Ubiquiti airFiber 4X
4 GHz Carrier Backhaul Radio

Ubiquiti airFiber 4X

Ubiquiti Products
airFiber X Series
airFiber 4X
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airFiber XOverview:

The airFiber X features up to 17.1 Mbps/MHz of industry-leading spectral efficiency and uses proprietary Hybrid Division Duplexing technology to achieve the highest TDD throughput available for long-range, PtP links.

Ubiquiti Networks introduces the airFiber AF-4X, Ubiquiti’s first licensed spectrum radio designed for the public safety sector. It meets the growing need of broadband capacity and optimizes use of the 4.9 GHz radio band with its industry-leading spectral efficiency and TDD throughput. The AF-4X allows you to customize airFiber backhaul links or upgrade existing Rocket Point-to-Point (PtP) links.

Engineered for PerformanceEngineered for Performance

Ubiquiti's INVICTUS custom silicon and proprietary radio architecture are designed specifically for long-distance, outdoor wireless applications. Our INVICTUS core communications processing engine surpasses all of the limitations inherent to generic Wi-Fi chips to provide superior performance, long-range capability, DFS flexibility, and higher delivered throughput.

The airFiber X features industry-leading spectral efficiency of up to 17.1 Mbps/MHz, line-rate data packet processing of up to 525 Mbps of real data throughput, and innovative xtreme Range Technology (xRT) for up to 200+ km in range.



Deployment Flexibility

The AF-4X supports ± 45° slant polarization for improved noise immunity and Signal-to-Noise Ratio (SNR). The compact form factor of the airFiber X allows it to fit into the radio mount of Ubiquiti antennas, so installation requires no special tools.

The airFiber X antennas are purpose-built with 45° slant polarity for seamless integration with the airFiber AF-4X.

Carrier Backhaul for the World

Deploy the 2.4, 3, or 5 GHz model that meets your specific spectrum requirements, anywhere around the world. The airFiber X features multiple channel width options to suit your deployment needs – up to 11 different channel sizes available for the AF-2X or AF-3X.

Carrier Backhaul for the World

Mission-Critical Communications

The AF-4X covers the 4.9 GHz spectrum for public safety. Additional frequencies, from 4.7 GHz to 4.9 GHz, are supported in Europe and other regions (subject to local country regulations). The AF-4X uses a proprietary radio communications protocol with AES-128 encryption to help ensure communication channels are secure.

Optimal Operation and Channel Configuration

The AF-4X supports up to 11 different channel width sizes* to suit your deployment needs. You can configure independent TX and RX channel frequencies and place them anywhere within the radio band, and the channel centers are selectable in 1 MHz increments. You also have the ability to program different uplink and downlink duty cycles to support asymmetric traffic requirements.

Ultra-Low Latency with HDD TechnologyUltra-Low Latency with HDD Technology

The AF-4X is designed to provide the highest TDD throughput and lowest latency available using proprietary Hybrid Division Duplexing (HDD) technology.


With tower space at a premium, the importance of being able to co-locate equipment is becoming an essential attribute for modern wireless networks. The airFiber X is engineered to permit multiple radios to operate side by side, allowing maximum spectral efficiency.

GPS Synchronization

Precise GPS frame synchronization enables co-located airFiber X radios to transmit and receive data without interfering with each other, enabling better frequency reuse and increased network stability.

Clean Power Output

Using advanced digital signal processing, the innovative AF-4X radio design has an ultra-clean transmitter output, reducing broadband noise, facilitating co-location, and enabling higher‑order modulations like 1024QAM for greater throughput.


2.4 GHz
The 2.4 GHz frequency band is free to use, worldwide; and with its proprietary protocol, the AF-2X increases both range and delivered throughput in this popular band.

3 GHz
The 3 GHz frequency band offers interference-free operation, enabling the AF-3X to provide a high-reliability backhaul solution, although a license may be required in some regions.
5 GHz Full-Band Certification with DFS
The AF-5X covers the entire, license-free, 5 GHz spectrum and includes DFS approval. Anyone around the world can deploy and operate the AF-5X in the 5 GHz range practically anywhere they choose (subject to local country regulations).

Optimal Operation in Unlicensed Bands

Channel width flexibility allows you to independently configure TX and RX channel frequencies and place them anywhere within the radio band to avoid local interference. You also have the ability to program different uplink and downlink duty cycles to support asymmetric traffic requirements.

You also have the ability to program different uplink and downlink duty cycles to support asymmetric traffic requirements.

