Admission Control and System Capacity Assessment of WiMAX with ACM and nb-LDPC Codes Simulation Study with ViMACCS ns2 Patch

Authors propose to use cell level simulation as a natural follow up of the link level tests and a preliminary stage of the systematic approach to the system level tests in the context of IMT-Advanced candidates performance evaluation. The system under test (SUT) consists of flexible realizations of the WiMAX physical layer abstraction (providing customized fidelity and thus simulation complexity) with the nb-LDPC codes. The preliminary assessment of system capacity under quasi-mobility conditions (with ACM) is performed using human mobility models and freeware software for radio coverage planning. Moreover two symbol reservation schemes are evaluated in terms of effective bandwidth utilization, blocking and dropping probability. Complete sharing admission control mechanism (CSCAC) is used to show system performance under various load and mobility patterns. It is shown that using nb-LDPC codes improves system throughput in poor radio conditions as compared to RS-CC coding as in the IEEE 802.16e-2005 specification.