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) ORDER ON RECONSIDERATION Adopted: July 30, 1999 Released: July 30, 1999 By the Deputy Chief, Wireless Telecommunications Bureau: I. INTRODUCTION 1. In this Order, the Wireless Telecommunications Bureau (Bureau), partly on its own motion and partly in response to a petition for reconsideration and clarification filed by AirCell, Inc. (AirCell), clarifies and reconsiders certain specific aspects of the Order the Bureau released on December 24, 1998 granting AirCell and its participating carriers a waiver of section 22.925 of the Commission's rules, subject to certain specified conditions. At that time, 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. The Bureau believed that its Order articulated an operating scheme that would enable AirCell to offer its air-ground voice and data link system to the public for a two-year period while also preserving for non-participating carriers the protection from harmful interference guaranteed in Commission rules. However, as set out in the record before us,implementation of the operating scheme set forth in the AirCell Order has not progressed as the Bureau intended. 2. Specifically, we clarify Special Condition 6 of the AirCell Order, which describes the notification or channel selection process AirCell and its partners must initiate to make their ground station channel selections. We also reconsider that aspect of Special Condition 6 of the AirCell Order that provides that "[a]ppropriate licensees to be notified are those having one or more co-block transmitter sites located within 270 kilometers (168 miles) of the proposed ground station." For the reasons set forth below, we reduce this notification distance from 270 kilometers (168 miles) to 151 kilometers (94 miles). Finally, we also clarify Special Condition 7 of the AirCell Order, which describes the limitations the Bureau imposed on the AirCell partners' channel selection process. We take these actions on our own motion to enable operation of the AirCell system as intended by the original Order. II. BACKGROUND 3. The AirCell System. AirCell has developed a system of specially engineered mobile cellular terminals for use aboard general aviation aircraft. The AirCell system operates on secondary status in order to guarantee 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. Customer traffic from an AirCell mobile telephone is interconnected with the public switched network through an AirCell partner's cellular switch. 4. AirCell's system has a number of features designed to avoid causing 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 is able to operate the airborne transmitters at a very low power level. Thus, while the forward link voice and control channels transmit from ground station sites at approximately the same power levels used by cellular base stations, the AirCell airborne mobile terminals operate with lower transmitter power than ordinary cellular telephones in order to reduce the likelihood of interference from the reverse link transmissions. AirCell mobile terminals typically transmit at power output levels of 5 milliwatts or less, considerably less than the power typically put out by cellular portable handsets. To further decrease the likelihood that the system will cause interference, the AirCell system was designed to use horizontal wave polarization as opposed to the vertical polarization used by most conventional cellular systems, thus providing a degree of additional isolation between the AirCell system's signals and those of terrestrial systems. Finally, the Bureau noted that AirCell claims 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. Frequency coordination with non- participating cellular licensees, as provided for in the AirCell Order, would further reduce the potential for interference. 5. The Bureau noted AirCell's 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. 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. 6. 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, and that the AirCell cellular partner would shut down an AirCell mobile terminal or cease AirCell operation from the relevant ground station altogether in the event of unresolved harmful interference. 7. On December 24, 1998, the Bureau granted a waiver of section 22.925 of the Commission's rules, which prohibits the airborne use of cellular telephones. 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. 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. 8. On January 25, 1999, AirCell filed its Petition for Reconsideration and Clarification of the AirCell Order, expressing its concern that the notification distance of 168 miles required in Special Condition 6 of the AirCell Order was overly burdensome. AirCell claims that the 168 mile notification limit, in conjunction with what it contends is the uncooperative nature of some of AirCell's cellular opponents, make it extremely difficult for AirCell to operate its system as contemplated by the AirCell Order due to its inability to obtain clearance for the channels it intends to use. On April 16, 1999, AirCell filed a Request for Expedited Relief, in which it states that "licensees that have opposed AirCell at the FCC . . . have refused, despite repeated requests on behalf of AirCell's cellular licensee partners, to coordinate as contemplated" in the AirCell Order. The opposing carriers maintain that they are complying with the AirCell Order. In their Consolidated Opposition to the AirCell Petition for Reconsideration, the opposing carriers also maintain that the distance requirement for notification and coordination is not burdensome on AirCell and should be maintained. III. DISCUSSION 9. In the AirCell Order, the Bureau concluded that AirCell had sufficiently shown that "unique circumstances exist which justify a limited waiver of section 22.925 and that a strict application of the Commission's rule prohibiting the airborne use of cellular telephones would be contrary to the public interest." The Bureau was mindful of the harmful interference concerns expressed by a number of commenters but believed that proper operation of the AirCell system would not be prejudicial to cellular licensees. The Bureau also believed it had developed an operating scheme that would enable AirCell to offer its air-ground voice and data link system to the public while preserving for non-participating carriers the protection from harmful interference guaranteed all primary carriers by Commission rules. The Bureau concluded that authorizing the operation of the AirCell system would provide greater access to public safety information and would better serve the public interest than strict application of section 22.925. 