This work contribution consists in the use of service differentiation techniques in the MAC 802.11e Enhanced Distributed Coordination Function (EDCF), altering the way each station gains medium access, and establishing access priorities among the stations that compose an Ad Hoc network. Some Quality of Service metrics were considered in order to provide service differentiation in the MAC sublayer and to evaluate the Ad Hoc networks performance; these metrics are throughput, latency, jitter and packet discard. The service differentiation techniques used were: package size variation, Arbitration Interframe Space (AIFS) size alterations, and Binary Exponential Backoff calculus. Simulations were performed to ensure the validity of the differentiation techniques combined use in the 802.11e MAC sublayer, to establish thresholds to Quality of Service metrics, to provide medium access priorities and to keep the high level of Ad Hoc network utilization. The simulations were performed using Network Simulator 2.