Before the FEDERAL COMMUNICATIONS COMMISSION Washington, D.C

Transcription

1 Before the FEDERAL COMMUNICATIONS COMMISSION Washington, D.C In the Matter of Amendment of the Commission s Rules with Regard to Commercial Operations in the MHz Band GN Docket No REPLY COMMENTS OF 4G AMERICAS 4G Americas is the leading industry association in the Americas representing the 3GPP family of technologies, including HSPA and LTE. The mission of 4G Americas is to promote, facilitate, and advocate the deployment and adoption of 3GPP technologies throughout the Americas. The 4G Americas Board of Governors members include Alcatel-Lucent, America Movil, AT&T, Blackberry, Cable & Wireless, CommScope, Entel, Ericsson, Gemalto, HP, Mavenir Systems, Nokia Siemens Networks, Openwave Mobility, Powerwave, Qualcomm, Rogers, T-Mobile USA, and Telefonica. In response to the Commission s proposal to dedicate the MHz band for small cell use, 1 4G Americas submitted its white paper on Developing and Integrating a High Performance HET-NET in the initial comment round in this 1 See Amendment of the Commission s Rules with Regard to Commercial Operations in the MHz Band, Notice of Proposed Rulemaking and Order, FCC , 27 FCC Rcd. 15,594, at 15,597 6 (2012) ( NPRM ).

2 proceeding. 2 4G Americas submits these reply comments to underscore the benefits of developing a band plan for the GHz spectrum that is internationally harmonized, through existing standards and licensing constructs, to the maximum extent possible. Introduction 4G Americas is comprised of leading mobile operators and vendors and serves its members and the broader LTE community primarily through educating on technology evolution in the Third Generation Partnership Project (3GPP), thereby contributing to the roll-out of mobile broadband technology throughout the Americas. In recent years, 4G Americas has published a number of white papers on deployment scenarios for LTE, LTE Advanced and technical issues relative to the ecosystem of LTE applications and devices. Whenever possible, cleared, auctioned, and licensed spectrum is preferred over shared spectrum 4G Americas joins other commenters in this proceeding in urging the Commission to prioritize clearing spectrum for licensed commercial mobile broadband services. Several of these comments have already addressed the soaring demand for and economic benefits of mobile broadband use. Spectrum sharing in bands suitable for commercial mobile broadband should only be considered where clearing a band of other uses is not possible or advisable. In this regard, 4G Americas thanks the Commission for the recent letter of the Chairman to the Assistant Secretary of Commerce notifying the Administration of the Commission s intent to 2 The Het-Net White Paper is available at Developing%20Integrating%20High%20Performance%20HET-NET%20October% pdf. 2

3 pair the sub-band of MHz in auction with MHz, consistent with the outcome of the Commercial Spectrum Management Advisory Council (CSMAC) review of the ability of commercial users to share this sub-band with those federal users that cannot be relocated out of the sub-band in the near term. 3 4G Americas continues to support clearing the MHz band to the greatest degree possible and agrees with the Chairman that pairing the MHz band in auction with MHz will advance America s broadband future, since that pairing is aligned with Band 10 in the 3GPP band plan for LTE. Band 10 is the last near-term opportunity for LTE roaming in the Americas, and hence, an important avenue for consumer benefit and innovation in the ecosystem of mobile broadband devices and applications. One of the services 4G Americas provides to the wireless industry is the tracking of LTE network deployments in the Americas and other regions. There have been no unlicensed deployments of LTE in any country, in any band. This is because mobile operators need the assurance of dedicated spectrum before undertaking investments in networks that are capital intensive, for services for which consumers have developed an expectation of quality of service for high-speed connectivity. That quality of service requires licensing. Many of the more innovative interference mitigation techniques and network reliability tools for mobile broadband are generally not implemented in unlicensed spectrum, including open and closed loop power control, which ensures devices transmit at the optimum power level to both ensure successful communication and minimize interference to other users, inter-cell interference management, and interference cancellation within devices. 4 3 See Letter from Chairman Julius Genachowski, FCC, to Assistant Secretary Lawrence Strickling, U.S. Dep t Of Commerce (March 20, 2013), available at fcc.gov/daily Releases/Daily Business/2013/db0321/DOC A1.pdf. 4 See Comments of Qualcomm Corporation at 18-19, GN Docket No (filed February 20, 2013) ( Qualcomm Comments ). 3