10. In order to ensure protection of other carriers from harmful interference, the Bureau not only carefully considered test evidence demonstrating the AirCell system's operation, but also imposed secondary status upon all AirCell operations. AirCell is thus explicitly barred from causing harmful interference to other carriers. In addition, the Bureau imposed the notification process contained in Special Condition 6 to help ensure that other carriers would not be harmed by AirCell operations. We note further that, since the AirCell Order was adopted, we have not received any information from AirCell's opponents to contradict the conclusion reached in the AirCell Order that AirCell's system is not likely to pose a significant risk of harmful interference to other carriers. Even with these protections, the Bureau believed that the original AirCell Order granted to AirCell and its cellular partners the opportunity to demonstrate the viability and benefits of the innovative service it proposed. Given that the operating scheme for the AirCell system is not functioning as intended, however, we clarify Special Condition 7 and the exact nature of the co-channel technology limitation we imposed on AirCell and its partners in their channel selection process. We also clarify the notification process described in the Special Condition 6. Finally, we reconsider the notification distance requirement contained in Special Condition 6. 11. Use of Digital Channels. Special Condition 7 reads as follows: Co-channel technology limitation. 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. In the AirCell Order, the Bureau thus limited AirCell operation to channels that are used for analog cellular service or are unused in the area in question, unless all relevant parties agree otherwise. The Bureau noted that "[a]lthough it is possible that the AirCell system does not interfere with digital cellular systems, we cannot reach that conclusion at this time based on the record in this waiver proceeding." To date, the record does not contain any data that add to our understanding of AirCell's effect on digital cellular systems. Therefore, for the time being, we will continue to impose Special Condition 7 on AirCell and its partners. However, in response to AirCell's request, we clarify that only channels that are currently carrying transmissions may be considered to be "in use" for the purposes of Special Condition 7. For example, channels that carriers plan to use for digital service at some time in the future are not off limits to AirCell under Special Condition 7. When a neighboring carrier puts a channel AirCell is using into digital service, AirCell may of course be required by that carrier to move its operation. Any move must occur by the later of: (1) 60 days after AirCell is notified by the carrier providing the service that digital service is planned, or (2) the date digital service actually commences. Similarly, channels that are immediately adjacent to channels that are in use, but that do not themselves have transmissions on them, are "unused" for the purpose of Special Condition 7. 12. Further, in response to a request by AirCell, we clarify the status of code division multiple access (CDMA) guard bands as they relate to Special Condition 7. Normally, CDMA cellular systems must remove analog compatible cellular operations from 42 AMPS channels for every CDMA channel introduced, and it is standard engineering practice to leave an additional 7 to 9 channels as a guard band between CDMA and analog cellular operations. Although the guard band is not used and is essentially wasted, the capacity gain from using CDMA on the other 42 AMPS channel segments more than makes up for the loss, in comparison to the capacity that could be achieved by AMPS operation only. The purpose of the guard band is to prevent sideband noise from AMPS mobiles that are in close proximity to a CDMA base station from adding to the system noise floor, which would reduce the range and capacity of that CDMA base station. AirCell contends that CDMA guard bands should not be considered "in use" for the purposes of channel selection. The opposing carriers argue that "AirCell operation on its requested control frequencies when they are in use as a CDMA guard band, will result in increased RF noise, reducing the CDMA system's capacity and coverage, and resulting in difficulty in call origination, a higher dropped call rate, and poorer quality service." We disagree with the opposing carriers' arguments on technical grounds. AirCell's terminals achieve low power operation by using attenuation in the transmit path after the final amplifier stage. This means that sideband noise is also attenuated and is well below typical analog cellular emissions as well as the FCC emission mask requirements for analog cellular. Furthermore, under normal operation AirCell's airborne terminals do not come within the immediate proximity of CDMA base stations. For these reasons, we believe that AirCell units can operate in the CDMA guard band channels without having adverse effects on the CDMA system. We therefore consider CDMA guard bands to be "unused" for the purpose of Special Condition 7. 13. Notification Process. Special Condition 6 reads as follows: Ground station channel selection. 