  This paper investigates a dynamic buffer management scheme for QoS control of
multimedia services in beyond 3G wireless systems. The scheme is studied in the
context of the state-of-the-art 3.5G system i.e. the High Speed Downlink Packet
Access (HSDPA) which enhances 3G UMTS to support high-speed packet switched
services. Unlike earlier systems, UMTS-evolved systems from HSDPA and beyond
incorporate mechanisms such as packet scheduling and HARQ in the base station
necessitating data buffering at the air interface. This introduces a potential
bottleneck to end-to-end communication. Hence, buffer management at the air
interface is crucial for end-to-end QoS support of multimedia services with
multiplexed parallel diverse flows such as video and data in the same end-user
session. The dynamic buffer management scheme for HSDPA multimedia sessions
with aggregated real-time and non real-time flows is investigated via extensive
HSDPA simulations. The impact of the scheme on end-to-end traffic performance
is evaluated with an example multimedia session comprising a real-time
streaming flow concurrent with TCP-based non real-time flow. Results
demonstrate that the scheme can guarantee the end-to-end QoS of the real-time
streaming flow, whilst simultaneously protecting the non real-time flow from
starvation resulting in improved end-to-end throughput performance.
