# Before the

# Federal Communications Commission

# Washington, D.C. 20554

In the Matter of )

)

**AIRCELL, INC.** )

)

Petition, Pursuant to Section 7 of the Act, )

For a Waiver of the Airborne Cellular Rule, )

Or, in the Alternative, for a Declaratory Ruling )

# MEMORANDUM OPINION AND ORDER

**Adopted:** **May 24, 2000 Released: June 9, 2000**

By the Commission:

######### I. INTRODUCTION

1.  AirCell, Inc. (AirCell) has developed and tested a system of
    modified cellular telephones and specially equipped ground stations
    designed to provide airborne cellular service to airborne mobile
    terminals installed on board general aviation aircraft. The AirCell
    system design is intended to coexist with and not cause harmful
    interference to terrestrial cellular systems. Number range
    level0Number range level1Number range level2Number range
    level3Number range level4Number range level5Number range
    level6Number range level7With this Memorandum Opinion and Order, we
    resolve the outstanding issues that have been presented to the
    Commission regarding the AirCell system and its implementation.

2.  By this Order, we affirm two orders of the Wireless
    Telecommunications Bureau ("Bureau") that granted AirCell and
    certain cellular partners a waiver of section 22.925 of the
    Commission's rules, which prohibits airborne operation of cellular
    telephones, and then modified and clarified the procedures set up to
    implement that waiver. We also affirm three Bureau orders granting
    section 22.925 waivers to additional AirCell partners. We therefore
    deny four Applications for Review and four Stay Requests filed
    against the Bureau Orders by a number of cellular carriers. We also
    reset the two-year term of the waiver to begin on the effective date
    of this Order. We also clarify the Bureau's Orders as they pertain
    to interference protection given to E-911 location technology.

3.  By this Order, we also resolve outstanding issues related to
    AirCell's operation under experimental authorization of the Office
    of Engineering and Technology ("OET") by affirming two OET Letter
    Rulings.

######### Number range level0Number range level1Number range level2Number range level3Number range level4Number range level5Number range level6Number range level7II. BACKGROUND

4.  *The AirCell System.* AirCell has developed a system of specially
    engineered mobile cellular terminals for use aboard general aviation
    aircraft.[^1] The AirCell system operates on secondary status in
    order to ensure that other carriers will be free of harmful
    interference from AirCell operations. The AirCell equipment, which
    includes a modified cellular mobile telephone and specially designed
    aircraft antenna, is designed to avoid causing harmful interference
    to terrestrial cellular systems. AirCell ground stations are
    collocated at cellsites of cellular licensees that have entered into
    partnership arrangements with AirCell.[^2] Customer traffic from an
    AirCell mobile telephone is interconnected with the public switched
    network through an AirCell partner\'s cellular switch.[^3]

5.  According to AirCell, the AirCell system has a number of features
    designed to avoid harmful interference to terrestrial cellular
    systems. To begin with, the design of the AirCell system is based on
    the difference in the ambient radio frequency noise level between
    heavily populated areas and sparsely populated areas. By locating
    its ground stations in quieter areas, AirCell asserts, it is able to
    operate the airborne transmitters at a very low power level.[^4]
    Thus, while the forward link[^5] voice and control channels transmit
    from ground station sites at approximately the same power levels
    used by cellular base stations, AirCell represents that its airborne
    mobile terminals operate with lower transmitter power than ordinary
    cellular telephones[^6] in order to reduce the likelihood of
    interference from the reverse link transmissions.[^7] According to
    AirCell, its mobile terminals typically transmit at a power output
    level of 5 milliwatts or less,[^8] considerably less than the normal
    output power of cellular portable handsets. To further decrease the
    likelihood that the system will cause interference,[^9] the AirCell
    system was designed to use horizontal wave polarization as opposed
    to the vertical polarization used by most conventional cellular
    systems, which AirCell contends provides a degree of additional
    isolation between the AirCell system\'s signals and those of
    terrestrial systems.[^10] Finally, AirCell states that it utilizes
    non-standard control channels, as well as specially shaped antenna
    patterns, in order to afford additional protection from interference
    to non-participating cellular systems.[^11] Frequency coordination
    with non-participating cellular licensees, as provided for in the
    Bureau's Orders, further reduces the potential for
    interference.[^12]

6.  AirCell claims that its system offers unique, cost-effective public
    safety benefits not now available to the general aviation industry,
    including potentially life-saving voice and data communications,
    such as real-time weather and air traffic data information.[^13]
    Governmental entities expert in air traffic safety, such as the
    Federal Aviation Administration and the National Transportation
    Safety Board, have expressed the belief that a system permitting
    general aviation aircraft to have access to up-to-the-minute weather
    information would reduce the incidence of air safety hazards.[^14]

7.  *Bureau Proceedings.* On October 9, 1997, AirCell filed a Petition
    for Waiver of Section 22.925 of the Commission's rules, which
    prohibits airborne operation of cellular telephones.[^15] On July
    31, 1998, AirCell and a number of cellular partners entering into
    resale agreements with AirCell jointly amended AirCell\'s petition
    for waiver, establishing that the cellular partners joined in the
    waiver request. The partners thereby agreed to modifications to
    their existing cellular licenses to authorize this secondary use of
    their licensed spectrum. AirCell and its cellular partners
    represented that they would work together to resolve any harmful
    interference caused to non-participating cellular carriers. Further,
    AirCell and its partners stated that, in the event of unresolved
    harmful interference, they would shut down the relevant AirCell
    mobile terminal or cease AirCell operation from the relevant ground
    station altogether.[^16]

8.  On December 24, 1998, the Bureau released an Order granting AirCell
    and certain participating cellular carriers a waiver of the
    Commission's prohibition on the airborne operation of cellular
    telephones.[^17] Specifically, the Bureau granted AirCell and its
    participating partners a waiver of section 22.925 of the
    Commission\'s rules,[^18] subject to certain conditions.[^19] The
    Bureau reviewed the extensive record of the AirCell proceeding and
    was persuaded that AirCell had shown that a limited waiver of
    section 22.925 was justified.[^20] The Bureau was convinced that the
    AirCell system warranted an opportunity to operate for a limited
    two-year term and believed that the *AirCell Order* articulated an
    operating scheme that would enable AirCell to offer its air-ground
    voice and data link system to the public while also protecting
    non-participating carriers from harmful interference.[^21] The
    waiver authorized certain specified cellular providers to furnish
    system capacity for the provision of cellular service on a secondary
    basis to airborne mobile units utilizing AirCell technology, and
    established a number of mandatory conditions and recommended
    guidelines regarding operation of the AirCell equipment.[^22] The
    Bureau stated that AirCell\'s acceptance of secondary status with
    respect to the primary terrestrial operations of cellular licensees
    was a significant factor in its evaluation.[^23]

9.  In response to the Bureau's action in this matter, we received a
    Stay Request[^24] and Consolidated Application for Review[^25] of
    the *AirCell Order* on January 25, 1999, contending that the
    Bureau's action was arbitrary and capricious and unsupported by the
    record.[^26] The pleadings were filed by AirTouch Communications,
    Inc., Ameritech, AT&T Wireless Services, Inc., Bell Atlantic Mobile,
    Inc., BellSouth Cellular Corporation, GTE Wireless Incorporated, and
    SBC Wireless, Inc. (collectively, \"opposing carriers\"). On the
    same date, AirCell filed a Petition for Reconsideration and
    Clarification of the *AirCell Order*,[^27] expressing its concern
    that the notification distance of 168 miles required in Special
    Condition 6 of the *AirCell Order* was overly burdensome and
    requesting that the Bureau extend the term of its waiver.[^28]

10. The Bureau subsequently reconsidered a portion of its *AirCell
    Order* to address certain implementation issues.[^29] On July 30,
    1999, the Bureau granted, in part, the AirCell Petition by modifying
    Special Condition 6 of the *AirCell Order*,[^30] which had provided
    that \"\[a\]ppropriate licensees to be notified \[of an impending
    service offering\] are those having one or more co-block transmitter
    sites located within 270 kilometers (168 miles) of the proposed
    ground station.\"[^31] Persuaded by the technical record before it,
    the Bureau reduced the notification distance from 270 kilometers
    (168 miles) to 151 kilometers (94 miles).[^32] In that
    *Reconsideration Order*, the Bureau also clarified that AirCell was
    not precluded from placing its narrowband control channels in code
    division multiple access (CDMA) guardband spectrum.[^33] In a
    companion *Additional Waivers Order*, the Bureau granted section
    22.295 waivers to seven additional AirCell partners.[^34] On August
    30, 1999, the opposing carriers filed a second Consolidated
    Application for Review[^35] and Request for Stay,[^36] this time
    pertaining to the *Reconsideration Order* and *Additional Waivers
    Order*. The Bureau subsequently granted section 22.295 waivers to
    seven more AirCell partners, in two orders.[^37] On December 20,
    1999 and January 19, 2000, the opposing carriers filed a third and
    fourth Application for Review and Request for Stay,[^38] this time
    pertaining to the *Second Additional Waivers Order*[^39] and *Third
    Additional Waiver Order*, respectively. In addition, we have before
    us a Petition for Clarification of the *AirCell Order*, filed by
    TruePosition, Inc. (TruePosition) on January 25, 1999, in which
    TruePosition asks that the Commission expressly prohibit Aircell
    from interfering with carriers' deployment of Automatic Location
    Identification (ALI) technology (E-911 technology).[^40]

11. *OET Proceedings*. Also before us are an Application for Review of a
    May 30, 1997 Letter Ruling[^41] released from OET, filed by AirCell
    on June 30, 1997;[^42] and a Motion for Stay[^43] and an Application
    for Review[^44] of a February 11, 1998 OET Letter Ruling,[^45] filed
    by certain opposing carriers on March 12, 1998. We will discuss the
    OET proceedings in a separate section below.

######### III. DISCUSSION - BUREAU PROCEEDING

12. Upon review, we largely affirm the Bureau Orders. We agree with the
    Bureau\'s technical assessment of the AirCell system, including its
    judgment that there is little risk the system will cause harmful
    interference to non-participating carriers, as well as its
    evaluation of the system\'s potential benefit for general aviation.
    We also agree with the terms of the waivers granted by the Bureau
    and the procedures set out in the Orders for implementing the
    AirCell system, though we add some technical operating conditions to
    the waiver to ensure that the AirCell system will in fact operate
    within the technical parameters on which the Bureau's decision was
    based.[^46] We therefore deny the opposing carriers' Applications
    for Review and Stay Requests of the *AirCell Order*,
    *Reconsideration Order*, *Additional Waivers Order*, *Second
    Additional Waivers Order*, and *Third Additional Waiver Order*.
    Although we agree with an initial two-year waiver term, we partially
    grant the AirCell Petition in that we will reset the term to begin
    on the effective date of this Order. Further, we clarify the
    *AirCell Order* as it pertains to interference protection given to
    E-911 location technology.

13. As we will explore further below, we find that the Bureau, in the
    *AirCell Order*, *Reconsideration Order*, and various *Additional
    Waivers Orders*, carefully considered the evidence presented by all
    parties in this proceeding and correctly concluded that the airborne
    cellular service provided by AirCell is in the public interest. The
    record indicates that the AirCell service operates at a power level
    and in a manner that poses little or no threat of harmful
    interference to primary cellular service. Indeed, the evidence
    indicates that the AirCell signal is undetectable in most
    circumstances. In this decision we rely on the voluminous record
    provided by AirCell, its partners, its opponents, and other
    interested commenters, including extensive testing under the aegis
    of a Part 5 Experimental Service license. Our review of the record
    convinces us that the Bureau acted properly in finding that the
    AirCell system of airborne mobile units can operate with their
    corresponding ground stations without causing harmful interference
    to primary cellular services.

14. In this Order, we also rely heavily on the Bureau's limitation of
    the AirCell system to secondary status in the cellular band.
    Stations with secondary status, such as those of which the AirCell
    system is comprised: (1) shall not cause harmful interference to
    stations of primary services to which frequencies are already
    assigned or to which frequencies may be assigned at a later date;
    and (2) cannot claim protection from harmful interference from
    stations of a primary service to which frequencies are already
    assigned or may be assigned at a later date.[^47] We find that
    restricting AirCell and its partners to secondary status throughout
    their system helps ensure that all primary cellular service is and
    will be protected from harmful interference throughout the waiver
    term.

