Performance Characteristics of an Operational WiMAX Network

The term WiMAX is used to refer to a collection of standards, products, and service offerings derived from the IEEE 802.16 family of standards for wireless networks. These standards define physical and MAC layer elements that ensure interoperability of compatible equipment. However, the standards leave both the details of the packet scheduling algorithms and the values of performance related configuration parameters to the discretion of the equipment vendor or network operator. These algorithms and parameters ultimately determine fundamental performance characteristics such as round-trip latency and sustainable throughput on the network. In this paper, we examine performance characteristics of an operational WiMAX testbed upon which we were able to conduct controlled experiments in the absence of competing traffic. We characterize latency, throughput, protocol overhead, and the impact of WiMAX on TCP dynamics. We show that scheduling policies and parameter values impact actual performance in ways that are not possible to characterize in generic studies of WiMAX.