Optimal Operation in Unlicensed Bands

Product Views:

Angle View
Angle View
Front View
Front View
Rear View
Rear View
Side View
Side View
Bottom View
Bottom View

Top View
Top View
Ports View
Ports View

airFiber X with Dish


Front View
Front View

Ports View
Ports View

Signal LEDs
Signal LEDs

airFiber 4X Specification
Dimensions 224 x 82 x 48 mm (8.82 x 3.23 x 1.89")
Weight 0.35 kg (0.77 lb)
RF Connectors (2) RP-SMA Weatherproof (CH0, CH1)
(1) SMA Weatherproof (GPS)
GPS Antenna External, Magnetic Base
Power Supply 24V, 1A PoE Gigabit Adapter (Included)
Power Method Passive Power over Ethernet
Pins 1, 2, 4, 5 (+) and Pins 7, 8, 3, 6 (-)
Max. Power Consumption 12W
Supported Voltage Range 19-29VDC
Mounting airFiber X Mount (Rocket Mount Compatible)
GPS Pole Mount (Included)
Certifications CE, FCC, IC
Operating Temperature -40 to 55° C (-40 to 131° F)
Networking Interface
Data Port (1) 10/100/1000 Ethernet Port
Management Port (1) 10/100 Ethernet Port
Maximum Throughput 500+ Mbps1
Maximum Range 200+ km1
Encryption 128-bit AES
OS airOS F
Wireless Modes Master/Slave
Radio Frequency
Frequency Range FCC: 4940 - 4990 MHz
IC: 4940 - 4990 MHz
ETSI: 4700 - 4990 MHz
Other Regions: 4700 - 4990 MHz2
Max. Conducted TX Power 29 dBm2 (Dependent on Regulatory Region)
Frequency Accuracy ± 2.5 ppm without GPS Synchronization
± 0.2 ppm with GPS Synchronization
Channel Bandwidth 3.5/5/7/10/14/20/28/30/40/50/56 MHz Selectable3
Programmable Uplink and Downlink Duty Cycles

1 Throughput and range values may vary depending on the environmental conditions.
2 For region-specific details, refer to the Compliance chapter of the airFiber X User Guide at downloads.ubnt.com/airfiber
3 Channel widths may vary according to country/region regulations.

Package Contents

Receive Sensitivity:

airFiber 4X Suggested Max. TX Power
8x 19 - 20 dBm
6x 21 - 22 dBm
4x 23 - 24 dBm
2x 26 dBm
1x 26 dBm

airFiber 4X Receive Sensitivity
Rate Modulation Sensitivity
(10 MHz)
(20 MHz)
(30 MHz)
(40 MHz)
(50 MHz)
8x 256QAM MIMO -66 dBm -64 dBm -62 dBm -61 dBm -60 dBm
6x 64QAM MIMO -74 dBm -71 dBm -69 dBm -68 dBm -67 dBm
4x 16QAM MIMO -81 dBm -78 dBm -76 dBm -75 dBm -74 dBm
2x QPSK MIMO -88 dBm -85 dBm -83 dBm -82 dBm -81 dBm
1x ½ Rate QPSK xRT -90 dBm -87 dBm -85 dBm -84 dBm -83 dBm


airOS on MonitorairOS
Loaded with Powerful Features

airOS F is an intuitive, versatile, highly developed Ubiquiti firmware technology that resides on airFiber. It is exceptionally intuitive and was designed to require no training to operate. Behind the user interface is a powerful firmware architecture which enables hi-performance network backhauls.

airOS F Tools

  • Speed Test
  • Antenna Alignment
  • Device Discovery
  • Site Survey
  • Ping
  • Traceroute

airOS F Integrated Technologies

airFiber's purpose-built hardware provides superior wireless performance, higher capacity, and lower latency. Unlike standard WiFi protocols, Ubiquiti airFiber's Hybrid Division Duplex (HDD) provides the best of both worlds — latency performance of Frequency Division Duplex (FDD) with the spectral efficiency of Time Division Duplex (TDD).

Wireless Modes
  • Master
  • Slave

Wireless Network Configuration

  • Transmit Frequency
  • Receive Frequency
  • Output Power
  • Modulation Rate
  • Automatic Modulation Rate Adaptation
  • Duplex: Half or Full
  • High/Low RX Gain
  • Wireless Security: AES-128

Network Mode

  • Transparent Layer 2 Bridge

Network Configuration

  • In-Band Management
  • Management VLAN
  • Automatic check for airOS F Updates
  • Configuration Test Mode
  • Firmware Recovery via TFTP
  • Reset to Factory Defaults
  • Configuration Management: Backup/Restore Device Configuration
  • Administrator/Read-Only Access
  • WEB/SSH/Telnet Access
  • Dynamic DNS
  • NTP Client
  • Ping Watchdog
  • SNMP v1 Support
  • System Log: Local/Remote
  • Full Statistical Performance Reporting


  • Speed Test
  • Antenna Alignment
  • Device Discovery
  • Ping
  • Traceroute


Download the Ubiquiti airFiber 4X Datasheet (PDF).

Pricing Notes:

Ubiquiti Products
airFiber X Series
airFiber 4X
Get a Quote!