Date: Feb 11, 2004
FCC Proposes "Interference Temperature" Approach5 GHz Band Now Available for Expanded Unlicensed OperationsNew Proceeding Addresses "Cognitive Radios"
FCC Proposes "Interference Temperature" Approach
5 GHz Band Now Available for Expanded Unlicensed Operations
New Proceeding Addresses "Cognitive Radios"
Dissent and Delays Plague 800 MHz Band ProceedingFCC Grants Stay of January Narrowbanding DeadlineHigh Power Freeze Continues in 460-470 MHz Band
Dissent and Delays Plague 800 MHz Band Proceeding
FCC Grants Stay of January Narrowbanding Deadline
High Power Freeze Continues in 460-470 MHz Band
Comments Sought in ESV ProceedingNegotiation Period Has Begun in 2.1 GHz MSS Band
Comments Sought in ESV Proceeding
Negotiation Period Has Begun in 2.1 GHz MSS Band
The Federal Communications Commission has initiated a proceeding to consider and implement the concept of "interference temperature." While the current approach to interference management focuses on specifying and limiting the transmit powers of individual radiating devices, the interference temperature approach would set a maximum cap on the cumulative radio frequency ("RF") energy that may be transmitted in the aggregate by spectrum-based devices, taking into account the interactions between transmitters and receivers. The Commission believes that the implementation of such an approach could provide licensees with greater certainty regarding maximum permissible interference and greater protection against harmful interference, while also presenting an opportunity for the operation of additional transmitters (either licensed or unlicensed).
Three possible approaches to implementing the interference temperature concept are discussed: (1) measurement of interference temperatures and processing of information within individual transmitting devices; (2) aggregation of interference temperature measurements at a central site; or (3) a grid of monitoring stations to determine interference temperatures. Under any approach, the operator of a device could have several options in instances where transmissions cannot be made without exceeding the interference temperature limit, including the selection of a different transmitting frequency, reducing the transmitter power and/or changing the direction or shape of the transmit antenna pattern. The FCC has requested comment on various technical and other issues relating to the development and use of the interference temperature metric and the process of transitioning from the existing approach to this new model.
Of potential concern to certain existing licensees is the fact that the agency is proposing to apply the interference temperature approach, essentially on a test basis, to allow new unlicensed operations in portions of the 6 GHz and 12/13 GHz bands currently used for licensed Fixed Service and Fixed Satellite Service (uplink) operations. These bands were targeted because the Commission believes that they offer the possibility to implement the approach in a simplified manner and that, due to various factors, incumbent operations in these bands can tolerate an expansion of unlicensed operation without suffering harmful interference. The agency seeks comment on its proposals and the assumptions on which they are based.
Comments in this matter will be due on April 5, 2004, and Reply Comments will be due on May 5, 2004. Heavy participation is expected.
5 GHz Band Now Available for Expanded Unlicensed Operations
Effective February 19, 2004, the Federal Communications Commission will permit the use of the 5.470-5.725 GHz band for Unlicensed National Information Infrastructure ("U-NII") devices, including Radio Local Area Networks, operating under Part 15 of the Commission's Rules and Regulations. U-NII devices, which also may be operated in other portions of the 5 GHz band, use wideband digital modulation techniques to provide a wide array of high data rate mobile and fixed communications services.
U-NII devices in the 5.470-5.725 GHz band will be required to conform to the existing U-NII rules for the frequency band 5.25-5.35 GHz. These rules limit U-NII operations to one watt e.i.r.p. However, the Commission has initiated a proceeding regarding cognitive radios that will consider the possibility of allowing higher powered unlicensed operations in various frequency bands. (See separate article in this Washington Report). New U-NII operations also will be subject to certain additional restrictions aimed at preventing interference to licensed services in the 5.470-5.725 GHz band, including certain federal government operations. In particular, new U-NII devices will be required to employ a listen-before-talk mechanism known as dynamic frequency selection ("DFS"), as well as transmit power control ("TPC"), a mechanism that regulates a device's transmit power in response to an input signal or condition.
In Comments filed in the FCC proceeding that led to the adoption of the new U-NII rules, the American Petroleum Institute ("API") urged the Commission to allow unlicensed spread spectrum operations in the 5.470-5.725 GHz band, together with U-NII devices. Although the Commission's U-NII decision does not specifically respond to API's position, it appears that spread spectrum devices could be operated in the new U-NII band as long as they complied with the U-NII technical rules (including the power limit and the DFS and TPC requirements) and satisfied the Commission's general definition of U-NII devices. Given these somewhat rigorous technical restrictions, however, manufacturers may be reluctant to develop and produce spread spectrum products (particularly point-to-point devices) for this band.
