More than half of U.S. home have access to the internet, most access the internet via dial-up voice modems. Multimillion dollar investments have been made to develop the infrastructure to support cable modems and DSL (digital subscriber line) modems to develop broadband acceptance. It is expected that by the end of 2004 more than one third of all US homes will subscribe to "always on" broadband access services to the internet.
The home networks of near future will require throughputs of up to 100Mbps with QoS mechanisms, ease of installation and maintance, low cost and most important "futureproofing."
The HomePNA standard was developed by the Home Phoneline Networking Alliance. This consortium of industry-leading companies developed the group as a non-profit association. These forward thinking companies worked together to develop and focused their effort created a single, unified phoneline networking industry standard of HomePNA. This group helped ensure a single unified standard would bring rapid deployment of a full range of interoperable home networking solutions.
- Founded in June 1998, HomePNA is led by seven forward-thinking companies (Agere Systems, AT&T, Broadcom, Conexant, Hewlett-Packard Co., Motorola and 2Wire). Membership also includes other cutting-edge companies spanning the networking, telecommunications, hardware, software, and consumer electronics industries.
- POTS, (plain old telephone service) signaling and ring voltages that produce significant transients.
- AC in-home wiring couple impulse noise into the wiring.
- Variable wire transmission parameters and types, especially at higher frequencies.
- Reflections amd frequency-defined media transfer functions.
- Varying termination impedances due to different telephone instruments.
With little or no certifcation testing preformed on this type of home wiring, it can be expected that the robustness and throughput would be impaired. One way to overcome the imperfections of this wiring media would be to lower the expected data rates or limit the distances. This concept has been utilized in most power line sustems, such as X-10. But with today's high data rate needs that is not accepable.
The HPNA technology concept is really quite simple: it allows the concurrent transmission of data and voice signals, using frequency division multiplexing on the same wire pair without having any two signals interfere with the other. Simply HPNA technology provides the introduction of data or telemetry signals on to existing voice or coaxial wires within the customer's premise. In this manner there is no need to rewire the dwelling, MDU or business premise because the information can be transmitted over the "existing" wires.
HPNA technology must tolerate completely random and unspecified wiring medias. It has been designed to consider the unknown and its very typical large degree of signal attenuation that will incur in the random wiring topology. As the HPNA data pulse is attenuated and bounced around the wiring it is attenuated more and reflected in many varying degrees. The HPNA technologies encounter high and varying levels of signal noise and must tolerate the dynamically changing transmission line characteristics, while coexisting with telephone service and complying with FCC Part 68. HPNA must maximize data throughput given the above.
The differences between the premise wiring of twisted -pair Ethernet media of UTP Cat 5 (and higher) and other multi-conductor technologies is the QUALITY of the media channel. Transmitting over Cat 5 cable, Ethernet runs on a channel that has a number of excellent properties. Those properties include; point to point communications, correct termination, a defined channel response (attenuation, bandwidth and nulls) and excellent crosstalk.
The "No New Wires" technologies" available for networking within homes and small businesses have the difficulties with the media channel because it is typically severely impaired.
The exisiting premise wiring topology results in:
HomePNA transmit levels
HPNA transmit levels have designed to be fully compliant to FCC Part 68; defining "maximum signal levels on telephone lines (note: typically unshield)." This level also avoids audible noise in telephone sets caused by accidental envelope detection of the HPNA thusly severly restricting the transmit power of HPNA over the entire network
Overview of HomePNA Evolution
HPNA 1.0 was developed to run over existing phone line wiring in a symmetrical mode at a rate up to 1Mbps with an area of geographical coverage of no greater than a 5,000 sq ft or point to point distance no greater than 500 feet, (150 meters). HPNA 1.0 uses pulse position modulation (PPM) resulting in a 1Mbps data rate without any QoS (Quality of Service) provisions.
HomePNA 1.0 operational frequency is 4 - 10Mhz with it's center at 7.0Mhz. The lower limit of 4Mhz allows the use of filtering to reject out-of-band interferance from splitterless applications DSL and the operating HPNA on the same wiring within the home or dwelling. The upper limits of 10Mhz was defined by; a/ crosstalk between phone lines INCREASES with frequency. It has also be determined that the frequencies above 10Mhz are more likely to have wider and deeper nulls caused by wired networks reflections.