    **1. Waiver Standard**

15. In 1984, Commission staff issued a Public Notice banning the use of
    all cellular telephones on airborne aircraft because of the
    possibility of interference to cellular systems.[^48] In 1991, the
    Commission codified the policy.[^49] Until the release of the
    *AirCell Order*, no waivers of that rule had been granted.[^50]

16. "\[T\]he essence of waiver is a narrow, particularized exception to
    a rule based on a showing by a particular party that such an
    exception will not subvert the rule under that party\'s unique
    circumstances."[^51] The opposing carriers argue that AirCell's
    proposal does not meet the standard for waiver consideration because
    AirCell does not demonstrate that its system presents the Commission
    with unique circumstances.[^52] In response, AirCell contends that
    the Bureau\'s *AirCell Order* was expressly based on use of
    specially designed, low-power airborne mobile terminals.[^53]
    Further, AirCell contends that the *AirCell Order* bars any
    \"harmful interference\" as well as any sustained, continuous
    non-harmful interference, placing the burden on AirCell and
    participating licensees to continue to find solutions to any
    interference issues that may arise as cellular technologies
    develop.[^54]

17. We find that unique circumstances do exist that justify the grant of
    a waiver of Section 22.295. To begin with, the Bureau based the
    waiver on careful examination of the technical design of the AirCell
    system and analysis of its potential effects on cellular services
    offered by other carriers. Based on the record before us, we agree
    with the Bureau's conclusion that the AirCell system is not likely
    to cause harmful interference to terrestrial systems, which is the
    basis of Section 22.925 of the Commission's rules. Furthermore, as
    described below, the evidence indicates that the AirCell system
    offers public interest benefits such as enhanced safety to general
    aviation. Finally, the Bureau properly crafted its waiver in such a
    manner as to offer non-participating licensees adequate, indeed
    redundant, interference protection. First, the AirCell system's
    secondary status helps ensure non-participants a regulatory remedy
    for any incidents of harmful interference. Second, the underlying
    Orders establish a notification procedure that affords
    non-participating carriers the opportunity to steer AirCell away
    from the use of particular channels if they so choose.

18. The Bureau reached its technical conclusion regarding the AirCell
    system as the result of a proceeding in which AirCell was required
    to make an affirmative showing that its system is not likely to
    cause harmful interference to terrestrial cellular operations.
    Because AirCell carried this burden, on the basis of the design
    characteristics of its system and field tests in Texas in July 1997,
    we reject the opposing carriers' contention that the Bureau unfairly
    shifted the burden of proof regarding harmful interference.[^55]
    Special Condition 4 to the waiver provides that, if a
    non-participating cellular licensee brings forth factual evidence of
    harmful interference, the relevant AirCell cellular partner must
    resolve any such problem in a timely fashion or face termination or
    modification of its authority under the waiver.[^56] Special
    Condition 4 further invites non-participating cellular licensees to
    bring forth factual evidence that the operation of the AirCell
    system is resulting in certain interference to their operations,
    even if such interference does *not* rise to the level of harmful
    interference -- and, again, the relevant AirCell partner is subject
    to termination or modification of its authority.[^57] These
    procedures do not shift the burden of proof to an opposing carrier
    but merely place upon that carrier the burden to come forward with
    *prima facie* evidence that it has suffered interference that is
    likely to have been caused by AirCell's operations. We find this
    arrangement to be reasonable, because AirCell has carried its
    initial burden to demonstrate that its system is not likely to cause
    harmful interference.

19. We do not agree with the opposing carriers' assertions regarding the
    likelihood that AirCell operations will cause interference to
    terrestrial cellular operations[^58] because we do not find
    persuasive the evidence they have presented in support of these
    assertions. First, the opposing carriers contend that the
    possibility of harmful interference is demonstrated by the results
    of the July 1997 Texas field test of Aircell\'s system,[^59] upon
    which the Bureau relied in making its technical findings in support
    of the waiver. The Texas field test consisted of two days of
    testing. On the first day, AirCell configured its system to operate
    "normally," *i.e.*, with all the various design features that
    AirCell had engineered to reduce the threat of interference. AirCell
    also flew "normal" flight paths, *i.e.*, more or less
    point-to-point.[^60] On the second day, at the opposing carriers's
    request, AirCell disabled the dynamic power control element[^61] of
    the AirCell equipment, which eliminated, for the duration of these
    tests, the benefits of one of the main elements of the AirCell
    design. The opposing carriers also flew abnormal flight patterns,
    specifically, circular flight paths around the "victim" cell site.
    For these reasons, the Bureau used data gathered on the first day of
    the Texas test to characterize the normal operation of the AirCell
    system, and used data gathered on the second day to study the extent
    of harmful effects that might result from a major malfunction of the
    AirCell system. We find that this use of the Texas field test data
    by the Bureau was reasonable. The test data from the second day
    provided no evidence that the AirCell system would cause harmful
    interference when operating as designed, but only that a major
    malfunction could lead to interference. In such an event, however,
    the terms of the waiver granted by the Bureau clearly would require
    Aircell to cease the operations causing interference until the
    malfunction is corrected.

20. Opposing carriers also cite the results of a test they conducted in
    Florida on September 22, 1998, as supplying evidence of actual
    interference by the Aircell system.[^62] We find that the Florida
    test was based on unrealistic test conditions and is not reliable.
    In the Florida test, the opposing carriers again flew abnormal,
    circular flight patterns around the "victim" cell site at close
    range and at low altitude. This put the main lobe of the aircraft
    antenna pattern into the cell site antenna. In addition, AirCell
    showed that the opposing carriers installed the wrong type of
    antenna for the type of airplane involved;[^63] did not record the
    AirCell airborne mobile transmitter power output;[^64] and
    deliberately matched the supervisory audio tone, thus preventing the
    AirCell telephone from hanging up once it had lost a usable signal
    from the AirCell ground station.[^65] For all these reasons, the
    data drawn from the Florida test, and the conclusions based upon
    these data, cannot be credited as reflecting the nature or
    interference potential of the AirCell system as it was designed to
    operate.

21. Similarly, other assertions made by the opposing carriers regarding
    the interference potential of the AirCell system lack foundation in
    credible evidence. The conclusion of Dr. William C.Y. Lee that
    "AirCell's operations will create 'a significant level of harmful
    interference' over 30 percent of the time that an AirCell-equipped
    plane placing a call overflies a terrestrial system"[^66] was based
    on unrealistic assumptions, including his use of an unrealistically
    low interference threshold.[^67] The opposing carriers' assertion
    that "as many as 400 terrestrial cellular conversations could be
    disrupted by a single airborne call"[^68] is an assertion not
    supported by evidence in the record.[^69] The opinions of the Chief
    Technical Officers of six major cellular carriers stating that they
    "are convinced that the proposed AirCell operations would
    significantly interfere with our operations"[^70] are not persuasive
    because the record does not contain credible evidence supporting
    those opinions. The assertion that "AirCell high power base stations
    with uptilted antennas will cause interference to terrestrial mobile
    units"[^71] is adequately addressed by the ordinary coordinating
    process that every cellular licensee, including AirCell partners,
    must already go through under the Commission's rules.[^72] Finally,
    AirCell's probability study was not a factor in the Bureau's
    decision, which therefore did not need to settle any "\[d\]isputes
    over AirCell's probability study."[^73]

22. *Technical Conditions / Guidelines*. The opposing carriers contend
    that, although the Bureau based the *AirCell Order*,
    *Reconsideration Order*, and *Additional Waivers Orders* on specific
    assumptions about how AirCell\'s system was unlikely to interfere
    with non-participating cellular systems, the Bureau refused to
    impose conditions that would require AirCell and its cellular
    partners actually to operate in the prescribed manner.[^74]
    Specifically, opposing carriers claim that the Bureau expressly
    relied on particular AirCell technical and operating parameters to
    justify granting the waiver[^75] \-- *i.e.*, the specific parameters
    in Appendix B to the *AirCell Order*, which the Bureau found
    constituted the \"unique and special circumstances required to
    justify a waiver of Section 22.925\"[^76] \-- but did not condition
    the waiver on compliance with those parameters.[^77] Instead,
    opposing carriers state, the Bureau called them \"recommended
    guidelines,\"[^78] and said that they were \"not intended to be
    mandatory.\"[^79] Opposing carriers contend that \"\[o\]nce the
    Bureau found that a waiver was justified specifically because of the
    protections afforded by specific technical and operating parameters,
    it was obliged to limit the waiver to situations where those
    parameters would govern.\"[^80]

23. AirCell contends that the *AirCell Order* dispenses with the need
    for technical conditions by using a more onerous, results-oriented
    solution to ensure that non-participating carriers cannot be harmed,
    and contends that a similar policy approach underpins the entire
    concept of the Part 5 experimental licensing regime. AirCell further
    claims that the Commission has never adopted specific technical
    requirements governing the operations of experimental licensees,
    relying instead on the general mandate that experimental licensees
    not cause harmful interference to primary licensees.[^81] AirCell
    argues that it is not the specific technical attributes of the
    AirCell technology but the non-interfering result of those
    attributes that constitute the unique and special circumstances
    justifying the waiver. Finally, AirCell contends that incorporating
    the technological features summarized in Appendix B of the *AirCell
    Order* as mandatory conditions would only require further
    proceedings if AirCell is able to make changes improving its
    technology while having the same non-interfering result.[^82]

24. We agree with AirCell that the results-oriented conditions imposed
    on the AirCell system in the *AirCell Order* are more stringent than
    any specific technical conditions we might impose. The Bureau was
    clear in its insistence that the AirCell system produce no harmful
    interference. We also share the Bureau's expectation that AirCell
    continue to improve its technology, including its interference
    protection functions, and we do not wish to restrict AirCell\'s
    ability to make technical improvements to its service as long as
    primary cellular service is protected from harmful interference.
    However, we will add to the mandatory conditions set forth in the
    *AirCell Order* a limited number of technical conditions that are
    based on the Bureau's analysis of the features of the AirCell system
    that justified granting the waiver. While we believe that AirCell's
    secondary status is sufficient to ensure non-interference to
    terrestrial cellular operations, we adopt this conservative approach
    to regulating the relationship between AirCell operations and those
    of the terrestrial cellular carriers in order to give addded
    assurance that AirCell's operations under the waiver will not
    compromise the non-interference policy behind the rule that has been
    waived. Attached to this order, therefore, is an Appendix containing
    both the original conditions to the waiver (from Appendix A to the
    *AirCell Order*, as modified by the *Reconsideration Order*) and new
    technical conditions regarding transmitting power, antenna pattern
    and installation, and wave polarization. This Appendix of conditions
    supersedes and replaces both appendices attached to the original
    *AirCell Order*. [^83]

    **2. Cellular Carriers' Rights to Provide Service Within Cellular
    Geographic Service Areas**

25. We reject the opposing carriers' arguments that the AirCell system
    violates these carriers' exclusive channel block assignments.[^84]
    The opposing carriers state that in 1981 the Commission adopted a
    licensing structure for the then-new cellular service that limits a
    licensee to providing cellular service on a dedicated channel block
    in a discrete geographic area unique to each carrier, known as its
    Cellular Geographic Service Area (\"CGSA\").[^85] The carriers
    contend that each licensee is entitled to be free from any other
    carrier\'s provision of cellular service on the same channel block
    within its CGSA, and they argue that under the rules, no cellular
    licensee can provide service in another licensee\'s exclusive CGSA
    without the other licensee\'s express permission.[^86] The opposing
    carriers assert that the *AirCell Order* and *Reconsideration Order*
    violate their rights by allowing AirCell to provide cellular service
    within their CGSAs.

26. We take issue with the opposing carriers' analysis of the rights and
    protections provided to them as licensees by our cellular rules. The
    CGSA of a cellular system is the geographic area considered by the
    FCC to be served by the cellular system.[^87] Within its CGSA, a
    cellular system is entitled to protection from co-channel and
    first-adjacent channel interference and from capture of subscriber
    traffic by adjacent systems on the same channel block.[^88]
    Licensees must cooperate in resolving co-channel and first-adjacent
    channel interference by changing channels used at specific cells or
    by other technical means.[^89] Subscriber traffic is captured if a
    service area boundary (SAB)[^90] of one cellular system overlaps the
    CGSA of another operating cellular system. Cellular licensees are
    entitled to have a CGSA free of SABs from other cellular systems on
    the same channel block.[^91] Therefore, cellular licensees must not
    operate any facility that would cause an SAB to overlap the existing
    CGSA of another cellular system on the same channel block, without
    first obtaining the written consent of the licensee of that
    system.[^92] None of these rules places any limitations on where a
    cellular licensee may provide non-interfering service from its own
    facilities.

