A method of allocating bandwidth to co-existence groups of a connected set in a spectrum access system (SAS) is provided. The method comprises: receiving data about co-existence groups in the connected set of the SAS, where such data includes a number of the co-existence groups, G, in the connected set, and a number of radios, ni, in each co-existence group; determining an allocated bandwidth for each of the G co-existence group by subtracting a splitting disincentive bandwidth for a co-existence group from a co-existence incentive bandwidth for the co-existence group; and sending the determined allocated bandwidths for the co-existence groups.