A random access algorithm for data networks carrying high priority traffic

Consideration is given to data networks carrying mixed low- and high-priority traffic. For such networks, the authors propose a synchronous limited sensing random access algorithm per channel, which gives a delay advantage to the high-priority traffic. The algorithm basically consists of two dynamically coupled window algorithms, one for the high- and one for the low-priority packets. Assuming limit Poisson user models for both the traffic classes, the authors optimize the windows of the mixed algorithm for: (a) throughput maximization under no specific delay constraints and (b) throughput maximization subject to expected delay constraints for high-priority traffic. For both cases, the delay characteristics of the algorithm are studied for the two classes of data traffic. With appropriate selection of the two window sizes, the algorithm can attain relatively high throughput, while it simultaneously maintains low expected per high priority packet delays, whose values are only slightly affected by the total traffic rate