A Notice of Proposed Rulemaking ("NPRM") released by the Federal Communications Commission in December 2003 seeks comment on issues relating to the development of cognitive radio technologies. Radios using these technologies have "adaptive awareness capabilities," which enable them to perform such functions as, for example: making location-based modifications; sensing spectrum use by nearby users; engaging in dynamic frequency selection; adjusting power output; and employing enhanced security features. Comments and Reply Comments are due 75 and 105 days, respectively, from publication of the NPRM in Federal Register, which has yet to occur.
This proceeding will address, in general, what technical capabilities should be incorporated into cognitive radio devices and which frequency bands and services are most likely to benefit from such technologies. The NPRM also raises more specific proposals, such as: whether the Commission should permit unlicensed devices in rural or underserved areas to operate with a higher power output in order to reduce infrastructure costs; and, how cognitive radio devices can facilitate interoperability, especially among public safety responders.
Additionally, the Commission anticipates that cognitive radio technology may facilitate access to secondary markets. In this regard, the Commission has requested comment on the feasibility of creating lease arrangements whereby licensees and lessees can exchange information via communications links that identify the available spectrum and the terms for the use of that spectrum.
The FCC also has incorporated its consideration of Software Defined Radios ("SDRs") into this proceeding. With respect to SDRs, the Commission is concerned that, because the certification requirements adopted for SDRs are not compulsory, applicants for equipment authorization are not declaring some SDRs as such when seeking certification from the Commission. As a result, the FCC is inquiring whether its SDR rules should be mandatory to ensure that only approved hardware/software combinations are employed.
Finally, the Commission has proposed modifications to its Part 15 rules that govern automatic frequency selection devices operating in the unlicensed bands. Manufacturers have been seeking the ability to certify unlicensed devices that operate over a wider frequency range than that permitted in the United States. The FCC proposes to allow manufacturers to produce equipment capable of operating on non-Part 15 frequencies, provided that the devices incorporate certain technical safeguards.
Although almost two years have passed since the Federal Communications Commission initiated its proceeding to resolve pervasive interference problems between public safety and commercial operators in the 800 MHz band, it remains unclear what course the Commission will take, and a decision may not be reached for several more months.
Much focus has been placed upon the proposed "Consensus Plan" submitted by a coalition of public safety entities, private wireless groups, and Nextel, which entails the realignment of the 800 MHz band into separate segments for public safety/industrial and commercialized operations. Nextel would forfeit spectrum in the 700 MHz, 800 MHz and 900 MHz bands in exchange for receiving a 10 megahertz nationwide license in the 1.9 GHz band. Nextel also would provide up to $850 million in funding for public safety and private wireless relocations; all existing 800 MHz band licensees would be permitted to remain in the band, and no licensee would be expected to relocate or retune its system without full compensation. The most vocal opposition to the Consensus Plan continues to come from a coalition consisting of the United Telecom Council, members of the cellular industry, and others that are recommending the use of technical solutions, enhanced interference resolution procedures and privately negotiated frequency swaps, in lieu of rebanding.
Although the Commission had planned to issue its decision in this matter by the end of the first quarter of this year, recent trade press reports indicate that an Order may not be forthcoming until this summer. The apparent source of the delay at this time is the Commission's focus on claims by opponents of the Consensus Plan that Nextel would receive a substantial windfall if provided with the replacement spectrum that it has requested in the 1.9 GHz band. Nextel has vigorously disputed these claims, but the Commission reportedly is considering the possibility of requiring Nextel to make additional payments above and beyond the $850 million that it already has pledged for relocation funding.
As a result of the Commission's failure to act quickly in this matter, four public safety organizations -- the Association of Public-Safety Communications Officials-International, the International Association of Chiefs of Police, the International Association of Fire Chiefs, and the National Sheriffs' Association -- filed a joint letter with President Bush on January 29, 2004 that asks for his support in urging the FCC to adopt the Consensus Plan and bring this proceeding to a prompt conclusion. It is too early to tell whether the White House will elect to become involved in this matter.
As previously reported, the Federal Communications Commission adopted various "date certain" deadlines last year for the conversion to narrowband (12.5 kHz) equipment in the land mobile bands below 512 MHz. In August 2003, the American Petroleum Institute and the United Telecom Council filed joint pleadings that asked the Commission to reconsider and, in the meantime, stay its deadline of January 14, 2004 with respect to the filing of applications for new operations or expansions to existing operations using 25 kHz channels. More than a dozen other parties also filed petitions for reconsideration of certain aspects of the Commission's mandatory narrowbanding decision.
