, good MoCA performance is easily achievable, but certain circumstances will affect data rates.  Engadget HD found issue with video signal splitters, common in many TV installations, inline between MoCA bridges being a serious detriment.  Four port splitters are common where service enters a home, but as a worst case, they encountered a 16-port splitter that reduced throughput to 30 Mbits/s.  Odds are that HPNA over coaxial will suffer similar difficulty with inline video splitters.  Poor performance may require a bit of clean up to eliminate any unnecessary or junk hardware on the line.

Using MoCA is similar to HPNA with service providers supplying gateways that can be used as the main network interface at a central node, and one or more bridges required to connect Ethernet nodes to the coaxial backbone.  Bridges run around $200 a pair, but are easy to use and provide enough bandwidth with headroom to stream HD media and still have room for other network and Internet connections.  The coaxial bridges will pass through ATSC broadcast and cable TV signals but not satellite TV.  The MoCA system is also not compatible with HPNA simultaneously on coaxial wiring, but will obviously not have any conflicts with HPNA over phone lines.

Engadget HD has a review of a Netgear bridge and currently available products are listed on the MoCA website.

HomePlug Powerline Alliance

HomePlug is one of several groups looking to make use of existing copper wiring used for power distribution that typically runs to every single room of a house.  This makes it somewhat more convenient than using phone or coaxial wiring, neither of which is as wide spread as power outlets in most homes.  The downside is, that unlike the other mediums that were designed for communication, electrical wiring was not, with the lack of isolation making performance results more dependent on random power line signal to noise ratios (SNR), which varies with wiring quality, signal path, and whatever else is being used on the line.

The original HomePlug 1.0 specification released in 2001 allowed for speeds up to a gross bit rate of 14 Mbit/s in half-duplex mode while the more recent HomePlug AV specification released in 2005 upped speeds to a 200 Mbits/s gross bit rate.  There is also a HomePlug Turbo specification, which at 85 Mbits/s, falls between the other two standards.  The current AV standard claims a minimum QoS for 2 HD video streams, or about 40 Mbits/s over noisy lines.

HomePlug has also been bolstered by adoption as of May 2008 into the Telecommunications Industry Association (TIA) TIA-1113.  This document supports the MoCA 1.0 standard, giving it an American National Standards Institute (ANSI) backed accreditation.

Use of home plug is as simple as plugging in a minimum of two adapters, one connected to the central node or Internet service, and one or more at any outlying nodes.  Again, a single networked device can be plugged into the Ethernet port or a switch can be added for multiple connections.  However, while HomePlug is convenient, there are several issues to be considered.

First is that is that the evolution of the standard does not require backwards compatibility, only that they must be able to coexist on the same power line network.  What this means is that one can have both HomePlug Turbo and AV connections on the same electrical wiring, but each type needs at least two adaptors, one of each connected to the central node or ISP connection.  Outlying nodes can then be of either type as long as the Turbo and AV specified adaptors have an Ethernet bridge at the central node to act as a middleman to allow cross communication.

Second is security, which like Wi-Fi is not automatic and may be an issue in certain circumstances.  The range of HomePlug signals, up to 200 meters, can extend beyond a home’s internal wiring, making it is possible for anyone using HomePlug compliant gear to access a home network or to inadvertently merge with a neighbor’s HomePlug network.

Like Wi-Fi, to simplify initial setup, HomePlug modules default to a standard network password/encryption key and automatically link to all devices in range with the same password/encryption.  Setting up a secure network will require downloading a driver/utility program from the manufacturer to access the adapters and change the password.  HomePlug security is two-tiered using this network password and physical security.  A common network password is set that is hashed into an encryption key shared between all the adapters.  Any HomePlug with a different password/encryption key will then be excluded.  Changing the network password of each module requires either a direct physical connection or the use of a hardwired password unique to each module.  The network password should be set for remote adapters first as they will, one by one, disappear from the network formed with the node directly connected to the computer.  Once all the remote adapters are changed, change the local adapter, restart the utility program and the network will reappear based on the new password/encryption.

The final issue is susceptibility to line noise and signal path that, like interference for Wi-Fi, can rapidly reduce useable bandwidth.  HomePlug field tests performed when the 1.0 standard were current found size and age of a house were significant factors affecting transmission line quality.  Performance results in actual use can vary widely with HomePlug adapters on the same circuit performing better than over several circuits that have to loop back through the fuse box/circuit breaker.  In personal use, I am able to achieve bit rates of 38.9 Mbits/s as the slowest and 82.7 Mbits/s as the fastest connections between two of the three HomePlug Turbo devices currently in my home.  Others have reported worse results lending support to the sensitivity of this type of networking connection to line quality.

Various HomePlug products that are available are listed on the HomePlug website products page and I have compiled a list of product reviews:

• Belkin Powerline AV+ Starter Kit
• Netgear XAVB101 Powerline AV Ethernet Adapter Kit
• Devolo dLAN 200 AVdesk HomePlug AV network adaptor
• Solwise PL-200AV 200Mbps powerline Ethernet adaptor

Universal Powerline Association

UPA is another of the several competing but similar powerline networking standards.  Overall, UPA performance is similar to HomePlug AV on paper, although HomePlug contends better performance at various SNR over UPA, but a UPA product review I found indicates better UPA performance than with several HomePlug products tested by the same reviewer.

