AT&T Services, Inc. v. FCC ( 2021 )


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  •  United States Court of Appeals
    FOR THE DISTRICT OF COLUMBIA CIRCUIT
    Argued September 17, 2021           Decided December 28, 2021
    No. 20-1190
    AT&T SERVICES, INC.,
    PETITIONER
    v.
    FEDERAL COMMUNICATIONS COMMISSION AND UNITED
    STATES OF AMERICA,
    RESPONDENTS
    APPLE INC., ET AL.,
    INTERVENORS
    Consolidated with 20-1216, 20-1272, 20-1274, 20-1281,
    20-1284
    On Petitions for Review of an Order
    of the Federal Communications Commission
    Jonathan E. Nuechterlein argued the causes for petitioners
    Joint Issues. Mark Reddish argued the causes for petitioner
    APCO. With them on the joint briefs were Jeffrey S. Cohen, C.
    Frederick Beckner III, Rick Kaplan, Jerianne Timmerman,
    Craig A. Gilley, Mitchell Y. Mirviss, Elizabeth C. Rinehart, and
    Russell P. Hanser. Michele Farquhar, Brett Kilbourne, Jay
    2
    Morrison, Brian W. Murray, Delia D. Patterson, Christopher
    T. Shenk, and Ian D. Volner entered appearances.
    Trey Hanbury and Jessica L. Ellsworth were on the brief
    for amicus curiae Southern Company Services, Inc. in support
    of petitioners.
    James M. Carr, Counsel, Federal Communications
    Commission, argued the cause for respondents. With him on
    the brief were Daniel E. Haar and Robert J. Wiggers,
    Attorneys, U.S. Department of Justice, Jacob M. Lewis,
    Associate General Counsel, Federal Communications
    Commission, and Thaila K. Sundaresan, Counsel. Richard K.
    Welch, Deputy Associate General Counsel, and Adam Crews,
    Counsel, entered appearances.
    Christopher J. Wright argued the cause for intervenors. With
    him on the joint brief were David Paul Murray, Russell H. Fox,
    Robert G. Kidwell, Paul J. Caritj, and Jason Neal in support of
    respondents. Rick C. Chessen and Neal M. Goldberg entered
    appearances.
    Matthew A. Brill and Matthew T. Murchison were on the
    brief for amicus curiae Cable Television Laboratories, Inc. in
    support of respondents.
    Andrew Jay Schwartzman and Harold Feld were on the
    brief for amici curiae Public Knowledge, et al. in support of
    respondents.
    3
    Before: TATEL, MILLETT, and WALKER, Circuit Judges.
    Opinion for the Court filed by Circuit Judge TATEL.
    TATEL, Circuit Judge: By order dated April 24, 2020, the
    Federal Communications Commission opened the 6 gigahertz
    (GHz) band of radiofrequency spectrum to unlicensed
    devices—routers and the devices they connect to, such as
    smartphones, laptops, and tablets. In doing so, the Commission
    required that such unlicensed devices be designed and operated
    to prevent harmful interference with licensees now using the
    6 GHz band, i.e., commercial communications providers,
    electric utilities, public safety services, and network
    broadcasters. Those licensees, emphasizing that existing uses
    of the band involve vital public safety and critical
    infrastructure, argue that harmful interference could
    nonetheless occur and that the Order therefore runs afoul of
    both the Communications Act of 1934 and the Administrative
    Procedure Act. But as explained in this opinion, petitioners
    have failed to provide a basis for questioning the Commission’s
    conclusion that the Order will protect against a significant risk
    of harmful interference, just the kind of highly technical
    determination to which we owe considerable deference. We
    therefore deny the petitions for review in all respects save one.
    The exception relates to the petition brought by licensed radio
    and television broadcasters using the 6 GHz band. Because the
    Commission failed adequately to respond to their request that
    it reserve a sliver of that band exclusively for mobile licensees,
    we remand to the Commission for further explanation on that
    point.
    I.
    Many users of the radiofrequency spectrum operate by
    transmitting information through microwaves—short waves of
    890 megahertz (MHz) or higher. See 
    47 C.F.R. § 101.3
    4
    (defining microwave frequencies). To prevent such users from
    interfering with one another, the Federal Communications
    Commission, pursuant to its authority under the
    Communications Act of 1934, 
    47 U.S.C. § 151
     et seq.
    (“Communications Act”), awards licenses to operate in specific
    frequency ranges, or “bands.” See 
    id.
     §§ 151, 301 (creating the
    Commission to carry out the Act’s provisions and providing for
    licensing).
    Historically, the 6 GHz band, comprising frequencies
    between 5.925 and 7.125 GHz, has been reserved for licensed
    users that “support a variety of critical services provided by
    utilities, commercial and private entities, and public safety
    agencies.” Unlicensed Use of the 6 GHz Band; Expanding
    Flexible Use in Mid-Band Spectrum Between 3.7 and 24 GHz,
    35 FCC Rcd. 3852, 3855 ¶ 7 (2020) (“Order”). Some of these
    licensees transmit signals through a “fixed-microwave
    system,” in which “a transmitter on one tower beams 6 GHz
    signals to a receiver on another tower within its line of sight.”