HomeCNA & HomePNA 2.0 was developed to run over existing phone line and coaxial wiring in a symmetrical mode at a peak data rate up to 32Mbps, with throughputs approaching 20Mbps. The HPNA 2.0 network uses a shared physical media (wiring) has no need for a switch or hub, unlike Ethernet that requires dedicated (homerun) UTP CAT 3 or 5 cable. HPNA 2.0 will serve geographical coverage area of up to 10,000 sq ft or point to point distance no greater than 1,000 feet, (300 meters). HPNA 2.0 places no restructions on wiring type, wiring topology or termination. The system is designed to operate with a network point to point loss of no more than 28dB. HPNA 2.0 uses the same bandwidth HPNA 1.0 but combines quadrature amplitude modulation (QAM) 10Mbps data rate uses Ethernet-like carrier sensing multiple access with collision detection (CSMA/CD) for media access control (MAC) behavior. The HPNA 2.0 QoS (Quality of Service) provisions, its MAC layer introduces eight priority levels and improves collision resolution.
Overview of HomePNA Evolution Con't
HomePNA 2.0 con't
HPNA 2.0 average throughput of 10Mbps is more than adequate for most applications, but burst loads presented by TCP transfers and dowloads, can at times, make the network unable to provide necessary band width and latency guarantees necessary without some QoS mechanics.
Latency in voice connections MUST BE CONTROLLED below 10 to 20ms on the home network segment if acceptable voice qualitiy is to be maintained. Streaming video and audio connections must be guaranteed bandwidth as demanded by the applications determined from the network.
Furthermore, bandwidth allocations within a given class of service should be fair. The HPNA 2.0 network's support of eight priority levels of QoS from zero to seven (highest). A time-division scheme is used to enable prioritized access. For every priority level, a designated time slot is established. Devices are allowed to start the transmission of a packet only in (or after) the time slot that corresponds to the packet's priority as determined by the device.
HomePNA 2.0 QoS Provisions
The initial motivation for home networking was to share resources among multiple PCs such as Internet access, files and device sharing. Applications that now will command the home network will include; transport of digital audio, digital voice (IP telephone), digital video (IP television) and telemetry (medical and home security). With these home networking applications of today and the future driving CoS (Class of Service) provisions HomePNA 2.0 has adapted.
HPNA 1.0 & HPNA 2.0 was introduced well before before the broadband era. The orginal intent was file sharing and networking of peripherals, this application was shortly dominated by wireless technologies adopted by consumers and commerical users. In 1999 many tech publications were writting of the demise of HomePNA. Actually, the earliest manufacture of HomePNA chipsets stepped away into WiFi wireless, leaving HomePNA technology to die.
In early 2000, it was discovered that HPNA was well adapted for use within coaxial cable AND at the same time twisted pair media. The author of this natative developed the HCNA balun that allowed the application of HomePNA to HomeCNA.
The Chart below provides the generations of HomePNA from 1998 to the technology of today. please note the slight increase in frequency spectrum utilzed vs. the increase in data throughput;
HomeCNA (HomePNA) 3.0 has been developed to for applications used by today's telephone, cable TV and satellite companies that are competing to deliver the "TRIPLE PLAY" services required by today's consumers of "EVERYTHING DIGITAL".
HomeCNA 3.0 delivers a solid 128Mbps over exisit in-home coax while co-exisiting with other analogy and QAM delivered programming. PLEASE NOTE;HomeCNA's operational frequency range of 4 - 36Mhz will interfer with the return path operation of DOCSIS® cable modems. Applications of HomeCNA (PNA);
- Netwoked DVR (Digital Video Recorders) that allow a prgram to be recorded from a IPTV or satellite delivery source. The same coax that provided the transmission media for the recorded program can be utilzed allow that SAME content to be routed another video receiver located in another room on the same coax.
- HomeCNA's reservation based QoS (Quanlity of Service) would allow VoIP telephone calls. The provisions of the guaranteed bandwidth will insure the voice call would ha
- ve priority over any vedio streams on the network.
Examples of bandwidth (Mbps) that the HomeCNA network can transport aren the next below listed chart;
HomeCNA (HomePNA) 3.1 was developed to provide solid throughput rates beyond 320mbps required for todays IPTV delvery methods currently as currently being deployed by AT&T U-Verse® technologies. In the near future we will see HomePNA 3.1 deployment within the new RURAL BROADBAND as part of the American Recovery and Reinvestment act of 2009.
Multiple HD streams combined with whole-home DVRs has becoming a reality for commercial IPTV service provider. HomePNA 3.1 technologies adequately provdes bandwidth inside the home. The existing wiring inside the house is no longer just wiring; it is a high performance IP network critical to delivering differentiating features while driving down costs. Products are now required that deliver the high capacity and headroom needed by service providers for advanced applications."
While PhonePNA 3.0 delivers a solid 128Mbps over exisit in-home coax while co-exisiting with other analogy and QAM delivered products, 3.1 takes the "no new wires" technologies over the top.