4 With respect to the prospect of auctioning spectrum in a reallocated 3.5 GHz band, several commenters noted that a Spectrum Access System enabling users to have secondary exclusive access to the spectrum in areas or at times incumbent federal or Fixed Satellite Service (FSS) feeder links were not operational could enable auctions of that spectrum. 5 4G Americas encourages the Commission to require auctions for priority access spectrum in the band, thereby enabling commercial providers to deploy quality of service mobile broadband solutions. Internationally Harmonized Spectrum Preferable As the Commission and many others have noted in recent years, internationally harmonized spectrum should be preferred, due to the global economies of scale and scope it provides to U.S. consumers. 6 Commission policy that allows internationally-harmonized spectrum facilitates common system design, benefitting U.S. consumers. 7 LTE standards and band plans include Time Division Duplex (TDD) mode in the spectrum bands considered in the Commission s proposed rulemaking. 3GPP TDD Band 42 is GHz and TDD Band 43 is GHz. 8 Today, there is no single 3GPP band that covers the entire MHz range, but that band could be segmented into two blocks of 50 MHz each that would be covered by the existing TDD Bands 42 and 43 the 50 MHz at MHz included in Band 42 and the 50 5 See, e.g., Comments of Alcatel-Lucent at 10-11, GN Docket No (filed February 20, 2013) ( Alcatel- Lucent Comments ); Qualcomm Comments at See, e.g., President s Council of Advisors on Science and Technology, Executive Office of the President, Report to the President: Realizing the Full Potential of Government-Held Spectrum to Spur Economic Growth at 50-2 and 61-2 (noting the benefits of internationally harmonized spectrum to reduce interference, enhance interoperability and roaming, improve spectral efficiency and cross-border coordination, as well as enabling new products to achieve market economies of scale) ( PCAST Report ). 7 See Comments of Ericsson at 13, GN Docket No (filed February 20, 2013) ( Ericsson Comments ). 8 See 3GPP Technical Specification , V

5 MHz in MHz is included in Band Permitting a TDD option at 3.5 GHz would also allow expansion of the Commission s framework upwards to 3700 MHz in the event the Commission adopts enabling rules, while still being covered by 3GPP Band 43 ( MHz). 4G Americas cautions that any new band plan that is unique to the U.S. could delay availability of devices and infrastructure in our market. 10 As an indicator of the near-term prospect for the introduction of TD-LTE devices in the MHz band, single-band TD- LTE chipsets and devices are already available, and multi-mode band devices are expected in In order to enable an innovative ecosystem of LTE devices and applications, the final rules adopted in this proceeding should not preclude the deployment of TD-LTE at MHz. 12 Commission policy that allows harmonized deployment in the MHz band will also minimize interference and facilitate worldwide compatibility and global roaming. 13 4G Americas notes that a version of the licensing framework proposed by the Commission is being standardized in ITU Region 1 (Europe and Africa), referred to as Licensed Shared Access. 14 TD-LTE in the 3.5 GHz Band In addition to the benefits of global harmonization from the Commission allowing TD- LTE in the 3.5 GHz band, the LTE standards for TDD provide for efficient spectrum usage 9 See Comments of T-Mobile at 10, GN Docket No (filed February 20, 2013) ( T-Mobile Comments ). 10 See Comments of Nokia Siemens Networks US LLC at 9, GN Docket No (filed February 20, 2013) ( NSN Comments ). 11 By contrast, 4G Americas is not aware of any LTE Frequency Division Duplex product or chipset availability appropriate to this band. 12 See Alcatel-Lucent Comments at 13 (recommending the Commission reserve the 3.5 GHz band for TDD service); see also Qualcomm Comments at See Ericsson Comments at 13-14, n. 24 (noting that in Region 2, the MHz band is allocated to Fixed, Fixed Satellite and Mobile Services on a primary basis and the MHz band has been identified for IMT in various areas). 14 Licensed Shared Access is being standardized by ETSI for the GHz band. See, e.g., PCAST Report at 61; see also Ericsson Comments at 10; Qualcomm Comments at

