  When different type of packets with different needs of Quality of Service
(QoS) requirements share the same network resources, it became important to use
queue management and scheduling schemes in order to maintain perceived quality
at the end users at an acceptable level. Many schemes have been studied in the
literature, these schemes use time priority (to maintain QoS for Real Time (RT)
packets) and/or space priority (to maintain QoS for Non Real Time (NRT)
packets). In this paper, we study and show the drawback of a combined time and
space priority (TSP) scheme used to manage QoS for RT and NRT packets intended
for an end user in High Speed Downlink Packet Access (HSDPA) cell, and we
propose an enhanced scheme (Enhanced Basic-TSP scheme) to improve QoS
relatively to the RT packets, and to exploit efficiently the network resources.
A mathematical model for the EB-TSP scheme is done, and numerical results show
the positive impact of this scheme.
