The originality of FSR is inspired by the "fisheye" technique to reduce the size of information required to represent graphical data: The eye of a fish captures with high detail the pixels near the focal point, while the detail decreases as the distance from the focal point increases.
[2] The base principle was included in the widely used OLSRd daemon (an open source implementation of the OLSR routing protocol[3]).
FSR thus decreases the overall quantity of information spread in the network, since LSA are not sent with a fixed maximum TTL.
One of the typical issues with link-state protocols is that when a node or link breaks, temporary loops can be created.
FSR does this by design, it introduces areas in the network with potentially different information sets, so it increases the probability of creating temporary loops.