Submitted papers on WiMAX:
Delay Model for IEEE 802.16 Networks
Abstract - In this paper, we propose an analytical model to evaluate
average packet delay and its standard deviation in a saturated IEEE 802.16
network. In addition, bandwidth utilization of an uplink data frame and the
packet loss probability are also derived from the model. We show that our
analytical model is accurate for a range of parameters by comparing it with
simulation results. Using the analytical model we then suggest an appropriate
parameter setting for the uplink data frame to better utilize the bandwidth and
to minimize packet loss probability for both saturated and unsaturated
networks.
(We have developed an event-driven
simulation program using C++ to produce simulation results for this paper. To
download the executable file of this simulator for SPARC/Solaris platforms,
please click here. )
Performance Evaluation of
Contention-based Services in Unsaturated IEEE 802.16 Networks
Abstract - The IEEE 802.16 based WiMAX technology has great potential
for the fourth-generation mobile networks. Some of its service classes use the
contention based broadcast polling mechanism to request resources. In this
paper, we investigate the performance experienced by these services when the
network is unsaturated. In particular, we model each subscriber station as an
M/G/1 queue where the service time is determined by the parameters of the
network configuration and the binary exponential backoff contention resolution
algorithm. We develop a fixed point analysis to derive analytical expressions
for network throughput and packet access delay. The accuracy of the analytical
model is validated by comparing with simulation over a wide range of operating
conditions. The implications of various different parameter configurations on
the performance are investigated using the analytical model. Moreover, we show
that the model can be degenerated to the saturated condition. The utility of
both the unsaturated and saturated models is further demonstrated by finding
the optimal parameters which maximize the network throughput.
(We have developed an event-driven
simulation program using C++ to produce simulation results for this paper. To
download the executable file of this simulator for SPARC/Solaris platforms,
please click here. )