Summary: Parvez, Asad, Impact of actual interference on capacity and call admission control in a
CDMA network. Master of Science (Computer Science), May 2004, 57 pp., 2 tables, 41 fig-
ures, 42 titles.
An overwhelming number of models in the literature use average inter-cell interference
for the calculation of capacity of a Code Division Multiple Access (CDMA) network. The
advantage gained in terms of simplicity by using such models comes at the cost of rendering
the exact location of a user within a cell irrelevant. We calculate the actual per-user inter-
ference and analyze the effect of user-distribution within a cell on the capacity of a CDMA
network. We show that even though the capacity obtained using average interference is a
good approximation to the capacity calculated using actual interference for a uniform user
distribution, the deviation can be tremendously large for non-uniform user distributions.
Call admission control (CAC) algorithms are responsible for efficient management of
a network's resources while guaranteeing the quality of service and grade of service, i.e.,
accepting the maximum number of calls without affecting the quality of service of calls
already present in the network. We design and implement global and local CAC algorithms,
and through simulations compare their network throughput and blocking probabilities for
varying mobility scenarios. We show that even though our global CAC is better at resource
management, the lack of substantial gain in network throughput and exponential increase
in complexity makes our optimized local CAC algorithm a much better choice for a given
traffic distribution profile.