TY - GEN A1 - Buglia, Henrique A1 - Sillekens, Eric A1 - Vasylchenkova, Anastasiia A1 - Killey, Robert A1 - Bayvel, Polina A1 - Galdino, Lidia Y1 - 2022/09/18/ N1 - This version is the author accepted manuscript. For information on re-use, please refer to the publisher's terms and conditions. UR - https://opg.optica.org/abstract.cfm?uri=eceoc-2022-Tu1D.3&origin=search ID - discovery10159427 N2 - A closed-form formula for the nonlinear interference (NLI) estimation of arbitrary modulation formats, supporting short span lengths and low losses in ultra-wideband optical transmission systems is presented. The formula is tested over 20 THz and accurately estimates the NLI at every point of the fibre span. AV - public PB - Optica Publishing Group TI - An Extended Version of the ISRS GN model in Closed-Form Accounting for Short Span Lengths and Low Losses ER -