This paper presents an adaptive algorithm for managing the weights of a weighted round robin (WRR) scheduler. The weights calculation depends on the capacity variations present in a Digital Video Broadcasting-Second Generation (DVB-S2) satellite link. The algorithm optimizes the bandwidth utilization while satisfying the QoS requirements for different traffic classes. The operation of the proposed algorithm is demonstrated by using the NS-2 simulator environment. The results show that the proposed adaptive WRR algorithm optimizes the bandwidth utilization while enforcing the priority level of each service class even in an extreme reduction of bandwidth caused by rain events.