I've looked through Cambiums and Ceragon's literature on this topic, and there's not much information. It's clearly something different from GPS sync though.
Below is what Ceragon says about this technology. Does it actually works this well? Thanks for any help.
Advanced Frequency Reuse is based on Ceragon’s unique multi-core technology. Multi-core comprises an advanced, parallel radio-processing engine built around Ceragon’s in-house baseband modem and RFIC chipsets. Optimized for processing of multiple radio signal flows, the multi-core technology hosted on Ceragon’s leading IP20C wireless solution multiplies capacity and increases system gain over current technology.
Advanced Frequency Reuse uses revaluated channel parameters to mitigate the interference caused by an adjacent link. While interference naturally increases as angular separation decreases, Advanced Frequency Reuse includes a unique interference-mitigation technique. This is the key to enabling co-existence of lowangle, adjacent links with no fading or quality degradation.
With Advanced Frequency Reuse, the angular separation between links using the same frequency can decrease from 90O to as little as 15O allowing more links that use the same frequency channel to co-exist in close proximity.
advanced frequency reuse is a great feature for anyone who needs to deploy two links that have low angular separation in an area where spectrum is scarce. It's a fefature that needs to run within a PTP820C for two separate links that do not otherwise have enough angular separation to reuse a frequency pair. Typcally, depending on the radiation patterns of the dishes being used on links, the minimum angular separation angle is 90 to 120 degrees before a frequency pair can be reused. If it's any less than that then either a separate frequency pair will be needed or if that's not available then advanced frequency reuse can help.
AFR is an interference mitigation technique that can be likened to XPIC where each link samples the signal of the other to eliminate self-interference on the same channel. This reduces the interlink interference between two co-located links on the same tower where the same frequency pair is used on both links.
As you can see from the graph you posted class 3 and 4 antennas achieve about -45dB interlink interference at about 80-90 degrees of separation while AFR achieves that at about 15 degrees. If you have two co-located links and there isn't enough spectrum for both, but they're at least 15 degrees apart have your frequency coordinator re-run the paths with AFR taken into consideration.
