FCC PROPOSAL WOULD ADD FLEXIBILITY FOR NEW DEVICES UNDER PART 15

“There have been a lot of ideas generated over the last year about how to tweak the Part 15 rules in such a way as to allow even more powerful technologies to coexist,” said Washington attorney Scott Harris, who represented 3Com and other companies that sought partial reconsideration of original order that allowed HomeRF-type systems to operate in band. “This NPRM seems to collect all of those suggestions and propose their implementation. It’s yet another valuable step the Commission is taking to make unlicensed wireless devices operating in Part 15 a hotbed of innovation.”

Specifically, FCC Office of Engineering & Technology’s Neal McNeal said at meeting that further NPRM proposes to promote greater sharing in 2.4 GHz band by: (1) Revising rules for frequency hopping spread spectrum systems in 2.4 GHz band. (2) Providing for introduction of new digital modulation technologies. (3) “Eliminate unnecessary regulations” for spread spectrum requirements. Proposal would amend FCC rules to allow frequency hopping systems to use as few as 15 hopping channels irrespective of hopping channel’s bandwidth, McNeal said. Upward power of these systems would be limited to 125 milliwatts and devices would be required to use techniques to avoid transmitting on occupied channels. “We believe that the changes will provide equipment developers with more freedom to design frequency hopping systems that have a greater ability to avoid interference in the 2.4 GHz band,” McNeal said.

In general, proposal takes into account new digital technologies that allow spectrum to “hop” in given swathe of spectrum more intelligently. Agency’s previous rules were crafted before development of these technologies that avoid interference through so-called smart hopping, one source said. Two types of spread spectrum have been permitted to operate on unlicensed basis under Part 15 include frequency hopping spread spectrum that spreads energy by changing center frequency of modulated signal. Other type is direct sequence spread spectrum systems, in which data stream and high speed digital spreading code produce signal that has relatively wide bandwidth. Such spreading essentially reduces power density of signal at any frequency over transmitted bandwidth to reduce probability of creating interference to other signals in band. New digital technologies that use smart hopping techniques and have characteristics similar to spread spectrum haven’t been authorized under existing rules because they limit operation only to spread spectrum systems. Further NPRM essentially proposes lifting this restriction, Commission said. Proposal also would eliminate processing gain requirement for direct sequence spread spectrum systems.

Further NPRM proposes allowing systems that use digital modulation techniques that have spectrum characteristics similar to spread spectrum systems to operate in band formerly reserved for spread spectrum devices, McNeal said. Systems using digital modulation would be required to generally meet same technical requirement as spread spectrum systems, McNeal said. “We believe that this proposal would allow more diverse products in the band,” he said. On its face, proposal appears to be win for developers such as Texas Instruments and Wi-LAN, both of which have been seeking approval from Commission to operate new digital modulatoin technologies. Commission also granted so-called blanket interim waiver that would allow these new digital technologies that meet existing rules for direct sequence spread spectrum systems to obtain equipment certification from FCC before final rule in this proceeding is adopted. Under this blanket waiver, such systems would be required to have maximum peak power limit of 100 mW.

Generally, further NPRM appears to follow along lines of changes that had been sought by group of companies seeking clarification from FCC of last year’s HomeRF order. That order had altered Part 15 rules to permit spread spectrum devices at 2.4 GHz to user wider frequency hopping channels, permitting devices to operate on at least 15 nonoverlapping channels with bandwidths up to 5 MHz. Group of companies including 3Com had sought modification of requirements to reduce interference risk. Petition had sought clarification that Part 15 rules allow frequency hopping spread spectrum to use adaptive hopping techniques.

Calgary-based Wi-LAN, which had asked full Commission to review previous denials of its equipment certification application for Wideband Orthogonal Frequency Division Multiplexing system, would be covered by interim waiver. This is case even though technically, Commission affirmed prior staff decision turning down application for equipment certification. Terms outlined by FCC in further NPRM, however, appear to fully take into account operating parameters of Wi-LAN systems. “We're very pleased that the Commission took this action,” said attorney Mitchell Lazarus, who has represented Wi-LAN at FCC. “We're very pleased that Wi-LAN can get this product out to the public.” Blanket waiver also would appear to address concerns of Texas Instruments, which has touted ability of its Wi-Fi Local Area Network (LAN) -- also known as IEEE 802.11b -- technology to operate at 2.4 GHz.

Comr. Ness described Part 15 spectrum as “fertile test bed” that has fostered developments in new high-speed wireless technologies. Each time FCC amends unlicensed spectrum requirements “there is a trade-off,” Ness said. “That is basically a diminution of certainty on the part of existing players as to what the rules indeed are but [represents] a new opportunity for others to come into these bands,” she said. “We must continue to encourage those who are manufacturing in these bands to ensure that they have the flexibility to build into their systems the resilience not to interfere with others,” Ness said. Ness also referred to figures provided by OET Policy & Rules Div. Chief Julius Knapp about increases FCC has seen in applications for equipment certification in unlicensed bands. In 1990, Commission authorized fewer than 25 of these devices and in 2000, this figure grew to 350 new spread spectrum devices that were certified, Knapp said. Citing this trend, Ness said it is “imperative that we increase the resources for the [FCC] lab so that the approval process could be expedited.” Lab aims to get approval process to timeframe of 30 days or less, Ness. “It keeps inching back up because of the unbelievable number of devices that are appearing.” Such products typically have product cycle of 6 months or less, she said. “If it takes us almost that long to approve we are doing a disservice to manufacturers.”