Waiver permits Roomba manufacturer to market new self-guided lawn mower for residential use.

robot lawnmower-2The kid down the street who mows your lawn may have to change her business model. Automation is coming. The Roomba automatic floor cleaner, a favorite of cats everywhere, is heading outdoors.

iRobot Corporation, maker of the Roomba (and the best name of any tech company), has plans for an automatic, self-guided lawn mower. The problem is to keep it on the grass, away from the pool and the crabby neighbor’s flower beds. The owner will do this by driving stakes into the ground that mark the borders of the mowing area. These will transmit low-power, wideband radio signals that enable the mower to locate itself relative to the stakes, and thus to stay in the specified area.

iRobot cites several advantages over the conventional mower. One is safety; iRobot cites frightening statistics for accidents caused by walk-behind mowers, including amputations and deaths. Another is the environment: ordinary gas-powered mowers, it says, emit as much pollution per hour as 11 cars, and their owners spill 17 millions of gasoline each year, while the iRobot unit relies on rechargeable batteries . iRobot claims its device will also be quieter than gas-powered mowers and will benefit elderly and disabled consumers – not to mention those of us who just hate mowing the lawn.

There must be a catch, though, or you wouldn’t be reading about this in CommLawBlog.

iRobot wants the radio-emitting stakes to operate in the 6240-6740 MHz frequency range. The good news: this is part of a larger band whose rules permit the kind of low-power, wideband signals iRobot needs. The bad news: those rules prohibit “the use of a fixed outdoor infrastructure.” iRobot’s guidance stakes are unquestionably fixed in the ground (during mowing season) and outdoors.

iRobot accordingly asked for a waiver of this rule. It noted that the FCC originally adopted the rule to prevent devices in this band from working as fixed networks over wide areas. iRobot explained that its product can’t do this because the stakes communicate with each other only during set-up, otherwise only with the mower – and never with anything else.

The sole opposition to the waiver came from the National Radio Astronomy Observatory (NRAO) on behalf of radio astronomers who use the 6650-6675.2 MHz segment to observe chemical events in star-forming regions of the Universe. NRAO calculated that its radio-telescopes would receive interference from a lawn mower over a line-of-sight distance of 89 km (55.3 miles). It asked that the FCC require iRobot either to avoid the radio astronomy frequencies or else to install geolocation technology that would prevent operation close to radio astronomy facilities.

The FCC granted the waiver. In its view, NRAO had overestimated the risk of interference. Moreover, radio astronomy does not have an allocation at 6650-6675.2 MHz, only a footnote in the allocation table providing that “all practicable steps shall be taken to protect the radio astronomy service from harmful interference.” The FCC ruled that iRobot’s design, including low-to-the-ground transmitters pointing horizontally and a focus on residential marketing, incorporates the “practicable steps” referenced in the footnote. But it imposed conditions on the waiver:

  • iRobot can market the device only for residential use, and must warn purchasers (by labeling and in the instruction manual) that usage is limited to residences.
  • The radio-transmitting stakes may be no higher than 24 inches above the ground.
  • Neither the mower nor the stakes may communicate with other devices.

We look forward to seeing these on the shelf at Home Depot, and a few days after that, to sitting back with a cold drink and watching the lawn get mowed. The kid down the street is welcome to come and watch with us.

[Blogmeister Disclosure: Laura Stefani of FHH represented iRobot Corporation in this proceeding. The results in any particular case do not guarantee or predict a similar result in any future case.]