Transforming the 2.5 GHz Band April 24, 2018 13:57
On April 19th, the FCC opened a docket to collect comments related to "Transforming the 2.5 GHz Band". As background, the US 2.5GHz spectrum band encompasses 33 channels. 20 channels (A, B, C, D, and G groups) are designated for Educational Broadcast Service (EBS) and 13 (BRS1/2, E, F, and H) are designated for Broadband Radio Service (BRS).
Sprint owns a vast majority of the BRS licenses and leases a vast majority of the EBS licenses. The licensing limitations for this spectrum are drawn from its origins providing broadcast video services. The original licenses were formed as 35 mile radius circles centered on the video transmitting site. When two licenses overlapped, a football shaped area would be formed. A line would be drawn through the end points of the "football" splitting the overlapping license area between the two licensees. BRS licenses include both 35 mile radius licenses, geographic area licenses (entire BTA) and Entire BTA license with cutouts for existing 35 mile radius licenses.
In 2009, a Broadband Radio Service auction (Auction 86) included the remaining unlicensed areas within each BTA for the BRS channels, but the unlicensed area in each BTA for the EBS channels was not auctioned.
Channel Plan Transition:
Prior to this point, Clearwire was launching pre-WiMax networks on the EBS/BRS pre-transition band plan which was designed around video operation. As you can see in the Pre-Transition chart below, the A channels (A1, A2, A3, and A4) are separated by the B channels (B1, B2, B3, and B4). This allowed all of the A channels to be broadcast at a video site without interference. Clearwire would need to control both sets of the "interleaved" channels to have enough contiguous spectrum to launch their RAN network in a market.
To facilitate data network deployments and to protect the remaining video operations the FCC provided a way to transistion licenses to the Post-Transition band plan on a BTA market basis. If there was a significant commercial video operation in a market, that BTA market was able waived from transition and it stayed with the Pre-Transition band plan. The Post-Transition band plan put the remaining video operators into the mid-band segment (A4, B4, C4, D4, G4, F4, and E4) and provides contiguous spectrum (16.5MHz) for the rest of the channel group (e.g. A1, A2, and A3)
FCC Request for Comments:
The FCC has expressed a desire to make the EBS unlicensed area available for use. The FCC has asked whether the expansion of the licenses should include the entirety of the census tracks that license (35 mile) intersects or the entire county that the license intersects. The map below from the National EBS Association (NEBSA) illustrates the counties that would be added to each intersecting EBS license for the A1 channel. For the carriers that already lease these licenses, they would have the opportunity to deploy sites on the larger license area and would likely also pay the licensee a higher monthly payment due to the increase in licensed population. As you can also note below, this approach still leaves all of the white counties unlicensed.
The FCC would like to license the white counties in a 4 step manner:
- Existing licenses could extend their license areas to the borders of the counties they currently intersect but there may be requirements on how much of each county you must already cover.
- Rural tribal nations can apply for licenses covering their local area. License areas could be census tracks or counties.
- Accredited schools or governmental entities can apply for their local area licenses. License areas could be census tracks or counties.
- Auction remaining unlicensed area with competitive bidding.
The FCC is also proposing to change the service rules for the EBS spectrum to allow the spectrum to be sold to commercial operators rather than requiring leases.
Remaining Pre-transition Markets:
The FCC is also proposing to complete transitioning the remaining pre-transition markets so a consistent band plan would be in use nationwide. A few wireless cable operators had received waivers but most of those operators have ceased operations. This will clear interference issues between markets and facilitate the deployment of data in the Lower Band Segment (A,B,C, and D groups) and the Upper Band Segment (E,F,G, and H groups). Video operations will continue in the Mid Band Segment (A4, B4, C4, D4,G4,F4, and E4) in the markets where they operate today.