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The ns-3 WiMAX module lacks the implementation of a more sophisticated uplink scheduler for QoS provisioning. The main goal of this project is to port the uplink scheduler implemented in the ns-2 WiMAX module developed by the Computer Networks Laboratory ( at University of Campinas to the ns-3 WiMAX module. The second goal of this project is to implement propagation and error models to allow the simulation of more realistic scenarios.

Project Background

To support multimedia applications, the IEEE 802.16 standard defines five types of service flows (UGS, ertPs, rtPS, nrtPS and BE), each with different QoS requirements. However, the scheduling mechanism is left to be defined by proprietary implementations. Many scheduling algorithms for the IEEE 802.16 standard have been proposed in the literature, and one of them, proposed in [2], is implemented in the WiMAX module [1] developed for the ns-2 by the Computer Networks Laboratory (LRC - at University of Campinas. The ns-3 WiMAX module implements a FCFS scheduler and, therefore, it lacks the implementation of a more sophisticated scheduler for QoS provision. The scheduler is responsible by the resource allocation and, consequently, is fundamental for the QoS provision. While the downlink scheduling requires one scheduler in the base station, uplink scheduling needs two components, one in the base station and one in the subscriber station. The base station uplink scheduler allocates bandwidth to subscriber stations and the subscriber station scheduler defines which packets will be sent in the received grants.

In this project, a more sophisticated uplink scheduler to support the QoS requirements of multimedia applications will be implemented. The recent WiMAX module for ns-2 developed by LRC[1] supports bandwidth allocation and scheduling services. The uplink and the downlink scheduler developed by LRC will be ported to the ns-3 WiMAX module.

As secondary goals, propagation and error model for ns-3 will be implemented. These models can bring more realism to the module, with throughput and error rate closer to reality. Theses models may reflect the sub-urban environment of WiMAX networks.

Project Plan