    Pet’rs’ Br. 3. Fixed microwave systems support “emergency
    911 dispatch and other public safety operations,” id.;
    “commercial wireless providers,” Order ¶ 7; and “links for
    coordination of railroad train movements, control of natural gas
    and oil pipelines, management of electric grids, and long-
    distance telephone service,” id. In addition to fixed microwave
    users, other 6 GHz band licensees operate on a mobile basis.
    They employ transmitters and receivers affixed to portable
    bases, like news vans and broadcasting cameras, and send
    programing from remote locations back to studios. Still others
    employ mobile transmitters to support wireless microphones
    and backstage communications.
    Several decades ago, the Commission, charged by
    Congress to “generally encourage the larger and more effective
    use of” the spectrum, 
    47 U.S.C. § 303
    (g), opened the 2.4 GHz
    5
    and certain other bands to unlicensed radiofrequency
    transmitters. Today, these devices include routers and the
    smartphones, laptops, and tablets they support. Such devices,
    however, must refrain from causing “harmful interference”
    with licensed users. 
    47 C.F.R. § 15.5
    (b)–(c); see also
    Additional Spectrum for Unlicensed Devices Below 900 MHz
    and in the 3 GHz Band, No. 02-380, FCC-02-328 ¶¶ 3–4 (Dec.
    11, 2002) (describing the history of unlicensed operation).
    Commission regulations define “harmful interference” as
    interference that “endangers the functioning of a radio
    navigation service or of other safety services or seriously
    degrades,     obstructs     or     repeatedly    interrupts     a
    radiocommunications service.” 
    47 C.F.R. § 15.3
    (m). If harmful
    interference occurs, the Commission may order the interfering
    user to cease operations. 
    Id.
     § 15.5(c) (“The operator of a radio
    frequency device shall be required to cease operating the
    device upon notification by a Commission representative that
    the device is causing harmful interference.”); see also id.
    § 15.15(c) (“[O]perators [of unlicensed devices] are required to
    cease operation should harmful interference occur to
    authorized users.”).
    The Commission’s opening of the radiofrequency
    spectrum for unlicensed uses has taken on new import in recent
    years because of a boom in unlicensed devices that use Wi-Fi
    and Bluetooth technology. See Order ¶ 1. Such devices include
    internet “access points” (e.g., routers) and the myriad “client
    devices” that connect to them, like smartphones, tablets, and
    laptops. Id. ¶¶ 3, 12. Because these devices transmit large
    amounts of data, they require access to wide bands of the
    spectrum. “The demand for wireless broadband,” according to
    the Commission, “continues to grow at a phenomenal pace;”
    by 2024, a smartphone’s average data use is projected to grow
    almost sixfold relative to 2018 data levels. Id. ¶ 2.
    6
    In 2017, responding to this growing demand, the
    Commission announced that it was considering opening a
    portion of spectrum between 3.7 and 24 GHz to unlicensed use
    and sought public comment. Expanding Flexible Use in Mid-
    Band Spectrum Between 3.7 and 24 GHz, 32 FCC Rcd. 6373
    (2017). The following year, the Commission proposed a rule
    that would open the 6 GHz band to unlicensed devices, again
    seeking public comment. Unlicensed Use of the 6 GHz Band;
    Expanding Flexible Use in Mid-Band Spectrum Between 3.7
    and 24 GHz, 33 FCC Rcd. 10496 (2018). The Commission
    chose the 6 GHz band in part because of its proximity and
    similarity to the 5 GHz band, portions of which already allowed
    unlicensed use. Opening the adjacent 6 GHz band would allow
    unlicensed devices to “operate with wider channel bandwidths
    and higher data rates with increased flexibility.” Id. ¶ 14; see
    also id. ¶ 19. After considering comments, the Commission, at
    an open meeting on April 23, 2020, adopted the Order now
    before us. See generally Order, 35 FCC Rcd. 3852.
    The Order allows unlicensed devices to operate in the
    6 GHz band. Because the extent to which a signal may cause
    interference depends in part on the signal’s power, the Order
    distinguishes between internet access points that use standard
    power (like the devices that provide internet to stadiums,
    concert halls, and other large areas) and access points that use
    low power (like typical residential or office routers).
    The Order requires all standard-power access points to use
    an automated frequency coordination (AFC) system, a
    technology designed to ensure that unlicensed devices do not
    cause harmful interference with licensed devices. Id. ¶ 17. But
    because the AFC system requires knowing the “exact operating
    locations and times” of licensed uses, it offers little protection
    to licensed mobile operators, whose location “can change
    frequently.” Id. ¶ 93. For that reason, the Order prohibits
    7
    unlicensed standard-power access points from using those
    6 GHz sub-bands in which mobile licensees operate.
    By contrast, the Order allows unlicensed low-power
    access points to operate across the 6 GHz band. But to protect
    licensed users from harmful interference, the Order requires
    that routers (1) operate below specified maximum power
    levels—as relevant here, 5 decibel milliwatts per megahertz (5
    dBm/MHz); (2) use a “contention-based protocol,” through
    which a device “listens” to a channel to ensure it is free before
    transmitting a signal over it; and (3) remain indoors, thus
    decreasing the likelihood of interference with licensed outdoor
    users. Smartphones, laptops, and other client devices using
    these low-power access points must observe an even lower
    maximum power limit and employ contention-based protocol
    technology. To discourage the outdoor use of low-power
    routers, the Order (1) prohibits making them weather-resistant,
    (2) requires that they have integrated antennas, and (3) forbids
    equipping them with batteries. These multifaceted protections,
    the Commission concluded, “eliminate[] any significant risk of
    causing harmful interference” with licensed users. Id. ¶ 146.
