Band n261 (28 GHz)
Understanding Band n261
Band n261 exists because US spectrum allocation boundaries do not align with the global 3GPP Band n257 definition. The FCC allocated the 27.5 to 28.35 GHz range for LMDS in the late 1990s, originally intended for fixed wireless broadband. When LMDS failed commercially, the spectrum sat largely unused until the FCC repurposed it for 5G mobile use through Auction 101 in 2019. Verizon, which had accumulated the largest LMDS license portfolio through acquisitions, was positioned to deploy 5G mmWave faster than competitors.
With 850 MHz of total bandwidth, n261 supports two 400 MHz NR carriers for carrier aggregation. The band sits squarely in the Ka-band, where atmospheric absorption is low (oxygen absorption is negligible, water vapor absorption is less than 0.1 dB/km) but rain attenuation can reach 7 to 10 dB/km in heavy storms. Deployment is concentrated on street-level small cells in dense urban corridors, with typical cell spacing of 150 to 300 meters. Each small cell serves a sector of coverage using a phased array antenna that dynamically steers beams to individual users.
Band n261 Specifications
Lower edge: 27.500 GHz
Upper edge: 28.350 GHz
Total: 850 MHz (subset of n257's 3 GHz)
FCC License Structure:
2 blocks × 425 MHz per county
Auction 101 revenue: $2.02 billion
NR Channel Configuration:
Max channel BW: 400 MHz
Subcarrier spacing: 120 kHz (standard)
Maximum carriers: 2 (with 50 MHz guard)
Typical Small Cell Parameters:
Antenna: 64-256 elements, ≤ 65 dBm EIRP per beam
Cell radius: 100-300 m (LOS), 50-150 m (NLOS)
US mmWave 5G Band Summary
| Band | Range | BW | Auction | Primary Operators |
|---|---|---|---|---|
| n261 | 27.5-28.35 GHz | 850 MHz | Auction 101 ($2.0B) | Verizon, AT&T |
| n260 | 37-40 GHz | 3 GHz | Auction 103 ($7.6B) | T-Mobile, Dish |
| n262 | 47.2-48.2 GHz | 1 GHz | Auction 103 | Various (limited) |
Frequently Asked Questions
What is the relationship between Band n261 and Band n257?
Band n261 (27.5 to 28.35 GHz) is entirely contained within n257 (26.5 to 29.5 GHz). Equipment supporting n257 automatically covers n261. The distinction exists because US FCC allocation boundaries differ from the global 3GPP definition. US deployments operate within the n261 subset, while Japanese and Korean operators use the full n257 range.
How was Band n261 spectrum allocated in the United States?
The FCC auctioned 28 GHz spectrum in Auction 101 (January 2019), dividing 850 MHz into two 425 MHz blocks per county, raising $2.02 billion. Verizon and AT&T acquired the majority of licenses. Prior LMDS incumbents were given flexible-use conversion options. Verizon's pre-existing LMDS portfolio from its 1998 Nextlink/XO acquisition gave it a head start in mmWave 5G deployment.
What are the practical deployment characteristics of n261?
Verizon's Ultra Wideband network deploys n261 on street-level small cells in dense urban areas (New York, LA, Chicago). Cell radius is 100 to 300 meters in LOS. A single 400 MHz carrier delivers 1 to 2 Gbps downlink; carrier aggregation with two carriers pushes peaks above 4 Gbps. Coverage is outdoor-focused since indoor penetration through modern glass is limited to −20 to −40 dB.