Performance comparison of guard channel admission control schemes for IEEE 802.16 system with various turbo code FEC schemes

Although by default the Network Simulator 2 (NS2) does not implement the IEEE 802.16 networks, a few patches are available, that provide WiMAX specifications at different fidelity level. The ns2 environment is useful for system-level evaluation, but mainly with respect to wired networks. In order to provide an adequate QoS provisioning to different service flows and to prevent base station (BS) from running out of resources an appropriate connection admission control (CAC) algorithms needs to be considered. Since the introduction of IEEE 802.16e standard a lot of studies have focused on development of CAC. In this paper we present the ns-2 module with integrated Connection Admission Control support. Currently three admission control algorithms based on so called guard channel were implemented. In the final sections authors show the CAC performance as well as influence of various turbo-FEC schemes deployed in physical layer on the system level performance. Especially it is found that the nb-LDPC codes provide link level solution able to improve system level quality metrics.