airFiber - FAQ Getting Started


Click on the question that interests you to expand and collapse the answers. This article will be updated as more common questions are brought to our attention. If you feel that a question is missing, please click the feedback button at the bottom of this page and let us know! Find more information in the airFiber Help Center.

Frequenty Asked Questions

What is the minimum link distance between Master and Slave?

The minimum distance between Master and Slave ends of the link will depend on the model:

  • airFiber5: 10 meters
  • airFiber 2X, 3X, 4X, and 5X: this varies depending on the antenna gain, but a general rule would be 25 meters
  • airFiber24: 25 meters (using firmware 2.0 or higher)
  • airFiber11: 25 meters
What is the BER (Bit Error Rate) on airFiber radios?

BER (Bit Error Rate) is a very popular measurement of the percentage of packets with errors on a digital link. A BER value of 10 - 6 = (1/1000000), means that of every 1.000.000 received packets 1 has errors and must be retransmitted, which is considered a very good link. On the other hand, a link with a BER of 10 - 3 = (1/1000), is considered a very bad or damaged link (according to the IEC 608720-3 and IEC 60801-4).


Thanks to airFiber's revolutionary system it has an effective BER = 0, which means that of every received packets 0 has errors. How is this possible? airFiber uses hitless adaptive modulation and an ARQ scheme over the radio link to ensure that no bit errors are delivered over the link. More information about BER available here:

Is auto modulation a hitless protocol?

Yes, airFiber Adaptive Modulation is hitless. airFiber uses a selective acknowledgment-based protocol to ensure that no packets are lost as a result of link adjustments such as changes in modulation. The only thing you should see during a transition is a short spike in latency while the rates change. Make sure Flow Control is enabled to avoid any potential Rx buffer overflow when the link is heavily loaded.


IMPORTANT: If the link needs to modulate down it will be capable of carrying less traffic and thus may lose packets as a result of overflow (i.e. the user rate is 700 Mbits and the link negotiated to 500 Mbits).
Can the AF5 connect to the AF5U?

AF5 is a radio system designed to work between 5470MHz and 5850MHz (or 5950MHz in some regions). AF5U is a radio system designed to work between 5725MHz and 5850MHz (or 6200MHz in some regions). Both models support the UNII-3 band, 5725MHz to 5850MHz*, so a radio link using one AF5 and one AF5U on the other end will work fine as long as they use any frequency within the UNII-3 band.


*NOTE: International units can work up to 5950MHz depending on country limits.
Can the AF24 connect to the AF24HD?
AF24 and AF24-HD can create a link together. However maximum throughput will be limited by the AF24 (up to 6X, 64QAM).

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