Radio access network (RAN) sharing attracts much attention from telecom operators. However, current mechanisms applied to RAN sharing do not consider fairness among operators such that the RAN is not fairly shared, and either under-or over-utilized. Fairness cannot be guaranteed among operators because resources are distributed on a first-come-first-serve basis. 'Soft-partition with Blocking and Dropping' (SBD)' is proposed to offer inter-operator fairness based on a 'soft-partition' concept. Subscribers to an operator may overuse the predefined service-level-agreement (SLA) when the shared RAN is under-utilized, but become blocked or even dropped when over-utilized. According to our simulation results, SBD maintains inter-operator fairness at 0.997, even better than hard-partition at 0.98 and much better than nopartition at 0.6. Meanwhile, it retains high utilization of shared RAN at 98%. SBD reduces blocking rate from 35% of hard partition to almost 0%, while controlling dropping rate at 5%.