6 allowing networks to co-exist with federal RADAR and Fixed Satellite Service (FSS) incumbents as necessary. The LTE standards are complete for small cells no new standards need to be completed before deployment. The existing LTE standards for deployment at 3.5 GHz allow for macro, metro, micro, and pico cell operations in TDD Bands 42 and 43 ( MHz). 15 Moreover, LTE devices have embedded mitigation interference cancellation techniques, further facilitating spectrally efficient use through significant capacity gains. 16 A licensing construct akin to the Spectrum Access System Licensed Shared Access (LSA) can manage licensed networks deploying LTE technology, which includes standards for Self-Optimizing Networks (SON). SON will help realize many of the Commission s goals toward more efficient spectrum use, and consumer satisfaction of applications relying on mobile broadband technology. LSA licensees using SON techniques can more quickly move off the spectrum when incumbents need to operate, falling back to other bands if needed. 17 Commercial Mobile Broadband in the Priority Access Tier 4G Americas joins the many commenters who suggested that commercial mobile broadband providers be permitted access to the priority tier, given the market imperative to deliver controlled Quality Of Service (QOS). 18 Mobile operators can deploy small cells in the 3.5 GHz band as part of heterogeneous networks HetNets. 19 Small cells in the band can be used for off-loading traffic, much like WiFi is used today by mobile carriers. However, the use 15 See, e.g., Ericsson Comments at See Qualcomm Comments at See, e.g., id. at See, e.g., Ericsson Comments at See Comments of AT&T at 3, GN Docket No (filed February 20, 2013) ( AT&T Comments ); Alcatel- Lucent Comments at 6. 6

7 of TD-LTE small cells provide greater network management in the off-load. The selforganization of small cells allowed in the 3GPP standards enables small cells to expand and contract their coverage areas as needed to avoid interference with one another and to instantly recognize new cells and incorporate them into the carrier s network, as well as provide instant mobility with fallback to carrier networks where small cell connectivity is not available, thereby providing more capacity and reliability than offered by today s simple WiFi off-loading. 20 Consumers would therefore benefit by more reliable speed of service if commercial providers were allowed access to the priority tier at 3.5 GHz. In addition to off-loading, commercial broadband operation through LSA in the priority tier at 3.5 GHz would allow wireless backhaul links. 21 Licensing commercial providers as priority users in an LSA system would facilitate integration of backhaul links at 3.5 GHz into their networks. 22 Licensed operations at 3.5 GHz would allow commercial operators more reliable network planning. 23 Backhaul deployed over TD-LTE small cells would differ from traditional backhaul by operating with directional antennas in Non-Line of Sight (NLOS) scenarios. 24 Using large scale Multiple Input Multiple Output (MIMO) technologies over small cells, carriers can deliver cost effective high capacity backhaul solutions for their customers while using low transmit power. 25 These benefits apply to NLOS backhaul. 4G Americas urges the Commission to allow 3.5 GHz to be used by commercial operators for short range NLOS backhaul and support multi-antenna systems. Because of the small size of the cells, 2x2, 4x4, 20 See Qualcomm Comments at See AT&T Comments at 7-8; Alcatel-Lucent Comments at See T-Mobile Comments at See id. 24 See Ericsson Comments at See, e.g., Alcatel-Lucent Comments at 8. 7

