Less is better, but better: airFiber 5X is a new generation of radio channels, or Lutz * for your radio route is now in retail

* Lutz - (chatl.) Fuel for pepelats.

We didn’t have time to properly try out Ubiquiti ac solutions, we didn’t put it anywhere where conventional communication channels lacked capacity, airFiber 5 / 5u , and our favorite manufacturer already pleases us with another novelty - and the novelty promises to be faster Rocket AC, cheaper than airFiber 5 , and work at the same time for more than both of these solutions, distances.
Let's see what they offer us.
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Until today, Ubiquiti has, in essence, two competing equipment lines for building long-range point-to-point long-haul spans: airMAX and airFiber. AirFiber 5 / 5u had an unsurpassed capacity (up to 600 Mbit / s duplex), better real sensitivity, many times higher batch performance. AirMAX, on the other hand, was a solution at times lower cost and, more importantly, with higher gain antennas - however, these solutions have limited packet performance (about 18 thousand packets per second in normal and about 70 thousand packets per second in AC -variant).

Also, AirFiber 5 / 5U within the Russian Federation had a certain problem with the legality of use: in these bands, we are allowed to use only broadband TDD with one frequency band up to 40 MHz inclusive. Thus, it was legally possible to get only 450 Mbit / s simplex from airFiber, which is not so interesting, especially considering the cost of airFiber (about $ 2,000 per span).
Thus, a problem arose, aptly described in Kin-dza-dza “Luts are not sold in parts”, with the subsequent pushing of a gravitsapa over long distances by building a main canal on airMAX.
Today we meet a novelty - a system that combines the best of two lines: airFiber 5X (AF-5X (EU)).



The case of the device resembles an elongated Rocket case and can be installed on the corresponding antenna, the back wall of the device is a needle radiator.



Cable configuration is familiar with airFiber - a gigabit port of traffic transfer and a control port of 100 Mbps.

Technical parameters of airFiber X in comparison with airFiber 5 / 5U, airMAX:

Family	airFiber X	airFiber 5 / 5U	Rocket AC / PowerBeam AC	Rocket / PowerBeam
Frequency ratings, MHz	5150-5925	5470-5950 / 5725-6200	5150-5875	5150-5875
Channel capacity, max (duplex)	245	500 (640 to 256QAM at short distances)	300 to 256QAM at short distances	90
MHz frequency bands Technology	10,20,30,40,50 Tdd	10,20,30,40,50 TDD / FDD	10,20,30,40,50,60,80 Tdd	5,10,20,30,40 Tdd
Available Modes	Ptp	Ptp	PtP / PtMP	PtP / PtMP
Antennas	External: 24,30,34 dBi	23 dBi embedded	30,31,34 dBi external 27 dBi embedded	30,31,34 dBi external 27 dBi embedded
Power, dBm (16/64 / 256QAM)	24/22/20	24/22/20	27/27/23 22/22/18	27/24 / no
Sensitivity, dBm (16/64/256 QAM)	-78 / -71 / -64	-78 / -71 / -64	-90 / -83 / -69	-87 / -79 / no
Power supply (complete source)	24V 1A	50V 1.2A	24V 0.5A	24V 0.5A

Please note that airFiber X can be operated with airMAX parabolic antennas - that is, it can be used to upgrade existing PtP spans built on the equipment of the airMAX line. For new installations, however, specialized -45 antennas are recommended. Unlike airMAX antennas, polarizations of new antennas are tilted (slant), which provides a smaller variation in signal levels on polarizations in the case of signal reflections and / or partial violation of radio visibility and also some isolation from equipment operating in H and V polarizations (the manufacturer introduced antenna gain 24, 30, 34 dBi).
As a solution in this situation, the manufacturer offers a set of modernization of old antennas, changing their polarization:




As we can see, technically airFiber X is a greatly reduced version of airFiber 5 with connectors for external antennas.

Losses in the way of miniaturization

First of all, the claimed capacity - “more than 500 Mbit / s” attracts attention. In fact, this is a consequence of the refusal to support the FDD mode - now the system works only in one frequency band.
The second victim was a convenient indicator of the signal level - instead, it is now a series of LEDs traditional for airMAX.


A sufficient level for operation at maximum modulation is used as the reference level.

Incomplete list of benefits

• At times less than the cost of airFiber;
• The possibility of using external antennas, including airMAX series antennas (via an optional interface node);
• Package performance is several times higher than the airMAX and airMAX AC line;
• Better than airMAX and airMAX AC sensitivity (real);
• Support for the 5150-5470 MHz subband, unlike airFiber 5.

Distances, speeds, settings

We calculate the dependence of the range on the speed for airFiber 5, airFiber X, Rocket AC, using the real sensitivity of the equipment (the method of measuring the real sensitivity can be found in our previous article ):





The result is impressive.
In fact, the airFiber X solution provides a range not only more than the older airFiber, but also than the airMAX AC - here the merit of significantly greater sensitivity. For airFiber 5 / 5u, they can only work at frequencies higher than 5850 MHz and a large maximum performance due to the ability to work in FDD mode - however, it must be remembered that installations in this mode cannot be legalized, and hoping to find a free pair of 50 MHz nominal values ​​would be quite optimistically: in practice, most installations in the FDD mode in the CIS do not have such an air resource and operate in 30 by 40 or 50 by 30 MHz mode.



From a configuration point of view, the system repeats airFiber 5, so we consider only the most significant options.

Radio channel settings: here you need to select the TX / RX time slot allocation setting, the available options are 25/33/50/65/75% - this is not possible in the older airFiber models: it looks like we have found another advantage of the new device.



Advanced tab: when you enable inband management here you need to remember to enable multicast filter:



And, in fact, the result of tuning is a legal high-capacity radio channel using already existing airMAX antennas:



Of the additional, albeit controversial, system capabilities, I would like to mention the possibility of TDD transceivers in different frequency ratings. This mode can be useful in conditions of asymmetric interference and the absence of a free nominal on both sides of the channel, which is already encountered in highly populated communication facilities. In such a situation, you can choose a different frequency of transmission reception, achieving the optimal signal-to-noise ratio on each side of the channel.



Practical mode operation on the spectrum analyzer - each channel is occupied half the time:

Sensitive subject

At the end of the material I again have to mention a sore subject - the question of equipment grounding.
Pay attention to the requirements of the manufacturer:
And voiding your electrical damage: Failure to properly ground your airFiber radio will void your warranty.
Manufacturer's recommended wiring diagram ( Ubiquiti lightning protection review ):



Grounding terminal on the device case:

Summary

• The performance of airFiber X in performance significantly exceeds airMAX, including airMAX AC;
• In actual practice, the use of airFiber 5 in most cases does not have advantages relative to airFiber X;
• The possibility of using external antennas, including the airMAX line, allows building airFiber X channels with a length of over 100 km with high performance and modernizing previously deployed airMAX channels;
• The disadvantage of airFiber X is 24 volt power supply, not 802.3at, which, when using third-party switches, can make power management from the switch impossible (the high consumption of the device also attracts attention - it exceeds the capabilities of TOUGHswitch \ EdgeSwitch, forcing to use the complete power injector).

And, of course, the most important information: the price of one airFiber X device in CompTek will be $ 440 .

Addition: the manufacturer confirmed the possibility of powering airFiber 5X from TOUGHswitch and EdgeSwitch switches
community.ubnt.com/t5/airFiber/AF5X-Power-Consumption-and-Receive-sensitivity/mp/1175961#M17963