Either standard is probably just as suitable as the other is for home networking purposes and price may be the deciding factor, but they are not directly compatible and at present and may not be able to coexist on the same line.  The possibility of coexistence will be dependant on an upcoming IEEE standard that various powerline networking groups are participating in; more on that below.  One small advantage for UPA, making it a bit simpler than HomePlug, exists in that there is just a single standard on the market at present; there are no legacy UPA compatibility issues, yet.

Setting up UPA network is very similar to HomePlug and requires two or more adapters, one at the central node, and one at each outlying node to be connected.  The security issues with UPA are also similar to those with HomePlug with the possibility of data transmission beyond the home that will require setting network passwords and encryption keys for assured security.

Available UPA products are listed on the organization's website and I have found a review for one of the products for further reading:

• D-Link Powerline HD Network Starter Kit DHP-303 

HD-PLC Alliance

The HD-PLC Alliance is a third powerline networking organization started and dominated by Panasonic that appears to mostly operate in Japan.  The organization website does not appear to show any available products, but this may become a valid option in the future if the group looks to promote the standard in other territories. 

Summary of Alternate Networking Technology Performance

As I said earlier, the jumble of sources for networking speeds, glossed over by marketing and imprecise jargon, make it difficult to discern what speeds the various technologies are theoretically capable of producing much less what performance can expected in the real world.  To that end, I have endeavored to sort out and summarize throughputs between ideal theoretical performances and actual usable throughput consistent with the terminology defined above.

Alternate Networking Performance

As I said previously, typical throughput/goodput will vary depending on particulars of an actual network installation, but phoneline and coaxial cable methods should be the most consistent.

General Issues with Networks on Existing Home Wiring

Surge suppressors and line filtering for Ethernet over existing wiring may cause problems, so route network connections around any filtering of phone line, coaxial, and power outlets to avoid problems.  In particular, with powerline networking as susceptible as it is to line noise and signal path, avoid any sort of power strip or extension cord and plug directly into the wall outlet.  Other electronic devices that do not direct or receive network throughput can be connected as normal through suppressors.

Interoperability between HPNA, MoCA, HomePlug, UPA, etcetera does not exist between any of these standards when they are used on the same wiring system.  HPNA over coaxial and MoCA cannot be on the same line.  The various powerline technologies have taken steps that will at least allow coexistence on the same wiring through the IEEE P1901 Draft Standard for Broadband over Power Line Networks: Medium Access Control and Physical Layer Specifications.  However, the suggestion that a standard that allows multiple coexistent but un-interoperable sub standards is an oxymoron that has generated controversy and will likely confuse consumers.

This is not to say a hybrid network cannot be built, but take care when mixing and matching.  Furthermore, it is possible to build a hybrid with a Wi-Fi network.  The HPNA gateway I use includes wireless functionality and a number of the powerline solutions available have Wi-Fi capability built into the wall adapters.

Some additional help with home networking can be found on Microsoft's website. 

The Future

There currently is a push with many of these disparate home wiring network technologies for convergence and interoperability.

One such push is the G.hn standard being developed by the International Telecommunication Union (ITU) and supported by the HomeGrid Forum.  The standard is an attempt to provide networking interoperability across power lines, phone lines, and coaxial cable at improved data rates of a Gbit/s.  The intent is to produce a single piece of silicon that can use any of the existing home wiring mediums to communicate and to include such chips directly in future electronics with the ultimate goal of leading the standard to smart grid energy management functionality.

However, not all the home networking over existing wiring players are happy about the proposed G.hn standard.  MoCA and HomePlug in particular are unhappy due to incompatibility of the G.hn specification with their own proprietary technology.

One Final Word

Over the last few years, there has been an increase in the pace of development for alternate home networking technologies driven by the blurring and convergence of traditionally separate mediums.

Just a few years ago, home networking using existing wiring was more or less stalled with solutions barely capable of sharing an Internet connection, much less streaming entertainment throughout a home.  Pushed by service providers looking to provide HD quality IPTV throughout customer’s homes, many of these technologies have moved forward and matured into fast and reliable standards.  For those who are familiar with any older versions of the technology and remember the limitations should consider looking again.  They all have the potential to be good options for anyone looking to provide reliable connectivity through a home with a minimum of trouble.

References

Park, Network performance, An Overview of Key Concepts, Computer Science 422, Purdue University

Bicket, J.C., Bitrate Selection in Wireless Networks, Masters Thesis, Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology

International Telecommunication Union: Recommendation G.9954 (01/07): Home networking transceivers - Enhanced physical, media access, and link layer specifications

Multimedia over Coax Alliance: Cable and Satellite Digital Entertainment Networks

HomePlug Powerline Alliance: How HomePlug Technologies Enhance the Consumer Experience

HomePlug Powerline Alliance: HomePlug AV White Paper

HomePlug Powerline Alliance: HomePlug 1.0 Technology White Paper

Universal Powerline Association: Digital Home Specification White Paper