The IEEE 802.16 standard, also known as WiMAX is oriented to fixed broadband wireless metropolitan access. This work presents a novel proposal for the PHY layer and propagation model that allows a faster and more detailed the link level simulations execution. This paper describes the development process for the model and the implementation details in NS2 (Network Simulator NS2 v 2.8) for PMP (point multi point) topologies. We show the parameters used, the channel model, the PHY layer model and the SER (Symbol Error Rate) calculation method. We also present typical simulation scenarios and the results obtained.