Achievable QoS for multiple delay classes in cellular TDMA environments

In a real-time wireless TDMA environment, every packet generated by applications has a deadline associated with it. If the system cannot allocate enough resources to serve the packet before the deadline, the packet would be dropped. Different applications have different delay requirements that should be guaranteed by the system so as to maintain some given packet dropping probabilities. In this paper, a single-cell system traffic of multiple delay classes is mathematically analyzed, and it is proved to be independent of the scheduling algorithm used, for all work-conserving earliest-due-date (WC-EDD) scheduling algorithms. The dropping requirements of all individual applications are guaranteed using deadline-sensitive ordered-head-of-line (DSO-HoL) priority schemes. Verification of the model is shown through extensive simulations.