How does 4.5 GHz propagation compare to 3.5 GHz?

Band n79 at 4.5 GHz has 2.2 dB more path loss than Band n78 at 3.5 GHz. This means approximately 20% less coverage area per cell at the same power. However, the shorter wavelength enables more antenna elements per panel area, providing slightly higher beamforming gain. With equivalent massive MIMO (64T64R), the net coverage difference is reduced to approximately 10-15%. The primary trade-off is between coverage (favors 3.5 GHz) and raw bandwidth (favors 4.5 GHz with 600 MHz available).

Deployment Guide

Band n79 (4.5 GHz) Deployment Guide

Q: Why is Band n79 important for high-capacity 5G?

Band n79 provides 600 MHz of contiguous TDD spectrum (4400-5000 MHz), the widest mid-band allocation in 3GPP. This enables 100 MHz NR carriers with room for multiple operators without fragmentation. At 4.5 GHz, massive MIMO with 64T64R or 128T128R panels achieves very high beamforming resolution due to the shorter wavelength (~6.7 cm). Japanese operators deploy n79 alongside n78 (3.5 GHz) for dual mid-band 5G, delivering aggregate throughput exceeding 4 Gbps.

Q: Which countries deploy Band n79?

Japan is the primary deployer of Band n79, with NTT Docomo, KDDI, SoftBank, and Rakuten allocated 100-200 MHz each in the 4.5-4.9 GHz range. China has allocated portions of the 4.8-5.0 GHz range to operators. South Korea is evaluating 4.7 GHz allocations. The WRC-23 conference identified 4.4-4.8 GHz for potential IMT use globally, which could expand n79 deployment to Europe and other regions. The US has not yet allocated 4.5 GHz for commercial 5G due to competing federal government spectrum requirements.

/four-point-five gig/

Technical deployment reference for 5G NR Band n79 (4400 to 5000 MHz TDD, 600 MHz), the widest mid-band allocation in 3GPP. Primarily deployed in Japan by NTT Docomo, KDDI, and SoftBank for ultra-high-capacity urban 5G. Combined with Band n78 (3.5 GHz) for dual mid-band coverage, delivering aggregate throughput exceeding 4 Gbps. WRC-23 identified 4.4 to 4.8 GHz for expanded global IMT use.

Band: n79 (4400 – 5000 MHz)

Total BW: 600 MHz TDD

Primary: Japan, China

Upper Mid-Band 5G NR

Band n79 represents the upper boundary of FR1 (Frequency Range 1) mid-band spectrum. At 4.5 GHz, it sits between traditional C-Band (3.5 GHz, n78) and mmWave (24+ GHz, FR2). The 600 MHz total allocation is massive, supporting multiple operators with 100 MHz or more each. This makes n79 a capacity powerhouse for dense urban environments.

Japanese operators pioneered n79 deployment, combining it with n78 for dual mid-band 5G. NTT Docomo, for example, aggregates 100 MHz of n78 (3.5 GHz) with 100 MHz of n79 (4.5 GHz) for 200 MHz of total mid-band capacity. With 64T64R massive MIMO on each band, aggregate throughput exceeds 4 Gbps in good conditions. The shorter wavelength at 4.5 GHz (~6.7 cm vs. ~8.6 cm at 3.5 GHz) enables tighter antenna element spacing and higher beamforming precision.

Band n79 Technical Parameters

Frequency Range:
4400 – 5000 MHz (600 MHz TDD)
Japan allocation: 4500–4900 MHz (400 MHz)

Path Loss Comparison:
vs. n78 (3.5 GHz): +2.2 dB (20% less coverage)
vs. n77 (3.7 GHz): +1.7 dB
vs. n41 (2.5 GHz): +5.1 dB

Massive MIMO at 4.5 GHz:
Wavelength: ~6.7 cm
64T64R panel: ~0.7m × 0.4m (more compact than n78)
Beamforming gain: ~27 dBi (slightly higher than n78)

Japanese 5G Spectrum Allocation

Operator	n78 (3.5 GHz)	n79 (4.5 GHz)	mmWave (n257)
NTT Docomo	100 MHz	200 MHz	400 MHz
KDDI	100 MHz	100 MHz	400 MHz
SoftBank	100 MHz	100 MHz	400 MHz
Rakuten	100 MHz	100 MHz	400 MHz

Common Questions

Frequently Asked Questions

Why is Band n79 important for high-capacity 5G?

600 MHz contiguous TDD, widest mid-band in 3GPP. Supports multiple 100 MHz carriers. Combined with n78 for dual mid-band exceeding 4 Gbps. Shorter wavelength enables higher beamforming resolution with compact 64T64R panels.

How does 4.5 GHz compare to 3.5 GHz?

+2.2 dB path loss (20% less coverage area). Shorter wavelength enables more elements per panel. Net coverage difference is 10 to 15% with equivalent MIMO. Trade-off: coverage (3.5 GHz better) vs. raw bandwidth (4.5 GHz has 600 MHz).

Which countries deploy Band n79?

Japan (primary: NTT Docomo, KDDI, SoftBank, Rakuten). China (4.8 to 5.0 GHz). Korea evaluating 4.7 GHz. WRC-23 identified 4.4 to 4.8 GHz for global IMT use. Not yet allocated in the US.

Related Terms

← Band n78 Detail Band n8 →

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