    Petitioners either hold licenses to operate in the 6 GHz
    band or represent entities that do. Specifically, petitioners are
    commercial communications providers AT&T Services and
    Lumen Technologies, electric utilities, the Association of
    Public-Safety Communications Officials International
    (APCO), and the National Association of Broadcasters.
    Petitioners contend that the Order fails to protect licensees
    from harmful interference and therefore runs afoul of both the
    Communications Act and the Administrative Procedure Act
    (APA), 
    5 U.S.C. § 706
    (2)(A). They urge us to vacate the Order
    and remand to the Commission to implement further
    safeguards. Several industry groups and companies, including
    Apple, Broadcom, and Cisco Systems, which manufacture
    8
    devices or provide services that rely on unlicensed spectrum,
    have intervened to defend the Order.
    II.
    Fundamental       and     longstanding     principles    of
    administrative law guide our review of petitioners’ challenges
    to the Commission’s order. To demonstrate that a regulation is
    arbitrary and capricious, a challenger must show that the
    agency “relied on factors which Congress has not intended it to
    consider, entirely failed to consider an important aspect of the
    problem, offered an explanation for its decision that runs
    counter to the evidence before the agency, or is so implausible
    that it could not be ascribed to a difference in view or the
    product of agency expertise.” Motor Vehicle Manufacturers
    Ass’n v. State Farm Mutual Automobile Insurance Co., 
    463 U.S. 29
    , 43 (1983). Where, as here, the Commission “‘foster[s]
    innovative methods of exploiting the spectrum,’ it ‘functions
    as a policymaker’ and is ‘accorded the greatest deference by a
    reviewing court.’” Mobile Relay Associates v. FCC, 
    457 F.3d 1
    , 8 (D.C. Cir. 2006) (quoting Teledesic LLC v FCC, 
    275 F.3d 75
    , 84 (D.C. Cir. 2001)). Of course, “we do not hear cases
    merely to rubber stamp agency actions.” Natural Resources
    Defense Council, Inc. v. Daley, 
    209 F.3d 747
    , 755 (D.C. Cir.
    2000). But to survive judicial review, the Commission’s
    technical judgments need rest upon only “‘a modicum of
    reasoned analysis,’ ‘absent highly persuasive evidence to the
    contrary.’” Mobile Relay Associates, 457 F.3d at 8 (quoting
    Hispanic Information & Telecommunications Network, Inc. v.
    FCC, 
    865 F.2d 1289
    , 1297–98 (D.C. Cir. 1989)). Moreover,
    the Commission’s “‘predictive judgments about areas’” within
    its “‘discretion and expertise are entitled to particularly
    deferential review, as long as they are reasonable.’” EarthLink,
    Inc. v. FCC, 
    462 F.3d 1
    , 12 (D.C. Cir. 2006) (emphasis
    omitted) (quoting In re Core Communications, Inc., 
    455 F.3d 267
    , 282 (D.C. Cir. 2006)).
    9
    A.
    All petitioners argue that the Commission has understated
    the risk of harmful interference. Central to this argument,
    petitioners claim that the Commission intended the Order to
    eliminate all risk of harmful interference. “[I]n the
    [Commission’s] view,” petitioners assert, the Order
    “eliminate[s] any ‘significant risk’ that any of the hundreds of
    millions of unlicensed 6 GHz devices will cause harmful
    interference to any of the nation’s nearly 100,000 licensed
    microwave links, at any point in the foreseeable future.” Pet’rs’
    Br. 21. Dissecting the studies upon which the Commission
    relied and critiquing the Order’s safeguards for licensed users,
    petitioners argue that some harmful interference will occur at
    some point, thus rendering the Order arbitrary and capricious.
    Petitioners mischaracterize the Commission’s goal. It
    never claimed that the Order would reduce the risk of harmful
    interference to zero. To the contrary, the Commission
    repeatedly explained that the Order makes the “potential for
    harmful interference to incumbent services operating in the
    6 GHz band . . . insignificant.” Order ¶ 104 (emphasis added);
    see also id. ¶¶ 110, 122 n.317, 145–46, 245 (repeatedly
    characterizing such risk as low or insignificant, not zero). The
    Commission acknowledged that it had to “balance unlicensed
    device access and incumbent protection,” id. ¶ 63, and
    explained that “in the unlikely event that harmful interference
    does occur,” “the Commission’s Enforcement Bureau has the
    ability to investigate reports of such interference and take
    appropriate enforcement action as necessary,” id. ¶ 149. This
    aligns perfectly with existing Commission regulations, which
    (1) acknowledge that full compliance “will not prevent harmful
    interference under all circumstances” and (2) authorize the
    Commission to order interfering users to cease operations. 
