Is 4G on 1800 MHz possible at distances over 30 km?

16 May 2025

A client said: "That’s impossible"

We’ve heard it many times:

“You can’t have stable 4G on 1800 MHz beyond 10–15 km. It’s physically impossible.”

That’s false.
We analyzed technical parameters, calculated path loss, considered Earth’s curvature — and proved that with the right equipment, a 4G connection at 1800 MHz (Band 3) from 30–35+ km is absolutely possible.

1. Which antenna do we use?

ENERGY MIMO 24 dBi Panel Antenna (1700–2700 MHz)
Link: https://5g.in.ua/antena-panelna-energy-mimo-24-db/

Parameter	Value
Frequency	1700–2700 MHz (B3, B7, B1)
Type	MIMO × 2
Gain	24 dBi per channel
Design	Sealed panel, weatherproof
Polarization	±45° (ideal for LTE MIMO)
Mount	Rugged bracket for mast/wall

This antenna is engineered for long-distance links and focused directional gain.

2. Theoretical Calculations: Will the Signal Reach?

Free Space Path Loss at 30 km

Formula:

FSPL = 20 · log₁₀(d) + 20 · log₁₀(f) + 32.44

where:
d — distance in kilometers,
f — frequency in megahertz.

For 30 km and 1800 MHz:

FSPL = 20 · log₁₀(30) + 20 · log₁₀(1800) + 32.44 ≈ 127.1 dB

Power Budget

Downlink (tower → modem):

43 dBm (TX) + 18 dB (base station antenna) + 24 dB (user antenna) - 127.1 dB = -42.1 dBm

Uplink (modem → tower):

23 dBm (TX) + 24 dB (user antenna) + 18 dB (base station antenna) - 127.1 dB = -62.1 dBm

Conclusion: both received signal levels are above the typical receiver sensitivity threshold (–100…–104 dBm).
→ The connection will be stable.

3. Geometry: What About the Curvature of the Earth?

Correct: even if the power is sufficient, the signal cannot bend around the Earth.
A clear line of sight (LOS) is required.

Line-of-Sight Distance Calculation:

D = √(2·R·h₁) + √(2·R·h₂)

Or in simplified form:

D ≈ 3.57 · (√h₁ + √h₂)

where:
R — Earth's radius ≈ 6371 km,
h₁ = 40 m — tower height,
h₂ = 15 m — user antenna height.

Calculation:

D ≈ 3.57 · (√40 + √15) ≈ 3.57 · (6.32 + 3.87) ≈ 36.4 km

Conclusion: line-of-sight is possible up to 36 km.
In real-world conditions (flat terrain, open fields, water), due to atmospheric refraction, the distance may be slightly greater.

4. Practical requirements for stable long-range 4G

Component	Recommendation
Antenna	ENERGY MIMO 24 dBi (link above)
Coaxial Cable	LMR-400 or better, ≤15 m
Mounting height	≥10–15 m
Antenna alignment	Precisely toward tower, ±45° polarization
Router/modem	With Band 3 support and dual SMA connectors
Environment	Clear LOS or unobstructed terrain

5. What if the tower is farther than 30 km?

Still possible.

We calculated:

35 km → Signal ≈ -65 dBm → stable
40–45 km → Still usable, nearing limits
50+ km → Only under ideal terrain/height conditions

But again — the limit is usually not frequency or power, it’s geometric line-of-sight.

6. Conclusion

Yes — it is absolutely possible. Physics and field tests agree.

The ENERGY 2×24 dBi MIMO Panel Antenna can provide stable 4G LTE signal on 1800 MHz from 30–35+ km with proper setup.
Even 40+ km is feasible over open terrain.