27. We conclude that the waiver conditions imposed by the Bureau's
    Orders and those we have added here fully protect the opposing
    carriers' service. Most importantly, the opposing carriers are
    protected by AirCell's secondary status, which requires it to
    refrain from harmful interference to primary cellular licensees,
    both co-channel and first-adjacent channel. Furthermore, based on
    our review of the extensive record before us and "real world"
    experience gained with the AirCell system under its experimental
    license, we find that the AirCell system is not likely to be
    detected in normal operation and is not likely to cause harmful
    interference even in unusual circumstances. In addition, under the
    *AirCell Order*, opposing carriers have an even greater opportunity
    to coordinate channel selection to avoid interference than is
    afforded under the rules.

28. The opposing carriers also err in their analysis regarding their
    protection from subscriber traffic capture. The AirCell system
    cannot capture other carriers' traffic. The AirCell system only
    serves AirCell mobile units and cannot interact with ordinary
    cellular telephones. Thus, the AirCell partners only capture their
    own airborne mobile subscribers, an action provided for in the
    Bureau's waiver grant. Further, the fact that an airborne subscriber
    flying over an opposing carrier's CGSA may receive service from the
    adjacent-market AirCell partner does not equate to SAB overlap.[^93]

29. *License Modification*. We also reject the opposing carriers'
    related contention that the *AirCell Order* improperly modified
    nonparticipating cellular carriers\' licenses by diminishing their
    protection from interference, without notice or an opportunity to be
    heard, in violation of Section 316. They further argue that the
    Bureau modified existing carriers\' licenses by authorizing
    AirCell\'s partners to serve airborne units without any geographical
    limitation. Opposing carriers claim such action by the Bureau is in
    direct conflict with the Commission\'s rules, specifically 47 CFR §§
    22.905(a) and 22.911, under which a cellular licensee is granted an
    exclusive license to use a specific channel block in a defined
    geographic area.[^94] Opposing carriers claim that if the Commission
    authorizes a second carrier to use a block of cellular spectrum in a
    given carrier\'s defined service area, it thereby modifies the
    authorized carrier\'s license and must comply with the procedures
    for license modification set forth in 47 USC § 316.

30. We do not agree that the Bureau\'s actions have improperly modified
    non-participating carriers\' licenses, either directly or
    indirectly. First, as we discuss above, the waiver does not diminish
    non-participating carriers' protection from interference; through
    the *AirCell Order* and the *Reconsideration Order*, the Bureau took
    steps to ensure that the AirCell system would not cause harmful
    interference to the operations of any non-participating licensee.
    Second, in the conditions it imposed on the AirCell system, the
    Bureau established notification and coordination procedures that
    encouraged, but did not obligate, non-participants to cooperate with
    AirCell and its partners in the initial configuration of the AirCell
    system. Non-participating parties are not subject to any new
    obligations or changes in their rights or responsibilities.[^95]
    Those parties need do no more in operating their systems today than
    they did before the limited waiver was granted allowing operation of
    the AirCell system. Third, as we discuss above, nothing in the
    Bureau\'s orders allows AirCell or its cellular partners to violate
    any aspect of the assignment of channel blocks to other
    licensees.[^96] We therefore conclude, as the Bureau did, that
    because \"non-participating cellular licensees are not required to
    accept harmful interference, nor are they required to alter their
    operations to accommodate AirCell operations in any way\... there
    can be no indirect modifications triggering a section 316 or section
    1.87 notice and hearing requirement \....\"[^97]

    **3. Notification Distance**

31. We reject the opposing carriers' challenge to the Bureau's
    reconsideration of the notification distance AirCell must observe.
    In the *AirCell Order*, the Bureau initially required AirCell and
    its cellular partners to notify all carriers with sites located
    within 168 miles of an AirCell partners' site of the frequencies on
    which AirCell signals would be carried. In its *Reconsideration
    Order*, the Bureau reduced this notification distance to 94 miles.
    We find that the Bureau acted properly in reducing the notification
    distance from 168 miles to 94 miles. The Bureau\'s reasoning for
    reducing the distance was that \"the normal signal from the AirCell
    airborne terminal is not detectable by typical OET-53 compatible
    analog cellular base stations when the airborne terminal is more
    than 10 miles away....\"[^98] This is because of \"the airborne
    antenna pattern and polarization, combined with the low airborne
    transmitter power,\" and the fact that the \"design of each AirCell
    ground station\'s link budget limits its effective range to aircraft
    at 5000 feet altitude to 135 kilometers (84 miles).\"[^99] By adding
    these two distances, the Bureau concluded that a notification
    distance of 94 miles provided conservative protection. The opposing
    carriers disagree with the decision\'s rationale because, they
    argue, it is premised on what the Bureau considers to be \"normal\"
    AirCell operation but AirCell is not obligated to operate in any
    particular manner. Specifically, the carriers argue that AirCell is
    not obligated to use any particular antenna pattern or polarization,
    is not limited to using \"low\" power, and is not bound by any
    \"link budget\" it may have employed in any proposal or test.[^100]
    Further, opposing carriers argue that AirCell's interference range
    is increased by its use of an omnidirectional antenna pattern.[^101]
    Finally, opposing carriers contend that their urban base stations
    are more sensitive to AirCell's interference than predicted by
    AirCell's analysis[^102] and that AirCell's airborne units may
    operate at higher powers 84 miles from their ground stations than
    AirCell admits.[^103]

32. The Bureau based its decision to reduce the notification distance on
    a comprehensive analysis of the empirical data gathered from the
    July 1997 Texas tests, in which the opposing carriers participated
    and which we believe indicate that the original 168-mile
    notification distance was overly conservative.[^104] With regard to
    urban cellular base station receivers, opposing carriers overlook,
    and the Bureau took into account, the fact that the higher noise
    floor[^105] in urban areas will ensure that the AirCell units\'
    signal remains substantially below a detectable level.[^106] Based
    on the record, therefore, it is reasonable to expect the AirCell
    system actually to operate as designed. Moreover, the opponents'
    argument that AirCell is not obligated to operate in any particular
    manner is addressed by the additional technical conditions we adopt
    in this Order. However, we will review the determination regarding
    the notification distance at the conclusion of the waiver term. In
    the meantime, as discussed above, AirCell is relegated to secondary
    status and is forbidden to cause harmful interference.

    **4. CDMA Guardbands**

33. We agree with the Bureau's analysis of the propriety of AirCell's
    use of CDMA guardband channels and reject the opposing carriers'
    contention that the Bureau erred when it allowed AirCell to operate
    on CDMA guardbands.[^107] The opposing carriers take issue with the
    Bureau's characterization of the guardband channels as \"not used\"
    and \"essentially wasted.\"[^108] The opposing carriers claim that
    part of the CDMA signal is actually contained within the guardbands
    and that if AirCell is allowed to put its analog FM control channel
    signals in the opponents\' CDMA guardbands, AirCell\'s analog
    signals will destroy the CDMA bits residing in the guard
    channels.[^109] Second, opposing carriers contend that the Bureau
    misconstrues the purpose of the guardbands, which they argue is not
    merely to prevent sideband noise[^110] generated by nearby analog
    mobiles from adding to the noise floor but also to prevent an
    increase in the noise floor caused by the existence of a mobile unit
    carrier in the guardband.[^111] The opponents, for example, contend
    that an AirCell unit operating at a power of +27 dBm on the first
    guardband channel, while located 9 miles from the CDMA cell, would
    raise the noise floor by 9 dB, which they say would be devastating
    to the CDMA cell site.[^112] Finally, the opposing carriers argue
    that the Bureau\'s belief that AirCell airborne units will not come
    within the \"immediate proximity\" of a CDMA cell site has no
    basis.[^113] With AirCell\'s 84-mile range and plans to provide
    coverage to the entire United States, the opposing carriers contend,
    every CDMA cell site in the country will be at risk of having its
    service degraded when AirCell-equipped planes fly in the \"immediate
    proximity\" of CDMA sites.[^114]

34. The arguments submitted by the opposing carriers do not persuade us
    that the Bureau erred in its conclusion that AirCell can use the
    analog cellular channels contained within a CDMA guardband[^115]
    without adversely affecting the adjacent CDMA signals. First, we
    find that the persuasiveness of the opponents' arguments is limited
    because the technical statements, hypothetical example, and
    conclusions concerning the CDMA guardbands in the opposing carriers'
    pleading are unsupported by any technical data or analyses.
    Additionally, as noted by AirCell in its response, the transmitting
    power attributed to the AirCell mobile terminal in the opposing
    carriers' example (27 dBm) is 8 dB higher than that which AirCell is
    actually designed to use (19 dBm).[^116] One of the additional
    conditions we adopt today limits airborne terminal power to 19 dBm,
    which we hope will end discussion of the effect of higher-power
    operation.[^117]

35. Second, while we agree with opposing carriers that the purpose of
    the CDMA guardband is to prevent an increase in the noise floor
    experienced by the CDMA cell site receiver as a result of the
    operation of ordinary analog cellular telephones in the immediate
    vicinity (by this we mean within a half mile) of that CDMA cell
    site,[^118] we note that the guardband is considered necessary only
    for cellular systems that are transitioning from analog to CDMA and
    wish to provide both types of service in the same area, and in
    particular from the same or proximate cell sites. Thus, if a
    cellular system were to convert entirely to CDMA, the guardbands
    would no longer be needed. In fact, the principal purpose of the
    CDMA guardbands is to protect a cellular system's CDMA operations
    from its own remaining analog subscribers.[^119] We also disagree
    with the opposing carriers that the guardbands are provided or
    intended to serve in any way as conduits for portions of the
    adjacent CDMA signal. In fact, any energy from the CDMA signal that
    may be emitted in the guardband would be outside of what is normally
    considered to be the occupied bandwidth of a CDMA transmission.
    Consequently, we disagree with the opposing carriers' contention
    that the guardbands are used for digital transmissions. We instead
    agree with the Bureau that these guardbands are unused.[^120]

36. Turning now to how analog transmissions in the guardbands might
    affect a CDMA operation, we first consider the opposing carriers'
    contentions that certain bits of information from a CDMA
    transmission are normally transmitted in the guardbands, that an
    analog signal transmitted there could destroy these bits, and that
    this would adversely affect telephone calls on a CDMA system. This
    description does not agree with our understanding of CDMA systems as
    they are commonly explained in the technical literature.[^121] To
    begin with, the CDMA modulation function is dominated by a
    pseudo-random spreading code that alone accounts for most of the
    overall bandwidth of a CDMA emission.[^122] Typically, 128 bits of
    the pseudo-random code ("code bits") are transmitted to carry each
    bit of the digitized telecommunications signal ("information bits").
    This means that the energy corresponding to each information bit
    does not appear in only one specific spot within the occupied
    emission bandwidth (much less an adjacent guardband) but rather is
    spread across the entire emission bandwidth. Thus, assuming for the
    sake of argument that there is a code bit in the guardband, the loss
    of this code bit would be unlikely to cause the loss of an
    information bit. But even if it did, CDMA employs an advanced
    forward error correction code that compensates for such losses in
    most cases.[^123] It is this characteristic, namely the ability to
    recover from loss of part of the signal, that makes CDMA robust in
    the face of selective fading and multipath, when compared to
    narrower emission types. Consequently, it is not the possibility of
    the loss of a code bit or even an information bit that necessitates
    the CDMA guardbands, and we therefore reject the opposing carriers'
    argument concerning loss of bits transmitted in the guardband.

37. Rather, the function of the guardband is to protect against an
    unduly increased noise floor in the CDMA receiver. This occurs
    because any uncorrelated energy appearing in the passband[^124] of a
    CDMA receiver will be spread across the entire receiver bandwidth by
    the demodulation function and appear as broadband noise. When an
    increase in the noise floor occurs, either because of additional
    telephone calls being carried, or because of some interfering signal
    in the passband of the CDMA receiver,[^125] the system responds by
    requiring all CDMA cellular telephones with ongoing calls to
    increase power by the same amount to maintain an acceptable signal
    to noise ratio.[^126] In the event one of these telephones is
    already operating at its maximum power and cannot increase, it could
    possibly be dropped, although in most cases control of it will be
    picked up by cell faces at other cell sites.[^127] This is called
    "soft hand-off" and is possible because CDMA cellular telephones
    normally communicate with multiple cell faces simultaneously.