In an Order released in December 2003, the Commission agreed to stay the January deadline pending the resolution of the various petitions for reconsideration that have been filed concerning the narrowbanding rules. Accordingly, parties may continue to file applications for new or modified 25 kHz bandwidth operations unless and until the Commission rules on the petitions and establishes a new deadline.
The FCC's ultimate deadlines of January 1, 2013 for all non-public safety licensees to migrate to narrowband systems and January 1, 2018 for all public safety licensees remain in effect. Also remaining in effect (at least for the time being) are the Commission's rules prohibiting the certification of any equipment that includes a 25 kHz mode beginning on January 1, 2005 and prohibiting the manufacture and importation of any 25 kHz equipment beginning on January 1, 2008.
As a result of the Federal Communications Commission's proceeding to "refarm" the land mobile bands below 512 MHz, former low power 12.5 kHz "offset" channels are to be made available for new high power operations. However, a "freeze" has been in effect for several years that prohibits the licensing of such new high power systems in the 460-470 MHz band. The Commission imposed the freeze to allow time for the migration of medical telemetry users in this band to new spectrum that was allocated for their use.
Although the freeze originally was scheduled to be lifted on October 16, 2003, the FCC, by Public Notice dated October 15, 2003, extended the freeze for "up to 180 days" in order to seek comments on and consider a proposal submitted by the American Hospital Association ("AHA") on behalf of the medical telemetry industry. Under AHA's proposal, the freeze would be extended for six months, during which time hospitals operating in the 460-470 MHz band would be expected to register their pertinent operating information with a database administrator; after that, certain coordination procedures would be required between land mobile and medical telemetry users for another two years.
The Land Mobile Communications Council ("LMCC") filed comments that opposed the AHA's proposed frequency coordination requirements but, in the interests of compromise, stated that the LMCC would not oppose an extension of the freeze for a period of one year from the FCC's October 2003 Public Notice. The LMCC envisions that, during this one-year period, land mobile coordinators would be able to continue the current practice of approving new high power systems with certification that no interference will be caused to medical telemetry operations. In response, the AHA argued that new high power systems should not be allowed anywhere near (i.e., closer than 40 miles to) existing medical telemetry systems until at least April 2005.
On January 7, 2004, representatives of the AHA and the LMCC met with FCC staff members in an effort to resolve the stalemate. Much of the discussion focused on the LMCC's contention that, if coordination is required between new high power land mobile systems and existing medical telemetry operations during an interim period before the freeze is completely lifted, land mobile coordinators should not be required to pay the AHA and/or its coordinator for access to database information regarding medical telemetry operations. Although no resolution to this issue was reached during the meeting, the parties agreed to explore various options, including the possibility of entering medical telemetry information into the FCC's Universal Licensing System.
Assuming that a solution to the above-noted database sharing issue can be identified and implemented, it is possible that the coordination of new high power systems may begin as early as May 1, 2004. Even once such coordination begins, however, it is likely that new high power land mobile systems on former offset channels in the 460-470 MHz band will only be approved if located more than 40 miles from any hospital that utilizes medical telemetry devices. It is anticipated that the freeze may be fully lifted (without any further requirement to coordinate with medical telemetry operations) by October 2005.
The Federal Communications Commission released a Notice of Proposed Rulemaking ("NPRM") in November 2003 to establish a framework for the licensing of satellite earth stations on board vessels ("ESVs") in the C-band (5925-6425 MHz/3700-4200 MHz) and Ku-band (14.0-14.5 GHz/11.7-12.2 GHz). Because a portion of the C-band is used for Fixed Service ("FS") operations, FS licensees have been seeking to ensure that the shared use of this band by ESVs will not pose a risk of harmful interference to FS systems.
The Commission's stated goal in this proceeding is "to develop approaches for licensing ESVs that would maximize the efficient use of both Ku-band and C-band spectrum while balancing the expectations of incumbent operators to operate free from harmful interference and to have growth potential in the bands." In the Ku-band, the Commission is proposing to permit blanket licensing of ESV networks on a primary basis, similar to the licensing rules for very small aperture terminals ("VSATs") that currently operate in that band. With regard to the C-band, the Commission requests comment on two potential methods for licensing ESVs: a Non-Coordination Approach and a Coordination Approach.