    47 C.F.R. § 15.15
    (c); see also supra at 5.
    10
    B.
    Petitioners argue that the Order falls short in other ways.
    We start with petitioners’ contention that the Commission
    should have estimated the frequency and cost of harmful
    interference. In support, they cite Competitive Enterprise
    Institute v. National Highway Traffic Safety Administration, in
    which our court remanded a fuel efficiency rule to the agency
    for failing to consider the standard’s impact upon car size and
    safety. 
    956 F.2d 321
     (D.C. Cir. 1992). But unlike the agency in
    Competitive Enterprise, the Commission “conduct[ed] a
    serious analysis of the data,” revealing the likelihood of harm
    to be vanishingly low. 
    Id. at 327
    . Moreover, even if harmful
    interference does occur, its victims may petition the
    Commission for relief. See Order ¶ 149 & n.397 (discussing
    the Commission’s ability to respond to complaints); see also
    supra at 5.
    Accusing the Commission of a “textbook APA violation,”
    petitioners argue that the agency failed to explain why it did
    not require low-power devices to use an AFC system, as must
    standard-power devices. Pet’rs’ Reply Br. 6–7. Oral Arg. Tr.
    4–5. We disagree. In the Order, the Commission explained that
    the requirements for low-power devices (power limits,
    contention-based protocol, and indoor operation), together
    with Commission enforcement authority, “reduce[] the
    possibility of harmful interference to the minimum that the
    public interest requires.” Order ¶ 146; see also id. ¶¶ 147–50
    (acknowledging comments seeking an AFC system and
    explaining why the Order’s other requirements reduce the risk
    of harmful interference to an acceptably low level). Put
    differently, the Commission concluded that even without an
    AFC system, “the restrictions and requirements . . .
    establish[ed] for indoor use of low-power access points
    11
    eliminates any significant risk of harmful interference.” Id.
    ¶ 146; see also id. ¶¶ 147–50.
    Petitioners also raise several technical objections to the
    principal study on which the Commission relied. A simulation
    submitted by Cable Television Laboratories (“CableLabs”), a
    nonprofit supporting broadband providers, the study models
    the likelihood that hypothetical unlicensed 6 GHz devices
    scattered across New York City will interfere with transmission
    from a local microwave tower. To simulate a city filled with
    unlicensed routers, the study uses what is known as Monte
    Carlo analysis. Id. ¶ 117. Developed by scientists working on
    the Manhattan Project, Monte Carlo analysis differs from more
    traditional mathematical models in how it accounts for
    variables. Nick T. Thomopoulos, Essentials of Monte Carlo
    Simulation: Statistical Methods for Building Simulation
    Models 1 (2013). Here the variables are those factors that affect
    a router’s transmission, such as its power, location, and
    frequency range. While traditional models select a single value
    (e.g., an average) for each variable, Monte Carlo analysis uses
    a range of possible values for each variable, runs hundreds of
    simulations, and produces a range of possible outcomes. In
    situations where “interactions between the possible outcomes
    become [exceptionally] complex,” Monte Carlo analysis can
    provide a “more complete view of potential outcomes and their
    associated likelihoods.” Federal Judicial Center & National
    Research Council, Reference Manual on Scientific Evidence
    469 (3d ed. 2011) (first quote); CableLabs Amicus Br. 7–8
    (second quote).
    The CableLabs study uses sales projections and statistical
    distributions drawn from real-world data and industry
    standards to analyze the effect of approximately 800,000
    hypothetical routers on a microwave tower in New York City.
    CableLabs ran 1,500 simulations, generating data on more than
    12
    1.2 billion hypothetical routers. Not one of the hypothetical
    routers caused harmful interference.
    Calling the study a “black box,” petitioners argue that the
    Commission should have made available “spreadsheets,
    formulas, detailed datasets, and transparent explanations of
    how those datasets were obtained.” Pet’rs’ Br. 14. In support,
    they cite American Radio Relay League, Inc. v. FCC, in which
    we faulted the Commission for cherry-picking the data it
    disclosed. 
    524 F.3d 227
    , 237 (D.C. Cir. 2008). Here, by
    contrast, the Commission disclosed all data in its possession.
    The Commission, moreover, emphasizes that CableLabs’s
    submission was “typical [of] FCC proceedings”—that is, it
    “presented the results of its study by describing the sample size,
    simulation parameters, methodology, and results.”
    Commission Br. 46. According to the Commission, such
    information, not raw data, “allows parties to meaningfully
    comment.” 
    Id.
     at 46–47. Indeed, our court has explained that
    “requiring agencies to obtain and publicize the data underlying
    all studies on which they rely would be impractical and
    unnecessary.” American Trucking Ass’ns, Inc. v. EPA, 
    283 F.3d 355
    , 372 (D.C. Cir. 2002) (internal quotation marks
    omitted).
    Petitioners also criticize the CableLabs study for ignoring
    those rare cases when a router’s signal might experience zero
    “building loss,” a variable that measures the extent to which a
    building’s characteristics, such as insulation and wall
    thickness, weaken router signals. Pet’rs’ Br. 45–48. Although
    the Commission acknowledged that “it would be more
    appropriate for CableLabs to have used the full statistical
    distribution” of building loss values, it nonetheless concluded
    that the range used in the CableLabs study was “not different
    enough from the [full] statistical distribution to materially alter
    the likelihood of harmful interference occurring.” Order ¶ 122.