38. With this background, we now consider how AirCell airborne mobile
    transmissions differ from those of ordinary analog cellular
    telephones, and why we believe the difference makes it possible for
    AirCell mobile terminals to transmit in the CDMA guardband without
    causing harmful interference. First, as stated clearly in the
    record, the received power of an AirCell transmission in a typical
    cellular base receiver is generally several orders of magnitude
    lower than that of an ordinary analog cellular telephone. As noted
    by the Bureau in its *Reconsideration Order*, the sideband power
    from an AirCell airborne mobile, which could fall into the CDMA
    receiver passband if the nearest analog channels in the guardband
    were employed, is likewise attenuated far below that of an ordinary
    analog cellular telephone. Second, while an ordinary analog cellular
    telephone could get within a few hundred feet of a CDMA cell site,
    an airborne AirCell mobile terminal, even if directly overhead, will
    be nearly a mile away. Moreover, directly overhead AirCell
    transmissions would typically not be detected by cellular base
    stations because of the null cast by the AirCell airborne
    antennas.[^128] Thus, we agree with the Bureau that a transmitting
    AirCell airborne terminal cannot physically enter the immediate
    vicinity of a CDMA cell site, *i.e*., close enough to cause the
    effects against which the CDMA guardband is designed to guard.
    Third, while an ordinary analog cellular telephone may be located
    alongside a CDMA telephone, and thus transmit energy into all of the
    cell site faces with which the CDMA telephone is in communication,
    an AirCell airborne terminal, by contrast, will be far enough away
    that the physical geometry would only permit its signal to
    illuminate one common cell site face. Thus, even assuming the
    AirCell signal were strong enough to raise the noise floor a
    significant amount (which our analysis does not lead us to expect),
    the CDMA call would merely be "soft handed off" to the other faces
    with which it is in communication. For all of the foregoing reasons,
    we agree with the Bureau that the CDMA guardbands should be
    considered to be unused for our purposes here and thus need not be
    off limits to AirCell when it is considering possible channel usage.

    **5. Authority to Grant Waivers**

39. We reject the opposing carriers' contention that the Bureau has
    unlawfully delegated authority to AirCell to exempt cellular
    carriers from the airborne cellular rule via a discriminatory,
    non-particularized waiver process.[^129] It is well established that
    the grant of waivers must be based on a \"general standard\" and
    \"nondiscriminatory.\"[^130] In this case, however, the opposing
    carriers contend that, simply by signing on with AirCell, cellular
    licensees can receive a waiver of the airborne cellular rule without
    undertaking any technical measures to prevent interference or even
    making any technical showings.[^131] In other words, the opposing
    carriers argue, AirCell has effectively been given the power to
    grant a waiver to any cellular licensee without any showing that the
    licensee has met the basic requirements for a waiver.[^132] AirCell
    contends that it would be arbitrary and capricious (as well as
    \"unprincipled and discriminatory\") for the Bureau not to grant a
    waiver to one party showing the same special circumstances and the
    same public interest factors previously found sufficient to justify
    a waiver to another party.[^133] In any event, AirCell claims that
    the opposing carriers are in no position to complain about this
    \"additional waiver\" procedure because they have been the frequent
    beneficiaries of this routine and appropriate Commission
    procedure.[^134]

40. Only the Commission or the Bureau acting within its delegated
    authority can issue a waiver of the airborne cellular rule. We take
    issue with the opposing carriers\' contention that prospective
    AirCell partner licensees can \"become exempt from the rule without
    making any showing of unique circumstances and without undertaking
    any technical means to prevent interference.\"[^135] AirCell has
    adequately demonstrated the interference-reducing design of its
    AirCell system. In conjunction with the Bureau-imposed secondary
    status of AirCell's operations, we conclude that the harm that
    section 22.925 was designed to prevent is not likely to occur from
    the operation of the AirCell system. Consequently, we believe that
    special circumstances exist here which justify a waiver of section
    22.925. The additional waiver recipients all must commit that they
    will abide by the same conditions that apply to AirCell and the
    licensees already covered by the *AirCell Order* and the
    *Reconsideration Order*,[^136] and they therefore demonstrate the
    same circumstances as the original waiver recipients.

    **6. Responsibilities of AirCell Partners**

41. We reject the opposing carriers' argument, in their opposition to
    the *AirCell Order* and in subsequent filings, that AirCell and its
    authorized partners have not complied with the terms imposed on them
    by the *AirCell Order*.[^137] The opponents contend that AirCell\'s
    cellular partners have delegated to AirCell complete responsibility
    for complying with the notification, coordination, contact, and
    system shutdown responsibilities that the *AirCell Order*
    specifically imposed on them as licensees.[^138] The opposing
    carriers conclude that this effects an unauthorized transfer of
    control of the licensees\' operations to AirCell.[^139] The
    opponents contend that the *Additional Waivers Order* did not fully
    consider these documented violations, did not even mention the
    \"unauthorized transfer of control\" issue, and simply endorsed what
    AirCell had done.[^140]

42. In our view, the Bureau has examined the allegations of the opposing
    carriers in this regard and addressed each of them fairly and
    adequately. The Bureau considered allegations regarding the AirCell
    partners\' delegation to AirCell of authority to perform certain
    notification, coordination and system management functions, and
    found that \"\[t\]his delegation of authority is consistent with the
    *AirCell Order* and is not inconsistent with each of the AirCell
    partners being ultimately responsible for the operations conducted
    under their respective cellular licenses and at all times fully
    retaining their rights and obligations as Commission
    licensees.\"[^141] The Bureau correctly reiterated in the various
    *Additional Waivers Orders* that the AirCell licensee partners are
    ultimately responsible for all aspects of the operations of their
    individual stations.[^142] In the case of a nationwide network such
    as AirCell is attempting to build, we agree that the AirCell
    partners, while remaining responsible for complying with Commission
    requirements in their participation in the AirCell system, may
    reasonably and prudently assign a single entity the task of being a
    central contact point for system management and system/site
    termination purposes. We therefore agree that this does not effect
    an unauthorized transfer of control of the licensees' operations to
    AirCell.

    **7. Public Interest Claims**

43. We agree with the Bureau's finding that the waiver makes available
    to general aviation aircraft air-ground communications capabilities
    that would otherwise be unavailable, enhancing public safety by
    giving pilots access to safety-related communications.[^143] The
    opposing carriers argue that this rationale does not withstand
    scrutiny,[^144] claiming that the AirCell system was \"certified
    \[by the FAA\] only for use in other than safety critical
    applications.\"[^145] The opposing carriers further assert that the
    provision of air-ground service to general aviation is not a valid
    reason for waiving the rule even if such service might have some
    public safety benefits.[^146] For support, the opposing carriers
    cite the Bureau\'s *JET-TEL Order*, in which the Bureau denied a
    build-out waiver requested by an 800 MHz air-ground licensee on
    \"similar\" grounds, stating that there were alternative sources of
    communications available to general aviation aircraft for
    safety-related communications.[^147] In this instance, however, we
    find few viable alternatives that may provide \"safety-related voice
    communications between pilots and emergency personnel, and can be
    used to uplink in-cockpit, up-to-the-minute weather and air traffic
    information as well as potentially provide in‑flight monitoring of
    airframe and engine operations, serving to better inform ground
    personnel of aircraft operations."[^148] It is clear that although
    the FAA did not certify the AirCell system as dedicated public
    safety equipment, the FAA did note that several public benefits
    could be derived from the system.[^149] On balance, as long as
    primary cellular service is protected as described above,
    consideration of these benefits supports grant of the waiver with
    the safeguards the Bureau has imposed.

    **8. Stay Requests**

44. Because of our resolution of the issues raised by the opposing
    carriers, we deny their requests to stay the *AirCell Order*,
    *Reconsideration Order*, *Additional Waivers Order*, *Second
    Additional Waivers Order*, and *Third Additional Waiver Order*. In
    requesting a stay, a petitioner must demonstrate that: 1) it is
    likely to prevail on the merits; 2) it will suffer irreparable harm
    if a stay is not granted; 3) other interested parties will not be
    harmed if the stay is granted; and 4) the public interest favors
    granting a stay.[^150] The decision we make here resolves the merits
    of this matter and consequently renders petitioners\' requests for
    stay moot.

    **9. Waiver Term**

45. Special Condition 9 of the *AirCell Order*[^151] allows cellular
    licensees that provide cellular service to airborne terminals in
    accordance with the *AirCell Order* to \"submit a comprehensive
    report to assist the Commission in evaluating whether continuation
    of the waiver is in the public interest.\"[^152] The *AirCell Order*
    then provides that \"\[u\]nless the Commission shall determine
    otherwise as a result of evaluation of these reports, the waiver
    will terminate two years after the date of grant.\"[^153] AirCell
    asks that the two-year waiver term be extended to five years or made
    permanent,[^154] contending that by narrowly limiting the duration
    of this waiver, the Bureau may have unnecessarily jeopardized
    AirCell\'s commercial deployment before AirCell and its cellular
    partners can obtain sufficient operating experience.[^155] AirCell
    argues that due to the contentious nature of these proceedings, only
    the first year of operation will form the basis for the
    Commission\'s decision whether or not to continue the waiver,
    whereas the second year will be consumed by efforts to persuade the
    Commission of the need to extend the waiver.[^156] Therefore,
    AirCell requests that it be granted a permanent waiver of the
    airborne cellular rule, with the Commission reserving the
    opportunity to reconsider the waiver based on a full two years of
    operation.[^157] Under AirCell\'s proposal, the Bureau could still
    accept reports filed by cellular licensees at the end of the first
    and second years of operation to ensure that the technology operates
    as expected.[^158] At a minimum, AirCell requests that the waiver be
    given a five-year term.[^159]

46. We agree with the Bureau's setting of an initial two-year term for
    the waiver, but we believe it is appropriate to re-start that term.
    We are sympathetic to AirCell\'s contention that any decision on its
    future operation should be based on a reasonable period of actual
    operation. Because of the substantial uncertainties attendant on
    this proceeding, we believe that the two-year term of this waiver
    should be reset to begin on the effective date of this Order. Only
    in that way can we ensure that there will be enough operational
    experience to judge the technical characteristics of this system.
    Therefore, we will affirm the Bureau\'s grant of a two-year waiver,
    but reset the term to begin on the effective date of this Order.
    [^160]

    **10. TruePosition Petition for Clarification**

47. In its Petition for Clarification, TruePosition requests that the
    Commission expressly prohibit AirCell from interfering with
    carriers\' deployment of Automatic Location Identification (ALI)
    technology (E-911 technology) developed by TruePosition.
    TruePosition requests that the Commission establish that 1) if
    AirCell\'s operation interferes with TruePosition\'s ALI technology,
    AirCell is required to cooperate with TruePosition to resolve the
    problem; and 2) if harmful interference with a carrier\'s ALI
    technology cannot be eliminated, AirCell must cease operation. As
    stated above, AirCell and its partners are authorized to operate
    only as a secondary service and AirCell is prohibited from
    interfering with any primary Commission licensee. AirCell is
    therefore required to cooperate with all primary carriers in
    resolving interference conflicts and is required to cease operation
    if it causes harmful interference into any primary carrier\'s
    system, whether the primary carrier uses E-911 technology or not. We
    do not believe we need to impose any further restrictions on the
    AirCell system to protect E-911 technology.

