Modeling and analysis of impatient packets with hard delay bound in contention based multi-access environments for real time communication

In this paper, we study problem of impatient packets in multimedia multi-access communication channel. Impatient users generally mean the users who leave the system if their service is not started before their respective deadlines. Their characteristic is perfect match to that of the packets with hard delay bound in real-time communication. In real-time communication, one of the most critical performance measure is the percentage of packets that are transmitted within hard delay bound. We assume contention based reservation ALOHA type MAC protocol, which is basic framework in next generation multimedia wireless LAN, and develop analytical model for the performance evaluation of defection probability of impatient packets. Our results show that proposed model is strong tool to evaluate packet loss probability due to expiration of deadline in contention based MAC protocols, which matches well with the simulation results.