In large scale networks like the IEEE 802.16 (WiMAX), it is very important not only to monitor, but also to control the amount of traffic injected into the network. This process helps in decreasing congestion and by consequence, in guaranteeing the Quality of Service (QoS) requirements for each class of traffic. In this study we propose a traffic policer based on token bucket concept for WiMAX networks. Token bucket parameters (token rate and bucket size) are adjusted according to the traffic characteristics for each traffic class individually. Simulation results show that the proposed traffic policing technique greatly enhances the network performance. It decreases the average delay for real time traffic like rtPS, and therefore, reduces data drop probability due to missed deadlines. It also decreases data loss probability for non real time service class like nrtPS.