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Home Computer Networking RFI The use of personal computers in the home has created a demand for easy to install home computer networks. Vendors are shipping simple to install solutions that use existing wiring - telephone extensions and AC power line wiring - or wireless networking solutions. Systems that use existing wiring("no new wires"), however, have been shown to cause significant inteference to shortwave listeners and ham radio operators. These systems are also highly susceptible to interference from nearby transmitters. These problems occur because they use HF radio frequencies to send computer data over unshieled in-home wiring. An existing telephone wiring based computer network operates between 5.5 Mhz and 9.5 MHz and generates radio frequency interference across that spectrum. It is also extremely sensitive to Amateur transmissions in the 7 MHz band. A newer form of telephone networking is under development and will use a different set of HF frequencies. Major companies including AT&T, Intel, Microsoft, Lucent, Broadcom, 3Com and Compaq Computer are backing this technology. As of July 27, 1999, a version 2 specification has been reached. Version 2 (not yet published for the public) will, according to press releases, achieve 10 Mbps in late 1999 and 30 Mbps in late 2000. According to industry white papers, these higher speeds are made possible by modulating signals across the HF radio spectrum from 2 to 30 Mhz. Power line networks operate in a similar fashion, modulating computer data signals between 2 to 30 MHz. Since the quality of a home's internal AC or telephone wiring is an unknown in any installation, these technologies may spew large amounts of noise into the radio spectrum. Recently, a well known telephone line extender (using AC power lines in a house for the link) generated very strong signals in the 3.5 MHz band; in some situations, signals were traced to units over 6 miles away! This page is to provide links to resources and information regarding these technologies: The original Ham Radio Online report that brought this issue to public attention: Special Reports: The Death of HF Radio Operation? Home Phone Networking Version 2 Spec Reached Via link to Cnet News, 27 July 1999 Home phone networking vendors (See "RFI From Home Computer Networks" for more information) have reached agreement for a version 2 specification. Version 2 will raise home phone line computer network speeds to 10 Mbps and 30 Mbps expected by the end of the year 2000. According to this whitepaper, these networks will operate in the 2 to 30 Mhz HF spectrum. Home Networking via Telephone Lines Becoming a Top Seller Via link to Cnet News, 16 July 1999 As of May 1999, sales of telephone wire based home computer networking kits have reached 22.1% marketshare, with just two vendors (Intel, Diamond) presently in the market and performance limited to 1 Mbps. These networks modulate data signals between 5.5 to 9.5 Mhz, producing tremendous amounts of RF interference to the HF radio spectrum. See "RFI From Home Computer Networks" for more information. The following links are courtesy of  WA7NBF and other sources:  WA7NBF website presentation at NW ARRL Convention, Seaside, Oregon, June, 1999 Includes audio recordings of actual interference coming from a home networking product. Home Phone Line Networking HOMEPNA web site: http://www.homepna.org Epigram WEB site: http://www.epigram.com/ Broadcom web site: http://www.broadcom.com Lucent Microelectronics:http://www.lucent.com TUT Systems: http://www.tutsys.com  IPO info on TUT Systems: http://www.ipocentral.com/ml_ipo/57396ml.html Intel "Anypoint" networking: http://developer.intel.com/anypoint/home.htm LinkSys (HomePNA supplier): http://www.linksys.com/products/homelink/default.htm Home Power Line Networking Intelogis, (power line networking): http://www.intelogis.com/ Intellon, (power line, OFDM) http://www.intellon.com/ Phonex (power line phone ext.): http://www.phonex.com/ Cnet News article, June 1, 1999:  "Powerline: The future of broadband?" Media Fusion Corporation (power transmission line and home AC networking technology): http://mediafusioncorp.net/ (According to the hype, Media Fusion claims to be able to deliver multi-gigabits per second data streams to each household. The Cnet news article says that Congressional representatives are considering using government funding to make this technology a reality and come to market as soon as the year 2000. While not yet confirmed, this technology undoubtedly uses a broad swatch of the radio spectrum and uses power lines as a crude form of antenna transmission line.) Electric Power Research Institute: http://www.epri.org Wireless Computer Networking HomeRF working group: http://www.homerf.org/ Bluetooth Alliance: http://www.bluetooth.com/v2/default.asp Home Networking Technology Microsoft Home Networking: http://www.microsoft.com/homenet/ Broadcom: http://www.broadcom.com/ Diamond Multimedia: http://www.diamondmm.com/homefree/ HomeFree WEB site: http://www.aptest.com.au/diamhomefree.htm