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 270 kilometers (168 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. 14. As stated above, the Bureau determined that the AirCell system poses little likelihood of harmful interference to terrestrial cellular systems. Beyond the design of the AirCell system, additional protection for primary services against any possible harmful interference is guaranteed by the AirCell operation's status as a secondary service. The notification process provided in Special Condition 6 was adopted by the Bureau to help facilitate ground station channel selection. More precisely, the notification process gives non-AirCell carriers the opportunity (but not the obligation) to steer AirCell and its partners toward or away from particular ground station channels. We clarify Special Condition 6 to indicate that it is consistent with the AirCell Order for AirCell or its relevant partner to notify other carriers of intended channel usage by submitting a channel list of any length, even including all 395 potentially free channels that each channel block may contain, with channels listed in the order in which AirCell proposes to use them. If the notified carrier wishes, it may point AirCell toward or away from particular channels on this list. If the notified carrier does not wish to do so, AirCell will nevertheless have satisfied the AirCell Order's notification requirement and may proceed to operate, subject as always to the "no harmful interference" requirement. If AirCell inadvertently operates on a channel in use by another carrier for digital services, because the notified carrier did not choose to steer AirCell away from use of that channel, and AirCell is shown to have thereby caused harmful interference, AirCell will be required to move. 15. Notification Distance. On reconsideration, we also reduce the notification distance in Special Condition 6 from 270 kilometers (168 miles) to 151 kilometers (94 miles). We now believe that the radius distance of 151 kilometers is sufficient to encompass all locations where normal transmissions from AirCell airborne terminal units (in communication with the ground station for which notification is being given) are likely to be strong enough to be detectable by typical OET-53 compatible analog cellular base station receivers. First, 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). Second, based on tests in the record, the airborne antenna pattern and polarization, combined with the low airborne transmitter power, produce a signal that is not detectable by typical cellular base receivers located more than 16 kilometers (10 miles) away from the aircraft. If the airplane can receive transmissions 135 kilometers from the base station and the airplane's signal may be detectable another 16 kilometers on the other side of the plane, the combined distance at which an AirCell signal may be detected is 151 kilometers (94 miles) from the base station. 16. In the AirCell Order, the Bureau adopted the 270 kilometer notification distance, which was suggested by one of the opposing parties (GTE), because we believed that it was a conservative distance. In its Petition for Reconsideration and Clarification, AirCell argues that this notification distance is "unduly burdensome and restrictive" because it requires notification of "as many as five times the number of co-block licensees than would be required under a more realistic standard. In their Consolidated Opposition to the AirCell Petition for Reconsideration, the opposing parties argue that the distance requirement for notification and coordination is not burdensome on AirCell, that the OET experimental license notification distance was 160 miles, and that therefore the 270 kilometer (168 mile) notification distance should be maintained. As explained above, based an analysis of the July 1997 Texas tests, we believe that the assumption in the experimental license that regular cellular operators' base stations, as opposed to specially configured AirCell base stations, could hear airborne mobile units 80 miles away was overly conservative. Instead, we believe 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. We thus conclude that a 151 kilometer (94 mile) notification distance is a sufficient, reasonably conservative distance as a technical matter to protect other carriers. We also find that, as a practical matter, the overly conservative notification distance in the AirCell Order has unduly burdened deployment of the AirCell system contemplated by that order. Therefore, we now adopt a 151 kilometer (94 mile) notification distance. IV. CONCLUSION 17. The AirCell Order granted AirCell a 2-year waiver because the Bureau was persuaded that the AirCell system did not present the same potential for harmful interference to terrestrial cellular operations as use of ordinary cellular telephones aboard airborne aircraft. The Bureau was persuaded that the AirCell system could successfully operate in an environment with terrestrial cellular operations without causing harmful interference to those terrestrial operations. We intend this clarification and limited reconsideration to allow AirCell the opportunity to operate its air-ground voice and data link as envisioned in the AirCell Order. V. ORDERING CLAUSES 18. Accordingly, IT IS ORDERED, pursuant to sections 1.3 and 22.119(a) of the Commission's rules, 47 C.F.R.  1.3, 22.119(a), that Special Condition 6 of 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) IS AMENDED to reduce the notification distance from 168 miles to 94 miles. 19. IT IS FURTHER ORDERED, pursuant to sections 1.3 and 22.119(a) of the Commission's rules, 47 C.F.R.  1.3, 22.119(a), that Special Conditions 6 and 7 of 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 CLARIFIED as described herein. 20. This action is taken pursuant to the authority delegated in section 0.331 of the Commission's rules, 47 C.F.R.  0.331. FEDERAL COMMUNICATIONS COMMISSION James D. Schlichting Deputy Chief, Wireless Telecommunications Bureau