######### DISCUSSION -- OET PROCEEDING

48. AirCell has operated under various OET experimental authorizations
    and special temporary authorizations since 1992.[^161] On December
    24, 1994, OET granted AirCell a Part 5 authorization, call sign
    KI2XCS, authorizing operation as an experimental radio station. On
    May 30, 1997, in response to oppositions filed by a number of
    cellular licensees operating on the same channel block as AirCell\'s
    partners, OET requested information from AirCell about its
    compliance with the terms of its experimental license and Part 5
    rules, and imposed limitations on AirCell\'s experimental operations
    pending the results of field testing with the opposing cellular
    operators. Specifically, OET suspended AirCell\'s licensed authority
    to conduct a limited marketing study of its experimental AirCell
    system and further limited the AirCell system to the equipment
    (*i.e.*, base stations, mobile units and infrastructure) AirCell
    then had in place \-- namely, 25 base stations and 33 mobile units.
    Also, the *May 1997 OET Letter* reduced the maximum number of
    authorized mobile units from 6,000 to 250.[^162] OET stated that it
    \"froze\" the AirCell system in place pending the completion of
    interference tests, a detailed report on those tests, and OET\'s
    review of that report.[^163]

49. On June 30, 1997, AirCell filed an Application for Review of the
    *May 1997 OET Letter*, in which AirCell opposed the \"freeze\" and
    the reduction in the maximum number of authorized mobile units.
    Subsequently, AirCell jointly conducted field tests with AT&T
    Wireless, GTE Wireless Corp., and BellSouth Cellular Corp. on July
    10-11, 1997, using four cell sites in Texas and Oklahoma. AirCell
    filed a test report prepared by a consulting firm under contract to
    AirCell that it believed supported the conclusion that normal
    operation of the AirCell system produces very low signal strengths
    with little possibility of interfering with cellular base station
    receivers.[^164] On October 9, 1997, AirCell filed a Request to lift
    the \"freeze,\" in which it also requested that the maximum number
    of authorized mobile units be increased from 250 to 4500. Opponents
    of the AirCell experimental license contested the AirCell request,
    arguing that their evaluation of the test results showed that the
    AirCell system could cause interference.[^165]

50. In its February 11, 1998 Letter, OET lifted the AirCell system
    freeze, increased the maximum number of authorized mobile units from
    250 to 1800, and stated that, although there is a possibility that
    AirCell\'s airborne mobile terminals could cause co-channel
    interference to cellular systems, it believed that this interference
    potential is limited to rural areas, the probability of such
    interference occurring is low and, if it occurred, would be
    transitory due to the mobility of the airborne terminals. In
    response to this OET action, certain opposing carriers filed the
    March 1998 Motion for Stay and the March 1998 Application for Review
    of the *February 1998 OET Letter*. In both pleadings, these carriers
    oppose the lifting of the \"freeze\" and the increase in the maximum
    number of authorized mobile units, citing their interpretation of
    the May 1997 Texas/Oklahoma tests that the AirCell system could
    cause harmful interference to primary ground-based cellular systems.

51. Because the freeze has been lifted, the only remaining issue before
    us from the June 1997 AirCell AFR is whether the Commission should
    increase the maximum number of authorized mobile units in the
    AirCell system beyond the level subsequently authorized in the
    *February 1998 OET Letter*. We deny this request because it is not
    justified on this record. We have nothing presently before us to
    indicate that the 1800 mobile units currently authorized under the
    OET experimental license are insufficient for AirCell's testing
    purposes. [^166] We emphasize that there is no legal relation
    between the number of mobiles authorized under the OET experimental
    license and AirCell's operations under the Bureau waiver, and that
    there is no limit on the number of mobile units AirCell may deploy
    as part of its commercial operations pursuant to that waiver.

52. The opposing carriers that filed the March 1998 Stay Request and the
    March 1998 AFR cite four major concerns regarding the *February 1998
    OET Letter*. First, the opponents assert that the Letter reaches
    conclusions regarding the interference potential of the AirCell
    system that are unsupported by and contrary to the weight of the
    evidence. Second, the opponents allege that the Letter, despite
    claiming otherwise, prejudges the interference issue that was being
    considered by the Commission at that time in the context of
    AirCell\'s then pending petition for waiver. Third, the opponents
    claim that the Letter improperly and incorrectly assumes that
    meaningful interference data will be derived from continuing and
    expanding the AirCell experiment. Finally, the opponents contend
    that the Letter will allow AirCell to interfere with terrestrial
    cellular systems.[^167] The carrier opponents request that the
    Commission review the *February 1998 OET Letter* and reinstate the
    freeze on AirCell\'s operations until the Commission has decided the
    issues pending in the waiver proceeding.

53. First, as described in greater detail above, we believe the weight
    of the evidence gathered in both the OET and Bureau proceedings
    does, in fact, justify the conclusion that the AirCell system is
    unlikely to cause harmful interference to terrestrial cellular
    systems. Second, because of our decision in this order upholding the
    Bureau's waiver, the claim regarding the prejudging of the
    interference issue is rendered moot. Third, in light of our decision
    here supporting OET and the Bureau in their interpretation of the
    1997 Texas/Oklahoma test data, we find that meaningful data were and
    can be derived from continuing and expanding the AirCell
    \"experiment.\" Therefore, we deny both the March 1998 Stay Request
    and the March 1998 AFR for the reasons stated above.

######### V. ORDERING CLAUSES

54. ACCORDINGLY, IT IS ORDERED that Appendix A and Appendix B to In re
    AirCell, Inc., Petition, Pursuant to Section 7 of the Act, for a
    Waiver of the Airborne Cellular Rule, or, in the Alternative, for a
    Declaratory Ruling, 14 FCC Rcd 806 (Wireless Tel. Bur. 1998), are
    hereby deleted and that the waiver granted to AirCell, Inc. in that
    order is hereby subject to the conditions set forth in the Appendix
    to this Order.

55. IT IS FURTHER ORDERED that the Application for Review filed by
    Ameritech, AirTouch Communications, Inc., BellSouth Cellular
    Corporation, AT&T Wireless Services, Inc., GTE Wireless
    Incorporated, Bell Atlantic Mobile Inc., and SBC Wireless Inc. on
    January 25, 1999 is hereby DENIED.

56. IT IS FURTHER ORDERED that the Motion for Stay Pending Action on
    Petitioners\' Application for Review filed by Ameritech, AirTouch
    Communications, Inc., BellSouth Cellular Corporation, AT&T Wireless
    Services, Inc., GTE Wireless Incorporated, Bell Atlantic Mobile
    Inc., and SBC Wireless Inc. on January 25, 1999 is hereby DENIED in
    part and is otherwise DISMISSED as moot.

57. IT IS FURTHER ORDERED that the Application for Review filed by
    Ameritech, AirTouch Communications, Inc., BellSouth Cellular
    Corporation, AT&T Wireless Services, Inc., GTE Wireless
    Incorporated, Bell Atlantic Mobile Inc., and SBC Wireless Inc. on
    August 30, 1999 is hereby DENIED.

58. IT IS FURTHER ORDERED that the Motion for Stay Pending Action on
    Petitioners\' Application for Review filed by Ameritech, AirTouch
    Communications, Inc., BellSouth Cellular Corporation, AT&T Wireless
    Services, Inc., GTE Wireless Incorporated, Bell Atlantic Mobile
    Inc., and SBC Wireless Inc. on August 30, 1999 is hereby DENIED in
    part and is otherwise DISMISSED as moot.

59. IT IS FURTHER ORDERED that the Application for Review filed by
    AirTouch Communications, Inc., AT&T Wireless Services, Inc., Bell
    Atlantic Mobile Inc., BellSouth Cellular Corporation, GTE Wireless
    Incorporated, and SBC Wireless Inc. on December 20, 1999 is hereby
    DENIED.

60. IT IS FURTHER ORDERED that the Request for Stay filed by AirTouch
    Communications, Inc., AT&T Wireless Services, Inc., Bell Atlantic
    Mobile Inc., BellSouth Cellular Corporation, GTE Wireless
    Incorporated, and SBC Wireless Inc. on December 20, 1999 is hereby
    DENIED in part and is otherwise DISMISSED as moot.

61. IT IS FURTHER ORDERED that the Application for Review filed by
    AirTouch Communications, Inc., AT&T Wireless Services, Inc., Bell
    Atlantic Mobile Inc., BellSouth Cellular Corporation, GTE Wireless
    Incorporated, and SBC Wireless Inc. on January 19, 2000 is hereby
    DENIED.

62. IT IS FURTHER ORDERED that the Request for Stay filed by AirTouch
    Communications, Inc., AT&T Wireless Services, Inc., Bell Atlantic
    Mobile Inc., BellSouth Cellular Corporation, GTE Wireless
    Incorporated, and SBC Wireless Inc. on January 19, 2000 is hereby
    DENIED in part and is otherwise DISMISSED as moot.

63. IT IS FURTHER ORDERED that the Petition for Reconsideration filed by
    AirCell, Inc. on January 25, 1999 is hereby DENIED in part and
    GRANTED in part, as described herein.

64. IT IS FURTHER ORDERED that the Petition for Clarification filed by
    TruePosition, Inc. on January 25, 1999 is hereby DENIED in part and
    GRANTED in part, as described herein.

65. IT IS FURTHER ORDERED that the Application for Review filed by
    AirCell, Inc. on June 30, 1997 is hereby DENIED in part and is
    otherwise DISMISSED as moot, as described herein.

66. IT IS FURTHER ORDERED that the Application for Review filed by
    BellSouth Cellular Corp., GTE Wireless Products and Services,
    Southwestern Bell Mobile Systems, Inc., and Airtouch Communications,
    Inc. on March 12, 1998 is hereby DENIED.

67. IT IS FURTHER ORDERED that the Motion for Stay Pending Action on the
    March 12, 1998 Application for Review filed by BellSouth Cellular
    Corp., GTE Wireless Products and Services, Southwestern Bell Mobile
    Systems, Inc., Bell Atlantic Mobile, Inc. and Airtouch
    Communications, Inc. on March 12, 1998 is hereby DENIED in part and
    is otherwise DISMISSED as moot.

68. IT IS FURTHER ORDERED, pursuant to section 1.4(b)(2) of the
    Commission's rules, 47 C.F.R. § 1.4(b)(2), that the effective date
    of this Order shall be the date of release of this Order.

FEDERAL COMMUNICATIONS COMMISSION

Magalie Roman Salas

# APPENDIX

# Special Conditions

Authority to provide cellular service to airborne terminals pursuant to
this Order is subject to the following conditions derived from the
record of this proceeding:

1.  [Secondary service]{.underline}. Cellular service provided to
    airborne terminals is deemed a secondary service and as such will be
    held subject to the provisions of section 2.104(d)(4) of the
    Commission\'s rules (47 C.F.R. § 2.104(d)(4)).

2.  [Contact]{.underline}. A contact point capable of shutting down,
    either individually or collectively, the ground stations that
    provide cellular service to airborne terminals, must be available at
    all times. The telephone number of this contact point must be
    provided to notified licensees (see Special Condition 6).

3.  [Duty to provide information]{.underline}. Cellular licensees
    providing cellular service to airborne terminals must promptly
    provide upon request by the Commission any information relating to
    any complaint of interference. Such information could include, but
    is not be limited to, call records for specific ground stations
    including abnormal terminations and information regarding channel
    usage. Records of such information must be retained for at least 30
    days.

4.  [Harmful interference]{.underline}. Harmful interference, for the
    purpose of this condition, is defined as the serious degradation,
    obstruction, or repeated interruption of cellular service. *See*
    definition of \"harmful interference\" in section 2.1 of the
    Commission\'s rules (47 C.F.R. § 2.1). Any cellular licensee
    providing cellular service to airborne terminals must immediately
    take action to resolve any instance of harmful interference, where
    factual evidence (*e.g.*, time of incident and channel coincide)
    shows that the instance is likely to have occurred as a result of
    the operation of ground stations or airborne terminals under its
    control. In addition and notwithstanding the foregoing, any cellular
    licensee providing cellular service to airborne terminals must
    promptly take action to resolve any complaint concerning the effect
    of unwanted energy on reception in a cellular radiotelephone system,
    manifested by a measured degradation in actual performance relative
    to that normally attained in the absence of such unwanted energy,
    where factual evidence shows that such effect is likely to be
    occurring as a result of the operation of ground stations or
    airborne terminals under its control. *See* definition of
    \"interference\" in section 2.1 of the Commission\'s rules. Factual
    evidence means actual operational data (such as abnormal
    terminations or other relevant performance measures), collected over
    a substantial continuous period, which shows degradation of
    performance on channels used for airborne service as compared to
    other channels in service using the same antenna. The Commission may
    terminate or modify authority for any cellular licensee to provide
    cellular service to airborne terminals from any or all ground
    stations under the control of that licensee, without opportunity for
    a hearing, if any valid complaint under this condition is not
    satisfactorily resolved in a timely fashion.

5.  [Operational requirements]{.underline}. Airborne terminals may
    transmit only when in communication with a ground station. Airborne
    terminals must be designed such that unintended interoperation with
    co-block terrestrial cellular systems is prevented.

6.  [Ground station channel selection]{.underline}. Each ground station
    may use no more than six paired channels taken from those specified
    as communication channels in Section 22.905 of the Commission\'s
    rules (47 C.F.R. § 22.905). Licensees providing cellular service to
    airborne terminals must notify appropriate co-block licensees at
    least 30 days prior to commencement of testing or initiation of
    service of each ground station. The purpose of such notification is
    to provide the notified licensees an opportunity to participate in
    determining which channels are to be used at the ground station.
    Appropriate licensees to be notified are those having one or more
    co-block transmitter sites located within 151 kilometers (94 miles)
    of the proposed ground station. Notification must contain relevant
    technical details including the geographical coordinates of the
    ground station antenna site, the channels proposed to be used, and
    the designed communication range of the ground station to airborne
    mobile terminals. If a notified licensee fails to respond within 30
    days, the notifying cellular licensee may consider this to be
    concurrence with the channel selection set forth in the
    notification. This latter 30-day period begins on the date of
    receipt of the notification by the licensee being notified.

