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  • The CBRS Band - What is it and what does it mean for you?



    I'm sure many of you have questions upon reading the FCC's 187 page report regarding Commercial Operations in the 3550-3650 MHz Band released on April 21, 2015.  While I know there are a lot of very heated opinions surrounding this issue, I wanted to take this opportunity to summarize the key points and make some assertions regarding what this means for you as an existing license holder within the 3650-3700 MHz frequency band.

    So what is the CBRS Band?

    The Citizen's Broadband Radio Service will encompass the band of spectrum from 3550 MHz to 3700 MHz.

    To date, only the 3650-3700 MHz portion of the band has been accessible to non-federal operators using a non-exclusive licensing process, leading to what has been commonly referred to as a "lite" or "quasi" license for the 3.65 GHz band. (This licensing process requires cooperation between operators in the same area to avoid interference issues).

    The new CBRS band will open up an additional 150 MHz of spectrum, employing a 3-tier access/licensing model.

    A groundbreaking Spectrum Allocation System (SAS) will be used to improve availability of the spectrum for all users.

    3 Access Tiers

    Incumbent Access - This highest tier is intended to protect and yield highest priority to incumbent Federal users (military ground stations, government, etc...) that have and continue to occupy portions of the band.  Incumbent Access users will be protected from PAL and GAA users by the SAS.

    Priority Access Licenses (PAL) - Up to 7 of these 10 MHz spectrum blocks per census tract will be awarded to the highest bidders.  If there is no competition, then the prices will be very low.  PAL users will be protected from GAA users by the SAS.

    General Authorized Access (GAA) - Opportunistic spectrum usage.  "License by Rule" (no license required as long as the rules are being followed).  Unprotected from higher tiers.

    PAL Tier Details

    • Commercial operators requiring guaranteed spectrum allocations will want to apply for exclusive PAL licenses, but they will need to enter a competitive bidding process.
    • Since PAL licenses are applied for on a census-tract basis, competition should not be huge, especially for rural operators, so obtaining these licenses should be affordable.
    • PAL licenses are exclusive and awarded for a 3-year, non-renewable term.  During the first application process only two consecutive terms (6 years total) may be applied for.
    • No PAL licenses will be awarded in the 3650-3700 MHz portion of the band as this spectrum is reserved for GAA users.
    • Each PAL license covers 10 MHz of spectrum in a census tract. However, the spectrum allocation is not static.  It can move around the band from time to time as governed by the SAS.
    • The SAS may allocate unused PAL spectrum to GAA users on a dynamic basis, buy PAL users will always receive priority.
    • When an operator owns multiple PALs within an area the SAS will strive to maintain contiguous channel assignments.
    • Although 7 PALs may be awarded within any given census tract, a maximum of 4 may be held by any given licensee.

    GAA Tier Details

    • The GAA Tier offers users the ability to utilize CBRS spectrum beyond the portions that they have licensed, if any.
    • A PAL holder may utilize additional spectrum as a GAA user.
    • Each census tract will generally offer at least 80 MHz and as much as 150 MHz of spectrum for GAA users, depending upon the number of active PAL users in the area.
    • GAA users will receive their channel allocations from the SAS, but will not receive guaranteed protection from other GAA users.

    Equipment Requirements 

    •  PAL and GAA users obviously must comply with all rules set forth by the FCC with respect to maximum TX power, out of band emissions, etc...
    • Base station equipment must be capable of interfacing with an SAS system which will dynamically govern its channel allocations (similar to DFS on 5.4 GHz).
    • Equipment must be capable of tuning across the entire 150 MHz of CBRS spectrum.  Existing "grandfathered" equipment is an exception.

    Existing 3650-3700 MHz License Operators

    •  Current licensees of the 3650-3700 MHz band are to be considered "grandfathered" as of April 17, 2015.
    • These grandfathered users will be afforded protection just like a PAL user for the the remainder of its 10-year license term or 5 years from April 17, 2015 (whichever is longer) unless they applied for the license after January 8, 2013, in which case the 5-year period will apply.
    • Grandfathered equipment will receive a lifetime waiver from the 150 MHz tuning requirement.

    Exclusionary Zones

    • Specific "exclusionary zones" are currently associated with the spectrum included by the CBRS band.
    • These are off-limits geographical regions within which no commercial usage of the spectrum will be permitted.
    • Exclusionary zones will remain as such at least until the SAS systems are up and running.
    • However, once they are in place, the hope is that the spectrum will become opportunistically available to GAA users where and when it is not in conflict with incumbent government usage.

    The Spectrum Allocation System (SAS)

    •  SAS systems will be developed and deployed commercially by 3rd parties.
    • SAS owners will be authorized and allowed to charge for their services according to guidelines developed by the FCC.
    • The scheduling granularity of an SAS is likely to be days and possibly even hours eventually, but certainly no shorter than that.
    • Federated Wireless and Google appear to be the leading players in SAS development.  Current details of this are sketchy and vague at best.

    All in all, this is a very unique opportunity for you to grow and expand the footprint of your service areas.  It is crucial to remain informed so you understand the auction process and how you can participate in them.  You need to take part in this "land grab" because your value as a 3.65 license holder has increased.  The FCC has stopped accepting new license applications.  This 3.65 "land grab" will be similar to what we've seen with 2.5 GHz and other LTE frequencies in years past.

    Some equipment manufacturers will require a complete hardware re-calibration in order to support the additional spectrum, while others simply require a software update.  A software update will definitely be required to integrate the capability to inter-operate with an SAS.  Can you say, "SAS interface function as an NMS feature" please?

    So... To deploy or not to deploy... Which technology should you choose?  Which manufacturer should you choose?  Proprietary, WiMAX, LTE, 802.11??  What will you do and whom do you trust?

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