FCC amends Part 15 rules for more flexibility, power, avoidance: the FCC issued an order today that allows more flexibility for Part 15 unlicensed devices in three bands (915 Mhz, 2.4 GHz, and 5.7 GHz). New, but unspecified modulations that are similar to direct sequence (DSSS) -- 802.11b's technique -- can be used in those bands as if they were DSSS. This may allow more and different technology to fill in niche gaps, as well as provide a future path for 802.11b/g and 802.11a development.
The order also allows for lower-power use of fewer hopping channels in 2.4 GHz for frequency hopping (FHSS) systems, like HomeRF and Bluetooth. Bluetooth has 79 channels of 1 MHz each that it hops among, changing 1,600 times per second. These narrow bands, which limit its current bandwidth to 1 Mbps, allow it the potential of using more power. HomeRF, on the other hand, uses wider bands (5 MHz) to carry its restricted power (125 mW) signals, which still allows them to operate at 10 Mbps.
The order will allow more leeway for avoiding interference by reducing the hopping requirement from 75 hopping channels down to as few as 15 using up to 5 MHz of bandwidth, but only at 125 mW. This allows devices employing this technique to more effectively avoid occupied bandwidth. 802.11b sits on 22 MHz of bandwidth in each channel in use, but even in a dense Wi-Fi installation, 15 channels for an FH device would almost certainly be available. (HomeRF already deploys certain time-bound avoidance techniques, but this would add another tool to its arsenal.)
The FCC also removed a constraint on DSSS systems: The Commission also eliminated the processing gain requirement for DSSS systems, concluding that manufacturers have market-driven incentives to design products that they can withstand interference from other radio frequency devices.
A couple of weeks ago, I had the chance to have a talk with Ken Haase, the director of product marketing at Proxim. Proxim has been one of the chief developers and backers of the HomeRF specification, a 10 Mbps wireless protocol that works over the same 2.4 GHz band as Bluetooth, and 802.11b/g.
Proxim also has an extensive line-up of IEEE protocol wireless products: PC cards, access points, USB adapters for both 802.11b and 802.11a. They’ve been first to market lately with a number of technologies, and offer consumer and enterprise products.
It would seem like a contradiction to try to sell both HomeRF and Wi-Fi and 802.11 gear, but Haase explained how, although the technology isn’t per se complementary, that both protocols have a place in the market. There isn’t a “one size fits all” technology for consumers, Ken said.
It may surprise Wi-Fi advocates and users, but 45 percent of home wireless networks by unit volume purchased in 2000 were HomeRF-based, while that decreased to 30 percent in 2001, according to estimates from a Cahners InStat report.
This may sound like a retreat, until you examine the numbers: home networking shipments increased well over fivefold in the same period. Wi-Fi may be growing fast in the home, but HomeRF cannot be discounted. European sales of HomeRF equipment account for some of its strength, as the standard is compatible with the DECT protocol for cordless phones, unlike Wi-Fi.
Haase showed me the first real convergence product for HomeRF, which will start making a difference in how the product is product into homes. The Siemens Voice Data Gateway (PDF of press release) announced earlier this year will ship in the United States soon. It can accept a broadband feed via Ethernet and up to four phone lines. It can support up to 16 networks computing devices (through USB or PC Cards) and eight telephone handsets.
As I’ve said in previous analyses, until the HomeRF manufacturers could provide cable companies with an offering that they want to sell into the home as a value-added offering to subscribers, it would be a tough row to hoe. The Siemens device does that. Haase said that cable providers can see a tenfold increase in revenue per household between cable modem service and equipment sales and leasing.
Does this benefit the consumer? Sure. The HomeRF equipment is designed to be plug-and-play, unlike Wi-Fi, which requires tweaking for security and configuration. Add to that the telephone handsets, each with a (reportedly) crystal-clear quality, and, well, I have to think about whether my home can support both Wi-Fi and HomeRF at the same time.
Fortunately for my decisionmaking process, there are no Mac drivers for HomeRF equipment yet, but Haase promised that there would be. Proxim’s history includes its acquisition of Farallon, a long-time Mac firm that continues to be one of a couple of non-Apple providers of wireless and wired technology with Mac drivers and Mac support.
Haase noted that there are about 46 million households with a single computer, in which networking isn’t important at all—it’s one of Wi-Fi strengths. Rather, the ability to dial a phone number through a handset by clicking the number in Outlook, or scanning the subject line of email from a phone handset while sitting in the backyard may interest those houses more. That sort of integration is also one of the benefits of Bluetooth, but HomeRF can operate at Wi-Fi distances, instead of the dozen to few dozen feet that Bluetooth carries.
Haase explained some of their customer testing, as well, in which they discovered that an initial version of their software required 11 clicks to fully install. They’ve now reduced this to a short wizard that asks a few questions, easing setup.
Proxim’s recent merger with Western Multiplex makes them a top-to-bottom wireless company, too: Western Multiplex sells final mile high-speed wireless, often in licensed bands. They have one product, for instance, that offers “five nines” or 99.999 percent reliability at 2 to 5 miles and speeds of 1 Gbps (full duplex: 480 Mbps each way). It’ll go farther, but they can’t guarantee it to the same degree.
Proxim is shipping plenty of 802.11a gear, but they haven’t made any announcement about a/b convergence: dual radio APs or cards. Haase was nice about avoiding the question, since no decisions are yet public, but he pointed out that system design for the two protocols are quite different, and that a combined a/b access point wouldn’t offer all the advantages of 802.11a. Pure 802.11a hubs be deployed more closely together and densely, as more nonoverlapping channels are available, and the signal can’t travel as far as the highest speeds.
I have seen the mermaids JPEGing each to each. I do not think they will GIF to me: Rob Flickenger used EtherPEG at the O'Reilly Emerging Technology Conference to stare directly into the minds of attendees. When Tim O'Reilly speaks, however, people stop thei tomfool browsing.