    13
    Petitioners have offered no reason for us to depart from our
    court’s longstanding practice of according “considerable
    deference” to the Commission’s expertise on such a “highly
    technical question.” American Radio Relay, 
    524 F.3d at 233
    (internal quotation marks omitted).
    Petitioners next criticize the CableLabs study for assuming
    an “average activity factor of 0.4%,” meaning that routers
    “transmit only one minute out of every 250.” Pet’rs’ Br. 43
    (internal quotation marks omitted). “Where,” they ask, “does
    that strikingly low figure come from?” 
    Id.
     Answering that
    question in the Order, the Commission explained that the
    CableLabs study uses “a distribution of airtime utilization
    based on data taken from 500,000 Wi-Fi access points to model
    how often each access point in the simulation transmits”—the
    average activity factor was 0.4%. Order ¶ 117; see also
    CableLabs Ex Parte Letter on AT&T’s Comment Letter (Feb.
    14, 2020), at 1–2 (explaining the source of this figure). True,
    this does seem low, but as intervenors explained at oral
    argument, routers, especially those operating in the 6 GHz
    band, transmit huge amounts of data in “really tiny burst[s].”
    Oral Arg Tr. 52. For example, counsel explained, in “a matter
    of seconds or less,” a router can receive the data necessary to
    enable “watching [a video] for two hours.” 
    Id.
     Determining a
    router’s activity factor “is precisely the type of technical issue
    on which we defer to the Commission’s expertise,” Keller
    Communications, Inc. v. FCC, 
    130 F.3d 1073
    , 1077 (D.C. Cir.
    1997), especially “absent highly persuasive evidence” from
    petitioners that routers have a higher activity factor than the one
    used by CableLabs, Mobile Relay Associates, 457 F.3d at 8
    (internal quotation marks omitted).
    Last, petitioners fault the CableLabs study for assuming
    that “1500 snapshots in time provide[] a sample sufficient for
    drawing a statistically sound conclusion that harmful
    14
    interference will never occur.” Pet’rs’ Br. 48. But as explained
    above, the Commission never said that no harmful interference
    would occur; it concluded only that, given the Order’s
    safeguards, “the potential for harmful interference to
    incumbent services operating in the 6 GHz band is
    insignificant.” Order ¶ 104 (emphasis added).
    Petitioners’ next set of challenges centers on the
    Commission’s rerun of a study prepared and submitted by
    petitioner AT&T. That study identifies several buildings with
    direct lines of sight to various microwave towers and assumes
    that the buildings contain 6 GHz routers that might interfere
    with the towers’ signals. Unlike the Monte Carlo analysis used
    in the CableLabs study, the AT&T study, as originally
    designed and submitted to the Commission, selects single,
    worst-case values for all but one variable—that is, values likely
    to cause harmful interference. The AT&T study concludes that
    hypothetical routers could interfere with a microwave tower in
    every case.
    The Commission discounted that conclusion because the
    AT&T study uses worst-case scenarios and so does not “rebut
    the persuasive showing by CableLabs based on a reliable
    probabilistic assessment derived from measurements
    associated with hundreds of thousands of actual Wi-Fi [access
    points].” Id. ¶ 130. Notwithstanding the Commission’s
    preference for Monte Carlo analyses, it reran the AT&T study
    “to show that even under AT&T’s preferred mode of analysis
    . . . the likelihood of harmful interference [is] insignificant.”
    Id. ¶ 127 n.331. To accomplish this, the Commission revised
    the AT&T study in several respects, two of which are relevant
    here. First, it modified how the AT&T study deals with
    building loss, the one variable for which that study uses a range
    of values. Because the Commission believed that treating
    building loss differently from all other variables undermined
    15
    the study’s accuracy, it replaced the range with a single,
    average value. Second, for two of the six scenarios, the
    Commission substituted what it believed to be more reasonable
    values for “clutter loss,” signal attenuation caused by terrain,
    trees, and other structures. Id. ¶ 124. Thus modified, the AT&T
    study demonstrates that only one of the six scenarios could
    result in “a nontrivial possibility of harmful interference,” and
    the Commission discounted even that because it did “not
    believe this one case poses a significant potential for actual
    harmful interference.” Id. ¶ 131.
    Petitioners criticize the Commission for using an average
    value instead of a statistical distribution for building loss and
    for failing to respond to comments on this subject. But the
    Commission did respond, explaining that treating only building
    loss “as a probabilistic quantity while not considering all the
    other [relevant] statistical quantities” exaggerated the
    likelihood of interference. Order ¶ 127. Petitioners quibble
    with this conclusion, but they have given us no real basis for
    second-guessing the Commission’s analysis, which, as in much
    of this case, “requires a high level of technical expertise”
    meriting deference to the Commission’s “informed discretion.”
    Marsh v. Oregon Natural Resources Council, 
    490 U.S. 360
    ,
    377 (1989) (internal quotation marks omitted).