Under the Non-Coordination Approach, ESV operations would be authorized for only a two-year license term on a non-harmful interference basis for vessels 300 gross tons or larger while within 300 kilometers of the U.S. coastline. To protect FS operations, this approach would require real-time tracking of vessel locations, real-time FS operator access to the tracking data on a secure basis, and the provision by ESV network operators of a "24/7" point of contact. Moreover, the ESV network operator would be required to immediately terminate or relocate operations on the ESV that is the subject of an interference complaint until the complaint has been successfully resolved. License renewal under this approach would be evaluated on a case-by-case basis.
The proposed Coordination Approach would involve prior coordination by each ESV operator of 36 megahertz of uplink and 36 megahertz of downlink spectrum per satellite, per location over a maximum of two satellites. If harmful interference were to occur, the parties would be expected to cooperate in resolving the interference in the same manner as in other bands and situations where coordination has been successfully completed. The license term would be fifteen years. The Commission requests comment on the specific coordination methodologies and criteria that would be utilized under the Coordination Approach and proposes to apply the coordination rules to all C-band ESV operations within 300 kilometers of the U.S. coast. The NPRM also discusses other issues relating to this proposed approach, including: whether and how ESV operators that complete the coordination process could be provided some level of certainty that their operations can continue and will not be displaced by subsequently constructed FS stations; whether it is possible for FS and ESV operators to timeshare coordinated spectrum; and whether the ESV rules should be applied to earth stations on oil rigs and other fixed platforms at sea.
Finally, in order to better understand the potential for interference, the Commission seeks comment and documentary evidence regarding any incidents of interference from authorized ESV operations to FS or other systems. The FCC also asks whether any other technical measures could be implemented to address potential concerns about interference.
The Commission has established a somewhat expedited schedule for the filing of comments in this matter: Comments in response to the NPRM are due on February 23, 2004, and Reply Comments are due on March 8, 2004.
Due to the reallocation by the Federal Communications Commission of portions of the 2.1 GHz band for various new communications services, incumbent Fixed Service ("FS") microwave licensees in this band ultimately will be required to relocate their systems to alternative spectrum bands. There have been several recent developments of potential import to 2.1 GHz band FS incumbents, including the onset of the mandatory negotiation period in the 2180-2200 MHz band.
Many private FS licensees operate paired microwave links in the 2130-2150/2180-2200 MHz band. The 2180-2200 MHz band has been reallocated for the Mobile Satellite Service ("MSS"), while the 2130-2150 MHz band has been reallocated for new Advanced Wireless Services ("AWS"). New licensees will be required to pay for the relocation of incumbents to comparable facilities before commencing service in the 2.1 GHz band that would cause interference to incumbent operations. The FCC has adopted relocation rules and policies modeled on (but not identical to) those that were employed with regard to the relocation of FS licensees from the 1850-1990 MHz band to make way for the Personal Communications Service
In a decision released in November 2003, the Commission adopted several changes to the rules governing the relocation of FS licensees from the 2180-2200 MHz band by MSS providers. Perhaps most notably, the Commission shortened the duration of the mandatory negotiation period from three years to two years for public safety licensees and from two years to one year for non-public safety licensees. This mandatory negotiation period began on December 8, 2003. Because MSS licensees are unlikely to be prepared to deploy their systems until at least 2005, it is quite possible that the mandatory negotiation period in the 2180-2200 MHz band (particularly for non-public safety licensees) may well elapse without any actual negotiations occurring. MSS providers would then be able to initiate involuntary relocation procedures. It also should be noted that the Commission declined to adopt rules whereby incumbents may recover for the costs of voluntarily relocating their own systems to leased facilities, alternative media or any other replacement facilities.
In the 2130-2150 MHz band, AWS licenses will be assigned via competitive bidding, most likely in the next 12 to 18 months. Although the Commission recently (in a separate proceeding than that governing the MSS allocations) adopted rules regarding the AWS auction, there remain some ambiguities and uncertainties with respect to the relocation rules to be applied in this band. For instance, the existing rules are silent as to the duration of the mandatory negotiation period and the date of onset of negotiations.
The American Petroleum Institute and the United Telecom Council filed a joint Petition for Clarification and Reconsideration in January 2004 that addresses relocation issues with regard to both the AWS and MSS portions of the 2.1 GHz band. Among other things, the joint Petition urges the FCC to adopt a two-year mandatory negotiation period for all non-public safety licensees in the 2.1 GHz band and to require that new service licensees simultaneously relocate both paths in a paired microwave link.
Washington Report is reprinted with permission from ENTELEC News, Februrary 2004. Copyright © 2004, ENTELEC, www.entelec.org
For further information about this article, please contact Wayne V. Black at 202-434-4130 or by e-mail at firstname.lastname@example.org.