8 and even 8x8 MIMO radios could be built efficiently for high capacity fixed and mobile broadband and NLOS backhaul applications. Rules supporting the deployment by commercial providers in the LSA priority tier of backhaul and off-load solutions will help meet the welldocumented rising demand for mobile broadband capacity and applications. As many commenters have noted, deployment of lower-powered smalls cells at 3.5 GHz empowered with spectrally efficient TD-LTE technology would likely reduce exclusion zones from the hundreds of miles first identified in the NTIA report based on analysis of the interference from macro-cell networks, to just tens of miles. 26 Smaller exclusion zones would expand the area of operation available for priority access commercial users. In addition, the Commission s rules should permit higher-powered macro cells at 3.5 GHz outside exclusion zones established to protect incumbent federal and FSS users, to help meet the rising demand for mobile broadband services. 27 Such higher power could be authorized by the LSA system, based on input from the incumbents on their protection criteria. The LSA database would need to know the aggregate power level that a federal incumbent or FSS could tolerate at a given location, time, and frequency. 28 Commercial mobile broadband providers should be allowed to negotiate exclusion zones with the incumbents, based on the degree of interference commercial providers are prepared to tolerate from federal RADAR or FSS incumbents. Licensed Shared Access Facilitates Quality of Service for LTE Deployments 26 See Qualcomm Comments at 16-18; NSN Comments at See, e.g., NSN Comments at 19-21; see also Qualcomm Comments at See Qualcomm Comments at iv. 8

9 A licensed shared access (LSA) management system can facilitate the spectrally efficient technologies of Carrier Aggregation and Supplemental Downlink. The LSA database could notify the small cells in a mobile provider s network of spectrum availability in the LSA band or the provider s underlying licensed band, where the provider deploys Carrier Aggregation. A user device located in an area where the LSA band is temporarily unavailable could switch to the licensed band. The LSA database thereby manages against interference to the incumbent users while ensuring efficient sharing. But to ensure a reliable and predictable quality of service, LSA rights must provide exclusive access to the spectrum at the time, frequency and location that are not being used by federal incumbents or FSS links. The LSA framework could enable nearby small cells to dynamically adjust to assign a supplemental downlink to a user s device, thereby providing consistent and reliable quality of service. Significantly, no change to carrier networks nor to user handsets or other devices is required to implement LSA. TD-LTE standards can already accommodate this spectrally efficient model for licensed shared access. The only new technical specifications required would be for standardizing the interface between the carrier network and the LSA database. The network provider s Operations, Administration, and Maintenance (OAM) system would have to connect to the LSA database in order to obtain information from the database on what additional spectrum is available and the location of exclusion zones or their temporal or frequency parameters. The OAM system would transmit to the small cells at 3.5 GHz information on the availability of LSA licensed spectrum, subject to the network operator s quality of service requirements. As necessary, the OAM would also command the small cells to tune to different channels or power down As noted above, standardization work is underway in ETSI for LSA in the GHz bands, including on the development of technical specifications on a functional architecture for the interfaces between the logical entities 9

10 Given that the LSA database is intended to facilitate sharing with federal systems, security is paramount. The LSA database will contain sensitive, potentially classified information supplied by federal users that must be kept secure. At the same time, since priority or secondary exclusive users must seek registration in the LSA database, they are a known and limited group. Under the LSA framework, secondary exclusive users would operate under an agreement with the federal incumbents that regulates the terms of shared use, including how to vacate the spectrum when and if the incumbent requires. 30 A secure federal database could feed location information on sensitive systems via a secured link to the LSA. Both the federal source data for incumbent users and registration information for priority/secondary exclusive users can be secured with existing web-based security mechanisms, such as Transport Layer Security with certificate based authentication. 31 The LSA framework provides a secure connection to an operator s OAM system and relies on federal user inputs, rather than relying on publically available information. 32 Federal authorities should be required to provide timely and accurate updates to the LSA database rather than being allowed to reserve otherwise unused resources. Conclusion 4G Americas commends the Commission for taking yet another step toward America s mobile broadband future. LSA secondary exclusive licensing for commercial mobile broadband providers will help meet the sky-rocketing demand for more wireless broadband capacity. Permitting TD-LTE in the 3.5 GHz band will help meet that demand through established, and external entities and the interfaces between the request and response models and security procedures, among other requirements. See Qualcomm Comments at See, e.g., Ericsson Comments at See id. at See Qualcomm Comments at

11 spectrally efficient standards and internationally harmonized band plans. 4G Americas joins other commenters in recommending further study on co-existence and sharing in the concerned spectrum, particularly on whether the MHz band could also be repurposed for commercial use, so as to align with 3GPP TDD Band 43 for LTE. Respectfully submitted, Chris Pearson President, 4G Americas April 5,