DECTweb brings you occasional feature articles on timely topics and / or from well known names in the cordless telecommunications industry. If you would like to offer an article for consideration please e-mail us with your biographical details and an outline for the proposed feature.
This special feature focuses on the HomeRF Group and the Shared Wireless access Protocol, which is partly based upon DECT technology. This feature has been kindly contributed by Wayne Caswell of IBM Microelectronics. Wayne is the current Marketing Chair of the HomeRF Group, and the article was prepared specifically for a DECT audience.
HomeRF - GETTING WIRED ABOUT WIRELESS
The Home Radio Frequency Working Group (HomeRF WG) has a vision -- wireless home networking, in every major geographic market, at consumer price points. Established in March 1998, the group now includes over 90 leading companies from the personal computer, communications and consumer electronics industries. Companies such as IBM, Microsoft, Proxim, Intel, Compaq, Matsushita, Sharp and Radio Shack, with an in depth understanding of their industries, are working together to fulfil this shared vision.
In January of 1999, the HomeRF WG introduced a single specification -- the Shared Wireless Access Protocol (SWAP) -- for a broad range of interoperable consumer devices. SWAP is an open, royalty-free industry specification that is friendly to and partially derived from DECT. It allows PCs, peripherals, cordless telephones and other consumer electronic devices to share and communicate voice and data in and around the home without the complication and expense associated with running new wires. SWAP compliant products operate in the license-free 2.4 GHz frequency band and utilise digital, frequency hopping, spread spectrum, RF technology for secure and robust wireless communications.
In early June, the HomeRF WG announced with Proxim and Motorola the development of the first SWAP compliant products -- Proxim would SWAP-enable its entire Symphony line or wireless LAN products and work with Motorola to develop cable modems that let PCs share an Internet connection without wires. The first SWAP products are expected at the end of the year, with volume shipments starting the millennium. The HomeRF WG would like to encourage greater participation from companies in the DECT camp, since we naturally see significant synergy between the specs.
Even for homes with advanced wiring already installed, HomeRF lets home office users "UnPlug and Work" anywhere. That means on the dining table while doing tax returns, on the couch while watching the San Antonio Spurs beat the New York Knicks, on the deck when it's just too nice to work inside, or in the garage when servicing the car and using the Internet to access the shop manual online. HomeRF supports up to four bandwidth-protected voice lines (a subset of DECT), simultaneous and interoperable with data networking. This makes it attractive to set-top box and gateway developers and to service providers like AT&T that want to offer more phone lines in homes wired for just two. HomeRF lets consumers install networked devices where they forgot to run wires. And for the vast majority of us without advanced wiring, it offers an easy way to get into home networking without running new wires. That's why we're "wired about wireless."
HomeRF Technical Details
Frequency hopping network: 50 hops/second
Frequency Range: 2.4 GHz (globally available ISM band)
Transmission power: 100 mW
Range: typical home & yard (up to 150 meter radius)
Data Rate: 1.6 Mbps using 4FSK modulation, 0.8 Mbps using 2FSK
Data networking: up to 127 peer devices; technology derived from 802.11 & OpenAir
Voice networking: 4 voice lines; technology derived from DECT (digitally enhanced cordless telephony) standard
Compression: LZRW3-A algorithm
Security: Hopping, 24-bit network ID, optional 56-bit encryption (one Trillion codes)