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Other Home Networking Solutions

LAN 101: Networking Basics
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If you are working at home or in a small office, you have an alternative to hole-drilling, pulling specialized network cabling, or setting up a wireless network.

So-called “home” networking is designed to minimize the complexities of cabling and wireless configuration by providing users with a sort of instant network that requires no additional wiring and configures with little technical understanding.

The two major standards in this area are

  • HomePNA (uses existing telephone wiring)
  • HomePlug (uses existing power lines and outlets)


HomePNA

Other than using Ethernet (wired or wireless), the most popular form of home networking involves adapting existing telephone wiring to networking by running network signals at frequencies above those used by the telephone system. Because HomePNA is the most developed and most broadly supported type of home networking, this discussion focuses on the HomePNA standards that the Home Phoneline Networking Alliance (www.homepna.org) has created. This alliance has most of the major computer hardware and telecommunications vendors among its founding and active membership.

The Home Phoneline Networking Alliance has developed three versions of its HomePNA standard. HomePNA 1.0, introduced in 1998, ran at only 1 Mb/s and was quickly superseded by HomePNA 2.0 in late 1999. HomePNA 2.0 supported up to 32 Mb/s, although most products ran at 10 Mb/s, bringing it to parity with 10BASE-T Ethernet. Although some vendors produced HomePNA 1.0 and 2.0 products, these versions of HomePNA never became popular. Both of these products use a bus topology that runs over existing telephone wiring and are designed for PC networking only.

With the development of HomePNA 3.1 in 2007, the emphasis of HomePNA has shifted from strictly PC networking to a true “digital home” solution that incorporates PCs, set-top boxes, TVs, and other multimedia hardware on a single network.

HomePNA 3.1 is the latest version of the HomePNA standard. In addition to telephone wiring, HomePNA 3.1 supports coaxial cable used for services such as TV, set-top boxes, and IP phones. As shown in the figure below, HomePNA 3.1 incorporates both types of wiring into a single network that runs at speeds up to 320 Mb/s, carries voice, data, and IPTV service, and provides guaranteed quality of service (QoS) to avoid data collisions and avoid disruptions to VoIP and streaming media. HomePNA refers to the ability to carry VoIP, IPTV, and data as a “triple-play.” HomePNA 3.1 also supports remote management of the network by the service provider.

Because HomePNA 3.1 has been designed to handle a mixture of traditional data and Internet telephone (VoIP) and TV (IPTV) service, HomePNA 3.1 hardware is being installed and distributed by telephone and media providers, rather than being sold primarily through retail channels. For example, AT&T uses HomePNA 3.1 for its AT&T U-verse IPTV, broadband, and VoIP service.

A typical HomePNA 3.1 network interconnecting PC, telephone, and TV service via telephone and coaxial cables.A typical HomePNA 3.1 network interconnecting PC, telephone, and TV service via telephone and coaxial cables.

Power Line Networking

Home networking via power lines has been under development for several years, but electrical interference, inconsistent voltage, and security issues made the creation of a workable standard difficult until mid-2001. In June 2001, the HomePlug Powerline Alliance, a multi-vendor industry trade group, introduced its HomePlug 1.0 specification for 14Mbps home networking using power lines. The HomePlug Powerline Alliance (www.homeplug.org) conducted field tests in about 500 households early in 2001 to develop the HomePlug 1.0 specification.

HomePlug 1.0 is based on the PowerPacket technology developed by Intellon. PowerPacket uses a signaling method called orthogonal frequency division multiplexing (OFDM), which combines multiple signals at different frequencies to form a single signal for transmission. Because OFDM uses multiple frequencies, it can adjust to the constantly changing characteristics of AC power. To provide security, PowerPacket also supports 56-bit DES encryption and an individual key for each home network. By using PowerPacket technology, HomePlug 1.0 is designed to solve the power quality and security issues of concern to a home or small-office network user. Although HomePlug 1.0 is rated at 14 Mb/s, typical real-world performance is usually around 4 Mb/s for LAN applications and around 2 Mb/s when connected to a broadband Internet device such as a cable modem.

HomePlug 1.0 products include USB and Ethernet adapters, bridges, and routers, enabling most recent PCs with USB or Ethernet ports to use Powerline networking for LAN and Internet sharing. Linksys was the first to introduce HomePlug 1.0 products in late 2001; other leading vendors producing HomePlug hardware include Phonex, Netgear, and Asoka. HomePlug Turbo, an updated version of the HomePlug 1.0 standard, supports data rates up to 85 Mb/s, with typical throughput in the 15 Mb/s–20 Mb/s range.

The HomePlug AV specification with support for faster speeds (up to 200 Mb/s), multimedia hardware, and guaranteed bandwidth for multimedia applications was announced in the fall of 2002; the final HomePlug AV specification was approved in August 2005. When connecting HomePlug products, make sure that all of the devices support the same standard; that is, either HomePlug 1.0 (85 Mb/s) or HomePlug AV (200 Mb/s). Although HomePlug 1.0 and AV devices can coexist on the same powerline wiring, they can only communicate with devices supporting the same standard.

HomePlug AV2 is currently under development as the next generation for HomePlug, which will support 600 Mb/s speed.

The HomePlug Powerline Alliance uses certification marks to indicate which HomePlug certifications are supported by a particular device. The image below shows the original and new HomePlug certification marks.

The HomePlug Powerline Alliance certification marks. The original mark (left) for HomePlug 14 Mb/s network devices only is being replaced by the new multipurpose mark (right).The HomePlug Powerline Alliance certification marks. The original mark (left) for HomePlug 14 Mb/s network devices only is being replaced by the new multipurpose mark (right).

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