7.  [Co-channel technology limitation]{.underline}. Channels that may be
    used at each ground station are limited to those that either are (1)
    unused by the parties with whom coordination is required, or (2) are
    used by the parties with whom coordination is required to provide
    compatible analog cellular service as defined in Section 22.933 of
    the Commission\'s rules (47 C.F.R. § 22.933), unless all of the
    parties with whom coordination is required agree to allow the use at
    a particular ground station of channels that they are using to
    provide service using an alternative technology.

8.  [International limitation]{.underline}. Until such time as
    appropriate arrangements between the U.S. Government and the
    governments of Canada and Mexico, respectively, are agreed to
    concerning cellular service to airborne mobile terminals, the
    following restriction applies: No ground station may be established
    at that will enable cellular service to airborne mobile terminals on
    aircraft while such aircraft are in flight over Canada or Mexico.

9.  [Duration of waiver]{.underline}. One year after the effective date
    of this Order, which affirms the grant of the waiver allowing
    cellular licensees to provide cellular service to airborne terminals
    in accordance with these conditions, cellular licensees may each
    submit a comprehensive report to assist the Commission in evaluating
    whether continuation of the waiver is in the public interest.
    Reports from participating licensees should include a description of
    their experiences with the provision of cellular service to airborne
    terminals, including feasibility, quality of service, customer
    satisfaction, incidents of interference, if any, and how any such
    incidents were successfully resolved. Unless the Commission shall
    determine otherwise as a result of evaluation of these reports, the
    waiver will terminate two years after the release of this Order.

10. [Transmitting power]{.underline}. The transmitter output power of
    each airborne terminal must not exceed 19 dBm. The transmitter
    output power of each airborne terminal must be dynamically
    controlled by a ground station to the lowest power consistent with
    maintaining quality air-ground signals.[^168]

11. [Antenna pattern and installation]{.underline}. Each ground station
    must employ an uptilted antenna pattern. Each airborne mobile
    terminal antenna pattern must exhibit an electromagnetic null
    directly below the aircraft. Each airborne mobile terminal must
    employ only external, permanently installed antennas.

12. [Wave polarization]{.underline}. Electromagnetic waves emitted by
    each ground station must be horizontally polarized. Electromagnetic
    waves emitted by each airborne terminal must be predominantly
    horizontally polarized during normal flight.

[^1]:     ^?^ *See* In re AirCell, Inc., Petition, Pursuant to Section 7
    of the Act, for a Waiver of the Airborne Cellular Rule, or, in the
    Alternative, for a Declaratory Ruling, 14 FCC Rcd 806 (Wireless Tel.
    Bur. 1998) (*AirCell Order*) at 806, ¶ 1.

[^2]:     ^?^ *See id*. at 807, ¶ 3.

[^3]:     ^?^ *Id*.

[^4]:     ^?^ *See id*. at 809, ¶ 8.

[^5]:     ^?^ Forward links are normally the transmissions from a base
    station to mobile units. In AirCell\'s case, they are the
    transmissions from the ground station to airborne terminals. *See
    AirCell Order* at 809, ¶ 8.

[^6]:     ^?^ AirCell Petition for Waiver filed October 9, 1997 at 48;
    *see AirCell Order* at 809, ¶ 8.

[^7]:     ^?^ AirCell Petition for Waiver at 48. Reverse links in this
    situation constitute the transmissions from the airborne unit to a
    ground station. The reverse link from an airborne mobile unit can
    raise greater interference concerns because it is transmitted from a
    high aircraft antenna and is free of the obstructions encountered by
    terrestrial cellular systems. *See AirCell Order* at 809, ¶ 8.

[^8]:     ^?^ AirCell Petition for Waiver at 47; *see AirCell Order* at
    809, ¶ 8.

[^9]:     ^?^ To prevent such interference from occurring, the terminal
    employs a unique technology, which includes the following features:
    (1) a standard Motorola cellular phone with software modifications;
    (2) antennas specially configured for different aircraft designs in
    order to use the aircraft\'s fuselage or stabilizers to direct the
    radio signals; (3) horizontally polarized radio waves; (4) mobile
    units that operate at extremely low power levels, ranging between
    one-eighth and one-six-thousandth of the power level typically
    employed by terrestrial cellular telephones, made possible because
    the ground stations are located in low-noise rural environments and
    generally maintain a line-of-sight connection; and (5) dynamic power
    control by the ground stations, limiting the airborne units\' power
    to the minimum needed to complete the call. AirCell Inc.\'s
    Opposition to Request For Stay, filed February 1, 1999.

[^10]:     ^?^ AirCell Petition for Waiver at 44; *see AirCell Order* at
    809, ¶ 8.

[^11]:     ^?^ *See AirCell Order* at 809, ¶ 8.

[^12]:     ^?^ *Id*.

[^13]:     ^?^ *Id*. at 809, ¶ 9.

[^14]:     ^?^ *Id.*

[^15]:     ^?^ AirCell Petition for Waiver. *See* 47 C.F.R. § 22.925.

[^16]:     ^?^ *See* AirCell, Inc. Amendment to Petition (July 31,
    1998).

[^17]:     ^?^ *AirCell Order*.

[^18]:     ^?^ 47 C.F.R. § 22.925 (prohibition on airborne operation of
    cellular telephones).

[^19]:     ^?^ *AirCell Order*, Appendix A.

[^20]:     ^?^ *Id.* at 819, ¶ 28.

[^21]:     ^?^ *Id*.

[^22]:     ^?^ *Id.* at 806, 817-18, 821-23, ¶¶ 2, 23-24, Appendices A
    and B.

[^23]:     ^?^ *Id.* at 811, ¶ 13.

[^24]:     ^?^ Request for Stay of *AirCell Order*, filed by opposing
    carriers on January 25, 1999 (January 1999 Stay Request).

[^25]:     ^?^ Consolidated Application for Review of *AirCell Order*,
    filed by opposing carriers on January 25, 1999 (January 1999 AFR).

[^26]:     ^?^ January 1999 AFR at 1, 18.

[^27]:     ^?^ Petition for Reconsideration of the *AirCell Order*,
    filed by AirCell on January 25, 1999 (AirCell Petition).

[^28]:     ^?^ AirCell Petition at 4.

[^29]:     ^?^ In re AirCell, Inc., Petition, Pursuant to Section 7 of
    the Act, for a Waiver of the Airborne Cellular Rule, or, in the
    Alternative, for a Declaratory Ruling, Order on Reconsideration,
    DA-99-1522 (Wireless Tel. Bur. July 30, 1999) (*Reconsideration
    Order*), at ¶¶ 1-2.

[^30]:     ^?^ *AirCell Order,* Appendix A, Special Condition 6.

[^31]:     ^?^ *Reconsideration Order* at ¶ 13.

[^32]:     ^?^ *Id.* at ¶ 16.

[^33]:     ^?^ *Id.* at ¶ 12.

[^34]:     ^?^ In re AirCell, Inc., Pine Belt Cellular, Inc., Tennessee
    RSA No. 3 Limited Partnership, WESTEX Telecommunications, Inc., XIT
    Cellular, ETEX Cellular Co., Inc., Cellular Network Partnership, and
    North Alabama Cellular, LLC, Petitions for Waiver of the Airborne
    Cellular Rule, *Order*, DA 99-1523 (Wireless Tel. Bur. July 30,
    1999) (*Additional Waivers Order*).

[^35]:     ^?^ Consolidated Application for Review of *Reconsideration
    Order* and *Additional Waivers Order*, filed by opposing carriers on
    August 30, 1999 (August 1999 AFR).

[^36]:     ^?^ Request for Stay of *AirCell Order*, filed by opposing
    carriers on August 30, 1999 (August 1999 Stay Request).

[^37]: ^?^ In re AirCell, Inc., ALLTEL Communications, Inc., American
    Rural Cellular, Inc., Centennial Cellular Corporation, CenturyTel
    Wireless, Inc., Kentucky RSA 4 Cellular General Partnership, and
    Smith Bagley, Inc. d/b/a Cellular One of Northeast Arizona,
    Petitions for Waiver of the Airborne Cellular Rule, *Order*, DA
    99-2640 (Wireless Tel. Bur. November 24, 1999) (*Second Additional
    Waivers Order*); In re AirCell, Inc. and Western Wireless
    Corporation, Petitions for Waiver of the Airborne Cellular Rule,
    *Order*, DA 99-2950 (Commercial Wireless Div. December 21, 1999)
    (*Third Additional Waiver Order*).

[^38]: ^?^ Application for Review and Request for Stay of the *Second
    Additional Waivers Order*, filed by opposing carriers on December
    20, 1999 (December 1999 AFR); Application for Review of the *Third
    Additional Waiver Order*, filed by opposing carriers on January 19,
    2000 (January 2000 AFR). The December 1999 AFR incorporates by
    reference "\[t\]he issues presented for review and the grounds for
    the relief requested" set forth in the August 1999 AFR. December
    1999 AFR at 2. Similarly, the January 2000 AFR incorporates by
    reference the December 1999 AFR and the opposing carriers' Reply to
    Opposition to the December 1999 AFR, filed January 18, 2000.
    Therefore, in this Order we primarily refer to the issues and
    grounds as presented in the January 1999 AFR and August 1999 AFR.

[^39]: ^?^ In the December 1999 AFR, the opposing carriers ask for
    "vacation of \[the *Second Additional Waivers Order*\] in its
    entirety, dismissal or denial of all airborne cellular service
    waiver requests filed by AirCell and/or its cellular partners, a
    stay of the \[*Second Additional Waivers Order*\] and the prior
    Bureau orders, and a freeze on all further Bureau action." December
    1999 AFR at 2.

[^40]:     ^?^ Petition for Clarification of *AirCell Order*, filed by
    TruePosition on January 25, 1999 (TruePosition Petition).

[^41]:     ^?^ Letter from Richard M. Smith, Chief, Office of
    Engineering and Technology, Federal Communications Commission, to
    David Sieradzki, Esq., and Joel S. Winnick, Esq., Hogan and Hartson,
    Counsel for AirCell, Inc., dated May 30, 1997 (May 1997 OET Letter).

[^42]:     ^?^ Application for Review of the May 30, 1997 Letter Ruling
    released from the Office of Engineering and Technology, filed by
    AirCell on June 30, 1997 (June 1997 AirCell AFR).

[^43]:     ^?^ Motion for Stay of the February 1998 OET Letter, filed on
    March 12, 1998 by BellSouth Cellular Corp., GTE Wireless Products
    and Services, Southwestern Bell Mobile Systems, Inc., Bell Atlantic
    Mobile, Inc., and AirTouch Communications, Inc. (March 1998 Stay
    Request).

[^44]:     ^?^ Application for Review of the February 1998 OET Letter,
    filed on March 12, 1998 by BellSouth Cellular Corp., GTE Wireless
    Products and Services, Southwestern Bell Mobile Systems, Inc., and
    AirTouch Communications, Inc. (March 1998 AFR).

[^45]:     ^?^ Letter from Richard M. Smith, Chief, Office of
    Engineering and Technology, Federal Communications Commission, to
    David Sieradzki, Esq., and Joel S. Winnick, Esq., Hogan and Hartson,
    Counsel for AirCell, Inc., dated February 11, 1998 (February 1998
    OET Letter).

[^46]:     ^?^ *See* Appendix.

[^47]:     ^?^ *See* 47 C.F.R. §§ 2.104(d)(4). Stations of a secondary
    service can claim protection, however, from harmful interference
    from stations of the same or other secondary service(s) to which
    frequencies may be assigned at a later date.

[^48]:     ^?^ Public Notice, Cellular Units Not Authorized for Airborne
    Use, Report No. CL-142, Mimeo 0200 (CCB Oct. 11, 1984).

[^49]:     ^?^ Airborne Use of Cellular Telephones and the Use of Cell
    Enhancers in the Domestic Public Cellular Radio Service, 7 FCC Rcd
    23 (1991) (adopting 47 C.F.R. § 22.925).

[^50]:     ^?^ Airborne Use of Cellular Telephones and the Use of Cell
    Enhancers in the Domestic Public Cellular Radio Service, CC Docket
    88-411, Report and Order, 7 FCC Rcd 23, ¶ 4.