    Next, petitioners fault the adjustments the Commission
    made for clutter loss. According to AT&T, it selected the six
    case studies precisely because the towers all had a direct line
    of sight to at least one building assumed to have one or more
    routers, which meant that “clutter loss approached zero.”
    Pet’rs’ Br. 34. The Commission, however, explained that it
    found the assumption of zero clutter loss unrealistic for the two
    scenarios in which the tower and the router were more than one
    kilometer apart. “Based on [its] experience,” the Commission
    explained, AT&T’s model “drastically underpredicts [clutter]
    16
    loss for longer distances because, as a practical matter, there is
    almost always interaction with the environment that reduces
    the signal level.” Order ¶ 67. Besides, as noted above, the
    Commission explained that because the AT&T study uses
    worst-case scenarios, it does not “rebut the persuasive showing
    by CableLabs” that the likelihood of harmful interference is
    insignificant. Id. ¶ 130.
    C.
    In addition to challenging the CableLabs study and the
    Commission’s rerun of the AT&T study, petitioners challenge
    the Order’s requirements for low-power access points—that
    they not exceed a power limit of 5 dBm/MHz, that they be
    equipped with contention-based protocol technology, and that
    they operate only indoors.
    We begin with power limits, which the Order sets at
    5 dBm/MHz. According to petitioners, the Commission
    “plucked [that figure] out of thin air” and failed to “cite
    evidence . . . [for] pegging the power level to 5, rather than
    (say) 3 or 1.” Pet’rs’ Br. 51. Quite to the contrary, the
    Commission chose 5 dBm/MHz “[b]ased on [its] experience
    with unlicensed operations and interference analyses,”
    including using that precise power limit when it reran the
    AT&T study and found an insignificant risk of harmful
    interference. Order ¶ 110. Relying on its “engineering
    judgment,” the Commission concluded that 5 dBm/MHz “will
    both adequately protect all incumbents in the band from
    harmful interference as well as offer enough power to
    unlicensed devices, commensurate with the levels in . . . other
    . . . bands.” Id.
    Petitioners claim that contention-based protocol
    technology allows low-power devices to detect only devices
    like themselves that “transmit in all directions at once” and thus
    17
    offers no protection to licensed fixed microwave users that
    send “focused point-to-point beam[s].” Pet’rs’ Reply Br. 27.
    But the Commission never claimed that contention-based
    protocol would directly protect microwave towers from
    interference. Instead, it explained, “our rule requiring that low-
    power indoor access points employ a contention-based
    protocol ensures that none of these unlicensed devices will
    employ continuous transmissions,” thus making the occurrence
    of harmful interference “even less likely.” Order ¶ 141; see
    also id. n.374.
    Petitioners contend that even if power limits and
    contention-based protocol technology could protect licensees
    from indoor low-power devices, these precautions will fall
    short when such devices inevitably operate outdoors—for
    example, when people take their routers outside to conduct
    Zoom calls on their balconies. Fully aware of that risk, the
    Commission imposed several requirements to make outdoor
    use “impractical and unsuitable.” Id. ¶ 108. Specifically, it
    required that routers have incorporated antennas, no batteries,
    and no weather-resistant capability. Petitioners insist that
    “[a]lthough these measures might help discourage outdoor use
    . . . they cannot possibly prevent it.” Pet’rs’ Br. 53. But again,
    petitioners are measuring the Order against a standard the
    Commission never embraced; as explained above, the Order
    does not seek to reduce the risk of harmful interference to zero.
    Rendering outdoor router use impractical, as petitioners
    concede the Order does, rather than impossible, promotes the
    Commission’s goal of making the risk of harmful interference
    “insignificant.” Order ¶ 104.
    Petitioners argue that client devices, like smartphones and
    laptops, will interfere with licensed users when operating
    outdoors. Equally aware of this risk, the Commission imposed
    power limits on client devices to “ensure that [they] remain in
    18
    close proximity to the indoor access points.” Id. ¶ 103. By
    doing so, the Commission “authorize[d] indoor unlicensed
    devices with adequate power to be useful to the public while
    also protecting the licensed services in the 6 GHz band from
    harmful interference.” Id.
    D.
    Petitioners’ remaining arguments are equally without
    merit. They contend that the Commission arbitrarily rejected
    two studies that analyze situations with low clutter loss. The
    Commission, however, offered perfectly reasonable
    explanations for rejecting each. See id. ¶ 133 (“We have
    conducted a similar analysis of the [Cellular
    Telecommunications Industry Association] study as we did
    with AT&T’s study and arrived at similar results.”); id. ¶ 154
    (disagreeing with assumptions in the National Association of
    Broadcasters’ study, including that devices will have direct
    lines of sight to news gathering receivers and that the threshold
    for harmful interference is -10 dB). Petitioners disagree with
    the Commission’s view of worst-case assumptions in these and
    other studies, but disagreement by itself is insufficient to
    demonstrate that the Commission failed to “examine the
    relevant data and articulate a satisfactory explanation for its
    action including a ‘rational connection between the facts found
    and the choice made.’” State Farm, 
    463 U.S. at 43
     (quoting
    Burlington Truck Lines v. United States, 
    371 U.S. 156
    , 168
    (1962)).
