Fourth Generation wireless technologies depend on the
performance of their schedulers to deliver high data throughput and meet
quality-of-service commitments. We compare four schedulers for mobile WiMAX
using five industry-defined key performance indicators: sector and application
throughput, completion time, fairness index and delay. The selected scheduling algorithms
are: Proportional Fairness (PF), Modified Largest
Weighted Delay First (MLWDF), Highest Urgency First (HUF), and Weighted Fair
Queuing (WFQ). Three simulated environments are used:
controlled, stationary and mobile. The controlled environment provides insights
into the time-related behavior of flows with identical QoS
parameters and different RF conditions. Results for the stationary and mobile
environments show that algorithms meet QoS
requirements within system capacity. Opportunistic algorithms (PF and MLWDF)
achieve considerable throughput improvements. MLWDF's throughput results, while
better under stationary conditions, fall behind PF in the mobile scenario. No
statistically significant differences are observed in
the mobile environment for application completion time and fairness.