[^51]:     ^?^ *WAIT Radio v. FCC*, 418 F.2d 1153, 1159 (D.C. Cir.
    1969), *cert. denied*, 409 U.S. 1027 (1972).

[^52]:     ^?^ August 1999 AFR at 7.

[^53]:     ^?^ Opposition to Application for Review, filed by AirCell on
    September 14, 1999, at 13 (AirCell September 1999 Opposition).

[^54]:     ^?^ AirCell September 1999 Opposition at 13, *citing*,
    *AirCell Order*, Appendix A, Special Conditions 1 & 4.

[^55]: ^?^ *See*, *e.g.,* December 1999 AFR at 5.

[^56]: ^?^ *AirCell Order* at 817, ¶ 23.

[^57]: ^?^ *Id.*

[^58]: ^?^ *See, generally,* January 1999 AFR at 20-23.

[^59]: ^?^ *See id.* at 20, 22.

[^60]: ^?^ In addition, we note that on the first day, AirCell chose a
    "worst case" scenario for site location, *i.e.*, the tests were
    conducted in a rural area where there was no urban noise to mask the
    AirCell signal, and in a manner such that the AirCell airborne
    mobile unit was close to the "victim" site and far from the AirCell
    partner site. With this configuration, the AirCell mobile has to
    emit its highest power level in order to reach its partner site.
    Even under this configuration, the data from the first day of
    testing show that there is little likelihood of harmful
    interference.

[^61]: ^?^ All cellular systems use dynamic power control, which enables
    the cellular system to control the transmitting power of mobile
    units in order continually to use the least power necessary to
    sustain the call at the desired quality. Thus, the closer an AirCell
    airborne mobile unit is to the serving AirCell partner ground
    station, the less transmitting power it uses. Conducting a test with
    the power control element turned off may be useful for calibrating
    equipment or testing antenna patterns, but it does not give useful
    data regarding how that system functions *as designed*.

[^62]: ^?^ *See* January 1999 AFR at 20-21, 22.

[^63]: ^?^ The aircraft the opposing carriers used had a raised
    stabilizer; the antenna was installed underneath this stabilizer,
    which caused a downward antenna reflection instead of the usual null
    directly beneath the airplane. AirCell specifies a different type of
    antenna for this type of aircraft, to avoid this problem.

[^64]: ^?^ These data might have shown the power level at which the
    airborne unit was transmitting when the AirCell partner ground
    station lost control of it; automatic power control is one of the
    interference avoidance techniques fundamental to the AirCell design.

[^65]: ^?^ This made it possible to capture the AirCell airborne
    terminal with the base station. However, under normal circumstances,
    the AirCell caller would have terminated the call because of
    interference to the AirCell call before any interference occurred to
    the "victim" cell site.

[^66]: ^?^ January 1999 AFR at 21-22.

[^67]: ^?^ Dr. Lee used test data from both days of the Texas tests, but
    based his conclusions on use of an interference threshold of minus
    124 dBm. We believe that this is too conservative and that an
    interference threshold of minus 117 dBm is more realistic for
    typical analog systems. Based on our review of the evidence, it
    appears to us that use of the latter threshold would have led to a
    finding that AirCell would cause a significant level of harmful
    interference 0% of the time.

[^68]: ^?^ January 1999 AFR at 22.

[^69]: ^?^ This assertion appears to refer to an argument made by Bell
    Atlantic in comments filed against the AirCell Petition on December
    15, 1997. Comments of Bell Atlantic Mobile, Inc., in Opposition to
    Petition for Waiver, filed December 15, 1997, at 12. However, the
    discussion in the 1997 pleading concerned CDMA (digital) operations,
    whereas a condition in the AirCell waiver does not allow AirCell
    partners to use channels used for digital operations within the
    notification distance. Moreover, the 1997 pleading appears to assume
    that an AirCell airborne mobile unit could affect all three faces at
    a given cell site simultaneously, which we consider very unlikely
    because of geometrical considerations. *See infra* para. 37.

[^70]: ^?^ January 1999 AFR at 22.

[^71]: ^?^ *Id.*

[^72]: ^?^ *See* 47 C.F.R. § 22.907.

[^73]: ^?^ January 1999 AFR at 22. In this pleading, the opposing
    carriers also assert, at pages 22-23, that the Bureau ignored other
    disputes in the record and evidence that AirCell will cause
    interference. These assertions are not accompanied by record
    citations or other detail that would enable us to address them.

[^74]:     ^?^ January 1999 AFR at 7-10.

[^75]:     ^?^ August 1999 AFR at 7, *citing*, *AirCell Order* at ¶¶ 3,
    4, 8, 14, 15, 22, 23.

[^76]:     ^?^ *Id*., *citing*, *AirCell Order* at 817, ¶ 22.

[^77]:     ^?^ *Id*.

[^78]:     ^?^ *Id*.

[^79]:     ^?^ *Id*., *citing*, *AirCell Order* at 818, ¶ 24.

[^80]:     ^?^ August 1999 AFR at 10.

[^81]:     ^?^ AirCell September 1999 Opposition at 13 n. 24, *citing*,
    *e.g.*, Amendment of Part 5 of the Commission\'s Rules to Diminish
    Restrictions on the Licensing and Use of Stations in the
    Experimental Radio Services (other than Broadcast), Gen. Docket No.
    82-469, FCC 83-471 (released Nov. 16, 1983).

[^82]:     ^?^ AirCell September 1999 Opposition at 14.

[^83]:     ^?^ Special Conditions 6 and 7 continue to be subject to the
    clarifications made in the Bureau's *Reconsideration Order*. *See
    Reconsideration Order* at ¶¶ 10-16.

[^84]:     ^?^ January 1999 AFR at 11-12.

[^85]:     ^?^ January 1999 AFR at 2, *citing*, 47 C.F.R. § 22.905,
    22.909, 22.911, 22.912.

[^86]:     ^?^ See, *e.g.*, Amendment of Part 22 of the Commission\'s
    Rules to Provide for Filing and Processing of Applications for
    Unserved Areas in the Cellular Service and to Modify Other Rules,
    *Further Memorandum Opinion and Order on Reconsideration*, 12 FCC
    Rcd 2109 at 2116, 2118 (1997) (\"any non-consensual extension into a
    licensee\'s CGSA on the same channel block would constitute
    interference from which the licensee and its customers have a right
    to be protected, pursuant to Section 22.911\...\").

[^87]:     ^?^ 47 C.F.R. § 22.911.

[^88]:     ^?^ 47 C.F.R. § 22.911(d).

[^89]:     ^?^ 47 C.F.R. § 22.911(d)(1). However, because of AirCell's
    secondary status, licensees here may "steer" AirCell toward or away
    from any particular channel(s) on AirCell's proposed channel list.

[^90]:     ^?^ The service area of a cell is the area within its service
    area boundary (SAB), which is a line of points described by the
    mathematical formula in section 22.911(a)(1) and (3)-(6) of our
    rules. 47 C.F.R. § 22.911(a)(1), (3)-(6). The CGSA is the composite
    of the service areas of all the cells in the system. 47 C.F.R. §
    22.911(a).

[^91]:     ^?^ 47 C.F.R. § 22.911(d)(2)(ii).

[^92]:     ^?^ 47 C.F.R. § 22.911(d)(2)(i).

[^93]:     ^?^ The SAB of a cell site is determined only by use of a
    mathematical formula in § 22.911(a) of the Commission's rules and
    the height and the power of that site. The SAB is not determined by
    considering the physical locations where subscriber units can
    receive service, as the opposing carriers imply.

[^94]:     ^?^ 47 CFR § 22.905(a) provides: \"Each channel block is
    assigned exclusively to one licensee for use in that licensee\'s
    cellular geographic service area (*see* § 22.911).\" 47 CFR §
    22.911, in turn, provides in relevant part that \"\[t\]he cellular
    Geographic service area (CGSA) of a cellular system is the
    geographic area considered by the FCC to be served by the cellular
    system. The CGSA is the area within which cellular systems are
    entitled to protection....\"

[^95]:     ^?^ *AirCell Order* at 811, ¶ 13; *Reconsideration Order* at
    ¶ 10.

[^96]:     ^?^ In this context, we make clear that the only limitation
    our cellular service rules place on where mobile units (*i.e.*,
    cellular telephones, or in this case the AirCell airborne
    transmitters) may operate is the airborne cellular prohibition
    itself, section 22.925, the waiver of which is at issue in this
    proceeding.

[^97]:     ^?^ *AirCell Order* at 816-817, ¶ 21.

[^98]:     ^?^ *Reconsideration Order* at ¶¶ 15-16.

[^99]:     ^?^ *Id*.

[^100]:     ^?^ *Id*.

[^101]:     ^?^ *Id*.

[^102]:     ^?^ August 1999 AFR at 20, *citing*, Final Report, AirCell
    Flight test, July 10-11, 1997, at 53-56 (Exhibit C to the AirCell
    Waiver Application) (*Final Report*).

[^103]:     ^?^ August 1999 AFR at 20.

[^104]:     ^?^ *AirCell Order* at 813, ¶ 16.

[^105]: ^?^ Defined as the received power when there is no desired
    signal present, the "noise floor" is comprised of thermal noise,
    receiver noise, and environmental noise (including that caused by
    interfering signals). *See* C.J. Hall, "Evaluating Noise," on the
    Internet at
    [http://www.wirelessreview.com/issues/1998/81115/tm.htm]{.underline}.

[^106]:     ^?^ It appears from our analysis of the record that
    AirCell's contribution to the overall radio noise level is
    comparable to that of the existing sources of noise that cellular
    system planners must routinely overcome. Although very marginal
    quality calls in quiet rural areas may be affected, we believe such
    occurrences will be rare and are totally avoidable with careful
    channel selection. *See AirCell Order* at 812, ¶ 14.

[^107]:     ^?^ We also reject opposing carriers' complaint regarding
    the Bureau's clarification that, for the purposes of Special
    Condition 7, "unused" channels include channels that other carriers
    may plan to use for digital service in the future but that are not
    currently carrying digital transmissions. *See* *Reconsideration
    Order* at ¶ 11; August 1999 AFR at 15. We believe this is an
    appropriate clarification. We also believe that it was appropriate
    for the Bureau to require carriers to give AirCell and its partners
    sixty days' notice of a carrier's intention to put a channel
    currently being used for AirCell transmissions into digital service.
    Without notification, AirCell and its partners would be unaware that
    AirCell transmissions would no longer be permitted on that channel
    under the terms of the waiver. The notice period also gives AirCell
    and the partner time to re-engineer their operations and undertake a
    new 30-day notification period, as required by Special Condition 6,
    without unnecessary disruption of service to AirCell's customers.

[^108]:     ^?^ August 1999 AFR at 20, *citing*, *Reconsideration Order*
    at ¶ 12.

[^109]:     ^?^ *Id*.

[^110]: ^?^ Defined as that portion of a radio emission outside of its
    occupied bandwidth, "sideband noise" generally consists of ½% of the
    emission's power above and below the occupied bandwidth, for a total
    of 1%.

[^111]:     ^?^ August 1999 AFR at 21.

[^112]:     ^?^ *Id*.

[^113]:     ^?^ *Id*.

[^114]:     ^?^ *Id.*

[^115]: ^?^ A cellular CDMA guardband typically comprises 6 to 9
    contiguous unused analog cellular channels (180 to 270 kHz).

[^116]: ^?^ Additionally, the opposing carriers do not explain why
    AirCell would be using the closest channel to the CDMA channel
    rather than one several analog channels away. The coordination
    process set up in the *AirCell Order* and *Reconsideration Order*
    allows non-participating carriers to "steer" AirCell away from
    particular channels in favor of others if they so choose.

[^117]: ^?^ *See* Appendix, Special Condition 10.

[^118]: ^?^ The guardband may also help to reduce the noise floor
    increase experienced by a CDMA mobile telephone receiver as it
    passes in the immediate vicinity of an analog cell site (base
    station), but that situation is irrelevant to our analysis here
    because the AirCell ground stations would not be located within an
    opposing carrier's CGSA, and on the opposing carrier's channel
    block.

[^119]: ^?^ However, at the geographic juncture between a CDMA cellular
    system and an adjacent-market analog cellular system, some careful
    channel coordination is generally required to protect the CDMA
    operations from the adjacent-market system's analog subscribers, as
    well.