    Petitioners criticize the Commission for declining to
    impose a mandatory maximum activity factor for unlicensed
    devices. As indicated above, however, the Commission
    explained that “requiring [such] devices to use a contention-
    based protocol . . . will prevent [them] from transmitting”
    continuously, even though “the adopted rules do not [directly]
    limit the activity factor.” Order ¶ 120.
    19
    Finally, petitioners argue that the Order fails to “create[]
    an effective mechanism for immediately detecting, identifying,
    and turning off any device that . . . cause[s] harmful
    interference to licensed operations.” Pet’rs’ Br. 74. According
    to petitioners, the Commission’s “post-hoc enforcement
    mechanisms are designed to locate interference caused by
    pirate radio transmitters or enterprise-grade machinery, not the
    types of portable, sporadically transmitting consumer devices
    bought by hundreds of millions of” people and kept on private
    property. Id. at 75. The Commission disagreed, assuring
    licensed users that its “Enforcement Bureau has the ability to
    investigate reports of such interference and take appropriate
    enforcement action.” Order ¶ 149. To accomplish this, the
    Commission will rely on field agents with “fixed, vehicular-
    mounted, and portable commercial and specialized spectrum
    equipment to conduct investigations” and “work[] with entities
    at the federal, state, county, and local levels of government” to
    stop interference. Order ¶ 149 n.397. Petitioners have given us
    no basis for second-guessing this “predictive judgment[]. . .
    within the agency’s field of discretion and expertise.”
    EarthLink, 
    462 F.3d at 12
     (internal quotation marks omitted).
    Should it turn out that the Enforcement Bureau is not up to the
    task, petitioners can return to the Commission for relief.
    III.
    In addition to petitioners’ shared challenges to the
    adequacy of the Order’s safeguards against harmful
    interference, three groups of petitioners bring individual
    claims.
    A.
    APCO, representing public safety operators, argues that
    the Commission failed to consider the Order’s impact on 911
    dispatch and other public safety services. In support, it cites our
    20
    court’s recent decision in Mozilla Corporation v. FCC, where
    we faulted the Commission for its “failure to consider the
    implications for public safety of its changed regulatory posture
    in [a] 2018 Order.” 
    940 F.3d 1
    , 59 (D.C. Cir. 2019). There,
    however, the Commission failed entirely to consider public
    safety. Here, the Commission expressly acknowledged that
    public safety services use the 6 GHz band and adopted many
    of the very safeguards APCO sought. See Order ¶ 7 (noting that
    public safety services operate in the 6 GHz band); see also 
    id. ¶¶ 30
    , 39–40, 46, 81–83, 187–88 (adopting various safeguards
    that APCO suggested). APCO insists that the Commission
    could have done more, but it identifies no “‘fail[ure] to
    consider an important aspect of the problem.’” Mozilla, 940
    F.3d at 59 (quoting State Farm, 
    463 U.S. at 43
    ).
    APCO also challenges the Order’s approach to unlicensed
    standard-power devices—access points that provide broadband
    to large areas like stadiums, concert halls, and shopping malls.
    The Order requires that such devices, prior to transmitting,
    consult a centralized AFC system to determine available
    frequencies and maximum permissible power levels. APCO
    complains that this system will be effective only 95% of the
    time. The Commission, however, determined that based on its
    experience with other devices, an AFC system with a 95%
    confidence level will sufficiently protect licensees. “Our
    experience with this rule,” the Commission explained,
    “confirms that [such a confidence level] reliably ensures
    protection against harmful interference, at reasonable cost.”
    Order ¶ 41. This is just the kind of “predictive judgment[]
    about areas . . . within the agency’s field of discretion and
    expertise . . . entitled to particularly deferential review.”
    EarthLink, 
    462 F.3d at 12
     (internal quotation marks and
    emphasis omitted).
    21
    APCO next argues that AFC systems are unable to protect
    public safety services that operate on a temporary emergency
    basis in the wake of hurricanes and other major disasters. The
    Order, however, contains provisions designed to protect
    against that very possibility. Specifically, it instructs such
    licensees to “register the details of their [temporary]
    operation,” including temporary “transmitter and receiver
    location,” so that the AFC system can “protect [such licensees]
    from harmful interference.” Order ¶ 32. “Because temporary
    fixed links are not mobile and intended to operate at a specified
    location for up to a year,” the Commission explained, “we do
    not believe this registration requirement poses a significant
    burden on licensees.” 
    Id.
    Finally, APCO doubts that the Commission’s enforcement
    authority is adequate to protect licensees from interference
    from standard-power access points. But the Order includes
    several measures designed to ensure that the Commission can
    detect and end just such interference. See Order ¶ 83 (listing
    requirements for AFC operators to facilitate enforcement). We
    have no more basis for questioning the Commission’s
    judgment about its ability to stop harmful interference from
    standard-power access points than we did with respect to its
    ability to stop interference from low-power devices. See supra
    at 19.
    B.
    Electric utility petitioners argue that the Commission
    unreasonably dismissed two studies on which they relied to
    show that unlicensed low-power devices will interfere with
    licensed users. With respect to one of the studies, submitted by
    Southern Company Services, we agree with petitioners that the
    Commission seems to have mischaracterized the study’s
    treatment of clutter loss and ignored their clarifying comments.
    The Order, however, cites other perfectly sound reasons for
    22
    rejecting the study—in particular, the Commission’s
    preference for Monte Carlo analyses. Order ¶ 135 & n.345. The
    other study, a Critical Infrastructure Industry analysis, does
    employ Monte Carlo methodology, but, as the Commission
    explained, it relied on several unreasonable assumptions about
    the demand unlicensed devices place on the 6 GHz band. See
    id. ¶ 138 (listing unreliable assumptions, including that “every
    man, woman, and child living in the Houston area” would be
    using their own access points at the same time for a 4K video
    streaming service).
    Petitioners next argue that the Commission failed to
    respond to comments about the Southern and Critical
    Infrastructure Industry studies that they submitted in response
    to a draft order that the Commission circulated three weeks
    before its April 23, 2020 open meeting. See supra at 6. As for
    the Southern Study, the Commission acknowledged
    petitioners’ comments and explained why it nonetheless found
    the study less reliable than Monte Carlo simulations. Order
    ¶ 135 n.345. As for the Critical Infrastructure Industry study,
    the Commission explains in its brief that the utilities’ April
    comments “merely repeated arguments [they] had made in
    ‘technical submissions’ that were previously placed in the
    record” and to which the Commission had already responded.
    Commission Br. 70–71; see also Order ¶ 138 n.364
    (responding to utilities’ earlier submission); Thompson v.
    Clark, 
    741 F.2d 401
    , 408 (D.C. Cir. 1984) (“The failure to
    respond to comments is significant only insofar as it
    demonstrates that the agency’s decision was not based on a
    consideration of the relevant factors.” (internal quotation marks
    omitted)).
    C.
    The National Association of Broadcasters argues that
    because mobile operators frequently work indoors, the
    23
    provisions of the Order designed to restrict low-power routers
    to indoor operation offer mobile licensees little protection.
    Moreover, the Association informs us, after the Commission
    allowed unlicensed access in the 2.4 GHz band, “a contention-
    based protocol . . . failed to protect . . . licensed users[,] . . .
    rendering that band partially unusable.” Pet’rs’ Br. 71.
    The Association and others raised these concerns in
    comments to the Commission and requested that it reserve a
    sliver of 6 GHz band for licensed mobile operation. The
    Commission, however, never responded to their complaints
    about interference in the 2.4 GHz band. Although the
    Commission cited a study to support its conclusion that the
    Order sufficiently protects mobile operators, that study does
    not rebut the Association’s claims about interference in the 2.4
    GHz band. As we have explained, “the opportunity to comment
    is meaningless unless the agency responds to significant points
    raised by the public.” Sherley v. Sebelius, 
    689 F.3d 776
    , 784
    (D.C. Cir. 2012) (quoting Home Box Office, Inc. v. FCC, 
    567 F.2d 9
    , 35–36 (D.C. Cir. 1977)). We shall thus grant the
    Association’s petition for review on this point and remand to
    the Commission for it to respond to the Association’s concerns
    about interference in the 2.4 GHz band.
    The Association urges us to go further and vacate the
    Order. “The decision whether to vacate depends on [(1)] the
    seriousness of the order’s deficiencies (and thus the extent of
    doubt whether the agency chose correctly) and [(2)] the
    disruptive consequences of an interim change that may itself be
    changed.” Allied-Signal, Inc. v. Nuclear Regulatory
    Commission, 
    988 F.2d 146
    , 150–51 (D.C. Cir. 1993) (internal
    quotation marks omitted). Here both factors favor remand
    without vacatur. “It is conceivable that the Commission may
    be able to explain” why its experience in the 2.4 GHz band
    supports its ability to protect licensed mobile operators from
    24
    harmful interference. 
    Id. at 151
    . “At the same time, the
    consequences of vacating may be quite disruptive.” 
    Id.
     At oral
    argument, Commission counsel explained that “vacating this
    order would be incredibly disruptive given the fact that devices
    have already started to be deployed” and assured us that “it’s
    well within the Commission’s power to provide [more]
    explanation” if needed. Oral Arg. Tr. 44. Given the
    Commission’s failure to respond to the Association’s concerns
    about harmful interference in the 2.4 GHz band, further
    explanation is called for.
    IV.
    We end where we began, with the principles that guide our
    review of petitioners’ challenges. As explained in the foregoing
    pages, petitioners commercial communications providers,
    electric utilities, and APCO have failed to demonstrate that the
    Commission “relied on factors which Congress has not
    intended it to consider, entirely failed to consider an important
    aspect of the problem, offered an explanation for its decision
    that runs counter to the evidence before the [Commission], or
    is so implausible that it could not be ascribed to a difference in
    view or the product of [Commission] expertise.” State Farm,
    
    463 U.S. at 43
    . This failure is especially significant because in
    issuing the Order, the Commission was acting to “foster[]
    innovative methods of exploiting the spectrum,” thus requiring
    our “greatest deference.” Mobile Relay Associates, 457 F.3d at
    8 (internal quotation marks omitted). We therefore deny their
    petitions for review. But for the reasons set forth above, we
    grant the National Association of Broadcasters’ petition in part
    and remand for further proceedings consistent with this
    opinion.
    So ordered.