[^120]: ^?^ We do disagree with the Bureau's characterization of the
    guardbands as "essentially wasted." *Reconsideration Order* at ¶ 12.
    The basic rationale for CDMA guardbands is that using 42 analog
    channels for a single CDMA channel and refraining from using an
    additional 9 channels on each side (the guardbands) results in much
    greater capacity than if all 60 channels were used for analog
    service.

[^121]: ^?^ *See, e.g.*, "CDMA Technology & Benefits," Motorola Cellular
    Infrastructure Group; on the Internet at
    [[http://rf.rfglobalnet.com/library/ApplicationNotes/files/7/motcig.htm]{.underline}](http://www.rfglobalnet.com/library/applicationnotes/files/7/motcig.htm).

[^122]: ^?^ The bandwidth of an IS-95A CDMA emission is typically given
    as 1.25 MHz.

[^123]: ^?^ While the loss of numerous information bits may cause loss
    (erasure) of an entire frame of data (a frame is a basic interval of
    time, typically 20 milliseconds), a call can survive loss of some
    frames. Thus, CODECs (COder/DECoder units used in CDMA systems to
    convert analog signals into digital signals and vice versa) are
    generally tested for their performance under condition of a 3% frame
    erasure rate.

[^124]: ^?^ "Passband" is defined as the frequency range within which
    the receiver is designed to receive signals. Cellular receivers are
    designed to receive signals over a certain range and block signals
    not within that range.

[^125]: ^?^ The CDMA receiver front end should provide some attenuation
    to signals appearing in the guardband, which is actually outside of
    the receiver passband. For the purpose of analysis, however, we will
    assume the CDMA receiver would have some sensitivity to energy
    transmitted in the guardband in addition to spurious energy
    transmitted into its passband, such as sideband noise from
    transmitters operating in the guardband.

[^126]: ^?^ CDMA cellular systems automatically control the power of
    CDMA cellular telephones very precisely -- as often as 800 times per
    second in 1 dB steps over an 84 dB range.

[^127]: ^?^ CDMA cell sites are normally tri-sectored. Each sector or
    "face" independently uses the same CDMA channel.

[^128]: ^?^ AirCell Petition for Waiver, Appendix C at p. 20; Letter
    from David L. Sieradzki, Hogan and Hartson, Counsel for AirCell,
    Inc. to Magalie Roman Salas, Secretary, Federal Communications
    Commission, dated November 19, 1998, Attachment at p. 6 ("AirCell's
    Mobile Antenna Pattern has a Null Directly Downward to Minimize
    Radiated Power Downward"); Letter from Joel S. Winnik, Hogan and
    Hartson, Counsel for AirCell, Inc. to Magalie Roman Salas,
    Secretary, Federal Communications Commission, dated October 21,
    1998, Attachment at p. 17; s*ee also AirCell Order* at ¶ 8.

[^129]:     ^?^ August 1999 AFR at 11.

[^130]:     ^?^ *Id*.

[^131]:     ^?^ *Id*.

[^132]:     ^?^ *Id*.

[^133]:     ^?^ AirCell September 1999 Opposition at 23-24.

[^134]:     ^?^ *Id*., *citing*, *e.g.*, Petitions for Waiver of Part 69
    of the Commission\'s Rules to Establish Switched Access Rate
    Elements for SONET-based Service, 11 FCC Rcd 21010 (CCB 1996)
    (granting waivers to Bell Atlantic and six other \"me-too\" LECs \--
    Pacific Bell, BellSouth, US West, Ameritech, GTE, and SNET \-- to
    permit establishment of new rate elements to recover costs of
    switched transport services using Synchronous Optical Network
    (\"SONET\") technology); Bell Atlantic Telephone Companies,
    Southwestern Bell Telephone Company, Petitions for Waiver of Section
    69.4(b) of the Commission\'s Rules, 9 FCC Rcd 7868 (CCB 1994)
    (granting waivers to Bell Atlantic and \"me-too\" petitioner SWBT to
    permit establishment of additional rate elements for automated
    calling card handling, automated collect and billed-to-third-number
    handling, live operator handling of IXC \[interexchange carrier\]
    traffic); The Ameritech Operating Companies, Bell Atlantic Telephone
    Companies, BellSouth Telecommunications, Inc., Cincinnati Bell
    Telephone Company, GTE Services Corporation, The NYNEX Telephone
    Companies, Pacific Bell, Rochester Telephone Corp., Southern New
    England Telephone Company, Southwestern Bell Telephone Company, The
    United Telephone and Central Telephone Companies, and U S West
    Communications, Petitions for Waiver of Sections 69.4(b) and 69.106
    of Part 69 of the Commission\'s Rules, 9 FCC Rcd 7873 (CCB 1994)
    (granting waivers to permit establishment of separate rate elements
    for provision of 500 access service).

[^135]:     ^?^ *See* AirCell September 1999 Opposition at 22-23.

[^136]:     ^?^ *Id*.

[^137]:     ^?^ AirCell system implementation issues have been sharply
    contested by the opposing parties; *see, e.g.,* Letter from Kathryn
    A. Zachem, Wilkinson, Barker, Knauer, LLP, Counsel for BellSouth
    Cellular Corporation, *et al*., to Magalie Roman Salas, Secretary,
    Federal Communications Commission, dated May 28, 1999; Letter from
    David L. Sieradzki, Hogan and Hartson, Counsel for AirCell, Inc. to
    Magalie Roman Salas, Secretary, Federal Communications Commission,
    dated June 8, 1999; Letter from David L. Sieradzki, Hogan and
    Hartson, Counsel for AirCell, Inc. to Magalie Roman Salas,
    Secretary, Federal Communications Commission, dated June 15, 1999;
    Letter from C. Clairborne Barksdale, BellSouth Cellular Corp., *et
    al*., to Magalie Roman Salas, Secretary, Federal Communications
    Commission, dated June 22, 1999; Letter from Timothy E. Welch, Hill
    and Welch, Counsel for New-Call Inc, dba Cellcom, *et al*., to
    Magalie Roman Salas, Secretary, Federal Communications Commission,
    dated June 23, 1999; Letter from C. Clairborne Barksdale, BellSouth
    Cellular Corp., *et al*., to Magalie Roman Salas, Secretary, Federal
    Communications Commission, dated June 30, 1999; Motion to Dismiss
    \"Me-Too\" Waiver Requests filed by C. Clairborne Barksdale,
    BellSouth Cellular Corp., *et al*., on June 30, 1999; Letter from
    David L. Sieradzki, Hogan and Hartson, Counsel for AirCell, Inc. to
    Magalie Roman Salas, Secretary, Federal Communications Commission,
    dated July 7, 1999; Letter from Kathryn A. Zachem, Wilkinson,
    Barker, Knauer, LLP, Counsel for BellSouth Cellular Corporation, *et
    al*., to Magalie Roman Salas, Secretary, Federal Communications
    Commission, dated July 20, 1999.

[^138]:     ^?^ August 1999 AFR at 23.

[^139]:     ^?^ *Id*.

[^140]:     ^?^ *Id*.

[^141]:     ^?^ *Additional Waivers Order* at ¶ 8; *see also Second
    Additional Waivers Order* at ¶ 8.

[^142]:     ^?^ *Id*.

[^143]:     ^?^ *AirCell Order* at 812- 814, ¶¶ 15-17.

[^144]:     ^?^ August 1999 AFR at 21.

[^145]:     ^?^ *Id*. In its June 21, 1999 letter to the Commission,
    Aeronautical Radio, Inc. (ARINC) contends that although it took no
    position on \"whether, or under what conditions, AirCell should be
    permitted to operate in conjunction with terrestrial cellular
    systems,\" it noted that the \"AirCell system is certified only for
    use in *other than safety critical* applications.\" Letter from John
    L. Bartlett, Wiley, Rein and Fielding, Counsel for Aeronautical
    Radio, Inc. to Magalie Roman Salas, Secretary, Federal
    Communications Commission, dated June 21, 1999. We note that ARINC
    bases its conclusions on a Letter from Barry L. Valentine, Acting
    Deputy Administrator, Federal Aviation Administration (FAA) to
    William Caton, Secretary, Federal Communications Commission, dated
    December 19, 1997. In that letter, the FAA noted that \"\[a\]t the
    present time, the AirCell system is certified only for use in other
    than safety critical applications . . . \[b\]ecause it does not
    operate within the spectrum dedicated to aviation.\" However, the
    FAA also stated that \"reliable, real-time flight information
    provided to the cockpit can be very important,\" and that the FAA
    supports \"the development of technologies that may assist the
    pilot.\" Despite this limitation in the system\'s certification,
    therefore, we believe that AirCell\'s airborne cellular service
    offers significant public safety benefits, in particular the
    enhancement of navigational safety of general aviation aircraft.
    *See AirCell Order* at 806-807, ¶ 2.

[^146]:     ^?^ *Id*.

[^147]:     ^?^ August 1999 AFR at 22, n. 63, *citing*, *JET-TEL Group
    Limited Partnership*, 11 FCC Rcd 21,215, ¶ 15 (WTB 1996).

[^148]:     ^?^ *AirCell Order* at 812-813, ¶ 15, *citing*, GE Research
    Comments at 2-3; Harris Corporation at 1.

[^149]:     ^?^ *See* AirCell September 1999 Opposition at 11, *citing*,
    Letter from Barry L. Valentine, Acting Deputy Administrator, FAA, to
    William Canton, Secretary FCC (December 19, 1997) (Attachment A-2 to
    AirCell Reply Comments filed January 12, 1998).

[^150]:     ^?^ *Virginia Petroleum Jobbers Assoc. v. FPC*, 259 F. 2d
    921, 925 (D.C.Cir. 1958); *Washington Metropolitan Area Transit
    Comm. v. Holiday Tours, Inc. et al.*, 559 F.2d 841, 843 (D.C. Cir.
    1977); In re CBS Communications Services, Inc., Licensee of Private
    Operational Fixed Microwave Station WEH913, Miramar, Puerto Rico and
    Centennial Wireless PCS License Corporation, Licensee of B Block PCS
    Station KNLF 250, Puerto Rico-U.S. Virgin Islands MTA, *Order*, 13
    FCC Rcd. 4471, 4473 (Wireless Tel. Bur. 1997).

[^151]:     ^?^ *AirCell Order*, Special Condition 9.

[^152]:     ^?^ *Id*.

[^153]:     ^?^ *Id*.

[^154]:     ^?^ AirCell Petition at 1. The Petition also asks for Bureau
    reconsideration of the 168-mile notification distance requirement.
    The notification distance issue was resolved in the *Reconsideration
    Order,* in which the notification distance requirement was reduced
    from 168 miles to 94 miles. AirCell has not requested further review
    of that order.

[^155]:     ^?^ *Id*. at 7-8.

[^156]:     ^?^ *Id*.

[^157]:     ^?^ AirCell Petition at 9.

[^158]:     ^?^ *Id*.

[^159]:     ^?^ *Id*.

[^160]:     ^?^ By this action, we are not extending the waiver pursuant
    to Special Condition 9 of the Bureau's *AirCell Order*; instead, we
    are re-starting the two-year clock on the term of the waiver as of
    the effective date of this Order, for the reasons stated above.
    Special Condition 9 to the waiver shall apply, going forward and as
    modified in the Appendix to this Order to take account of the new
    start date, to any extension of the waiver by the Bureau. The
    reports contemplated in Special Condition 9 may be submitted on the
    basis of a year's experience under the waiver, as reset by this
    Order, *i.e.*, based on experience through one year from the
    effective date of this Order.

[^161]:     ^?^ AirCell first operated under Special Temporary
    Authority, call sign KS2XAT.

[^162]:     ^?^ May 1997 OET Letter.

[^163]:     ^?^ *Id*.

[^164]:     ^?^ *See* Final Report, *supra*, note 68.

[^165]:     ^?^ *See*, *e.g.*, Letter from C. Claiborne Barksdale,
    BellSouth Cellular Corp., and Andre J. Lachance, GTE Wireless
    Products and Services, to Richard M. Smith, Chief, Office of
    Engineering and Technology, dated Oct. 20, 1997.

[^166]:     ^?^ Because AirCell may properly wish to continue improving
    its technology through testing under the aegis of the OET license as
    it simultaneously continues commercial implementation of its system
    consistent with the restrictions set forth in the Bureau waiver,
    AirCell's OET experimental license is not superseded by our decision
    in this Order upholding the Bureau's waiver of Section 22.925 of our
    rules.

[^167]:     ^?^ March 1998 Application for Review at 2.

[^168]: ^?^ In addition, our rules require that the effective radiated
    power of each ground station transmitter must not exceed 500 Watts.
    47 C.F.R. § 22.913(a).